Articles de revues : « Chest scanner »

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Thakur, Yogesh, Thorarin A. Bjarnason, Patricia Baxter, Mitch Griffith et Kirk Eaton. « Radiation Dose Survey for Common Computed Tomography Exams : 2013 British Columbia Results ». Canadian Association of Radiologists Journal 67, n^o 1 (février 2016) : 88–95. http://dx.doi.org/10.1016/j.carj.2015.07.002.

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In 2013 Health Canada conducted a national survey of computed tomography (CT) radiation usage. We analysed contributions from all 7 public health authorities in the province of British Columbia, which covered scanner age, number of slices, and common adult protocols (≥19 years: 70 ± 20 kg, head, chest, abdomen/pelvis, and trunk). Patient doses were recorded for common protocols. Diagnostic reference levels (DRLs) was calculated using scanner data with >10 patient doses recorded for each protocol. Data was analysed based on image reconstruction (filtered backprojection vs iterative reconstruction [IR] vs IR available but not in use). Provincial response was 92%, with 59 of 64 CT data used for analysis. The average scanner age was 5.5 years old, with 39% of scanners installed between 2008-2013; 78.5% of scanners were multislice (>64 slices), and 44% of scanners had IR available. Overall British Columbia DRLs were: head = 1305, chest = 529, abdomen/pelvis = 819, and trunk = 1225. DRLs were consistent with Health Canada recommendations and other Canadian published values, but above international standards. For sites with IR available, less than 50% used this technology routinely for head, chest and trunk exams. Overall, use of IR reduced radiation usage between 11%-32% compared to filtered backprojection, while sites using IR vs IR available used 30%/43% less radiation for head/chest exams ( P < .05). No significant difference was observed for abdomen/pelvis exams ( P = .385). With the fast pace of CT technical advancement, DRLs should reflect the technology used, instead of just globally applied to anatomical regions. Federal guidelines should be updated at a higher frequency to reflect new technology. In addition, new technologies must be utilised to optimize image quality vs radiation usage.

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Minami, Masahide, KojiAbe et Munehiro Nakamura. « Discrimination of Pneumoconiosis X-Ray Images Scanned with a CCD Scanner ». Journal of Advanced Computational Intelligence and Intelligent Informatics 16, n^o 1 (20 janvier 2012) : 69–75. http://dx.doi.org/10.20965/jaciii.2012.p0069.

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This paper presents a discrimination of pneumoconiosis X-ray images obtained with a common CCD scanner. Since the current computer-aided diagnosis systems of pneumoconiosis are not practical due to high costs of usage, features for measuring abnormalities of pneumoconiosis are proposed as variables for the discrimination in this paper. In the images, abnormal levels of pneumoconiosis could depend on density distribution in each of intercostal and rib areas. Therefore, the proposed method measures the abnormalities by extracting characteristics of the distribution in the areas. Besides, using the abnormalities, the proposed method discriminates chest X-ray images into normal or abnormal cases of pneumoconiosis. Experimental results of the discriminations for 56 right-lung images have shown that the proposed abnormalities are well extracted for the discrimination.

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Olszynski, P., R. Woods, S. Netherton, Q. Hussain, B. Blondeau et S. Dunn. « P066 : Ultrasound localization to resuscitate in arrest (ULTRA) ». CJEM 21, S1 (mai 2019) : S87. http://dx.doi.org/10.1017/cem.2019.257.

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Introduction: There is increasing evidence supporting ultrasonography for the determination of optimal chest compression location during cardiac arrest. Radiological studies have demonstrated that in up to 1/3 of patients the aortic root or outflow tract is being compressed during standard CPR. Out-of-hospital-cardiac-arrests (OHCA) could benefit from cardiac localization, undertaken with scaled-down ultrasound equipment by which the largest fluid filled structure in the chest (the heart) is identified to guide optimal compression location. We intend to evaluate 1) where the left ventricle is in supine patients, 2) the accuracy and precision as well as 3) the feasibility and reliability of cardiac localization with a scaled down ultrasound device (bladder scanners). Methods: We are recruiting men and women over the age of 40. The scanning protocol involves using a bladder scanner on a 15-point grid over the subject's left chest and parasternal, midclavicular, and anterior axillary intercostal spaces 3-7. Detected volumes will be recorded, with the presumption that the intercostal space with the largest measured volume is centered over the heart. Echocardiography will then be used to confirm the bladder scanner accuracy and to better describe the patient's internal chest anatomy. Having assessed procedural feasibility on 3 pilot subjects, we are now recruiting 100 participants, with planned interim analysis at 50 participants for sample size reassessment. Maximal volume location frequencies from the echocardiograms will be described and assessed for variation utilizing the goodness-of-fit test. The proportion of agreement across the two modalities regarding the maximal volume location will also be examined. Results: Among the 3 volunteers (pilot study), the scanner identified fluid in 4-8 of 15 intercostal spaces. In each of the three pilot study patients, the maximal volume identified by the bladder scanner was found to be at the parasternal location of the 6th intercostal space. This was also the location of the mid left ventricular diameter on echocardiography. Conclusion: Our literature review and pilot study data support the premise that lay persons and emergency medical personnel may improve compressions (and thus outcomes) during OHCA by using a scaled-down ultrasound to identify the location of optimal compression. We are currently enrolling patients in our study.

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Ahdi Rezaeieh, Sasan, Ali Zamani, Konstanty Bialkowski, Graeme Macdonald et Amin Abbosh. « Three-Dimensional Electromagnetic Torso Scanner ». Sensors 19, n^o 5 (27 février 2019) : 1015. http://dx.doi.org/10.3390/s19051015.

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A three-dimensional (3D) electromagnetic torso scanner system is presented. This system aims at providing a complimentary/auxiliary imaging modality to supplement conventional imaging devices, e.g., ultrasound, computerized tomography (CT) and magnetic resonance imaging (MRI), for pathologies in the chest and upper abdomen such as pulmonary abscess, fatty liver disease and renal cancer. The system is comprised of an array of 14 resonance-based reflector (RBR) antennas that operate from 0.83 to 1.9 GHz and are located on a movable flange. The system is able to scan different regions of the chest and upper abdomen by mechanically moving the antenna array to different positions along the long axis of the thorax with an accuracy of about 1 mm at each step. To verify the capability of the system, a three-dimensional imaging algorithm is proposed. This algorithm utilizes a fast frequency-based microwave imaging method in conjunction with a slice interpolation technique to generate three-dimensional images. To validate the system, pulmonary abscess was simulated within an artificial torso phantom. This was achieved by injecting an arbitrary amount of fluid (e.g., 30 mL of water), into the lungs regions of the torso phantom. The system could reliably and reproducibly determine the location and volume of the embedded target.

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Gleadall-Siddall, Damien Oliver, Richard Lincoln Turpin, Caroline Clare Douglas, Lee Ingle et Andrew Thomas Garrett. « Test–retest repeatability of the NX-16 : a three-dimensional (3D) body scanner in a male cohort ». Sport Sciences for Health 16, n^o 2 (13 décembre 2019) : 337–46. http://dx.doi.org/10.1007/s11332-019-00611-8.

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Abstract Purpose Whole-body three-dimensional scanning is a tool utilised for the collection of body girths, volume, and surface area measurements. Few studies have investigated the validity and repeatability of this technology. The aim of the present study was to investigate the test retest variability of the NX-16 body scanner (NX-16, TC2, Cary, North Carolina, USA). Methods Phase one involved the measurement of a mannequin on 300 occasions (30 scans over 10 sessions). In phase two, 13 apparently healthy male participants were recruited; each participant was scanned a total of four times (two scans over two sessions). Stature, body mass, and body fat % were obtained. Fourteen girth measurements were obtained (chest, underbust, stomach, waist, seat, hip, R/L bicep, R/L thigh, R/L mid-thigh, and R/L calf). Coefficient of variation was calculated for measurements obtained. Results Coefficient of variation for phase one ranged from 0.0% for the R calf, to 3.3% for the L thigh measurement. For phase two, values were higher, ranging from 0.5% for calf and chest to 4.6% for thigh measurements. Conclusions Test–retest variability of the measurements provided by the NX-16 body scanner varied according to body location. However, variability within measurements was low using a mannequin or human participant. The NX-16 body scanner (TC2, Cary, North Carolina, USA) may be a useful tool for tracking changes in body composition over time during large population studies.

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Sveljo, O. B., Z. Markovic, B. Reljin, R. Semnic, Lucic Adjic, T. L. Stosic-Opincal et M. Prvulovic. « Dijagnosticki kvalitet slike CT pregleda grudnog kosa ». Acta chirurgica Iugoslavica 54, n^o 3 (2007) : 99–103. http://dx.doi.org/10.2298/aci0703099s.

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The paper is aimed at determining diagnostic quality of the images in different chest CT examination protocols. Two groups of patients underwent scanning based on two different protocols using Siemens Somatom 4 Plus scanner in the spiral mode. The study included the total of 64 patients divided in two groups according to their body weight (BW). Group one included 34 patients weighing above 80 kg and they were scanned according to the standard protocol. Group two comprised 30 patients weighting below 80 kg and they were scanned using the same protocol however with reduction of tube current of 13 mA. All the scans were subsequently reconstructed using noise-reduction filter (enhancement of low contrast resolution).

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Druzhinina, P. S., L. A. Chipiga, I. G. Shatskiy, A. V. Vodovatov, A. V. Pozdnyakov, V. G. Puzyrev, A. I. Tashchilkin, D. A. Malikov, N. N. Potrakhov et Yu N. Potrakhov. « Optimization of CT Protocols for Newborn Patients by Ingenuity 128, Philips. A Phantom Study ». Meditsinskaya Fizika 96, n^o 4 (30 janvier 2023) : 43–55. http://dx.doi.org/10.52775/1810-200x-2022-96-4-43-55.

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Purpose: To evaluate the impact of CT scan protocol parameters on patient dose and image quality for optimization of protocols for newborn patients. Materials and methods: Three anatomical areas (chest, abdomen and combined chest + abdomen area) of a newborn PH-50 Newborn Whole-Body Phantom (Kyoto Kagaku Co, LTD, Japan) were scanned on Ingenuity 128 CT scanner (Philips) using different scan parameters. The values of weighted CT dose index (CTDIvol) and dose length product (DLP) were used as dose characteristics and the noise of CT image was chosen to estimate the image quality. The noise was determined in the soft tissues in the areas of shoulder girdle and diaphragm in images with the reconstruction kernel B, as well as in lung tissue of lung apices for images with the reconstruction kernel YC for chest and chest + abdomen; and in soft tissues (for reconstruction kernel B) in the area of the diaphragm for abdomen. Results: The analysis of the impact of tube voltage and dose right index (DRI) on dose characteristics and image quality made it possible to determine the optimal parameters of CT protocols for selected CT department: chest – 80 kV at DRI -– 19, abdomen – 100 kV at DRI – 22, chest + abdomen – 120 kV at DRI – 22. These protocol parameters provide an effective dose of newborn patients – 1.4, 1.7 and 2,8 mSv for chest, abdomen and chest + abdomen scans, respectively. Conclusion: The impact of different scan parameters (tube voltage and DRI) of chest, abdomen and chest + abdomen protocols on patient dose and image noise was evaluated. The study allowed setting optimized protocol parameters to improve the image quality.

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Milosevic, Paula, et Slavica Bogovic. « 3D technologies in individualized chest protector modelling ». Textile & ; Leather Review 1, n^o 2 (septembre 2018) : 46–55. http://dx.doi.org/10.31881/tlr.2018.vol1.iss2.p46-55.a6.

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The application of 3D technology increases every day by discovering new ways of usage, which can make everyday life easier. It is most used in production of individualized items that become more accessible and fully customized to personal needs. 3D technologies such as 3D scanning, 3D modelling and additive technologies (3D printing) are used in various areas of human activity such as medicine, architecture, the movie industry, etc. In the clothing’s industry, 3D scanning the human body is digitized, which is after that used in computer software packages for custom-made clothing. Except for the fashion industry, there is a need for individualized protective work clothing and equipment production in other industries as well. The possibility of applying new technologies such as 3D scanning and 3D modelling of protective elements that can be made by using 3D printers is presented in this paper. In order to design a field hockey chest protector, male and female subjects were scanned using a 3D body scanner in several different positions specific to the sport. The chest protector was constructed and modeled based on the digitalized images. Software packages were used which enable point clouds preparation of the digitalized human body for constructing the protector, its modelling and preparation of virtually designed protectors for 3D printing. An individualized chest protector is modeled using a software program called Bender. The protector is integrated into the clothing item, completely follows the body shape and provides the necessary protection.

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Abdi, Ahmed Jibril, Bo Mussmann, Alistair Mackenzie, Benedikte Klaerke et Poul Erik Andersen. « COMPARISON OF RADIATION EXPOSURE TO THE PATIENT AND CONTRAST DETAIL RESOLUTIONS ACROSS LOW DOSE 2D/3D SLOT SCANNER AND TWO CONVENTIONAL DIGITAL RADIOGRAPHY X-RAY IMAGING SYSTEMS ». Radiation Protection Dosimetry 185, n^o 2 (27 février 2019) : 252–65. http://dx.doi.org/10.1093/rpd/ncz006.

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Abstract Purpose To assess and compare the radiation dose and image quality of the low dose 2D/3D EOS slot scanner (LDSS) to conventional digital radiography (DR) X-ray imaging systems for chest and knee examination protocols. Methods and materials The effective doses (ED) to the patient in the chest and knee clinical examination protocols for LDSS and DR X-ray imaging systems were determined using the dose area product and PCXMC Monte Carlo simulation software. The CDRAD phantom was imaged with 19 cm, and 13 cm thick Polymethyl Methacrylate (PMMA) blocks to simulate the chest and knees respectively of a patient of average adult size. The contrast detail resolution was calculated using image analysis software. Results The EDs for the LDSS default setting were up to 69% and 51% lower than for the DR systems for the chest (speed 4) and knee (speed 6) protocols, respectively, while for the increased dose level setting then the EDs were up to 42% and 35% lower than for the DR systems for the chest (speed 6) and knee (speed 8) protocols respectively. At the default setting, the contrast detail was lowest for the default setting of the 2D/3D low dose slot scanner (LDSS) for both chest and knee examinations, but at the highest dose levels then the threshold were equal or higher than the contrast resolution of DR imaging systems. Conclusion The LDSS has the potential to be used for clinical diagnosis of chest and knee examinations using the higher dose level. For speed 6 in chest protocol and speed 8 in knee protocol, the measured contrast detail resolution was comparable with the DR systems but at a lower effective dose.

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Baston, Cameron, et Sharad Patel. « A CT Scanner in Your Pocket ? Lung Ultrasonography Beats Chest Radiography* ». Critical Care Medicine 48, n^o 2 (février 2020) : 255–57. http://dx.doi.org/10.1097/ccm.0000000000004149.

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King, Dakota H., Muyang Wang, Eric E. Bennett, Dumitru Mazilu, Marcus Y. Chen et Han Wen. « Online Geometric Calibration of a Hybrid CT System for Ultrahigh-Resolution Imaging ». Tomography 8, n^o 5 (12 octobre 2022) : 2547–55. http://dx.doi.org/10.3390/tomography8050212.

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A hybrid imaging system consisting of a standard computed tomography (CT) scanner and a low-profile photon-counting detector insert in contact with the patient’s body has been used to produce ultrahigh-resolution images in a limited volume in chest scans of patients. The detector insert is placed on the patient bed as needed and not attached. Thus, its position and orientation in the scanner is dependent on the patient’s position and scan settings. To allow accurate image reconstruction, we devised a method of determining the relative geometry of the detector insert and the CT scanner for each scan using fiducial markers. This method uses an iterative registration algorithm to align the markers in the reconstructed volume from the detector insert to that of the concurrent CT scan. After obtaining precise geometric information of the detector insert relative to the CT scanner, the two complementary sets of images are summed together to create a detailed image with reduced artifacts.

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Servi, Michaela, Andrea Zulli, Yary Volpe, Rocco Furferi, Luca Puggelli, Antonio Messineo, Marco Ghionzoli et Flavio Facchini. « Handheld Optical System for Pectus Excavatum Assessment ». Applied Sciences 11, n^o 4 (15 février 2021) : 1726. http://dx.doi.org/10.3390/app11041726.

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Disruptive 3D technologies, such as reverse engineering (RE) and additive manufacturing (AM), when applied in the medical field enable the development of new methods for personalized and non-invasive treatments. When referring to the monitoring of pectus excavatum, one of the most common thoracic malformations, 3D acquisition of the patient chest proved to be a straightforward method for assessing and measuring chest deformation. Unfortunately, such systems are usually available in a dedicated facility, can be operated only by specialized doctors with the support of engineers and can be used only with patients on site. It is therefore impossible to perform any routine check-up when the patient is unable to reach the outpatient clinic. The COVID19 pandemic situation has placed even greater restrictions on patient mobility, worsening this problem. To deal with this issue, a new low-cost portable optical scanner for monitoring pectus excavatum is proposed in this work. The scanner, named Thor 2.0, allows a remote diagnostic approach, offering the possibility to perform routine check-ups telematically. Usability tests confirmed the user-friendly nature of the devised system. The instrument was used at the Meyer Children’s Hospital (Florence, Italy) chest-malformations center to treat PE patients. The performed measurements proved to be in line with the current state of the art.

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Shah, Pooja. « Estimation of effective dose from CT scanning using dose length product in a Nepalese hospital ». Radiography Open 6, n^o 1 (21 décembre 2020) : 56–63. http://dx.doi.org/10.7577/radopen.3565.

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Keywords: Effective dose, Dose Length Product, Computed Tomography Dose Indexvolume, Dose Reference Level AbstractAim: The aim of this study was to estimate the effective doses from CT scans using DoseLength Product (DLP) in a Nepalese hospital.Materials and methods: This prospective study was conducted in 150 patients above 18years of age who were referred for CT scan of head, chest and abdomen. The CT scan wasperformed on a 128 slice multi detector scanner. All the subjects who met the inclusioncriteria were included in the study. Following the non-contrast imaging phases of the head,chest and abdomen CTDIvol, DLP, kVp and pitch were recorded for each patient from theconsole display of the scanner. The effective dose was calculated for each examination usingDLP which were graphically analyzed and correlated with the age of the patient.Results: The study showed the mean CTDIvol for head, chest and abdomen to be 53.95±4.83mGy, 5.28±1.17 mGy and 11.15±2.71 mGy respectively along with mean DLP to be923.52±71.11 mGycm, 229.32±48.70 mGycm and 517.02±148.32 mGycm respectively. Usingthese values, the mean effective doses were calculated and found to be 1.93±0.14 mSv,3.20±0.68 mSv and 7.75±2.19 mSv respectively.Conclusion: The calculated effective dose values were lower than in other studies for CTexaminations of chest and abdomen while higher or similar for CT examination of head. Theresults of this survey could motivate other researchers to investigate the radiation doses inother hospitals and help establish national diagnostic reference levels.

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Khoramian, Daryoush, Soroush Sistani et Peyman Hejazi. « Establishment of diagnostic reference levels arising from common CT examinations in Semnan County, Iran ». Polish Journal of Medical Physics and Engineering 25, n^o 1 (1 mars 2019) : 51–55. http://dx.doi.org/10.2478/pjmpe-2019-0008.

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Abstract Objective: The literature has approved that the use of the concept of diagnostic reference level (DRL) as a part of an optimization process could help to reduce patient doses in diagnostic radiology comprising the Computed Tomography (CT) examinations. There are four public/governmental CT centers in the province (Semnan, Iran) and, to our knowledge, after about 12 years since the launch of the first CT scanner in the province there is no dosimetry information on those CT scanners. The aim of this study was to evaluate CT dose indices with the aim of the establishment of the DRL for head, chest, cervical spine, and abdomen-pelvis examinations. Methods: Scan parameters of 381 patients were collected during two months from 4 CT scanners. The CT dose index (CTDI) was measured using a calibrated ionization chamber on two cylindrical poly methyl methacrylate (PMMA) phantoms. For each sequences, weighted CTDI (CTDIw), volumetric CTDI (CTDIv) and dose length product (DLP) were calculated. The 75th percentile was proposed as the criterion for DRL values. Results: Proposed DRL (CTDIw, CTDIv, DLP) for the head, chest, cervical spine, and abdomen-pelvis were (46.1 mGy, 46.1 mGy, 723 mGy × cm), (13.8 mGy, 12.0 mGy, 377 mGy × cm), (40.0 mGy, 40.0 mGy, 572 mGy × cm) and (14.9 mGy, 12.1 mGy, 524 mGy × cm), respectively. Conclusion: Comparison with the others results from the other countries indicates that the head, chest and abdomen-pelvis scans in our region are lower or in the range of the other studies investigated in terms of dose. In the case of cervical spine scanning it’s necessary to review and regulate scan protocols to reach acceptable dose levels.

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Livingstone, RoshanS, Joe Pradip, PaulM Dinakran et B. Srikanth. « Radiation doses during chest examinations using dose modulation techniques in multislice CT scanner ». Indian Journal of Radiology and Imaging 20, n^o 2 (2010) : 154. http://dx.doi.org/10.4103/0971-3026.63036.

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Hemke, Robert, Kai Yang, Jad Husseini, Miriam A. Bredella et F. Joseph Simeone. « Organ dose and total effective dose of whole-body CT in multiple myeloma patients ». Skeletal Radiology 49, n^o 4 (15 octobre 2019) : 549–54. http://dx.doi.org/10.1007/s00256-019-03292-z.

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Abstract Objective To evaluate organ dose and total effective dose of whole-body low-dose CT (WBLDCT) performed on different CT-scanner models in patients with multiple myeloma (MM) and to compare it to the effective dose of radiographic skeletal survey and representative diagnostic CTs. Material and methods We retrospectively analyzed data from 228 patients (47.4% females, mean age 67.9 ± 10.4 years, mean weight 81.8 ± 22.4 kg) who underwent WBLDCT for the work-up or surveillance of MM. Patients were scanned using one of six multi-detector CT-scanners. Organ doses and total effective doses per scan were calculated using a commercially available dose-management platform (Radimetrics, Bayer Healthcare, Leverkusen, Germany). The median effective dose was compared to radiographic skeletal survey and representative diagnostic CTs. Results The mean effective dose of our WBLDCT-protocol was 4.82 mSv. A significantly higher effective dose was observed in females compared to males (4.95 vs. 4.70 mSv, P = 0.002). Mean organ dose ranged from 3.72 mSv (esophagus) to 13.09 mSv (skeleton). Mean effective dose varied amongst different CT-scanners (range 4.34–8.37 mSv). The median effective dose of WBLDCT was more than twice the dose of a skeletal survey (4.82 vs. 2.04 mSv), 23% higher than a diagnostic contrast-enhanced chest CT (3.9 mSv), 46% lower than a diagnostic contrast-enhanced abdomen/pelvis CT (9.0 mSv), and 45% lower than a lumbar spine CT (8.7 mSv). Conclusions WBLDCT in MM has a higher effective dose than a radiographic skeletal survey, but a lower effective dose than diagnostic CTs of lumbar spine, abdomen and pelvis. This underlines the broad applicability of WBLDCT in the management of MM patients.

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Ebner, Lukas, Felix Knobloch, Adrian Huber, Julia Landau, Daniel Ott, Johannes T. Heverhagen et Andreas Christe. « Feasible Dose Reduction in Routine Chest Computed Tomography Maintaining Constant Image Quality Using the Last Three Scanner Generations : From Filtered Back Projection to Sinogram-affirmed Iterative Reconstruction and Impact of the Novel Fully Integrated Detector Design Minimizing Electronic Noise ». Journal of Clinical Imaging Science 4 (31 juillet 2014) : 38. http://dx.doi.org/10.4103/2156-7514.137826.

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Objective: The aim of the present study was to evaluate a dose reduction in contrast-enhanced chest computed tomography (CT) by comparing the three latest generations of Siemens CT scanners used in clinical practice. We analyzed the amount of radiation used with filtered back projection (FBP) and an iterative reconstruction (IR) algorithm to yield the same image quality. Furthermore, the influence on the radiation dose of the most recent integrated circuit detector (ICD; Stellar detector, Siemens Healthcare, Erlangen, Germany) was investigated. Materials and Methods: 136 Patients were included. Scan parameters were set to a thorax routine: SOMATOM Sensation 64 (FBP), SOMATOM Definition Flash (IR), and SOMATOM Definition Edge (ICD and IR). Tube current was set constantly to the reference level of 100 mA automated tube current modulation using reference milliamperes. Care kV was used on the Flash and Edge scanner, while tube potential was individually selected between 100 and 140 kVp by the medical technologists at the SOMATOM Sensation. Quality assessment was performed on soft-tissue kernel reconstruction. Dose was represented by the dose length product. Results: Dose-length product (DLP) with FBP for the average chest CT was 308 mGy*cm ± 99.6. In contrast, the DLP for the chest CT with IR algorithm was 196.8 mGy*cm ± 68.8 (P = 0.0001). Further decline in dose can be noted with IR and the ICD: DLP: 166.4 mGy*cm ± 54.5 (P = 0.033). The dose reduction compared to FBP was 36.1% with IR and 45.6% with IR/ICD. Signal-to-noise ratio (SNR) was favorable in the aorta, bone, and soft tissue for IR/ICD in combination compared to FBP (the P values ranged from 0.003 to 0.048). Overall contrast-to-noise ratio (CNR) improved with declining DLP. Conclusion: The most recent technical developments, namely IR in combination with integrated circuit detectors, can significantly lower radiation dose in chest CT examinations.

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Woeltjen, Matthias Michael, Julius Henning Niehoff, Arwed Elias Michael, Sebastian Horstmeier, Christoph Moenninghoff, Jan Borggrefe et Jan Robert Kroeger. « Low-Dose High-Resolution Photon-Counting CT of the Lung : Radiation Dose and Image Quality in the Clinical Routine ». Diagnostics 12, n^o 6 (11 juin 2022) : 1441. http://dx.doi.org/10.3390/diagnostics12061441.

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This study aims to investigate the qualitative and quantitative image quality of low-dose high-resolution (LD-HR) lung CT scans acquired with the first clinical approved photon counting CT (PCCT) scanner. Furthermore, the radiation dose used by the PCCT is compared to a conventional CT scanner with an energy-integrating detector system (EID-CT). Twenty-nine patients who underwent a LD-HR chest CT scan with dual-source PCCT and had previously undergone a LD-HR chest CT with a standard EID-CT scanner were retrospectively included in this study. Images of the whole lung as well as enlarged image sections displaying a specific finding (lesion) were evaluated in terms of overall image quality, image sharpness and image noise by three senior radiologists using a 5-point Likert scale. The PCCT images were reconstructed with and without a quantum iterative reconstruction algorithm (PCCT QIR+/−). Noise and signal-to-noise (SNR) were measured and the effective radiation dose was calculated. Overall, image quality and image sharpness were rated best in PCCT (QIR+) images. A significant difference was seen particularly in image sections of PCCT (QIR+) images compared to EID-CT images (p < 0.005). Image noise of PCCT (QIR+) images was significantly lower compared to EID-CT images in image sections (p = 0.005). In contrast, noise was lowest on EID-CT images (p < 0.001). The PCCT used significantly less radiation dose compared to the EID-CT (p < 0.001). In conclusion, LD-HR PCCT scans of the lung provide better image quality while using significantly less radiation dose compared to EID-CT scans.

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O., Traore, Diarra O., Dembele B., Koumare I.B, Amadou I., Koumare Plea M., Dackouo M., Sidibe S. et Keita A.D. « THORACIC ANGIO SCANNER IN THE DIAGNOSIS OF PULMONARY EMBOLISM IN BAMAKO ». International Journal of Advanced Research 10, n^o 12 (31 décembre 2022) : 333–38. http://dx.doi.org/10.21474/ijar01/15844.

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Introduction:Pulmonary embolism is the sudden obliteration (total or partial)of the trunk of the pulmonary artery or one of its branches by a circulating foreign body, most often fibrino-cruoric. Objectives: To study the place of chest CT angiography in the diagnosis of pulmonary embolism Material And Method:This was a descriptive prospective study from February 1, 2020 to January 31, 2021 taking into account all patients referred during this period for clinical suspicion of pulmonary embolism to the medical clinic Marie Curie et les Etoiles. The examinations were performed with a GE 16-bar scanner in helical mode with and without injection of iodinated contrast product by an automatic injector. Results:We diagnosed 43 pulmonary embolisms out of 327 thoracic CT angiography performed by highlighting hypodense gaps inside one or more pulmonary arteries as well as certain branches of division and the sudden interruption of the opacification of certain distal arteries. The prevalence of pulmonary embolism was 13.15%. The female sex predominated with 52% (n=22) and the sex ratio was 1.16. The average age of patients in our series was 45 years with extremes (25 to 85 years). The age group of 41-50 years waspredominant. Dyspnea and chest pain were the most frequent clinical information with44.18% and 18.60% respectively. The seat of the pulmonary embolism concerned the right pulmonary arteries and the seat of the pulmonary embolism concerned the right and left pulmonary arteries in 60.46% and the right side was the most affected. Chronic Obstructive Pulmonary Disease (COPD) Pleurisy and Covid-19 were the lesions most associated with pulmonaryembolism (48.83%, 18.60% and 16.28%) Conclusion: Pulmonary embolism is a serious and life-threatening pathology. Its diagnosis of certainty is made with the thoracic CT angiography, the realization of which must not suffer from any delay.

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Mazzilli, Aldo, Claudio Fiorino, Alessandro Loria, Martina Mori, Pier Giorgio Esposito, Diego Palumbo, Francesco de Cobelli et Antonella del Vecchio. « An Automatic Approach for Individual HU-Based Characterization of Lungs in COVID-19 Patients ». Applied Sciences 11, n^o 3 (29 janvier 2021) : 1238. http://dx.doi.org/10.3390/app11031238.

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The ongoing COVID-19 pandemic currently involves millions of people worldwide. Radiology plays an important role in the diagnosis and management of patients, and chest computed tomography (CT) is the most widely used imaging modality. An automatic method to characterize the lungs of COVID-19 patients based on individually optimized Hounsfield unit (HU) thresholds was developed and implemented. Lungs were considered as composed of three components—aerated, intermediate, and consolidated. Three methods based on analytic fit (Gaussian) and maximum gradient search (using polynomial and original data fits) were implemented. The methods were applied to a population of 166 patients scanned during the first wave of the pandemic. Preliminarily, the impact of the inter-scanner variability of the HU-density calibration curve was investigated. Results showed that inter-scanner variability was negligible. The median values of individual thresholds th1 (between aerated and intermediate components) were −768, −780, and −798 HU for the three methods, respectively. A significantly lower median value for th2 (between intermediate and consolidated components) was found for the maximum gradient on the data (−34 HU) compared to the other two methods (−114 and −87 HU). The maximum gradient on the data method was applied to quantify the three components in our population—the aerated, intermediate, and consolidation components showed median values of 793 ± 499 cc, 914 ± 291 cc, and 126 ± 111 cc, respectively, while the median value of the first peak was −853 ± 56 HU.

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Abdi, Ahmed Jibril, Bo R. Mussmann, Alistair Mackenzie, Oke Gerke, Benedikte Klaerke et Poul Erik Andersen. « Quantitative Image Quality Metrics of the Low-Dose 2D/3D Slot Scanner Compared to Two Conventional Digital Radiography X-ray Imaging Systems ». Diagnostics 11, n^o 9 (17 septembre 2021) : 1699. http://dx.doi.org/10.3390/diagnostics11091699.

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The aim of this study was to determine the quantitative image quality metrics of the low-dose 2D/3D EOS slot scanner X-ray imaging system (LDSS) compared with conventional digital radiography (DR) X-ray imaging systems. The effective detective quantum efficiency (eDQE) and effective noise quantum equivalent (eNEQ) were measured using chest and knee protocols. Methods: A Nationwide Evaluation of X-ray Trends (NEXT) of a chest adult phantom and a PolyMethylmethacrylate (PMMA) phantom were used for the chest and knee protocols, respectively. Quantitative image quality metrics, including effective normalised noise power spectrum (eNNPS), effective modulation transfer function (eMTF), eDQE and eNEQ of the LDSS and DR imaging systems were assessed and compared. Results: In the chest acquisition, the LDSS imaging system achieved significantly higher eNEQ and eDQE than the DR imaging systems at lower and higher spatial frequencies (0.001 ≤ p ≤ 0.044). For the knee acquisition, the LDSS imaging system also achieved significantly higher eNEQ and eDQE than the DR imaging systems at lower and higher spatial frequencies (0.001 ≤ p ≤ 0.002). However, there was no significant difference in eNEQ and eDQE between DR systems 1 and 2 at lower and higher spatial frequencies (0.10 < p < 1.00) for either chest or knee protocols. Conclusion: The LDSS imaging system performed well compared to the DR systems. Thus, we have demonstrated that the LDSS imaging system has the potential to be used for clinical diagnostic purposes.

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Warner, D. O., J. F. Brichant, E. L. Ritman et K. Rehder. « Chest wall motion during epidural anesthesia in dogs ». Journal of Applied Physiology 70, n^o 2 (1 février 1991) : 539–47. http://dx.doi.org/10.1152/jappl.1991.70.2.539.

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To determine the relative contribution of rib cage and abdominal muscles to expiratory muscle activity during quiet breathing, we used lumbar epidural anesthesia in six pentobarbital sodium-anesthetized dogs lying supine to paralyze the abdominal muscles while leaving rib cage muscle motor function substantially intact. A high-speed X-ray scanner (Dynamic Spatial Reconstructor) provided three-dimensional images of the thorax. The contribution of expiratory muscle activity to tidal breathing was assessed by a comparison of chest wall configuration during relaxed apnea with that at end expiration. We found that expiratory muscle activity was responsible for approximately half of the changes in thoracic volume during inspiration. Paralysis of the abdominal muscles had little effect on the pattern of breathing, including the contribution of expiratory muscle activity to tidal breathing, in most dogs. We conclude that, although there is consistent phasic expiratory electrical activity in both the rib cage and the abdominal muscles of pentobarbital-anesthetized dogs lying supine, the muscles of the rib cage are mechanically the most important expiratory muscles during quiet breathing.

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Abdi, Ahmed Jibril, Bo Mussmann, Alistair Mackenzie, Oke Gerke, Gitte Maria Jørgensen, Thor Eriksen Bechsgaard, Janni Jensen, Lone Brunshøj Olsen et Poul Erik Andersen. « Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems ». Diagnostics 11, n^o 10 (19 octobre 2021) : 1932. http://dx.doi.org/10.3390/diagnostics11101932.

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The purpose of this study was to assess the image quality of the low dose 2D/3D slot scanner (LDSS) imaging system compared to conventional digital radiography (DR) imaging systems. Visual image quality was assessed using the visual grading analysis (VGA) method. This method is a subjective approach that uses a human observer to evaluate and optimise radiographic images for different imaging technologies. Methods and materials: ten posterior-anterior (PA) and ten lateral (LAT) images of a chest anthropomorphic phantoms and a knee phantom were acquired by an LDSS imaging system and two conventional DR imaging systems. The images were shown in random order to three (chest) radiologists and three experienced (knee) radiographers, who scored the images against a number of criteria. Inter- and intraobserver agreement was assessed using Fleiss’ kappa and weighted kappa. Results: the statistical comparison of the agreement between the observers showed good interobserver agreement, with Fleiss’ kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. Comparison of intraobserver agreement also showed good agreement with weighted kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. The LDSS imaging system achieved significantly higher VGA image quality compared to the DR imaging systems in the AP and LAT chest protocols (p < 0.001). However, the LDSS imaging system achieved lower image quality than one DR system (p ≤ 0.016) and equivalent image quality to the other DR systems (p ≤ 0.27) in the knee protocol. The LDSS imaging system achieved effective dose savings of 33–52% for the chest protocol and 30–35% for the knee protocol compared with DR systems. Conclusions: this work has shown that the LDSS imaging system has the potential to acquire chest and knee images at diagnostic quality and at a lower effective dose than DR systems.

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Sano, Atsushi. « Rib Radiography versus Chest Computed Tomography in the Diagnosis of Rib Fractures ». Thoracic and Cardiovascular Surgeon 66, n^o 08 (1 mai 2018) : 693–96. http://dx.doi.org/10.1055/s-0038-1645887.

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Background The accurate diagnosis of rib fractures is important in chest trauma. Diagnostic images following chest trauma are usually obtained via chest X-ray, chest computed tomography, or rib radiography. This study evaluated the diagnostic characteristics of rib radiography and chest computed tomography. Methods Seventy-five rib fracture patients who underwent both chest computed tomography and rib radiography between April 2008 and December 2013 were included. Rib radiographs, centered on the site of pain, were taken from two directions. Chest computed tomography was performed using a 16-row multidetector scanner with 5-mm slice-pitch without overlap, and axial images were visualized in a bone window. Result In total, 217 rib fractures were diagnosed in 75 patients. Rib radiography missed 43 rib fractures in 24 patients. The causes were overlap with organs in 15 cases, trivial fractures in 21 cases, and injury outside the imaging range in 7 cases. Left lower rib fractures were often missed due to overlap with the heart, while middle and lower rib fractures were frequently not diagnosed due to overlap with abdominal organs. Computed tomography missed 21 rib fractures in 17 patients. The causes were horizontal fractures in 10 cases, trivial fractures in 9 cases, and insufficient breath holding in 1 case. Conclusion In rib radiography, overlap with organs and fractures outside the imaging range were characteristic reasons for missed diagnoses. In chest computed tomography, horizontal rib fractures and insufficient breath holding were often responsible. We should take these challenges into account when diagnosing rib fractures.

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Satyo, Adhitio Satyo Bayangkari Karno, Dodi Arif, Indra Sari Kusuma Wardhana et Eka Sally Moreta. « Diagnosa COVID-19 Chest X-Ray Menggunakan Arsitektur Inception Resnet ». Journal of Informatic and Information Security 2, n^o 1 (3 juillet 2021) : 57–66. http://dx.doi.org/10.31599/jiforty.v2i1.646.

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The availability of medical aids in adequate quantities is very much needed to assist the work of the medical staff in dealing with the very large number of Covid patients. Artificial Intelligence (AI) with the Deep Learning (DL) method, especially the Convolution Neural Network (CNN), is able to diagnose Chest X-ray images generated by the Computer Tomography Scanner (C.T. Scan) against certain diseases (Covid). Inception Resnet Version 2 architecture was used in this study to train a dataset of 4000 images, consisting of 4 classifications namely covid, normal, lung opacity and viral pneumonia with 1,000 images each. The results of the study with 50 epoch training obtained very good values for the accuracy of training and validation of 95.5% and 91.8%, respectively. The test with 4000 image dataset obtained 98% accuracy testing, with the precision of each class being Covid (99%), Lung_Opacity (97%), Normal (99%) and Viral pneumonia (99%).

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Yang, Yang, Weihai Zhuo, Yiyang Zhao, Tianwu Xie, Chuyan Wang et Haikuan Liu. « Estimating Specific Patient Organ Dose for Chest CT Examinations with Monte Carlo Method ». Applied Sciences 11, n^o 19 (26 septembre 2021) : 8961. http://dx.doi.org/10.3390/app11198961.

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Purpose: The purpose of this study was to preliminarily estimate patient-specific organ doses in chest CT examinations for Chinese adults, and to investigate the effect of patient size on organ doses. Methods: By considering the body-size and body-build effects on the organ doses and taking the mid-chest water equivalent diameter (WED) as a body-size indicator, the chest scan images of 18 Chinese adults were acquired on a multi-detector CT to generate the regional voxel models. For each patient, the lungs, heart, and breasts (glandular breast tissues for both breasts) were segmented, and other organs were semi-automated segmented based on their HU values. The CT scanner and patient models simulated by MCNPX 2.4.0 software (Los Alamos National LaboratoryLos Alamos, USA) were used to calculate lung, breast, and heart doses. CTDIvol values were used to normalize simulated organ doses, and the exponential estimation model between the normalized organ dose and WED was investigated. Results: Among the 18 patients in this study, the simulated doses of lung, heart, and breast were 18.15 ± 2.69 mGy, 18.68 ± 2.87 mGy, and 16.11 ± 3.08 mGy, respectively. Larger patients received higher organ doses than smaller ones due to the higher tube current used. The ratios of lung, heart, and breast doses to the CTDIvol were 1.48 ± 0.22, 1.54 ± 0.20, and 1.41 ± 0.13, respectively. The normalized organ doses of all the three organs decreased with the increase in WED, and the normalized doses decreased more obviously in the lung and the heart than that in the breasts. Conclusions: The output of CT scanner under ATCM is positively related to the attenuation of patients, larger-size patients receive higher organ doses. The organ dose normalized by CTDIvol was negatively correlated with patient size. The organ doses could be estimated by using the indicated CTDIvol combined with the estimated WED.

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Smarda, Magdalini, Efstathios Efstathopoulos, Argyro Mazioti, Sofia Kordolaimi, Agapi Ploussi, Konstantinos Priftis, Nikolaos Kelekis et Efthymia Alexopoulou. « High-Resolution Computed Tomography Examinations for Chronic Suppurative Lung Disease in Early Childhood : Radiation Exposure and Image Quality Evaluations with Iterative Reconstruction Algorithm Use ». Canadian Association of Radiologists Journal 67, n^o 3 (août 2016) : 218–24. http://dx.doi.org/10.1016/j.carj.2015.10.003.

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Purpose High radiosensitivity of children undergoing repetitive computed tomography examinations necessitates the use of iterative reconstruction algorithms in order to achieve a significant radiation dose reduction. The goal of this study is to compare the iDose iterative reconstruction algorithm with filtered backprojection in terms of radiation exposure and image quality in 33 chest high-resolution computed tomography examinations performed in young children with chronic bronchitis. Methods Fourteen patients were scanned using the filtered backprojection protocol while 19 patients using the iDose protocol and reduced milliampere-seconds, both on a 64-detector row computed tomography scanner. The iDose group images were reconstructed with different iDose levels (2, 4, and 6). Radiation exposure quantities were estimated, while subjective and objective image qualities were evaluated. Unpaired t tests were used for data statistical analysis. Results The iDose application allowed significant effective dose reduction (about 80%). Subjective image quality evaluation showed satisfactory results even with iDose level 2, whereas it approached excellent image with iDose level 6. Subjective image noise was comparable between the 2 groups with the use of iDose level 4, while objective noise was comparable between filtered backprojection and iterative reconstruction level 6 images. Conclusions The iDose algorithm use in pediatric chest high-resolution computed tomography reduces radiation exposure without compromising image quality. Further evaluation with iterative reconstruction algorithms is needed in order to establish high-resolution computed tomography as the gold standard low-dose method for children suffering from chronic lung diseases.

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Hameed, Tariq A., Shawn D. Teague, Mani Vembar, Ekta Dharaiya et Jonas Rydberg. « Low radiation dose ECG-gated chest CT angiography on a 256-slice multidetector CT scanner ». International Journal of Cardiovascular Imaging 25, S2 (29 janvier 2009) : 267–78. http://dx.doi.org/10.1007/s10554-009-9428-3.

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Lopes, Joao A., Heidi L. Frankel, S. Jamal Bokhari, Matthew Bank, Manish Tandon et Reuven Rabinovici. « The Trauma Bay Chest Radiograph in Stable Blunt-Trauma Patients : Do We Really Need It ? » American Surgeon 72, n^o 1 (janvier 2006) : 31–34. http://dx.doi.org/10.1177/000313480607200108.

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The current study evaluates the need for trauma bay chest radiographs (CXR) in stable blunt-trauma patients who are scheduled for chest computed tomography (CCT). A retrospective review of 157 randomly selected, stable, adult blunt-trauma patients who were admitted to a level I trauma center between 2000 and 2002, who underwent both CXR and CCT (GE Light-Speed Scanner), was performed. Stable patients were defined as unintubated, normotensive (SBP >100 mm Hg), and without hypoxia (O2 saturation >90%). No interventions were conducted in the trauma bay based on chest radiograph findings. Among 95 patients with a “normal” CXR, 38 patients (40%) were found on CCT to have traumatic injuries. Among 62 patients with an “abnormal” CXR, 18 (29%) were found to be normal on CCT. Of the remaining 44 patients, 34 had additional findings on CCT. In 32 patients, CCT led to changes in management. CCT was more sensitive in diagnosing thoracic injuries and led to significant changes in management. We feel that CXR could be safely eliminated in favor of CCT in stable blunt-trauma patients.

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Nathaniel Mbaba, Awajimijan, Michael Promise Ogolodom, Rufus Abam, Olukunmi Yetunde Ijeruh, Joseph C. Eze, Chidinma Wekhe, Okechukwu Felix Erondu et Daniel Chimuanya Ugwuanyi. « PATTERNS OF CHEST COMPUTED TOMOGRAPHY FINDINGS IN COVID-19 PATIENTS IN PORT HARCOURT RIVERS STATE, NIGERIA ». International Journal of Advanced Research 9, n^o 08 (31 août 2021) : 82–88. http://dx.doi.org/10.21474/ijar01/13233.

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Background: The novel coronavirus disease (COVID-19) is usually under diagnosed in resource-constrained countries as Africa. Although Real-time-reverse-transcription polymerase chain reaction (RT-PCR) testing is considered to be the gold standard tool to diagnose or screen for COVID-19, chest imaging is a valuable tool to support the diagnosis of COVID-19 pneumonia. Therefore, Radiologists usually play an important role in the diagnosis of COVID-19 pneumonia, especially in resource-constrained environments. This study aimed to evaluate the patterns of chest CT findings in covid-19 pneumonia and to emphasize its diagnostic value in coronavirus disease. Materials and Method: This study was a retrospective cross-sectional study conducted in a reputable diagnostic center in Port Harcourt and comprised of 13 chest CT images diagnosed of Covid-19 pneumonia that met the inclusion criteria set for this study. All the chest CT examinations were performed by registered radiographers on a 64-slice CT scanner (GE Optima CT660, GE medical systems). Results: Chest CT findings in patients with confirmed covid-19 infection was evaluated and the results revealed that 13 (100%) had GGO. Out of 13 patients with GGO, bilateral distribution of the opacities was found in 11(84.62%), followed by peripheral opacities 9(69%) and the least 2 (15.38%) was unilateral distribution. Conclusion: The commonest chest CT appearance of covid-19 pneumonia is bilateral GGO with a predilection for the lower lobes of the lungs. Radiologists and clinicians should take cognizance of imaging appearances and diagnostic capabilities of Chest CT in covid-19 pneumonia, especially in the context of the current pandemic.

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Sesia, Sergio, Friederike Prüfer et Johannes Mayr. « Sternal Fracture in Children : Diagnosis by Ultrasonography ». European Journal of Pediatric Surgery Reports 05, n^o 01 (janvier 2017) : e39-e42. http://dx.doi.org/10.1055/s-0037-1606197.

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Because of its subcutaneous location, the sternum can be examined sonographically using a linear scanner. We report about two children who experienced blunt chest trauma. Anterior–posterior chest X-rays were normal. Ultrasonic imaging confirmed a fracture of the sternum with dorsal displacement of the distal fragment (by 0.97 cm) in the first child and a transverse fracture of the body of the sternum without displacement in the second child. In both children, pericardial effusion was excluded by sonography. The displaced fracture of the sternum was confirmed by magnetic resonance imaging (MRI), which ruled out concomitant injuries of the soft tissues adjacent to the sternum. Both sternum fractures were managed nonoperatively. These cases serve to emphasize the importance of sonography that represents an ionizing radiation free, noninvasive, efficient, and safe imaging modality to diagnose fractures of the sternum in children while also enabling the assessment of the pericardium.

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Kim, Yong-Seob, Cheon-Ung Park, Eun-Jung Kim, Sook-Hee Lee et Heung-Sun Im. « Investigating Decrease in Radiation Dose using Acute Chest Pain Coronary CT with 128 slice MDCT Scanner ». Korean Society of Computed Tomographic Technology 20, n^o 1 (13 février 2018) : 23–32. http://dx.doi.org/10.31320/jksct.2018.20.1.23.

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Nikolaev, A. E., O. A. Korkunova, I. A. Blokhin, A. V. Petraykin, M. V. Nikiforova, A. O. Gir’ko, E. A. Dyagileva et al. « Calcification density on computed tomography depending on scanning parameters : phantom study ». Medical Visualization 24, n^o 4 (12 décembre 2020) : 119–32. http://dx.doi.org/10.24835/1607-0763-2020-4-119-132.

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Purpose of research. The aim of the study is to evaluate changes in density, Agatston score, Volume and Mass scores of coronary calcium at different scanning parameters using phantom measurement.Materials and methods. 8 1-ml insulin syringes filled with potassium hydroorthophosphate solution of different densities were used in the study. The syringes were placed at regular intervals into two phantoms: type 1 phantom – container filled with water; type 2 phantom – Chest Phantom N1 “LUNGMAN”. The phantoms were scanned with a Philips Ingenuity Elite CT 128 scanner using protocols with different voltages (80, 100, 120, 140 kV), amperage (27–45, 166, 330–400 mA), and slice thickness (0.625, 1, 2.5, 3 mm).Results. Density and Agatston indexes were obtained at different scanning parameters (voltage, amperage, slice thickness) for different factors of calcification density in both phantoms. The results are presented as a table with mean density values, standard deviation (SD), Agatston score of coronary calcium, and scanning parameters.Conclusion. The study demonstrates the influence of various scanning parameters on coronary artery calcium scoring results. The obtained information can be used in practice for more accurate quantification of coronary artery calcium, regardless of the scanning parameters.

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Abuzaid, Mohamed M., Wiam Elshami, A. El Serafi, T. Hussien, J. R. McConnell et H. O. Tekin. « TOWARD NATIONAL CT DIAGNOSTIC REFERENCE LEVELS IN THE UNITED ARAB EMIRATES : A MULTICENTER REVIEW OF CT DOSE INDEX AND DOSE LENGTH PRODUCT ». Radiation Protection Dosimetry 190, n^o 3 (juillet 2020) : 243–49. http://dx.doi.org/10.1093/rpd/ncaa100.

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Abstract This multicenter study evaluated computed tomography dose index volume (CTDIvol) and dose length product (DLP) to contribute to establishing computed tomography (CT) national diagnostic reference levels (NDRLs) in the United Arab Emirates (UAE). Data from 240 patients, who underwent CT head, chest, abdomen–pelvis and urography examinations, were analyzed, including patient age, sex and weight, CTDIvol (mGy) and DLP (mGy cm). The proposed DRLs for each examination were calculated as the third quartile. DRLs are proposed using CTDIvol (mGy) and DLP (mGy cm) for CT head (67 and 1189, respectively), chest (8 and 302, respectively), abdomen–pelvis (28 and 1122, respectively) and urography (20 and 714, respectively). These values are comparable with the initial NDRLs and published international DRLs. Baseline values for International Radiology Center (IRC) CT DRLs were calculated on frequently performed CT examinations. Implementation of DRL values improves dose optimization based on procedures, scanner type and patient characteristics while maintaining acceptable image quality and diagnostic confidence.

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Hastomo, Widi. « Diagnosa COVID-19 Chest X-Ray Dengan Convolution Neural Network Arsitektur Resnet-152 ». KERNEL : Jurnal Riset Inovasi Bidang Informatika dan Pendidikan Informatika 2, n^o 1 (25 août 2021) : 26–33. http://dx.doi.org/10.31284/j.kernel.2021.v2i1.1884.

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The availability of medical aids in adequate quantities is very much needed to assist the work of the medical staff in dealing with the very large number of Covid patients. Artificial Intelligence (AI) with the Deep Learning (DL) method, especially the Convolution Neural Network (CNN), is able to diagnose Chest X-ray images generated by the Computer Tomography Scanner (C.T. Scan) against certain diseases (Covid). Resnet Version-152 architecture was used in this study to train a dataset of 10.300 images, consisting of 4 classifications namely covid, normal, lung opacity with 3,000 images each and viral pneumonia 1,000 images. The results of the study with 50 epoch training obtained very good values for the accuracy of training and validation of 95.5% and 91.8%, respectively. The test with 10.300 image dataset obtained 98% accuracy testing, with the precision of each class being Covid (99%), Lung_Opacity (99%), Normal (98%) and Viral pneumonia (98%).

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Milanese, Gianluca, Mario Silva, Thomas Frauenfelder, Matthias Eberhard, Federica Sabia, Chiara Martini, Alfonso Marchianò, Mathias Prokop, Nicola Sverzellati et Ugo Pastorino. « Comparison of ultra-low dose chest CT scanning protocols for the detection of pulmonary nodules : a phantom study ». Tumori Journal 105, n^o 5 (1 mai 2019) : 394–403. http://dx.doi.org/10.1177/0300891619847271.

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Purpose:To test ultra-low-dose computed tomography (ULDCT) scanning protocols for the detection of pulmonary nodules (PN).Methods:A chest phantom containing 19 solid and 11 subsolid PNs was scanned on a third-generation dual-source computed tomography (CT) scanner. Five ULDCT scans (Sn100kVp and 120, 70, 50, 30, and 20 reference mAs, using tube current modulation), reconstructed with iterative reconstruction (IR) algorithm at strength levels 2, 3, 4, and 5, were compared with standard CT (120kVp, 150 reference mAs, using tube current modulation). PNs were subjectively assessed according to a 4-point scale: 0, nondetectable nodule; 1, detectable nodule, very unlikely to be correctly measured; 2, detectable nodule, likely to be correctly measured; 3, PN quality equal to standard of reference. PN scores were analysed according to the Lung Imaging Reporting and Data System (Lung-RADS), simulating detection of nodules at baseline and incidence screening round.Results:For the baseline round, there were 17 Lung-RADS 2, 4 Lung-RADS 3, 8 Lung-RADS 4A, and 1 Lung-RADS 4B PNs. They were detectable in any ULDCT protocol, with the exception of 1 nondetectable part-solid nodule in 1 scanning protocol (120 reference mAs; IR strength: 3). For the incidence round, there were 4 Lung-RADS 2, 14 Lung-RADS 3, 2 Lung-RADS 4A, and 10 Lung-RADS 4B PNs. Ten were nondetectable in at least one ULDCT dataset; however, they were at least detectable in ULDCT with 70 reference mAs (IR strength: 4 and 5).Conclusions:ULDCT scanning protocols allowing the detection of PNs can be proposed for the purpose of lung cancer screening.

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Pelandré, Gustavo Lemos, Nathália Martins Pereira Sanches, Marcelo Souto Nacif et Edson Marchiori. « Detection of coronary artery calcification with nontriggered computed tomography of the chest ». Radiologia Brasileira 51, n^o 1 (février 2018) : 8–12. http://dx.doi.org/10.1590/0100-3984.2016.0181.

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Abstract Objective: To evaluate the accuracy of visual analysis and of the coronary artery calcium (CAC) score in nontriggered computed tomography (CT), in comparison with that of the CAC score in electrocardiogram-triggered CT, in identifying coronary calcification. Materials and Methods: A total of 174 patients for whom CT was indicated for CAC scoring underwent nontriggered and triggered CT in a 64-channel multislice scanner, in a single session without a change in position. The images were interpreted by a radiologist with seven years of experience in thoracic and cardiovascular radiology. The measurement of coronary calcium was carried out by three methods: CAC score with dedicated software in nontriggered CT, CAC score with dedicated software in triggered CT, and visual analysis without dedicated software in nontriggered CT. Results: In nontriggered CT, the CAC score presented an accuracy of 95.98% (95% CI: 91.93-98.04). The visual analysis showed an accuracy of 97.13% (95% CI: 93.45-98.77). Conclusion: Nontriggered CT showed excellent accuracy in the identification and exclusion of coronary calcification, either the CAC score was determined with dedicated software or through visual analysis.

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Schoenhagen, Paul, Brian Ghoshhajra, Stephan Achenbach et Suhny Abbara. « Interpretation of ‘incidental’ cardiovascular findings in standard chest CTs impact of evolving scanner technology on educational requirements ». Journal of Cardiovascular Computed Tomography 10, n^o 4 (juillet 2016) : 289–90. http://dx.doi.org/10.1016/j.jcct.2016.04.004.

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Warner, D. O., S. Krayer, K. Rehder et E. L. Ritman. « Chest wall motion during spontaneous breathing and mechanical ventilation in dogs ». Journal of Applied Physiology 66, n^o 3 (1 mars 1989) : 1179–89. http://dx.doi.org/10.1152/jappl.1989.66.3.1179.

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We measured the volume change of the thoracic cavity (delta Vth) and the volumes displaced by the diaphragm (delta Vdi) and rib cage (delta Vrc) in six pentobarbital-anesthetized dogs lying supine. A high-speed X-ray scanner (dynamic spatial reconstructor) provided three-dimensional images of the thorax during spontaneous breathing and during mechanical ventilation with paralysis. Tidal volume (VT) was measured by integrating gas flow. Changes in thoracic liquid volume (delta Vliq, presumably caused by changes in thoracic blood volume) were calculated as delta Vth - VT. Absolute volume displaced by the rib cage was not significantly different during the two modes of ventilation. During spontaneous breathing, thoracic blood volume increased during inspiration; delta Vliq was 12.3 +/- 4.1% of delta Vth. During mechanical ventilation, delta Vliq was nearly zero. Configuration of the relaxed chest wall was similar during muscular relaxation induced by either pharmacological paralysis or hyperventilation. Expiratory muscle activity produced 50 +/- 11% of the delta Vth during spontaneous breathing. We conclude that at constant VT the volume displaced by the rib cage is remarkably similar during the transition from spontaneous breathing to mechanical ventilation, while both diaphragmatic volume displacement and changes in intrathoracic blood volume decrease by a similar amount.

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Chung, N., X. Wu, K. R. Bailey et E. L. Ritman. « LV pressure-volume area and oxygen consumption : evaluation in intact dog by fast CT ». American Journal of Physiology-Heart and Circulatory Physiology 258, n^o 4 (1 avril 1990) : H1208—H1215. http://dx.doi.org/10.1152/ajpheart.1990.258.4.h1208.

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The relationship between left ventricular (LV) myocardial oxygen consumption (MVO2) and LV systolic pressure-volume area (PVA) was investigated in anesthetized closed-chest dogs with intact reflexes and subsequently with beta-adrenergic blockade, with or without simultaneous muscarinic blockade. LV chamber volumes were measured using a fast computerized tomography (CT) scanner (dynamic spatial reconstructor, DSR) at 33-ms intervals. Myocardial blood flow was measured from the DSR scans of aortic root angiograms. With intact reflexes, LV MVO2 (Y) related to PVA (X) values as Y = (4.28 +/- 1.81)X + (1.94 +/- 6.0) (n = 24) (mJ.g-1.cycle-1). With beta-adrenergic blockade, LV MVO2 (Y) related to PVA (X) value as Y = (4.24 +/- 1.03)X - (6.43 +/- 6.5), (n = 9) (mJ.g-1.cycle-1). With beta-adrenergic and muscarinic blockade, LV MVO2 (Y) related to PVA (X) value as Y = (2.84 +/- 1.72)X + (3.51 +/- 5.15), (n = 13) (mJ.g-1.cycle-1). The slopes of these regressions are higher than the slopes demonstrated by others in isolated ventricles but very similar to those demonstrated in open-chest dogs.

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Canellas, Rodrigo, Subba Digumarthy, Azadeh Tabari, Alexi Otrakji, Shaunagh McDermott, Efren J. Flores et Mannudeep Kalra. « Radiation dose reduction in chest dual-energy computed tomography : effect on image quality and diagnostic information ». Radiologia Brasileira 51, n^o 6 (1 novembre 2018) : 377–84. http://dx.doi.org/10.1590/0100-3984.2017.0136.

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Abstract Objective: To determine whether dual-energy computed tomography (DECT) of the chest can be performed at a reduced radiation dose, with an emphasis on images generated with post-processing techniques. Materials and Methods: In 21 patients undergoing DECT of the chest in a dual-source scanner, an additional image series was acquired at a reduced radiation dose. Four thoracic radiologists assessed both image series for image quality, normal thoracic structures, as well as pulmonary and mediastinal abnormalities, on virtual monochromatic images at 40 keV and 60 keV. Data were analyzed with Student's t-test, kappa statistics, analysis of variance, and the Wilcoxon signed-rank test. Results: The overall image quality of 60 keV virtual monochromatic images at a reduced radiation dose was considered optimal in all patients, and no abnormalities were missed. Contrast enhancement and lesion detection performance were comparable between reduced-dose images at 40 keV and standard-of-care images at 60 keV. The intraobserver and interobserver agreement were both good. The mean volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose-length product (DLP), and effective dose (ED) for reduced-dose DECT were 3.0 ± 0.6 mGy, 4.0 ± 0.6 mGy, 107 ± 30 mGy.cm, and 1.5 ± 0.4 mSv, respectively. Conclusion: DECT of the chest can be performed at a reduced radiation dose (CTDIvol < 3 mGy) without loss of diagnostic information.

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Adar, Adem, Hakan Erkan, Tayyar Gokdeniz, Aysegul Karadeniz, Ismail G. Cavusoglu et Orhan Onalan. « Aortic arch calcification is strongly associated with coronary artery calcification ». Vasa 44, n^o 2 (1 mars 2015) : 106–14. http://dx.doi.org/10.1024/0301-1526/a000415.

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Background: We aimed to investigate the association between aortic arch and coronary artery calcification (CAC). We postulated that low‐ and high‐risk CAC scores could be predicted with the evaluation of standard chest radiography for aortic arch calcification (AAC). Patients and methods: Consecutive patients who were referred for a multidetector computerized tomography (MDCT) examination were enrolled prospectively. All patients were scanned using a commercially available 64‐slice MDCT scanner for the evaluation of CAC score. A four‐point grading scale (0, 1, 2 and 3) was used to evaluate AAC on the standard posterior‐anterior chest radiography images. Results: The study group consisted of 248 patients. Median age of the study group was 52 (IQR: 10) years, and 165 (67 %) were male. AAC grades (r = 0.676, p < 0.0001) and age (r = 0.518, p < 0.0001) were significantly and positively correlated with CAC score. Presence of AAC was independently associated with the presence of CAC (OR: 11.20, 95 % CI 4.25 to 29.52). An AAC grade of ≥ 2 was the strongest independent predictor of a high‐risk CAC score (OR: 27.42, 95 % CI 6.09 to 123.52). Receiver operating characteristics curve analysis yielded a strong predictive ability of AAC grades for a CAC score of ≥ 100 (AUC = 0.892, P < 0.0001), and ≥ 400 (AUC = 0.894, P < 0.0001). Absence of AAC had a sensitivity, specificity and accuracy of 90 %, 84 % and 89 %, respectively, for a CAC score of < 100. An AAC grade of ≥ 2 predicted a CAC score of ≥400 with a sensitivity, specificity and accuracy of 68 %, 98 % and 95 %, respectively. Conclusions: AAC is a strong and independent predictor of CAC. The discriminative performance of AAC is high in detecting patients with low‐ and high‐risk CAC scores.

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Babiker, Ahmed Ali, Sayed Mansour Abbas, Alaa Ibrahim Ahmed, Rufida E. Ahmed, Maram Mohammed Fathi Ahmed, Mohamed A. Bayoumi et Asma Ahmed Ibraheem. « Assessment of Coronary Arteries Calcification in Diabetic Patients by using CT Calcium Score Technique ». Scholars Journal of Applied Medical Sciences 10, n^o 6 (10 juin 2022) : 900–905. http://dx.doi.org/10.36347/sjams.2022.v10i06.007.

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This study designed to define the role of computed tomography coronary angiography (CTA) in the diagnosis of patients with chest pain and suspected to have coronary artery disease (CAD) by measuring the calcium scoring in the coronary arteries (CAC) in patient with known diabetes and correlate the results with the (CTA) findings and other related variables. A descriptive analytical study for 84 patient with 36 diabetes and 48 patient with diabetes and hypertension examined using multi-detector computed tomography scanner MDCT64-Slice scanner (0.625 mm slices): 64 slice 0.625 mm collimation, table feed 10 mm/rotation, effective tube current 685 mAs at 120 kV. Pitch = 10/40 mm, collimation = 0.25 Average scan time = 5s, to scan the patient with coronary problems, detector array, fan beam shape, CT monitor for controlling scanning and processing. Cardiac trigger monitor with electrode leads (3000 TOSHEIBA) to monitor the heart rate, contrast injector (Medrao Toshiba-2ways) for flush contrast media to patient and VITREA SYSTYM (TOSHIBA) for diagnosis images and reconstruction and volume rendered purposes.(CAC) offers identifying the patients intended to have cardiac events, diagnosis of coronary arteries lesions and characterizing the plaque pattern .It is believable that measurements of calcium score will provide an acknowledged analytical radiological tool for the diagnoses of (CAD).

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Polemi, Andrew M., Annie K. Kogler, Patrice K. Rehm, Luke Lancaster, Heather R. Peppard, Patrick M. Dillon, Alexander V. Stolin, Stanislaw Majewski et Mark B. Williams. « Characterization and Pilot Human Trial of Dedicated Breast Ring Positron Emission Tomography (BRPET) System ». Instruments 5, n^o 3 (10 septembre 2021) : 30. http://dx.doi.org/10.3390/instruments5030030.

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We describe the design and performance of BRPET, a novel dedicated breast PET (dbPET) scanner designed to maximize visualization of posterior regions of the breast. BRPET uses prone imaging geometry and a 12-module detector ring built from pixelated LYSO crystals coupled to position sensitive photomultiplier tubes (PSPMTs). Optical coupling via slanted plastic fiber optic light guides permits partial insertion of the crystals into the exam table’s breast aperture. Image quality testing procedures were adapted from the NEMA NU4-2008 protocol. Two additional phantom tests quantified the posterior extent of the usable volume of view (VoV). BRPET axial, radial, and tangential FWHM spatial resolutions at the isocenter were 1.8, 1.7, and 1.9 mm, respectively. The peak absolute system sensitivity was 0.97% using an energy window of 460–562 keV. The peak noise equivalent counting rate was 5.33 kcps at 21.6 MBq. The scanner VoV extends to within ~6 mm of the plane defining the location of the chest wall. A pilot human study (n = 10) compared the diagnostic performance of FDG-BRPET to that of contrast enhanced MRI (CEMRI), with biopsy as ground truth. Averaged over three expert human observers, the sensitivity/specificity for BRPET was 0.93/1.0, compared to 1.0/0.25 for CEMRI.

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Habi, Jihane, Hind Guerroum, Mariam Kassimi, Nabil Chikhaoui et Mohamed Mahi. « Typical and Atypical Manifestations and Characteristics of the covid-19 Chest CT Scanner : Retrospective study of 28 patients ». International Journal of Scientific and Research Publications (IJSRP) 10, n^o 7 (18 juillet 2020) : 679–82. http://dx.doi.org/10.29322/ijsrp.10.07.2020.p10374.

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Chaikh, A., J. Y. Giraud et J. Balosso. « Effect of the modification of CT scanner calibration curves on dose using density correction methods for chest cancer ». IRBM 35, n^o 5 (octobre 2014) : 255–61. http://dx.doi.org/10.1016/j.irbm.2014.06.002.

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Aly, Antar, Shadi Ebrahimian, Mohammed H. Kharita, Mahmoud Heidous, Mohammad Zaya Ashruf, Davendra Kumar, Mannudeep K. Kalra et Huda Mohd Al Naemi. « Effect of technologist and patient attributes on centering for body CT examinations : Influence of cultural and ethnic factors ». PLOS ONE 17, n^o 8 (19 août 2022) : e0273227. http://dx.doi.org/10.1371/journal.pone.0273227.

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There are no published data on the effect of patient and technologist gender and ethnicity attributes on off-centering in CT. Therefore, we assessed the impact of patient and technologist variations on off-centering patients undergoing body CT. With institutional review board approval, our retrospective study included 1000 consecutive adult patients (age ranged 22–96 years; 756 males: 244 females) who underwent chest or abdomen CT examinations. We recorded patient (age, gender, nationality, body weight, height,), technologist gender, and scan-related (scanner vendor, body region imaged, scan length, CT dose index volume, dose length product) information. Lateral and anteroposterior (AP) diameters were recorded to calculate effective diameter and size-specific dose estimate (SSDE). Off-centering represented the distance between the anterior-posterior centers of the scan field of view and the patient at the level of carina (for chest CT) and iliac crest (for abdomen CT). About 76% of the patients (760/1000) were off-centered with greater off-centering for chest (22 mm) than for abdomen (15 mm). Although ethnicity or patient gender was not a significant determinant of off-centering, technologist-patient gender mismatch was associated with a significantly greater frequency of off-centering (p<0.001). Off-centering below the gantry isocenter was twice as common as off-centering above the gantry isocenter (p<0.001). The latter occurred more frequently in larger patients and was associated with higher radiation doses than those centered below the isocenter (p<0.001). Technologists’ years of experience and patient factors profoundly affect the presence and extent of off-centering for both chest and abdomen CTs. Larger patients are more often off-centered than smaller patients.

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Maqsood, Asma, Ahmed Zia Ud Din, Abdullah Saeed, Sadia ,. Abdullah et Muhammad Junaid Tahir. « Diagnostic accuracy and safety of CT-guided Lung and Mediastinal biopsies : a single center study ». Pakistan Journal of Medical and Health Sciences 16, n^o 12 (31 décembre 2022) : 150–52. http://dx.doi.org/10.53350/pjmhs20221612150.

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Background: Computed tomography (CT)-guided percutaneous needle biopsy plays a critical role in establishing tissue diagnosis of malignancy, guiding staging, and planning treatment for pulmonary abnormalities. Aim: To determine diagnostic accuracy and incidence of complications occurring after taking percutaneous CT-guided lung biopsy. Methodology: In this retrospective study, we evaluated 44 CT-guided chest biopsies (31 lung biopsies and 13 mediastinal biopsies) performed at our institution between September 2019 and March 2022. A coaxial core biopsy needle technique was used for all CT-guided biopsies. All procedures were performed by an experienced consultant interventional radiologist using using a commercially available helical multidetector-row CT scanner. Results: There were 29 men and 15 women among the 44 patients, ranging in age from 25 to 65 years. We found technical accuracy (described as tip of core biopsy needle within centre of lesion) of 100% (44/44) and diagnostic accuracy (described as adequate sample for histological assessment) of 97.7% (43/44) in our study. The overall incidence of complications during the procedure were recorded including pneumothorax (n = 2, 4.5%),pulmonary hemorrhage (n = 1, 2.3%), hemoptysis (n = 1, 2.3%). Conclusion: CT-guided chest biopsy is a safe procedure and has good diagnostic accuracy. However, radiologists approaching such interventional procedures must be experienced and well trained so that there are less chances of developing complications after the procedure. Practical implications: We suggest physicians performing chest biopsies to adopt better techniques and use shortest path to the lesion during needle insertion. Although CT-guided chest biopsy has fewer chances of complications, however, interventional radiologists should be conscious of potential complications. Keywords: CT-guided biopsy; Percutaneous biopsy; Imaging, Interventional radiology; Diagnosis.

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Ye, Xiaolu, et Ibrahim Mishaal. « Fuzzy Applications in Custom Clothing Design Technology Based on Intelligent 3D Simulation Technology ». Mathematical Problems in Engineering 2022 (24 juin 2022) : 1–12. http://dx.doi.org/10.1155/2022/6140915.

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This article integrates intelligent 3D simulation technology with an online customized clothing system to increase the impact of customized clothing design. The user uses a 3D scanner to scan his own body and acquire 3D body data, which include information of the head, chest, upper limbs, lower limbs, hands, and feet. Furthermore, this work enhances intelligent tracking and recognition technology, enhances the impact of human body parameter collection, and combines the enhanced algorithm to create a personalised clothing design system based on intelligent 3D simulation technology. Through experimental research, it can be seen that the customized clothing design system based on intelligent 3D simulation technology proposed in this paper has good effects and can effectively improve the service quality of online customized clothing.

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Whitelaw, W. A. « Shape and size of the human diaphragm in vivo ». Journal of Applied Physiology 62, n^o 1 (1 janvier 1987) : 180–86. http://dx.doi.org/10.1152/jappl.1987.62.1.180.

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Serial computerized tomograph (CT) sections at 5-mm intervals of a human diaphragm in relaxed and contracted states were obtained in one subject while he held his breath and lay supine in a CT scanner. All sections for one state were scanned at the same chest wall configuration as monitored by rib cage and abdominal dimensions, using magnetometers. Sections were scanned at relaxed functional residual capacity and after inspiring approximately 1 liter in such a way that rib cage dimensions increased only slightly. Models of the diaphragm dome in the two states were constructed from the sets of serial sections. Diaphragm length and volume displaced were measured, the zone of apposition of diaphragm to rib cage was mapped, and the line of the diaphragm silhouette in anteroposterior and lateral X-rays identified. Coronal and sagittal sections were constructed. In the inspiration studied, the diaphragm movement displaced 680 ml. Meridian lines in sagittal, coronal, and transverse directions over the right hemidiaphragm dome shortened by 6.7–7.2 cm, but over the left dome by only 4.0–4.3 cm. Lines of X-ray silhouettes were close to meridian lines, and estimates of shortening were similar to those made previously from X-rays. The peculiar saddle shape of the muscle may help the hemidiaphragms to operate independently, the fibers of the saddle acting as an anchor for midline directed fibers of the hemidiaphragm domes. The shape of the diaphragm also has implications for the distribution of transdiaphragmatic pressure and for the kind of distortion of thelower rib cage margin that is seen during inspirations at high lung volume.

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