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1
Abbott, J. Haxby, and n/a. "Accuracy in the diagnosis of lumbar segmental mobility disorders." University of Otago. Department of Anatomy & Structural Biology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070205.094640.
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Background: In the clinical examination of patients with low back pain (LBP), musculoskeletal physiotherapists routinely assess lumbar spinal segmental motion by performing physical examination procedures such as observation of active range of motion and palpation of intervertebral motion. The validity of manual assessment of segmental motion, however, has not been adequately investigated.
Methods: In this pragmatic, multi-centre, criterion-related validity study, 138 consecutive patients with LBP were recruited and examined by physiotherapists with postgraduate training in musculoskeletal manual therapy. Clinicians examined each patient�s spine for the presence of segmental motion abnormalities, described as lumbar segmental rigidity (LSR) and lumbar segmental instability (LSI), then referred the patients for flexion-extension (FE) radiographs. The physical examination procedures of interest were: 1) assessment of forward-bending (FB) active range of motion (AROM); 2) FB and backward-bending (BB) passive physiological intervertebral motion testing (PPIVMs) in the sagittal plane; and 3) central postero-anterior passive accessory intervertebral motion testing (PAIVMs). Sagittal displacement kinematics of the lumbar spinal segments were measured from the FE radiographs, and served as the criterion standard against which the clinical assessment results were compared. The kinematic parameters measured were sagittal rotation, sagittal translation, ratio of translation per degree of rotation (TRR), instantaneous axis of rotation (IAR), and centre of reaction (CR). Reference ranges for normal motion were calculated from the analysis of FE radiographs of 30 asymptomatic volunteers. The accuracy and validity of the clinical examination procedures were then calculated, and reported as sensitivity, specificity, and likelihood ratios for a positive test (LR+) and a negative test (LR-).
Results: In patients with LBP, sagittal rotation LSR and sagittal translation LSR had a prevalence of approximately 5.7% (p <0.0005) in this cohort. Sagittal rotation LSI was not found in statistically significant numbers. Sagittal translation LSI was found at a prevalence of 3.6% (p <0.05). Abnormal TRR (23.3%), IAR (17.7%), and CR (16.5%) were more prevalent findings (all p <0.0005). Observation of the quantity of AROM, during FB, is not valid for the assessment of either total lumbar segmental sagittal rotation, or detection of individual segments with abnormal segmental motion. PPIVMs and PAIVMs are specific, but not sensitive, for the detection of rotation LSI and translation LSI. A positive test (grade 4 on a scale from 0 to 4) with BB PPIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 8.4 and 7.1 respectively (and 95% CIs from around 1.7 to 38). Likelihood ratio statistics for FB PPIVMs were not statistically significant. A positive test (grade 2 on a scale from 0 to 2) with PAIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 2.7 and 2.5 respectively (and 95% CIs from around 1.01 to 7.5). Neither PPIVMs nor PAIVMs were useful for the detection of LSR, or abnormal quality of motion as measured by TRR, CR, and IAR.
Conclusions: Abnormal spinal segmental motion is associated with the symptom of LBP, in patients presenting to physiotherapists with a new episode of recurrent or chronic LBP, however prevalence is low due to highly variable lumbar segmental motion among asymptomatic individuals. Manual physical examination has moderate validity, but limited utility on its own, for the detection of translation LSI. Further research should investigate the utility of other clinical examination findings for the detection of lumbar segmental mobility disorders.
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Zannoni, Letizia <1982>. "Accuracy of new sonographic markers in the diagnosis of adenomyosis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/7818/3/ZANNONI%20LETIZIA_TESI%20DOTTORATO.pdf.
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Objective: to evaluate the diagnostic accuracies of well-known sonographic markers of adenomyosis and of two innovative ones, the question mark sign and the transvaginal ultrasound uterine tenderness.
Methods: 78 patients scheduled for hysterectomy for uterine benign diseases underwent preoperative transvaginal ultrasonography to evaluate the criteria of sonographic diagnosis of adenomyosis as reported by consensus statement MUSA. Adenomyosis was diagnosed in presence of two or more of the following parameters: asymmetry of the uterine walls, hyperechoic striae, anechoic myometrial cysts, hyperechogenic islands, echogenic subendometrial lines and buds, interruption/irregularities of the junctional zone and translesional vascular flow. In addition the question mark sign and the transvaginal ultrasound uterine tenderness were evaluated, the first being the longitudinal section of the uterus with a morphology similar to a question mark and the other being the dynamic ultrasound evaluation of uterine tenderness by the pressure of the transvaginal probe. Sonographic features were compared with histological examination.
Results: the prevalence of adenomyosis in the sample is 33.3%. Sensitivity, specificity, positive and negative predictive values and accuracy of transvaginal ultrasound in the diagnosis of adenomyosis are 83%, 96%, 91%, 89% and 92%. Asymmetry, hyperechoic striae and interruption of the junctional zone were the most accurate markers for the diagnosis of adenomyosis. Myometrial heterogeneity was the most frequently encountered feature (100%), but showed a low specificity (7%). The question mark sign and the transvaginal ultrasound uterine tenderness showed sensitivity, specificity, positive and negative predictive values and accuracy of 41%, 96%, 83%, 77%, and 69% and 69%, 65%, 66%, 81% and 67% respectively.
Conclusions: the sonographic markers proposed by consensus statement MUSA were confirmed accurate in the diagnosis of adenomyosis in our sample. The question mark sign and the transvaginal ultrasound uterine tenderness showed good diagnostic capacities and may be a useful complement in the sonographic diagnosis of adenomyosis.<br>Obiettivo: valutare le capacità diagnostiche dei marker ecografici già noti di adenomiosi e di due innovativi, ovvero il question mark sign e la transvaginal ultrasound uterine tenderness.
Metodi: 78 pazienti candidate ad isterectomia per patologia uterina benigna sono state sottoposte ad ecografia transvaginale preoperatoria per la valutazione dei criteri di diagnosi ecografica di adenomiosi riportati dal consensus statement MUSA. L’adenomiosi è stata diagnosticata in presenza di due o più fra i seguenti parametri: asimmetria delle pareti uterine, strie iperecogene, lacune anecogene, isole iperecogene, irregolarità sub-endometriali, interruzione o irregolarità della zona giunzionale, vascolarizzazione trans-lesionale. In aggiunta, sono stati valutati due marker ecografici innovativi: il question mark sign e la transvaginal ultrasound uterine tenderness, ovvero la sezione longitudinale dell’utero con morfologia a punto interrogativo e la valutazione ecografica dinamica della dolorabilità dell’utero alla pressione mirata della sonda vaginale. Le caratteristiche ecografiche sono state confrontate con l’esame istologico.
Risultati: La prevalenza di adenomiosi nel campione è risultata pari a 33.3%. Sensibilità, specificità, valore predittivo positivo e negativo e accuratezza dell’ecografia transvaginale nella diagnosi di adenomiosi sono risultate rispettivamente 83%, 96%, 91%, 89% e 92%. Asimmetria, strie iperecogene ed interruzione della zona giunzionale sono risultati i marker più accurati per la diagnosi di adenomiosi. La caratteristica più frequentemente riscontrata (100%) è stata l’eterogeneità miometriale, ma ha mostrato scarsa specificità (7%). Il question mark sign e la transvaginal ultrasound uterine tenderness hanno presentato sensibilità, specificità, valore predittivo positivo e negativo e accuratezza pari rispettivamente a 41%, 96%, 83%, 77%, e 69% e 69%, 65%, 66%, 81%, e 67%.
Conclusioni: I marker ecografici proposti dal consensus statement MUSA si confermano accurati nella diagnosi di adenomiosi. Il question mark sign e e la transvaginal ultrasound uterine tenderness hanno dimostrato buone capacità diagnostiche e potrebbero rivelarsi un utile complemento nella diagnosi ecografica di adenomiosi.
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Leonardi, Mathew. "The utility of advanced pelvic ultrasound techniques in the diagnosis and management of patients with endometriosis." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/28014.
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Endometriosis is a disease that affects approximately 10% of individuals assigned female at birth. Endometriosis is a chronic oestrogen-dependent and -promoted inflammatory response secondary to ectopic yet functional endometrial-like cell growth outside the uterine cavity. It is generally thought to be a pain-causing disease and has a strong link between endometriosis and infertility.
Imaging has emerged as the most optimistic non-invasive and non-surgical tool to diagnose endometriosis. In many centres in Australia and around the world, current evidence-based ultrasound techniques for endometriosis are not utilised or under-utilised. People are therefore reliant on healthcare providers either using clinical and physical examination information to be given a diagnosis, with high false positive or false negative diagnoses, or diagnostic laparoscopy, which is an invasive procedure with risks of surgical complications and poor surgical outcomes.
The goals of this thesis were to better understand the current limitations and gaps that exist for ultrasound as a diagnostic and management tool, increase awareness of evidence-based techniques internationally, and initiate solutions to overcome deficiencies. Altogether, the aim was to contribute original knowledge to improve the process of diagnosis and surgical management of patients with endometriosis.
The research performed and presented as part of this thesis has evolved our understanding of how ultrasound is a tool to diagnose and optimise the management of endometriosis. It has also evoked new research questions, challenged our way of thinking of old ideas, and established interdisciplinary international research teams. The novel ultrasound techniques studied in this thesis may have significant benefit for the endometriosis community who are left without a diagnosis or are destined for a delayed diagnosis.
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Carter, David E. "Diagnostic and classification accuracy for mildly mentally handicapped children." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/31112.
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The purpose of this study was to examine the diagnostic and classification accuracy of placement decisions for Mildly/Educably Mentally Handicapped (M/EMH) children in British Columbia. Evidence from the United States suggests that classification decisions are often made on the basis of idiosyncratic student behaviours and the subjective opinions of educators, not on the basis of empirical evidence. Although Canadian special education practice is often based on that of the U.S., no major study of the accuracy of diagnosis and classification has been undertaken in this country.
Based on a review of the literature, internationally accepted criteria for the diagnosis and classification of M/EMH students were formulated. In addition, variables that might influence the use of these criteria were identified.
Elementary age students from two metropolitan Vancouver school districts who had been suspected of being M/EMH during a two-year period served as subjects (n=106). Of these 57 were classififed as M/EMH and 49 were classified as regular education. An evaluation of IQ, adaptive behaviour, reading and arithmetic achievement, maladaption, and visual and hearing acuity was performed for each subject.
Preliminary data analyses permitted the formation of an achievement composite score and the pooling of subjects from the two districts. Using an internationally accepted two-factor diagnostic model, analyses were performed to investigate the classification accuracy for the sample. Cut-off criteria used with the two-factor model were adjusted to those of both the American Association for Mental Deficiency and the draft B.C. Special Education Guidelines. Where subjects could not be confirmed by the application of these models, sources of classification error were identified.
Next, a series of discriminant function analyses, each representing a historical step in the development of diagnostic and classification models, were performed and the classification accuracy of each examined. Finally, a full model of all measured variables was examined using both a forced discriminant function procedure and a step-wise technique.
The findings suggested that a combination of the adaptive behaviour, IQ, and achievement variables provided the highest classification accuracy. This result is consistent with much of the research from the U.S. IQ scores were found to consistently dominate classification decisions. In addition, academic achievement proved to be a
valid predictor, either in combination with social adaptation or maladaption. However, maladaptive behaviour, whenever entered with social adaptation, overwhelmed the latter as a descriminator of group membership. The highest classification rate for the total sample was 92.0% for the combination of adaptive behaviour, IQ, and academic achievement.
Although visual and hearing acuity were not found to be related to group membership, it was discovered that testing for these variables was not occurring in the districts studied in accordance with accepted best practice. A disproportionate number of M/EMH students proved to be untestable using school-based audiological and visual sweep testing techniques. In cases of untestability, the assumption that the child can see and hear within normal tolerances appears to be made, and efforts to use alternative testing procedures are not pursued. In addition, visual and hearing testing appears to occur after the administration of standardized cognitive tests, and not before, as best practices would dictate.
The principal contributions of this research are (1) that it is the first major study of diagnostic and classification accuracy with a Canadian M/EMH population, (2) that it advises the inclusion of academic achievement as
a domain of adaptive behaviour based on empirical evidence of the importance of that variable in diagnosing M/EMH, and (3) it examines the role of auditory and visual acuity testing in M/EMH diagnosis and classification.<br>Education, Faculty of<br>Educational and Counselling Psychology, and Special Education (ECPS), Department of<br>Graduate
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Rachaneni, Suneetha. "Accuracy of bladder ultrasound in the diagnosis of detrusor overactivity (BUS study)." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6723/.
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Objective To estimate the accuracy of bladder wall thickness (BWT), measurement by transvaginal bladder ultrasound (BUS) in diagnosing detrusor overactivity (DO) Methods A multicenter study in 687 women with overactive bladder or urgency predominant mixed incontinence in 22 centres was undertaken. Index test was BWT and urodynamics was the reference standard. Reproducibility of BWT and the acceptability of BWT and urodynamics were also studied. Results BWT showed poor sensitivity, specificity and likelihood ratios at all pre-specified cut-offs. The ROC curve showed no evidence of discrimination at any threshold between those with and without DO (p=0.25): the AUC was 0.53, 95%CI: (0.48, 0.57). In the prospective interobserver variation study of scans performed by two independent observers, the SD 0.95mm with an analytical variability of 0.76mm. There was a trend towards greater acceptability of BWT scan compared to urodynamics (p<0.001), (81% versus 56%). Conclusion Bladder wall thickness measurement did not discriminate women with DO versus those without DO and hence is not an accurate test for diagnosing DO. Transvaginal BWT does not have sufficient reliability and reproducibility. Women experienced higher levels of embarrassment and a lower rate of acceptability with urodynamics compared to the BWT scan procedure.
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Rawashdeh, Mohammad. "Radiologist and image characteristics that affect the accuracy of breast cancer diagnosis." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/12790.
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Aims Variations in the performance of mammography readers are well reported, but key lesion and reader features explaining such variations are not fully explored. This PhD study aims to: 1) measure the diagnostic accuracy of breast radiologists, 2) identify parameters linked to higher levels of performance, and 3) establish the key mammogram morphological features that impact upon the detection of breast cancer. Methods All studies received institutional ethics approval. There were two studies, Study A: a test set of mammograms was developed compromising 60 cases, 20 containing cancer, and these were shown to 129 readers. Each reader was asked to locate any malignancies and provide a confidence rating using a scale of 1-5. Details were obtained from each reader regarding experience and training and these were correlated with jackknifing free response operating characteristic (JAFROC) figure of merit. Cancers were ranked according to the “detectability rating”, that is, the number of readers who accurately detected and located the lesion divided by the total number of readers, and this was correlated with various mathematical lesion descriptors. Study B: to validate the methods used in the previous studies, another test set compromising 40 mammographic images, each containing a single lesion, were presented to nine expert breast radiologists using a high specification interactive digital drawing tablet with stylus. Each reader was asked to manually delineate the breast masses using the tablet and stylus and then classify the lesion according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) lexicon. Delineated shapes were quantified using v Matlab software. Intraclass Correlation Coefficient (ICC) was used to assess interobserver agreement for delineation, and nonparametric ICC (Kendall's W) for classification parameters. Results Higher reader performance was positively correlated with number of years reading mammograms (P≤0.01), number of mammogram readings per year (P≤0.001), and hours reading mammogram per week (P≤0.04). For readers with annual volumes of less than 1000 mammograms per year, JAFROC values was negatively related to years’ post-qualification as a radiologist (P≤0.004) and number of years reading mammograms (P≤0.002). For readers reading more than 5000 mammograms per year, JAFROC values was positively linked to years qualified as a radiologist (P≤0.01), number of mammograms readings per year (P≤0.002) and number of hours readings per week (P≤0.003). Number of mammograms readings per year was positively related with JAFROC scores for readers with an annual volume between 1000 and 5000 (P≤0.03). For image features and lesion descriptors there were correlations between “detectability rating” and lesion size (P≤0.005), breast density (P≤0.007), perimeter (P≤0.0004), eccentricity (P≤0.02), and solidity (P< 0.0001). Poor inter-observer agreement was found for BI-RADS shape (W= 0.50) and margin (W= 0.40) assessments. However, agreement for computer-based measures was excellent for compactness (ICC = 0.93) and good for lesion elongation (ICC = 0.82). Conclusions Radiologist experience and lesion morphology contributes significantly to cancer detection efficacy. Poor levels of agreement were found when readers classified lesions using BI-RADS, however, using computer metrics, good inter-observer agreement was found for lesion delineations. These studies have provided new information regarding factors that impact upon radiologists’ performance. The data provided should contribute to an improvement to the service women receive and help reduce radiology reporting variability in the future.
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Brazzelli, Miriam. "Studies to inform the methods for Cochrane systematic reviews of diagnostic accuracy in stroke medicine." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5566.
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Background A variety of tests are used in clinical practice to help the diagnostic process and so improve patient care. Many aspects of stroke management depend on accurate and rapid diagnosis. Brain imaging, including CT or MRI, is necessary to identify the location and extent of the cerebral lesion, and to determine the pathological type of stroke and its likely cause. Current treatments - such as thrombolysis - for ischaemic stroke have increased the need for clear evidence on which imaging test is optimal for diagnosis in the acute phase of stroke. Systematic reviews of diagnostic test accuracy may provide evidence on the best use of a diagnostic test in clinical practice and help clinicians to decide among alternative tests. The Cochrane Collaboration has recently included systematic reviews of diagnostic test accuracy within its remit. However, to prepare Cochrane systematic reviews of diagnostic test accuracy is challenging because the methods for such reviews are still in a state of flux. Materials and methods The research work undertaken for this thesis addresses four relevant methodological aspects of such reviews and, I hope, will contribute to informing the development of the methods for Cochrane systematic reviews of test accuracy: i) I assessed the quality of reporting of imaging studies in stroke medicine published between 1995 and 2008 with the current STAndards for the Reporting of Diagnostic accuracy studies (STARD) criteria; ii) I assessed the magnitude of publication bias in diagnostic accuracy studies in stroke medicine, by reviewing all diagnostic abstracts presented at two international stroke meetings between 1995 and 2004 and so evaluating the characteristics and findings of the identified abstracts; iii) I have evaluated the methods for preparing reviews of test accuracy by undertaking a pilot review according to the draft recommendations of the Cochrane Diagnostic Test Accuracy Working Group; iv) I conducted a survey to assess a) how well clinicians and health professionals interpret findings of Cochrane systematic reviews of diagnostic accuracy presented in summary documents; and b) what is the best format for summarising findings of Cochrane reviews of diagnostic accuracy. Conclusions In conclusion, methodological issues concerning the validity and reliability of findings of studies included in systematic reviews of diagnostic accuracy remain of fundamental importance. More empirical evidence is needed to address potential biases such as reporting bias and publication bias. To allow dissemination of diagnostic reviews findings in clinical practice better ways of communicating main characteristics and key results of systematic reviews of diagnostic accuracy should be considered. In the current literature, the quality of reporting and methodological quality of imaging studies for the diagnosis of stroke is less than satisfactory and leaves room for improvement. This is worrying, especially if current health imaging policies are in fact based on poor quality evidence and hence scarce health resources may not being deployed as effectively as they could be.
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Alonzo, Todd Allen. "Assessing accuracy of a continuous medical diagnostic or screening test in the presence of verification bias /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/9600.
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Lloyd, Aaron, Vinay Pasupuleti, Priyaleela Thota, et al. "Accuracy of loop-mediated isothermal amplification for the diagnosis of Clostridium difficile infection: a systematic review." Elsevier B.V, 2015. http://hdl.handle.net/10757/345286.
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Loop-mediated isothermal DNA amplification (LAMP) are currently used as standalone diagnostic test for C. difficile infection (CDI). We assessed the diagnostic accuracy of LAMP for the diagnosis of CDI. We searched 5 databases to identify studies that compared LAMP with culture cytotoxicity neutralization assay or anaerobic toxigenic culture (TC) of C. difficile. We used the random-effects model to calculate pooled sensitivities, specificities, diagnostic odds ratios and their 95% confidence intervals (CIs). The search of the databases yielded 16 studies (6,979 samples) that met inclusion criteria. When TC was used as the gold standard (6,572 samples), bivariate analysis yielded a mean sensitivity of 0.95 (95%CI, 0.93-0.97; I2 = 67.4) and a mean specificity of 0.99 (95%CI, 0.96-1.00; I2 = 97.0). LAMP is a useful diagnostic tool with high sensitivity and specificity for detecting CDI. The results should however be interpreted only in the presence of clinical suspicion and symptoms of CDI.<br>Revisión por pares
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Staal, Rozemarijn Nathalie. "Diagnostic Accuracy in Dual Diagnosis: The Development of the Screen for Symptoms of Psychopathology in Individuals with Intellectual Disability (SSP-ID)." Wright State University Professional Psychology Program / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wsupsych1347493083.
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Lee, Lisa Meredith. "Factors affecting accuracy ratings of an automated adolescent MMPI report /." Norfolk, Va. : Lee, 1989.
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Patel, Alpesh. "Sensitivity and Accuracy of Cone Beam Computed Tomography in Diagnosing Osseous Defects at the Mandibular Condyle." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1363606389.
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Sibanda, Lidion. "Diagnostic radiography requests in Zimbabwe’s public hospital complex: completeness, accuracy and justtification." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/1552.
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A thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Diagnostic Radiography
in the Faculty of Health and Wellness Sciences
at the Cape Peninsula University of Technology, 2012<br>Complete, accurate and justified radiological examination requests are prerequisite to
radiological exposures. However, global research shows evidence of high numbers of
incomplete and inaccurate requests as well as that up to 77% radiological exposures are
unjustified. Plain lumbar spine and plain skull radiology examinations are reported as being
procedures that generate high dose and a low diagnostic yield. This study was designed to
objectively measure the completeness, accuracy and justification of these two examinations
in an effort to make inferences that will contribute to an improved radiology service. This
research could therefore have positive effects on optimisation of radiation protection in
Zimbabwe.
Methodology
A non participatory prospective descriptive analytical document review of quota sampled
radiological request forms for 200 plain skull and 200 plain lumbar spine examinations was
employed. Data was captured using structured data collection instruments designed and
tested by the researcher for this study. The instrument was designed using the IAEA-HHS4
(2010) minimum prescribed request data as a framework and adding additional form fields
found to be relevant through a review of all identified radiological request template forms in
use at the research site. Data analysis involved central tendency measures and inferential
statistics.
Results: The central tendency demonstrated for the two examinations was that generally
referrers for plain lumbar spine and for plain skull radiology would respectively provide 38.9
+/- 0.6% and 40.2+/-0.5% overall examination request information. This information was
significantly below expectation. There was however no significant difference between the
samples’ means for the two examinations. The tendency demonstrated in patient information
for lumbar spine and skull requests was that generally referrers would respectively provide
48.4 +/- 0.8% and 49.5+/- 0.8% patient information. These values were inclusive of each
other and they were significantly (p=0.00 Sig.) below expectation. There was however no
significant difference between the two examinations’ data. The tendency demonstrated for
examination information was that referrers for the research site would generally provide
29.8+/-0.8% (lumbar) and 32.6+/-0.8% (Skull) examination information. These values were
significantly (p=0.000 Sig.) below expectation and demonstrated a significant difference
between the sample means for the two examinations. With respect to referrer information,
the tendency demonstrated was that generally referrers for plain lumbar spine and for plain
skull examinations would respectively provide 38+/- 1% and 38.5 +/- 0.8% referrer
identification information. These were significantly below expectation (p= 0.000 Sig.) but
there was no significant difference between the samples’ means with respect to referrer
information. With respect to accuracy of request data, it was observed that 5% plain lumbar
spine and 3% plain skull requests were specific in so far as information documented on
request forms could unambiguously identify the area to be imaged. It was also observed that
22.5% (lumbar spine) and 12% (skull) examination requests were indicated and therefore
justified. All requests forms were found to be legible.
Conclusions: Generally, referrers to this research site tend to provide incomplete,
inaccurate and unjustified radiological request data. The observed levels of completeness,
accuracy and justification of requests were generally consistent between the two
examinations relative to expectation. These levels had medico-legal implications and
negative effects on optimisation of radiation protection to patients. Further research to
establish causes of this variance in referral behaviour is recommended. The researcher also
recommends further research to establish whether there is an association between
requested examination and completeness, accuracy and justification of diagnostic radiology
examination requests.
Keywords: Radiation protection, radiological request, complete request, accurate request,
justified request, plain skull imaging, plain lumbar spine imaging.
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Kjellberg, Gustav, and Henrik Kälvegren. "A comparison of classification accuracy between MRI and PET datasets in computer aided diagnosis of Alzheimer's disease." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229704.
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The number of people suffering from Alzheimer’s disease (AD) is expected to increase rapidly in the coming years. Diagnosing the disease early is key to giving those affected a chance to maintain a higher quality of life. One of the most common ways to detect AD is to visually inspect scans of the patients’ brains. Computer aided diagnosis (CAD)can assist a physician’s judgement when searching for the disease in the brain scans, making the assessment more accurate. Progress has been made in this field throughout the years. This paper compares the machine learning classification accuracy of AD on images from two different brain scanning procedures - Magnetic resonance imaging (MRI) and Positron emission tomography (PET). Both the MRI and PET datasets contained 60 images. 30 of the images were AD cases and 30 were normal cases in each of the datasets. The images were processed into 1-dimensional signals using Discrete wavelet transform (DWT). The classification accuracy of Support vector machine (SVM), Random forest (RF) and Naive Bayes (NB) was obtained and then evaluated using 6-fold cross validation (CV). This study showed that PET images are more suitable than MR images for diagnosing AD using machine learning classifiers. The highest accuracy for PET and MRI from 6-fold CV was 100% and 90% respectively. The lowest accuracy was 60% for PET and 40% for MRI.<br>Antalet människor drabbade av Alzheimers sjukdom (AD) förväntas öka kraftigt de kommande åren. Att kunna diagnostisera sjukdomen tidigt är nyckeln till att ge dem insjukna en chans att leva ett liv av högre kvalitet. Ett av de vanligaste sätten att upptäcka AD är att visuellt undersöka bilder från hjärnskanningar av patienter. Datorassisterad diagnostisering (CAD) kan hjälpa en läkare i sitt omdöme vid undersökning för sjukdomen i hjärnbilderna, vilket ökar omdömets pålitlighet. Framsteg har gjorts inom området genom åren. Den här studien undersöker bedömningssäkerheten av maskinlärningsmetoder i klassifiering av AD på bilder från två olika skanningsmetoder för hjärnan - Magnetisk resonanstomografi (MRI) och Positronemissionstomografi (PET). Både PET- och MRI-datamängderna innehöll 60 bilder. 30 av bilderna var AD-fall och 30 var normala fall i varje datamängd. Bilderna processerades till endimensionella signaler med Discrete wavelet transform (DWT). Klassifieringssäkerheten av Support vector machine (SVM), Random forest (RF) och Naive bayes (NB) framtogs och utvärderades därefter med 6-delad korsvalidering (CV). Studien visade att PET-bilder är att föredra vid diagnostisering av AD med maskininlärningsklassifierare framför MR-bilder. Den högsta bedömningssäkerheten för PET och MRI utifrån 6-delad CV var 100 % och 90 % respektive. Den lägsta säkerheten var 60 % för PET and 40 % för MRI.
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Woznitza, Nick. "The diagnostic accuracy of reporting radiographer chest X-ray interpretations and their influence on clinicians' diagnostic decision-making : a comparison with consultant radiologists." Thesis, Canterbury Christ Church University, 2016. http://create.canterbury.ac.uk/15847/.
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Background: Diagnostic imaging plays an expanding and central role in patients' medical care. Radiographer clinical reporting is being increasingly used in patient focused services. There is a paucity of research that has examined radiographer chest X-ray reporting. Aim: To determine the diagnostic accuracy of reporting radiographer chest X-ray (CXR) reporting and the influence that CXR reports have on clinicians' diagnostic decision-making. Method: A quasi-experimental study determined the diagnostic accuracy of a cohort of reporting radiographers in CXR interpretation, using a free-response methodology. The influence of CXR reports on clinicians' diagnostic decision-making was determined with a cohort study. A non-inferiority approach was used, in line with Royal College of Radiologists and College of Radiographers guidance that reporting radiographers must be comparable to consultant radiologists. Results: The diagnostic accuracy of reporting radiographers (RR) was non-inferior to consultant radiologists (CR) for all measures, all p < 0.0001; unweighted JAFROC (RR Figure of Merit [FoM]=0.828, 95%CI 0.808-0.847; CR FoM=0.788, 95%CI 0.766-0.811), weighted JAFROC (RR FoM=0.830, 95%CI 0.811-0.849; CR FoM=0.786, 95%CI 0.764-0.808) and inferred ROC (RR Area Under the Curve [AUC]=0.909, 95%CI 0.887-0.931; CR AUC=0.903, 95%CI 0.882-0.924). No difference was found in the number of CXR reports that produced a correct most likely and/or most serious diagnosis (RR 876 of 1337 cases; CR 810 of 1368; p=0.103). Uncorrected most likely diagnostic confidence (RR 72.5 to 80.2; CR 71.0 to 80.4) and uncorrected most serious diagnostic confidence (RR 34.0 to 41.9; CR 33.5 to 39.2) of reporting radiographer CXR reports was non-inferior to consultant radiologists (p < 0.001). Corrected most likely diagnostic confidence, calculated using the Tsushima methodology, was lower (RR 4.61; CR 5.02) with no apparent difference, but noninferiority was not confirmed (p > 0.05). Conclusion: With appropriate postgraduate education, reporting radiographers are able to interpret chest X-rays at a level comparable to consultant radiologists.
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Aithal, Guruprasad Padur. "Hepatotoxicity : accuracy of diagnosis, long term outcome and role of genetic polymorphism in drug metabolism and adverse drug reactions." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327270.
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Cleary, Liam. "HbA1c Test’s Accuracy as a Predictor for Diabetes with Complications Diagnosis: Further Analysis of the HbA1c Diabetes Mellitus Test." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108925.
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Thesis advisor: Samuel Richardson<br>HbA1c levels are the most frequently used test for diagnosis and prognosis of diabetes mellitus. Recent studies have shown the biases this test has in particular cohorts, that was not noted when it was originally accepted by the American Diabetes Association in 2008. This study examined how these biases affect HbA1c’s ability as a predictor for complications that arise due to diabetes in specific cohorts, those of ethnicity, age, weight, and other patient attributes, compared to other established diabetes prognosis tests. We discovered that both glucose and HbA1c share similar biases as predictors for particular cohorts (the high glucose, high BMI, Asian, African, and Hispanic descent cohorts), HbA1c works better as a predictor when it is combined with the results of a glucose test and more characteristics of the patient compared to a HbA1c test alone with fewer variables, and glucose and HbA1c are better predictors for different diseases, respectively, that may arise due to diabetes mellitus<br>Thesis (BA) — Boston College, 2020<br>Submitted to: Boston College. College of Arts and Sciences<br>Discipline: Departmental Honors<br>Discipline: Economics
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Jagot, Khatija H. "The accuracy of 2D transvaginal ultrasound in the diagnosis of benign endometrial pathology: a comparison between ultrasonography and hysteroscopy." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29795.
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STUDY OBJECTIVE: To evaluate the diagnostic accuracy of transvaginal sonography compared to hysteroscopy in diagnosing benign endometrial pathology. DESIGN: Retrospective cross-sectional study. Canadian Task force classification II – 2 SETTING: Department of Gynaecology, Groote Schuur Hospital, Cape Town, South Africa. PATIENTS: Patients having an office hysteroscopy procedure between January 2014 and December 2016, with a record of a recent transvaginal ultrasound and endometrial histology were included in this study. All malignant cases were excluded. INTERVENTIONS: Transvaginal ultrasound, endometrial biopsy and office hysteroscopy. MEASUREMENTS AND MAIN RESULTS: A total of one hundred and forty two patients, pre- and postmenopausal, were included in this study. The most common indications for hysteroscopy were abnormal uterine bleeding and postmenopausal bleeding. Sensitivity, specificity, positive and negative predictive values were calculated for ultrasonography and hysteroscopy in diagnosing benign endometrial pathology by comparing them to histological diagnosis as gold standard. The most common pathologies identified at histology were polyps and fibroids. For those patients who had a normal endometrium at ultrasound (n=59), hysteroscopy revealed 33.9% polyps, 5.1% submucosal fibroids and 49.2% normal/atrophic endometrium. The remainder of these patients demonstrated proliferative or hyperplastic endometrium, suspicious endometrium and adhesions. For those patients who had a normal hysteroscopy (n=26), ultrasound demonstrated 7.7% polyps, 7.7% submucosal fibroids, 11.5% cystic areas, 3.9% no comment on endometrium and 69.2% normal endometrium. In diagnosing polyps, hysteroscopy had a higher sensitivity (78%) than ultrasound (37.3%). However, ultrasound had a higher specificity (85.5%), compared to that of hysteroscopy which was 71.1%. The negative predictive value of hysteroscopy for polyps was 81.9% and ultrasound, 65.7%. In the diagnosis of submucosal fibroids, ultrasound had a higher sensitivity than hysteroscopy but they both had similar specificity. Ultrasound and hysteroscopy had high negative predictive values and low positive predictive values. The combination of ultrasound and hysteroscopy did not improve sensitivity, PPV or NPV with a small decline in specificity. CONCLUSION: This study demonstrated that hysteroscopy was more accurate in the diagnosis of endometrial polyps than ultrasound with a higher sensitivity and negative predictive value. However hysteroscopy had a lower sensitivity when diagnosing submucosal fibroids.
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Amini, Hashem. "Fetal Anomalies Surveillance and Diagnostic Accuracy of Ultrasound and Magnetic Resonance Imaging /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-121503.
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Van, Zyl Johet Engela. "Accuracy of risk prediction tools for acute coronary syndrome : a systematic review." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97069.
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Thesis (MCur)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: Background: Coronary artery disease is a form of cardiovascular disease (CVD) which
manifests itself in three ways: angina pectoris, acute coronary syndrome and cardiac death.
Thirty-three people die daily of a myocardial infarction (cardiac death) and 7.5 million deaths
annually are caused by CVD (51% from strokes and 45% from coronary artery disease)
worldwide. Globally, the CVD death rate is a mere 4% compared to South Africa which has a
42% death rate. It is predicted that by the year 2030 there will be 25 million deaths annually
from CVD, mainly in the form of strokes and heart disease. The WHO compared the death
rates of high-income countries to those of low- and middle-income countries, like South
Africa, and the results show that CVD deaths are declining in high-income countries but
rapidly increasing in low- and middle-income countries. Although there are several risk
prediction tools in use worldwide, to predict ischemic risk, South Africa does not use any of
these tools. Current practice in South Africa to diagnose acute coronary syndrome is the use
of a physical examination, ECG changes and positive serum cardiac maker levels.
Internationally the same practice is used to diagnose acute coronary syndrome but risk
assessment tools are used additionally to this practise because of limitations of the ECG and
serum cardiac markers when it comes to NSTE-ACS.
Objective: The aim of this study was to systematically appraise evidence on the accuracy of
acute coronary syndrome risk prediction tools in adults.
Methods: An extensive literature search of studies published in English was undertaken.
Electronic databases searched were Cochrane Library, MEDLINE, Embase and CINAHL.
Other sources were also searched, and cross-sectional studies, cohort studies and
randomised controlled trials were reviewed. All articles were screened for methodological
quality by two reviewers independently with the QUADAS-2 tool which is a standardised
instrument. Data was extracted using an adapted Cochrane data extraction tool. Data was
entered in Review Manager 5.2 software for analysis. Sensitivity and specificity was
calculated for each risk score and an SROC curve was created. This curve was used to
evaluate and compare the prediction accuracy of each test.
Results: A total of five studies met the inclusion criteria of this review. Two HEART studies
and three GRACE studies were included. In all, 9 092 patients participated in the selected
studies. Estimates of sensitivity for the HEART risks score (two studies, 3268 participants)
were 0,51 (95% CI 0,46 to 0,56) and 0,68 (95% CI 0,60 to 0,75); specificity for the HEART
risks score was 0,90 (95% CI 0,88 to 0,91) and 0,92 (95% CI 0,90 to 0,94). Estimates of
sensitivity for the GRACE risk score (three studies, 5824 participants) were 0,03 (95% CI0,01 to 0,05); 0,20 (95% CI 0,14 to 0,29) and 0,79 (95% CI 0,58 to 0,93). The specificity was
1,00 (95% CI 0,99 to 1,00); 0,97 (95% CI 0,95 to 0,98) and 0,78 (95% CI 0,73 to 0,82). On
the SROC curve analysis, there was a trend for the GRACE risk score to perform better than
the HEART risk score in predicting acute coronary syndrome in adults.
Conclusion: Both risk scores showed that they had value in accurately predicting the
presence of acute coronary syndrome in adults. The GRACE showed a positive trend
towards better prediction ability than the HEART risk score.<br>AFRIKAANSE OPSOMMING: Agtergrond: Koronêre bloedvatsiekte is ‘n vorm van kardiovaskulêre siekte. Koronêre
hartsiekte manifesteer in drie maniere: angina pectoris, akute koronêre sindroom en
hartdood. Drie-en-dertig mense sterf daagliks aan ‘n miokardiale infarksie (hartdood). Daar
is 7,5 miljoen sterftes jaarliks as gevolg van kardiovaskulêre siektes (51% deur beroertes en
45% as gevolg van koronêre hartsiektes) wêreldwyd. Globaal is die sterfte syfer as gevolg
van koronêre vaskulêre siekte net 4% in vergelyking met Suid Afrika, wat ‘n 42% sterfte
syfer het. Dit word voorspel dat teen die jaar 2030 daar 25 miljoen sterfgevalle jaarliks sal
wees, meestal toegeskryf aan kardiovaskulêre siektes. Die hoof oorsaak van sterfgevalle sal
toegeskryf word aan beroertes en hart siektes. Die WHO het die sterf gevalle van hoeinkoms
lande vergelyk met die van lae- en middel-inkoms lande, soos Suid Afrika, en die
resultate het bewys dat sterf gevalle as gevolg van kardiovaskulêre siekte is besig om te
daal in hoe-inkoms lande maar dit is besig om skerp te styg in lae- en middel-inkoms lande.
Daar is verskeie risiko-voorspelling instrumente wat wêreldwyd gebruik word om isgemiese
risiko te voorspel, maar Suid Afrika gebruik geen van die risiko-voorspelling instrumente nie.
Huidiglik word akute koronêre sindroom gediagnoseer met die gebruik van n fisiese
ondersoek, EKG verandering en positiewe serum kardiale merkers. Internationaal word die
selfde gebruik maar risiko-voorspelling instrumente word aditioneel by gebruik omdat daar
limitasies is met EKG en serum kardiale merkers as dit by NSTE-ACS kom.
Doelwit: Die doel van hierdie sisematiese literatuuroorsig was om stelselmatig die bewyse
te evalueer oor die akkuraatheid van akute koronêre sindroom risiko-voorspelling
instrumente vir volwassenes.
Metodes: 'n Uitgebreide literatuursoektog van studies wat in Engels gepubliseer is was
onderneem. Cochrane biblioteek, MEDLINE, Embase en CINAHL databases was deursoek.
Ander bronne is ook deursoek. Die tiepe studies ingesluit was deurnsee-studies,
kohortstudies en verewekansigde gekontroleerde studies. Alle artikels is onafhanklik vir die
metodologiese kwaliteit gekeur deur twee beoordeelaars met die gebruik van die QUADAS-2
instrument, ‘n gestandaardiseerde instrument. ‘n Aangepaste Cochrane data instrument is
gebruik om data te onttrek. Data is opgeneem in Review Manager 5.2 sagteware vir
ontleding. Sensitiwiteit en spesifisiteit is bereken vir elke risiko instrument en ‘n SROC kurwe
is geskep. Die SROC kurwe is gebruik om die akkuraatheid van voorspelling van elke
instrument te evalueer en te toets.
Resultate: Twee HEART studies en drie GRACE studies is ingesluit. In total was daar 9 092
patiente wat deelgeneeem het in die gekose studies. Skattings van sensitiwiteit vir die HEART risiko instrument (twee studies, 3268 deelnemers) was 0,51 (95% CI 0,47 to 0,56)
en 0,68 (95% CI 0,60 to 0,75) spesifisiteit vir die HEART risiko instrument was 0,89 (95% CI
0,88 to 0,91) en 0,92 (95% CI 0,90 to 0,94). Skattings van sensitiwiteit vir die GRACE risiko
instrument (drie studies, 5824 deelnemers) was 0,28 (95% CI 0,13 to 0,53); 0,20 (95% CI
0,14 to 0,29) en 0,79 (95% CI 0,58 to 0,93). Die spesifisiteit vir die GRACE risiko instrument
was 0,97 (95% CI 0,95 to 0,99); 0,97 (95% CI 0,95 to 0,98) en 0,78 (95% CI 0,73 to 0,82).
Met die SROC kurwe ontleding was daar ‘n tendens vir die GRACE risiko instrument om
beter te vaar as die HEART risiko instrument in die voorspelling van akute koronêre
sindroom in volwassenes.
Gevolgtrekking: Altwee risiko instrumente toon aan dat albei instrumente van waarde is.
Albei het die vermoë om die teenwoordigheid van akute koronêre sindroom in volwassenes
te voorspel. Die GRACE toon ‘n positiewe tendens teenoor beter voorspelling vermoë as die
HEART risiko instrument.
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Matos, Fabiana Gonçalves de Oliveira Azevedo. "Fatores preditores da acurácia dos diagnósticos de enfermagem." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/7/7139/tde-13012011-152651/.
Full textAbstract:
A acurácia dos diagnósticos de enfermagem é importante para a escolha de intervenções adequadas, mas ainda pouco se conhece sobre os fatores que a influenciam. Objetivos: identificar os fatores preditores da acurácia de diagnósticos de enfermagem; descrever o grau de acurácia dos diagnósticos de enfermagem documentados na prática clínica e testar a concordância intra e entre avaliadores na aplicação da Escala de Acurácia de Diagnósticos de Enfermagem Versão 2. Método: estudo documental realizado num hospital público de ensino da cidade de São Paulo, Brasil. A acurácia dos diagnósticos de enfermagem documentados na admissão de pacientes foi estimada por meio da aplicação da EADE Versão 2, que possui 4 itens para o julgamento da presença, relevância, especificidade e coerência das pistas existentes para o diagnóstico em avaliação. As respostas aos itens são pontuadas e geram um escore final variando de 0 a 13,5 (0 / 1 / 2 / 4,5 / 5,5 / 9 / 10 / 12,5 ou 13,5). A amostra do estudo foi aleatória, composta pelos registros de admissão de 749 pacientes adultos internados na clínica médica ou cirúrgica entre julho de 2005 e junho 2008. Todos os enfermeiros que documentaram as admissões avaliadas forneceram informações de características pessoais e profissionais. Foram computados dados de caracterização dos pacientes que tiveram seus registros analisados. Foram realizados testes de associação entre o grau de acurácia dos diagnósticos e variáveis dos diagnósticos, variáveis dos pacientes e dos registros de admissão e variáveis dos enfermeiros. As variáveis que nos testes de associação com o grau de acurácia obtiveram valores de p 0,20 foram incluídas em modelos de regressão linear múltipla. Uma sub-amostra com 156 admissões foi sorteada para estimar a confiabilidade da escala intra avaliador e entre avaliadores. Resultados: Dos 749 registros de admissão foram avaliados 3.417 diagnósticos documentados por 21 enfermeiros. A maioria dos diagnósticos de enfermagem foi avaliada como altamente acurada (70,4%,) e a média geral da acurácia foi 9,8 (DP =5,6 e variação de 0 a 13,5). As análises de regressão linear múltipla permitiram ajustar três modelos (variáveis dos diagnósticos, variáveis dos pacientes e dos registros de admissão, variáveis dos enfermeiros). O modelo com as variáveis dos diagnósticos mostrou que diagnósticos de baixa frequência (p=0,000), diagnósticos do domínio funcional (p=0,000) e diagnósticos atuais (p=0,000) são preditores de graus mais elevados de acurácia, explicando 28% da variância; o modelo com as variáveis dos pacientes e registros de admissão mostrou que doenças crônicas (p=0,000), internações na clínica médica (p=0,000) e qualidade satisfatória dos registros (p=0,005) são preditores de acurácia mais elevada, com variância explicada de 14%; e o modelo com as variáveis dos enfermeiros mostrou que o relato da presença de conteúdo teórico e prático em diagnóstico de enfermagem na graduação (p = 0,011) foi preditor de graus elevados de acurácia, explicando 26% variância. O valor de Coeficiente de Correlação Intraclasse (ICC) intra avaliadores foi 0,96 e o ICC entre avaliadores foi 0,71 o que confere boa confiabilidade à EADE - Versão 2. Conclusão: O estudo oferece dados empíricos que contribuem para o conhecimento sobre os fatores preditores da acurácia dos diagnósticos de enfermagem.<br>The accuracy of nursing diagnoses is important in order to select appropriate interventions, however little is known about the factors that influence it. Objectives: To identify the predictors of accuracy of nursing diagnoses; describe the degree of accuracy of nursing diagnoses documented in clinical practice and to test the intra and interrater reliability of the Accuracy Scale for Nursing Diagnosis (NDAS) Version 2. Method: A documental study carried out in a public teaching hospital in São Paulo, Brazil. The accuracy of the nursing diagnoses documented during admission assessment of the patients was estimated by applying the NDAS Version 2, which has four items to judge the presence, relevance, specificity and consistency of the existing cues for a documented diagnosis. The responses to the items were scored and generated a final score ranging from 0 to 13.5 (0/1/2/4.5/5.5/9/10/12.5 or 13.5). The study sample was randomly composed of the admission records of 749 adult patients hospitalized in general medicine or surgical wards between July 2005 and June 2008. Each of the nurses who documented the admissions provided demographic and professional information. Also computed were the data of characteristics of patients who had their records reviewed. Association tests were performed between the degree of accuracy of diagnoses and variables of the diagnoses, variables of the patients and admission records and the variables of the nurses. The variables that obtained p values 0.20 in the association tests with the degree of accuracy were included in multiple regression models. A sub-sample of 156 admission records was randomly selected to estimate inter and intra-raters reliability of the scale. Results: Of the 749 admission records that were evaluated, 3.417 diagnoses were documented by 21 nurses. The majority of the nursing diagnoses were evaluated as highly accurate (70.4%) and average overall accuracy was 9.8 (DP = 5.6) and ranged from 0 to 13.5. Multiple linear regression analysis allows the adjustment of three models (variables of the diagnoses, variables of the patients and admission records and variables of the nurses). The model with variables of the diagnoses showed that diagnoses of low frequency (p = 0.000), diagnoses of the functional domain (p = 0.000) and actual diagnoses (p = 0.000) were predictors of a higher degrees of accuracy, explaining 28% of the variance; the model with variables of patients and admission records showed that chronic diseases (p = 0.000), admissions to the general medical ward (p = 0.000) and a satisfactory quality of the patient records (p=0.005) were predictors of higher accuracy, explaining 14% of the variance; and the model with variables of the nurses showed that reporting presence of theoretical and practical content of nursing diagnosis in the baccalaureate program (p = 0.011) was predictor of higher degrees of accuracy, explaining 26% of the variance. The ICC coefficient of intra and interraters was 0.96 and 0.71 respectfully, therefore demonstrating good reliability of the NDAS Version 2. Conclusion: This study provided empirical data to advance knowledge regarding predictors of the accuracy of nursing diagnoses.
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Minne, C. "The efficacy of intravenous iodinated contrast media in the diagnostic accuracy of cranial computed tomography (CT) in patients with a possible missed diagnosis at Dr George Mukhari Hospital, Pretoria." Thesis, University of Limpopo (Medunsa Campus), 2011. http://hdl.handle.net/10386/407.
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Thesis (M. Med (Rad. Diagn.)) --University of Limpopo, Medunsa Campus, 2011<br>Objective:
The objective was to determine the incidence of missed pathology on normal non contrast enhanced cranial computed tomography (NECT).Method:
Records of cranial computed tomography scans done over a 12 month period at the Dr George Mukhari Hospital were evaluated by three readers. The NECT and contrast enhanced cranial computed tomography (CECT) were read at separate occasions and readers did not have access to a history, each other’s interpretation or to their own interpretation of the NECT when the CECT was evaluated. The data was evaluated and analysed after the 3 readers had seen the cases individually. Interpretation discrepancies were resolved during a meeting between all 3 readers and consensus was reached. Cases with missed pathology on the NECT were evaluated retrospectively at a joint meeting between the 3 readers to determine whether the pathology was visible on the NECT and thus to determine the combined reader error rate. Results:
In this study 3.28 % of cases had pathology missed by 3 readers on the NECT. Retrospective viewing reduced this to 1.42% indicating a reader error of 1.85%. This incidence of missed pathology correlates with the most recent studies done. Having a thorough medical history of the patient and selecting those with clinical findings indicating the need for a CECT will reduce the incidence of missed pathology.Conclusion:
Patients with a normal NECT and no fever, meningism, confusion, focal/lateralizing signs, a history of tuberculosis or tumours, or risk factors for dural venous sinus thrombosis have a very small chance of missed pathology on NECT. The risk of contrast induced adverse events outweighs the risk of missing pathology on a normal NECT provided there is no clinical indication necessitating a CECT. Omitting unnecessary CECT will in turn reduce the risk of intravenous iodinated contrast and the radiation exposure to the patient. These two factors will ultimately reduce the running cost of the CT department and increase the throughput of patients. Alternatively omitting the NECT will reduce the radiation exposure to the patient.Reporting errors can be reduced by assessing and managing risk factors in each department i.e. viewing conditions and workload.
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Ma, Rui. "Recommendations Regarding Q-Matrix Design and Missing Data Treatment in the Main Effect Log-Linear Cognitive Diagnosis Model." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/9043.
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Diagnostic classification models used in conjunction with diagnostic assessments are to classify individual respondents into masters and nonmasters at the level of attributes. Previous researchers (Madison & Bradshaw, 2015) recommended items on the assessment should measure all patterns of attribute combinations to ensure classification accuracy, but in practice, certain attributes may not be measured by themselves. Moreover, the model estimation requires large sample size, but in reality, there could be unanswered items in the data. Therefore, the current study sought to provide suggestions on selecting between two alternative Q-matrix designs when an attribute cannot be measured in isolation and when using maximum likelihood estimation in the presence of missing responses. The factorial ANOVA results of this simulation study indicate that adding items measuring some attributes instead of all attributes is more optimal and that other missing data treatments should be sought if the percent of missing responses is greater than 5%.
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Payer, Nadine. "Suggested markers for sepsis in critically ill pediatric patients : accuracy of sCD14, G-CSF, IL-6, and IL-8 for advanced diagnosis /." [S.l.] : [s.n.], 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000297949.
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Umemura, Atsushi. "Diagnostic Accuracy of Apparent Diffusion Coefficient and 123I-Metaiodobenzylguanidine for Differentiation of Multiple System Atrophy and Parkinson's Disease." Kyoto University, 2015. http://hdl.handle.net/2433/200316.
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Stevenson, Amanda. "Mild cognitive impairment and the uncertainties of diagnosis : reviewing the accuracy of the Montreal Cognitive Assessment and exploring the process of psychosocial adjustment." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/16223.
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Background: Mild Cognitive Impairment (MCI) is a clinical construct reputed to represent an intermediate stage on a continuum between normal aging and cognitive decline. Conceptual and prognostic ambiguity can lead to significant diagnostic challenges and there is a need for accurate screening tests which can assist clinicians with decision-making. A diagnosis of MCI is also associated with considerable uncertainty for patients who may be adjusting to cognitive difficulties along with an increased risk of developing dementia. Beliefs about MCI may influence psychosocial adjustment, and individual differences in ‘psychological flexibility (PF)’, as conceptualised by the Acceptance and Commitment Therapy (ACT) model, may also be involved in this process. Objectives: In order to evaluate the accuracy and clinical utility of a recently developed screening tool for MCI, the Montreal Cognitive Assessment (MoCA), a systematic review of validation and diagnostic test accuracy (DTA) studies for this measure was conducted. Psychosocial adjustment to a diagnosis of MCI was also a key focus. An empirical study was therefore carried out with the aim of evaluating the possible relationships between cognitive impairment, illness representations about MCI, psychological wellbeing and quality of life (QoL), and to assess the potential involvement of PF. Method: Following a systematic search of relevant electronic databases and reference lists, validation and DTA studies of the MoCA were identified and evaluated for methodological quality. For the empirical study, patients recently diagnosed with MCI were recruited from local NHS memory clinic services and completed the MoCA and a questionnaire pack assessing illness representations, PF, mood, anxiety and QoL. Results: The systematic review identified 18 validation and DTA studies. Few of the studies achieved high ratings for methodological quality and problems with representativeness and generalisability were identified. Nevertheless, sensitivity levels appeared robust across studies, though specificity was variable. For the present empirical study, participants reported a spectrum of positive and negative beliefs about MCI. Distress attributed to MCI was associated with anxiety, along with perceptions of more serious illness consequences, while higher PF was associated with higher perceived QoL and mood. Lived experience of MCI appeared to have more relevance to psychosocial adjustment than objective cognitive impairment. Conclusions: The results of the systematic review indicate that while the MoCA is a robust tool overall in the identification of cognitive impairment, estimates of accuracy may be exaggerated by inter-study variation and bias. More rigorous validation studies are therefore needed. Implications for clinical decision-making regarding MCI are discussed and recommendations for future accuracy studies are outlined. The empirical study supported the findings of previous studies of the relevance of illness representations to psychosocial adjustment in MCI and added to the evidence base by providing preliminary support for the possible involvement of PF. The results suggest that both cognitive content and PF may represent possible vehicles for therapeutic change in patients with adjustment difficulties, and indicate that further investigation of these factors is warranted. Conclusions are limited, however, by small sample size and low statistical power. Replication of these findings with a larger and more representative sample is therefore recommended.
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Li, Zhongliang. "Data-driven fault diagnosis for PEMFC systems." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4335/document.
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Cette thèse est consacrée à l'étude de diagnostic de pannes pour les systèmes pile à combustible de type PEMFC. Le but est d'améliorer la fiabilité et la durabilité de la membrane électrolyte polymère afin de promouvoir la commercialisation de la technologie des piles à combustible. Les approches explorées dans cette thèse sont celles du diagnostic guidé par les données. Les techniques basées sur la reconnaissance de forme sont les plus utilisées. Dans ce travail, les variables considérées sont les tensions des cellules. Les résultats établis dans le cadre de la thèse peuvent être regroupés en trois contributions principales.La première contribution est constituée d'une étude comparative. Plus précisément, plusieurs méthodes sont explorées puis comparées en vue de déterminer une stratégie précise et offrant un coût de calcul optimal.La deuxième contribution concerne le diagnostic online sans connaissance complète des défauts au préalable. Il s'agit d'une technique adaptative qui permet d'appréhender l'apparition de nouveaux types de défauts. Cette technique est fondée sur la méthodologie SSM-SVM et les règles de détection et de localisation ont été améliorées pour répondre au problème du diagnostic en temps réel.La troisième contribution est obtenue à partir méthodologie fondée sur l'utilisation partielle de modèles dynamiques. Le principe de détection et localisation de défauts est fondé sur des techniques d'identification et sur la génération de résidus directement à partir des données d'exploitation.Toutes les stratégies proposées dans le cadre de la thèse ont été testées à travers des données expérimentales et validées sur un système embarqué<br>Aiming at improving the reliability and durability of Polymer Electrolyte Membrane Fuel Cell (PEMFC) systems and promote the commercialization of fuel cell technologies, this thesis work is dedicated to the fault diagnosis study for PEMFC systems. Data-driven fault diagnosis is the main focus in this thesis. As a main branch of data-driven fault diagnosis, the methods based on pattern classification techniques are firstly studied. Taking individual fuel cell voltages as original diagnosis variables, several representative methodologies are investigated and compared from the perspective of online implementation.Specific to the defects of conventional classification based diagnosis methods, a novel diagnosis strategy is proposed. A new classifier named Sphere-Shaped Multi-class Support Vector Machine (SSM-SVM) and modified diagnostic rules are utilized to realize the novel fault recognition. While an incremental learning method is extended to achieve the online adaptation.Apart from the classification based diagnosis approach, a so-called partial model-based data-driven approach is introduced to handle PEMFC diagnosis in dynamic processes. With the aid of a subspace identification method (SIM), the model-based residual generation is designed directly from the normal and dynamic operating data. Then, fault detection and isolation are further realized by evaluating the generated residuals.The proposed diagnosis strategies have been verified using the experimental data which cover a set of representative faults and different PEMFC stacks. The preliminary online implementation results with an embedded system are also supplied
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Shinkins, Bethany. "The evaluation and expansion of methodologies relating to the reporting and analyses of intermediate test results : improving the clinical utility of diagnostic research." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2df7fc16-51f5-4978-80bd-b69efdf9c8a2.
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<b>Background and objectives:</b> It has been argued that the binary framework frequently adopted to analyse test accuracy does not represent the clinical reality of diagnostic practice, and the recognition of an intermediate category of test result could make the utility of diagnostic tests more transparent. The objective of this thesis is to explore the value of moving away from the binary framework when evaluating and interpreting quantitative diagnostic tests. <b>Methods:</b> This thesis starts with an overview of the key arguments against dichotomising quantitative test results and a summary of some of the alternative methods proposed. Four distinct studies are then reported: 1) a systematic review of the methods currently used to evaluate the accuracy of quantitative cancer biomarkers, 2) a survey of GPs exploring preferences for threshold guidance 3) an evaluation of existing methods for identifying an intermediate range of test values, and 4) an assessment of the feasibility of applying these methods to the results of a meta-analysis. <b>Results:</b> The binary framework remains the most common method for evaluating the accuracy of quantitative tests, despite the survey of GPs indicating that a single threshold interpretation is less helpful than identifying rule-in and rule-out thresholds. Existing methods for identifying an intermediate range of values require some adaptation to incorporate the cost trade-offs relating to different outcomes but, given complete reporting at the primary research, could be applied to the results of a meta-analysis. <b>Conclusion:</b> The 2 x 2 diagnostic framework frequently fails to capture many of the realities and complexities of clinical research questions. Standardised methods that facilitate complete reporting of test accuracy in primary diagnostic accuracy studies are required to allow for greater flexibility when producing threshold recommendations further down the evidence pathway.
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ALBERO, FELIPE G. "Diagnostico de lesoes da tireoide pela espectroscopia de absorcao no infravermelho por tranformada de Fourier-FTIR." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9500.
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Made available in DSpace on 2014-10-09T12:27:22Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T14:06:37Z (GMT). No. of bitstreams: 0<br>Dissertacao (Mestrado)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Jacquemin, Maxime. "Arithmétiques relationnelles pour l'analyse par interprétation abstraite de propriétés de précision numérique." Electronic Thesis or Diss., université Paris-Saclay, 2021. http://www.theses.fr/2021UPASG050.
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L'arithmétique à virgule flottante est l'approche la plus utilisée pour réaliser des calculs mathématiques reposant sur les nombres réels avec un ordinateur. Cependant, elle souffre d'un défaut : chaque opération peut introduire une erreur, c'est-à-dire une différence avec le résultat que nous aurions obtenu en utilisant des réels. Bien que ces erreurs soient très faibles, elles peuvent s'accumuler et provoquer des bugs ayant parfois des conséquences graves, en particulier dans des domaines critiques comme l'aéronautique ou le nucléaire. Il est donc nécessaire de pouvoir garantir que les erreurs introduites par l'utilisation de l'arithmétique flottante ne causent pas de problème, ou, dit autrement, qu'elles soient suffisamment faibles pour que le programme se comporte comme attendu. Pour répondre à ce besoin, nous proposons une analyse statique par interprétation abstraite, reposant sur un nouveau domaine abstrait, et calculant une sur-approximation des erreurs introduites par l'arithmétique flottante. Cette analyse repose sur l'interaction, au travers d'un produit réduit, entre deux conceptions de la notion d'erreur: l'erreur absolue, intuitive et permettant de mieux comprendre le programme analysé, et l'erreur relative, plus proche du fonctionnement de l'arithmétique flottante. Notre analyse repose sur la combinaison des arithmétiques affines et d'intervalles, et dispose de capacités de raisonnements relationnels. Cette combinaison a cependant des difficultés à traiter les opérations non linéaires, dont la précision impacte fortement l'évaluation des erreurs relatives. Nous proposons donc deux approches pour répondre à ce problème. La première consiste en différentes améliorations de cette combinaison, permettant d'évaluer plus précisément multiplications et divisions sans impacter significativement les performances. La seconde consiste en la définition d'une nouvelle arithmétique relationnelle, spécifiquement conçue pour représenter l'erreur relative. Par ailleurs, nous avons implémenté un prototype de notre analyse au sein de l'outil Frama-C/Eva. Les premiers résultats expérimentaux montrent l'intérêt de notre analyse par rapport à l'état de l'art<br>Floating point arithmetic is the most used approach to perform mathematical computations using real numbers with a computer. However, this approach has a default : each operation can introduce an error, that is, a difference with the result we would have obtained using real numbers. Even if those errors are very small, they can accumulate et provoke serious bugs, particularly in critical domains like aeronautics or nuclear energy production for example. Thus, we have to be able to guarantee that the errors introduced by the use of floating point arithmetic do not cause problems, in other words, that they are small enough for the program to behave as expected. To answer this need, we propose an abstract interpretation based static analysis, along with a new abstract domain, that computes an overapproximation of the errors introduced by floating point arithmetic. This analysis is based on the interaction, performed through a reduced product, between two conceptions of the concept of error : absolute error, intuitive and helpful to understand the analyzed program, and relative error, closer of floating point arithmetic functioning. Our analysis relies on the combination of affine and intervals arithmetics, and thus have relational reasoning capacities. However, this combination has difficulties dealing with non linear operations, whose precision has a huge impact on relative errors evaluations. Thus, we propose two approaches to tackle this problem. The first one consists of several improvements of this combination that help evaluating multiplications and divisions more precisely without impacting performances significantly. The second one consists of the definition of a new relational arithmetic, specifically designed to represent relative errors. Besides, we have implemented a prototype of our analysis within the Frama-C/Eva tool. The first experimental results enlighten the advantages of our analysis against state of the art tools
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Russ, Andrew. "Diagnosing eyewitness accuracy." Thesis, University of Kent, 2015. https://kar.kent.ac.uk/53992/.
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Eyewitnesses frequently mistake innocent people for the perpetrator of an observed crime. Such misidentifications have led to the wrongful convictions of many people. Despite this, no reliable method yet exists to determine eyewitness accuracy. This thesis explored two new experimental methods for this purpose. Chapter 2 investigated whether repetition priming can measure prior exposure to a target and compared this with observers’ explicit eyewitness accuracy. Across three experiments slower responses to target faces were consistently observed irrespective of eyewitness accuracy in a lineup task. This indicates that repetition priming can provide a covert index of eyewitness accuracy. However this method could not reliably assess the accuracy of individual eyewitnesses. Chapter 3 therefore explored an alternative test of eyewitness accuracy which was based on a multiple lineup procedure for faces. The characteristics of this method were assessed over five experiments which showed that only some eyewitnesses can actually identify a perpetrator repeatedly. Chapter 4 then showed that such repeat-identifications can provide a direct index of eyewitness accuracy in a field study. Over two experiments, the success of this method was such that eyewitnesses who consistently acted on the same identity over six lineups were always accurate eyewitnesses. These results demonstrate that multiple lineups of faces could provide a useful method for assessing eyewitness accuracy. The implications of these findings, both for further study and for forensic application, are discussed.
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Hughes, Clifford. "Studies on improving the predictive markers for the diagnosis of acute pancreatitis after Endoscopic Retrograde Cholangiopancreatography (ERCP)." Thesis, Queensland University of Technology, 1999. https://eprints.qut.edu.au/37065/1/37065_Hughes_1999.pdf.
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Endoscopic Retrograde Cholangiopancreatography (ERCP) is a widely performed gastroenterological procedure often accompanied by the development of acute pancreatitis post-ERCP - the current literature quoting an incidence between 0% and 39.5%. Because acute pancreatitis can be a very serious outcome, sometimes leading to death, a method for predicting poor outcomes post-ERCP would be an advantage to the clinicians and patients. Described below is the development of two algorithms with a strong capacity to predict poor outcomes post-ERCP.
In addition to assessing a battery of common laboratory blood tests, this study also took the opportunity to study a recently described but still research-based analyte, the enzymatic activity of the trypsin bound to the serine protease inhibitor alpha- 2- macroglobulin ( a2M) complex called Macroglobulin-Trypsin complex-Like Substance (MTLS), high levels of MTLS have been identified in patients who developed acute pancreatitis post-ERCP. It was hypothesized that MTLS might be a useful, novel indicator of patients at risk of development of post-ERCP pancreatitis.
Three separate studies were carried out. The first was a retrospective study of 72 patients presenting for ERCP to the collaborating gastroenterologist, and the second was a prospective study involving 29 more patients. The retrospective study involved the analysis of previously collected blood specimens pre-ERCP and post-ERCP. On the pre-ERCP specimens 22 laboratory tests were performed to test the haematological, biochemical and coagulation status of the patients. Lipase, a classical diagnostic marker for acute pancreatitis, was measured on the patient's post-ERCP samples. From this study sophisticated statistical analysis was based on a 2-step process - Factor Analysis with Principal Component Extraction followed by Discriminant Analysis on the key components identified by Factor Analysis - in order to develop a predictive algorithm for poor outcomes post-ERCP.
The objective of the second, prospective, trial was to test algorthms developed by the initial
retrospective study. 29 patients were selected and their clinical outcomes using the system of Cotton (1991) compared in a blind trial with the predictions of the algorithm·. The third study involved developing a methodology for measuring the activity of trypsin in MTLS or associated with a2M. The investigation of the residual protease activity of the MTLS complexes, was based on the hypothesis that patients who develop post-ERCP acute pancreatitis, have abnormally active trypsin associated with MTLS or a2M before the ERCP. This was the least successful part of the research, as the methodology proved to be too insensitive and therefore not a useful marker for poor outcomes.
Two algorithms were derived from the retrospective trial. Algorithm 1 used a combination of gamma glutamyltransferase (GGT) and lipase, measured pre-ERCP, whereas Algorithm 2 used GGT, lipase and alpha - 1 - antitrypsin (AAT). Predictions were then made for the 29 prospective study patients using the two algorithms.
The results were: Algorithm 1, 27 out of 29 cases were predicted successfully with Pearson's correlation of 0.946 and significance p = <0.001 and likewise for Algorithm 2 - 27 out of 29 were successfully predicted with a comparable Pearson's correlation of 0.753 and p = <0.001.
Both algorithms have very strong capacities to predict poor outcomes and require additional clinical trials, Algorithm 2 has a better capacity to grade the predictions for poor outcomes, normal, mild and severe. Additional larger studies will be needed to refine these algorithms and to better appraise their clinical usefulness.
This study provides two very valid outcomes. The first is a method of statistical analysis with the capacity to produce predictive algorithms in a clinical setting and the second the development of two significant algorithms for predicting poor outcomes post-ERCP.
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Van, Dyk Zandri. "Diagnostic accuracy of CE Chirp." Diss., University of Pretoria, 2019. http://hdl.handle.net/2263/72463.
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The auditory brainstem response is an evoked potential that can be clinically used to estimate hearing sensitivity and to identify auditory nervous system pathology. Recently, there has been an increase in the implementation of the CE-Chirp stimulus in AABR equipment for neonatal hearing screening. The purpose of this study is to evaluate the diagnostic accuracy of the LS CE-Chirp-evoked ABR compared to the traditionally used click-evoked ABR for the identification of different degrees and configurations of sensorineural (SNHL) hearing loss.
An exploratory within-subject comparative research design was used. 49 ears with mild to moderate sensorineural hearing loss were assessed. Participants were assessed in a single session. Audiometric pure tone thresholds were obtained at 125-8000 Hz and ABR thresholds were measured using the click and LS CE-Chirp stimuli respectively. Click- and LS CE-Chirp-evoked thresholds were compared with each other and with behavioural pure tone average (PTA), high frequency average (HFA) and low frequency average (LFA). Diagnostic accuracy of the two ABR stimuli was also compared by using ROC curves.
Differences between click- and LS CE Chirp-evoked ABR, and behavioural thresholds were not statistically significant (p>0.05). The strongest significant correlation for ABR using clicks to behavioural thresholds was found at 2000 and 4000 Hz, whereas, the strongest correlation for LS CE-Chirp ABRs to behavioural thresholds was found at 1000, 2000 and 4000 Hz (r>0.7, p<0.001). A very strong, positive correlation was found between both click (r=0.805) and LS CE-Chirp (r=0.825) and the behavioural PTA (p<0.001). The mean differences for LS CE-Chirp were smaller than those of the click for PTA and low frequency range. ROC curves indicated better AUC values for the LS CE-Chirp at LFA and HFA compared to the click, also showing a narrower confidence interval and less variance than the click.
The predictive accuracy of the LS CE-Chirp-evoked ABR was slightly better than that of the click with reference to PTA, HFA and LFA thresholds; furthermore, it is less variable and more accurate than the click-evoked ABR with reference to HFA. Thus, the LS CE-Chirp is an accurate stimulus for estimation of hearing sensitivity using ABR when compared to the gold standard click stimulus for the purpose of identification of different configurations of SNHL.<br>Dissertation (MA Audiology) University of Pretoria, 2019.<br>Speech-Language Pathology and Audiology<br>MA (Audiology)<br>Unrestricted
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Chan, Ealine Y. L. "Diagnostic accuracy of tests for asthma." Thesis, Queen Mary, University of London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511810.
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Zheng, Yingye. "Semiparametric methods for longitudinal diagnostic accuracy /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9580.
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Busse, Harald, Tim Riedel, Nikita Garnov, Gregor Thörmer, Thomas Kahn, and Michael Moche. "Targeting accuracy, procedure times and user experience of 240 experimental MRI biopsies guided by a clinical add-on navigation system." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-176108.
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Objectives: MRI is of great clinical utility for the guidance of special diagnostic and therapeutic interventions. The majority of such procedures are performed iteratively (\"in-and-out\") in standard,
closed-bore MRI systems with control imaging inside the bore and needle adjustments outside the bore. The fundamental limitations of such an approach have led to the development of various assistance techniques, from simple guidance tools to advanced navigation systems. The purpose of this work was to thoroughly assess the targeting accuracy, workflow and usability of a clinical add-on navigation solution on 240 simulated biopsies by different
medical operators.
Methods: Navigation relied on a virtual 3D MRI scene with real-time overlay of the optically tracked biopsy needle. Smart reference markers on a freely adjustable arm ensured proper registration.
Twenty-four operators – attending (AR) and resident radiologists (RR) as well as medical students (MS) – performed well-controlled biopsies of 10 embedded model targets (mean diameter: 8.5 mm, insertion depths: 17-76 mm). Targeting accuracy, procedure times and 13 Likert scores on system performance were determined (strong agreement: 5.0).
Results: Differences in diagnostic success rates (AR: 93%, RR: 88%, MS: 81%) were not significant. In contrast, between-group differences in biopsy times (AR: 4:15, RR: 4:40, MS: 5:06 min: sec) differed significantly (p<0.01). Mean overall rating was 4.2. The average operator would use the system again (4.8) and stated that the outcome justifies the extra effort (4.4). Lowest agreement was reported for the robustness against external perturbations (2.8).
Conclusions: The described combination of optical tracking technology with an automatic MRI registration appears to be sufficiently accurate for instrument guidance in a standard (closed-bore) MRI environment. High targeting accuracy and usability was demonstrated on a relatively large number of procedures and operators. Between groups with different expertise there were significant differences in experimental procedure times but not in the number of successful
biopsies.
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Couto, Filho Carlos Eduardo Gomes do 1962. "Accuracy in the diagnosis of the anterior loop of the mental nerve between panoramic radiography and cone beam computed tomography = is clinically relevant? = Acurácia no diagnóstico da alça anterior do nervo mentual através de radiografias panorâmicas digitais e tomografia computadorizada de feixe cônico." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/289415.
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Orientador: José Ricardo de Albergaria Barbosa<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-08-24T08:11:33Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014<br>Resumo: A reabilitação bucal com implantes dentários revolucionou a odontologia. No entanto, conhecimentos anatômicos como também técnicos são essenciais para a realização de um adequado tratamento. Desta forma, a reabilitação através da instalação de implantes dentários na região interforaminal (forames mentuais) tornou-se comum em reabilitações totais mandibulares. Em consequência disto, um grande número de transtornos sensoriais tem sido descritos e relacionados a alças anteriores do nervo mentual. A divisão do canal mandibular em nervo mentual, responsável pela inervação de tecidos moles (mucosa vestibular, fundo de sulco vestibular, mucosa labial do lábio inferior, pele do mento e lábio inferior), e feixe incisivo, que pode localizar-se no canal incisivo e é responsável pela inervação da região ântero-inferior (dentes e tecidos periodontais) deve ser considerada no planejamento de intervenções nesta região. A injúria a alça do nervo mentual do canal mandibular e ao feixe incisivo poderá trazer transtornos como perda de sensibilidade, edema, hematoma e falha na osseointegração. Apesar de ser considerada uma área segura para cirurgias ela é muito negligenciada no planejamento de tais procedimentos. A associação do conhecimento anatômico, tanto clínico quanto de imagens, torna o procedimento mais previsível devido às variações anatômicas, fazendo-se necessários exames de imagens, essenciais no controle de acidentes relacionados aos procedimentos de implantes intraforaminais. Como um dos exames de imagem mais utilizado em implantes dentais, a radiografia panorâmica apresenta precisão diagnóstica questionável. Portanto, verificamos a precisão da radiografia panorâmica quando comparada com a tomografia computadorizada cone-beam no diagnóstico da alça anterior do nervo mentual. Palavras chave: radiografia.panorâmica, tomografia computadorizada de feixe cônico, alça anterior do nervo mentual.<br>Abstract: Oral rehabilitation with dental implants has revolutionized dentistry. However, both anatomical and technical knowledge are essential to provide an appropriate treatment. Thus, the rehabilitation by installing dental implants at interforaminal region (mental foramina) has become common in total mandibular rehabilitation. Consequently, a large number of sensory disorders has been described and related to the anterior loop of mental nerve. The division of the mandibular canal into mental nerve, responsible for innervation of soft tissues (buccal mucosa, bottom of buccal sulcus, labial mucosa of the lower lip, skin of the chin and lower lip), and incisive branch, which may be located in the incisive canal and is responsible for the innervation of the lower anterior region (teeth and periodontal tissues) should be considered during the planning of interventions in this region. Injury to the loop of the mental nerve of the mandibular canal and to the incisive branch will likely bring disorders such as loss of sensitivity, swelling, hematoma and failure of osseointegration. Although considered a safe area for surgery, it is very neglected in the planning of such procedures. The association of anatomical knowledge, both clinical and of images, makes the procedure more predictable due to anatomical variations, making the imaging examinations necessary, which are essential in the control of accidents related to intraforaminal implant procedures. As one of the most widely used imaging examinations in dental implants, panoramic radiograph presents questionable diagnostic accuracy. Therefore, we verified the accuracy of panoramic radiograph in comparison with cone-beam computed tomography in the diagnosis of the anterior loop of the mental nerve. Keywords: panoramic radiography, cone-beam computed tomography, anterior loop length, mental nerve.<br>Doutorado<br>Cirurgia e Traumatologia Buco-Maxilo-Faciais<br>Doutor em Clínica Odontológica
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Popeliuk, N. O. "Diagnostic accuracy with the pyloroduodenal pathology in children." Thesis, БДМУ, 2020. http://dspace.bsmu.edu.ua:8080/xmlui/handle/123456789/17710.
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Tsuchido, Yasuhiro. "Real-time quantitative PCR analysis of endoscopic biopsies for diagnosing CMV gastrointestinal disease in non-HIV immunocompromised patients: a diagnostic accuracy study." Kyoto University, 2019. http://hdl.handle.net/2433/242399.
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Gross, Susan I. "The Impact of Education and Experience on Diagnostic Accuracy." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1433424760.
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Rosa, Maria Inês da. "O papilomavirus humano e lesões do colo uterino." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/12119.
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Analisamos uma coorte de mulheres no sul do Brasil, com objetivo de identificar associações epidemiológicas para persistência e cura da infecção pelo HPV e realizamos uma metanálise para determinar a acurácia da telomerase nas lesões precursoras do câncer cervical. Métodos: O estudo de coorte foi iniciado em fevereiro de 2003. Foram coletados espécimes cervicais para citologia oncótica e para detecção do DNA HPV na entrada do estudo e no seguimento. O desfecho foi dividido em quatro categorias: (1) persistência, (2) conversão (3) cura. A quarta categoria (referência) eram mulheres negativas no início que permaneceram negativas. Foram usados o teste χ2 de Pearson, regressão logística multinomial e Kaplan- Meier para análise estatística. Para a metanálise foram incluídos estudos que comparavam o teste de telomerase (TRAP) e anatomopatológicos, obtidos por biópsias cervicais para diagnóstico de lesões cervicais. Resultados: A Incidência de HPV foi 12,3%. O HPV16 foi o tipo mais encontrado (18,6%), entre as 501 mulheres do estudo.Trinta e quatro mulheres (6,78%) ficaram persistentemente infectadas pelo HPV, estando essa categoria associada à idade da sexarca inferior a 21 anos (OR = 3,14, IC 95%, 1,43-6,87) e a quatro ou mais parceiros durante a vida (OR = 2,48 IC 95%, 1,14-5,41). No período mediano de 19 meses, 80,7 % das mulheres tinham curado o HPV, a cura foi significativamente associado à cor preta (OR= 3,44 IC 95%, 1,55-7,65), co-infecção com C. trachomatis no arrolamento (OR= 3,26, IC 95%, 1,85-5,76) e história de já ter realizado exame de Papanicolaou (OR= 3,48, IC 95%, 1,51- 8,00). Na metanálise dez estudos foram analisados, os quais incluíram 1069 mulheres. Para lesões intraepiteliais de baixo grau (LIEBG) vs. normal ou lesões benignas, encontrou-se uma positividade do teste da telomerase, sendo que o resultado da odds ratio para diagnóstico (DOR) foi de (DOR = 3,2, IC 95%,1,9-5,6). Nas lesões intraepiteliais de alto grau (LIEAG) vs LIEBG, normal ou benigna: (DOR = 5,8, IC 95%, 3.1-10). )]. Encontrou-se uma DORelevada de 8,1 (IC 95%: 3,2-20) nas lesões de câncer cervical vs LIEAG. Da mesma forma, nas lesões de câncer cervical vs. LIEBG, a razão de chance foi elevada, com uma DOR de 40,9 (IC 95%: 18,2-91). Conclusões: A persistência da infecção pelo HPV foi associada com a sexarca precoce e ao número de parceiros sexuais na vida, sugerindo que estratégias de orientação sexual podem modificar as taxas de persistência do HPV. A associação da cura do HPV com história prévia de realização de Papanicolaou salienta a importância de aprimorar os programas de rastreamento de câncer cervical. Futuros estudos da associação de infecções ginecológicas com cura da infecção pelo HPV são necessários. Na metanálise nossos dados suportam a corrente hipótese da atividade da telomerase como um evento precoce na carcinogênese e que poderia estar associado ao início e à progressão de lesões cervicais.<br>We analysed a cohort of women in Southern Brazil with the aim to identify epidemiological correlates for persistence and clearance of cervical HPV infection. A quantitative systematic review was performed to estimate the accuracy of telomerase assay in cervical lesions. Methods: A cohort study was started on February 2003. Cervical smears were collected to perform Pap cytology and HPV DNA detection at baseline and during the follow up. The outcome was constructed in four categories (1) persistence of HPV DNA; (2) conversion; (3) clearance of HPV. Pearson’s χ2 test, multinomial logistic regression and univariate analysis using the log-rank test were performed. Meta-analysis studies that evaluated the telomerase test (telomerase repeated amplification protocol) for the diagnosis of cervix lesions and compared it to paraffin-embedded sections as the diagnostic standard were included. Results: Incidence of HPV DNA: 12.3%. HPV16 was the most frequent type (18.6%) among 501 women in the study. Thirty-four women were persistently infected with HPV, which was associated with age below 21 years at first intercourse (OR 3.14, 95% CI, 1.43-6.87) and ≥ 4 sexual partners during lifetime (OR 2.48, 95% CI, 1.14-5.41). In a median period of 19 months, 80.7% of women had clearance of HPV, which was associated with black race (OR 3.44, 95% CI, 1.55-7.65), co-infection with C. trachomatis at baseline (OR 3.26, 95% CI, 1.85-5.76) and history of previous Pap smear (OR 3.48, 95% CI, 1.51-8.00). In meta-analysis ten studies were analyzed, which included 1,069 women. The diagnostic odds ratio (DOR) for a positive telomerase test for Lo-SIL vs. normal or benign lesions was 3.2 (95% CI, 1.9-5.6). The DOR for a positive telomerase test for Hi-SIL vs. Lo-SIL, normal or benign lesions was 5.8 (95% CI, 3.1-10). For cervix cancer vs. Hi-SIL, the DOR for a positive telomerase test was 8.1 (95% CI, 3.2-20.3) and for cervix cancer vs. Lo-SIL, normal or benign lesions, it was 40.9 (95% CI, 18.2-91). Conclusions: Persistence of HPV infection wasassociated with early age at first intercourse and number of sexual partners during lifetime, suggesting that strategies for sexual orientation may modify the rates of HPV persistence. The association of HPV clearance with a history of previous Pap smear screening highlights the importance of improving cervical screening programs. Further studies on the association of gynaecological infections with HPV clearance are needed. In meta-analysis our data support the current hypothesis that telomerase may activate an early event in cervical carcinogenesis, that could be associated with the initiation and progression of cervical lesions.
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Srinivasan, Soorya. "Reliability and Accuracy of Assessing TAD - Tooth Root Contact using CBCT." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1553782462280014.
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Coyle, Shannon Jean. "Improving Accurate Diagnosis and Treatment for Acute Viral Conjunctivitis." UNF Digital Commons, 2014. https://digitalcommons.unf.edu/etd/526.
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Conjunctivitis is the most common cause of red eye and one of the most frequent causes of visits to clinicians. There is significant controversy on the diagnosis and treatment of the disease and the use of ophthalmic antibiotics. The inconvenience of the untimely diagnostic tests led to the trend of treating conjunctivitis empirically with ophthalmic antibiotics. Subsequently, the diagnosis of bacterial conjunctivitis is higher than it should be resulting in overuse of antibiotics. Consequences of inappropriate diagnosis and treatment include increased virulence, increased health care costs, and incorrect use of antibiotics leading to possible adverse reaction and antibiotic resistance. Appropriate diagnosis and treatment will assist to reduce the diagnosis of bacterial conjunctivitis and use of ophthalmic antibiotics resulting in reduced virulence and reduced health care costs. The AdenoPlus test has been shown to be effective in appropriately diagnosing viral conjunctivitis and subsequently decreasing the use of ophthalmic antibiotics however this evidence in limited. A national retail clinic has adopted the use of this tool to assist with proper diagnosis and treatment of viral conjunctivitis. Data has not yet been analyzed to determine if the implementation of this test changes the practice of clinicians at the national retail clinic.
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Powers, James Murray. "Population-averaged models for diagnostic accuracy studies and meta-analysis." Thesis, The University of North Carolina at Chapel Hill, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3562789.
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<p> Modern medical decision making often involves one or more diagnostic tools (such as laboratory tests and/or radiographic images) that must be evaluated for their discriminatory ability to detect presence (or absence) of current health state. The first paper of this dissertation extends regression model diagnostics to the Receiver Operating Characteristic (ROC) curve generalized linear model (ROC-GLM) in the setting of individual-level data from a single study through application of generalized estimating equations (GEE) within a correlated binary data framework (Alonzo and Pepe, 2002). Motivated by the need for model diagnostics for the ROC-GLM model (Krzanowski and Hand, 2009), GEE cluster-deletion diagnostics (Preisser and Qaqish, 1996) are applied in an example data set to identify cases that have undue influence on the model parameters describing the ROC curve. In addition, deletion diagnostics are applied in an earlier stage in the estimation of the ROC-GLM, when a linear model is chosen to represent the relationship between the test measurement and covariates in the control subjects. The second paper presents a new model for diagnostic test accuracy meta-analysis. The common analysis framework for the meta-analysis of diagnostic studies is the generalized linear mixed model, in particular, the bivariate logistic-normal random effects model. Considering that such cluster-specific models are most appropriately used if the model for a given cluster (i.e. study) is of interest, a population-average (PA) model may be appropriate in diagnostic test meta-analysis settings where mean estimates of sensitivity and specificity are desired. A PA model for correlated binomial outcomes is estimated with GEE in the meta-analysis of two data sets. It is compared to an indirect method of estimation of PA parameters based on transformations of bivariate random effects model parameters. The third paper presents an analysis guide for a new SAS macro, PAMETA (Population-averaged meta-analysis), for fitting population-averaged (PA) diagnostic accuracy models with GEE as described in the second paper. The impact of covariates, influential clusters and observations is investigated in the analysis of two example data sets.</p>
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Dinnes, Jacqueline. "The influence of spectrum (case-mix) on diagnostic test accuracy." Thesis, University of Southampton, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509464.
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Martinez, Austin A. "A Comparison of the Diagnostic Accuracy of Three Diagnostic Tests for Anterior Cruciate Ligament Lesions." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1491775474846951.
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Elkhafifi, Faiza F. "Nonparametric Predictive Inference for ordinal data and accuracy of diagnostic tests." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/3914/.
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This thesis considers Nonparametric Predictive Inference (NPI) for ordinal data and accuracy of diagnostic tests. We introduce NPI for ordinal data, which are categor- ical data with an ordering of the categories. Such data occur in many application areas, for example medical and social studies. The method uses a latent variable representation of the observations and categories on the real line. Lower and upper probabilities for events involving the next observation are presented, with specic attention to comparison of multiple groups of ordinal data. We introduce NPI for accuracy of diagnostic tests with ordinal outcomes, with the inferences based on data for a disease group and a non-disease group. We intro- duce empirical and NPI lower and upper Receiver Operating Characteristic (ROC) curves and the corresponding areas under the curves. We discuss the use of the Youden index related to the NPI lower and upper ROC curves in order to deter- mine the optimal cut-o point for the test. Finally, we present NPI for assessment of accuracy of diagnostic tests involving three groups of real-valued data. This is achieved by developing NPI lower and upper ROC surfaces and the corresponding volumes under these surfaces, and we also consider the choice of cut-o points for classications based on such diagnostic tests.
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Schwarz, Betty Anne. "Developing a standardized tool for interpretation of radiology diagnostic accuracy trials." Thesis, Middlesex University, 2016. http://eprints.mdx.ac.uk/21171/.
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Within the health sciences, action research is a methodology well suited to the goal of collaboratively improving practice. As the Royal College of Radiology recommends the use of published clinical trials as guides for achieving higher standards of accuracy, it is important for radiologists to reflect deeply on the results from diagnostic accuracy studies. When the results of the gold standard (or reference standard) are used to confirm a particular diagnosis or disease by comparing the diagnostic accuracy to a newer or index test, this is referred to as diagnostic accuracy research. In the reporting of all research, every effort must be made to reduce the incidence of bias. In 2003, the STARD (Standards for Reporting Diagnostic Accuracy) tool was developed for clinicians to enhance the quality of reporting diagnostic accuracy studies. Based on previous studies, experiential knowledge, and an extensive review of the literature, this research demonstrates that the STARD tool is not being fully optimized. The overall aim of this research was to conduct a work-based project within the department of radiology to develop a revised tool, based on the current STARD, which could then be used to more accurately report and interpret the results of radiology diagnostic accuracy trials. This study was conducted in accordance with participatory action research. Methods The development of this new reporting tool was conducted in collaboration with a group of physicians, and in two distinct phases. First, a needs assessment was sent to eight radiological experts who had agreed to participate in the study. Based on their responses, and feedback from my mentor and colleagues, the next phase of tool development was done using the Delphi technique, after two rounds of which consensus was met. Each phase and cycle iteration to complete the needs assessment and Delphi technique are synonymous with the cycles of action research. The new reporting tool was named the RadSTARD (Radiology Standards for the Reporting of Diagnostic Accuracy Studies), and an elaboration document was written to provide guidance to the end-user. Radiology residents and Fellows at The Ottawa Hospital were then asked to rate their level of confidence in interpreting a diagnostic accuracy article specific to radiology while referring to the RadSTARD. They were also provided a second diagnostic article, the STARD tool, and an elaboration document for comparison. Data was collected using questionnaires that allowed for additional comments. Findings The validation phase of the RadSTARD tool was completed via triangulation of data, as both a quantitative and qualitative analysis was completed. The results found no significant statistical difference between the two groups as per the Mann-Whitney and chi-square analysis. Likewise, both physician groups indicated that they found RadSTARD increased their level of confidence when interpreting the diagnostic accuracy article. Concomitantly, when combined, 96% of the two physician groups indicated they would use the tool again. Interpretation These results may be interpreted as generalizable, as there was no discrepancy or statistical difference found in the results between the radiology residents’ and Fellows’ scores, despite the differences in their level of training. Both groups found the RadSTARD tool and elaboration document to be beneficial to them when interpreting the literature. RadSTARD is thus a reliable tool that can be used to validate the results of diagnostic accuracy studies specific to radiology. It will aid radiologists in reporting and interpreting radiology diagnostic accuracy studies, impacting their practice for generations to come.
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Erhardt, Gerber. "Accuracy of plain radiographs for diagnosing histologically proven malignant bone lesions." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29291.
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Karlson, Gunilla, and Helena Tengvall. "The accuracy of apical palpation and percussion when diagnosing apical periodontitis." Thesis, Malmö högskola, Odontologiska fakulteten (OD), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-19930.
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Syftet med den aktuella studien var att undersöka tillförlitligheten av apikal palpation och perkussion vid diagnostik av symtomatisk apikal parodontit och asymptomatisk apikal parodontit på icke rotfyllda tänder.Femton patienter undersöktes; åtta patienter med symtomatisk apikal parodontit och sju patienter med asymptomatisk apikal parodontit. Patienterna rekryterades från tre kliniker i södra Sverige. Först besvarade patienterna frågor om aktuellt läkemedelsintag och graderade sin smärta på en Visuell Analog Skala. Observatören utförde de två diagnostiska testerna på testtanden, kontrolltanden samt deras intilliggande tänder. Som referenstest kontrollerades pulpans tillstånd genom direkt inspektion vid kavumpreparation av testtanden. För apikal palpation, vid diagnostik av symtomatisk apikal parodontit/asymptomatisk apikal parodontit, var sensitiviteten 0,50/0,14, specificiteten 1/1, det positiva prediktiva värdet 1/1 samt det negativa prediktiva värdet 0,67/0,54. För perkussion, vid diagnostik av symtomatisk apikal parodontit/asymptomatisk apikal parodontit, var sensitiviteten 0,38/0,29, specificiteten 1/1, det positiva prediktiva värdet 1/1 samt det negativa prediktiva värdet 0,62/0,58. Inga generella slutsatser kan dras från studien på grund av den begränsade studiepopulationen. Resultatet indikerar dock att tillförlitligheten för apikal palpation och perkussion vid diagnostik av symtomatisk apikal parodontit och asymptomatisk apikal parodontit på icke-rotfyllda tänder är låg. Dessa två diagnostiska tester bör inte användas enskilt för att identifiera tänder med symtomatisk apikal parodontit och asymptomatisk apikal parodontit.<br>The aim of this study was to evaluate the accuracy of apical palpation and percussion when diagnosing symptomatic apical periodontitis and asymptomatic apical periodontitis in non-root filled teeth.Fifteen patients participated in the study; eight patients with symptomatic apical periodontitis and seven with asymptomatic apical periodontitis. The patients were recruited from three different clinics in the south of Sweden. Initially, the patients answered questions concerning recent intake of medication and graded their pain on a Visual Analogue Scale. The observer performed the two diagnostic tests on the test tooth, the control tooth and their adjacent teeth. As reference test, the pulp condition was examined by direct inspection at the access opening of the test tooth. For apical palpation, when diagnosing symptomatic apical periodontitis/asymptomatic apical periodontitis, the sensitivity was 0.50/0.14, the specificity was 1/1, the positive predictive value was 1/1 and the negative predictive value was 0.67/0.54. For percussion, when diagnosing symptomatic apical periodontitis /asymptomatic apical periodontitis, the sensitivity was 0.38/0.29, the specificity was 1/1, the positive predictive value was 1/1 and the negative predictive value was 0.62/0.58.No general conclusions can be made from this study due to the small population size. However, the results indicate that the accuracy of apical palpation and percussion when diagnosing symptomatic apical periodontitis and asymptomatic apical periodontitis in non-root filled teeth is low. The two diagnostic tests should not be used alone to identify teeth with symptomatic apical periodontitis and asymptomatic apical periodontitis.