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Chen, Haisong, Zengjie Wu, Wenjian Xu, Jing Pang, Meng Jia, Cheng Dong e Xiaoli Li. "Evaluating the Scope of Malignant Bone Tumor Using ADC Measurement on ADC Map". Technology in Cancer Research & Treatment 18 (1 gennaio 2019): 153303381985326. http://dx.doi.org/10.1177/1533033819853267.
Abstract (sommario):
Background: It is very important for surgeons to know the accurate borders of malignant bone tumors before they can precisely resect the tumors. The objective of the study is to investigate the usefulness of apparent diffusion coefficient value for estimating the extent of malignant bone tumor. Methods: VX2 tumor fragments were implanted into the tibiae of 30 rabbits. After 4 weeks, magnetic resonance plain scans were performed and then tumor specimens were cut into sagittal sections and partitioned into histology slices for dot-to-dot comparisons with microscopic findings. The sizes of the tumors measured separately on specimen, conventional magnetic resonance imaging sequences, and diffusion-weighted imaging (by measuring apparent diffusion coefficient value on apparent diffusion coefficient mapping) were compared statistically with each other. Results: The mean tumor sizes measured on specimen and apparent diffusion coefficient mapping (by calculating apparent diffusion coefficient value) were 5.20 ± 0.89 cm and 5.31 ± 0.87 cm, respectively; there was no significant difference between the 2 ( P > .05). The tumor sizes measured on T1WI, T2WI, T2WI with fat suppression were 4.82 ± 0.87 cm, 5.58 ± 0.87 cm, 5.63 ± 0.85 cm, respectively, and these values were significantly different from that measured on specimen (5.20 ± 0.89 cm, P < .05). Conclusion: The extent of the VX2 malignant bone tumor can be estimated accurately by measurement of apparent diffusion coefficient value.
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Teixeira, Sara Reis, Paula Condé Lamparelli Elias, Andrea Farias de Melo Leite, Tatiane Mendes Gonçalves de Oliveira, Valdair Francisco Muglia e Jorge Elias Junior. "Apparent diffusion coefficient of normal adrenal glands". Radiologia Brasileira 49, n. 6 (dicembre 2016): 363–68. http://dx.doi.org/10.1590/0100-3984.2015.0045.
Abstract (sommario):
Abstract Objective: To assess the feasibility and reliability of apparent diffusion coefficient (ADC) measurements of normal adrenal glands. Materials and methods: This was a retrospective study involving 32 healthy subjects, divided into two groups: prepubertal (PreP, n = 12), aged from 2 months to 12.5 years (4 males; 8 females); and postpubertal (PostP, n = 20), aged from 11.9 to 61 years (5 males; 15 females). Diffusion-weighted magnetic resonance imaging (DW-MRI) sequences were acquired at a 1.5 T scanner using b values of 0, 20, 500, and 1000 s/mm2. Two radiologists evaluated the images. ADC values were measured pixel-by-pixel on DW-MRI scans, and automatic co-registration with the ADC map was obtained. Results: Mean ADC values for the right adrenal glands were 1.44 × 10-3 mm2/s for the PreP group and 1.23 × 10-3 mm2/s for the PostP group, whereas they were 1.58 × 10-3 mm2/s and 1.32 × 10-3 mm2/s, respectively, for the left glands. ADC values were higher in the PreP group than in the PostP group (p < 0.05). Agreement between readers was almost perfect (intraclass correlation coefficient, 0.84-0.94; p < 0.05). Conclusion: Our results demonstrate the feasibility and reliability of performing DW-MRI measurements of normal adrenal glands. They could also support the feasibility of ADC measurements of small structures.
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Verbanck, Sylvia, e Manuel Paiva. "Acinar determinants of the apparent diffusion coefficient for helium-3". Journal of Applied Physiology 108, n. 4 (aprile 2010): 793–99. http://dx.doi.org/10.1152/japplphysiol.01230.2009.
Abstract (sommario):
The apparent diffusion coefficient (ADC) obtained by helium-3 magnetic resonance imaging over several seconds is thought to reflect diffusion impairment due to both intra- and interacinar structure. In this study, numerical simulations of intra-acinar gas mixing and effective diffusion were performed in a multiple-branch-point model of the human acinus. Using a previously described method, we computed the instantaneous effective diffusion resulting from the diffusive impairment imposed by intra-acinar branching for varying times up to 5 s. We also tested the influence on effective diffusion of intra-acinar collateral channels in the fully alveolated intra-acinar airways to mimic the effect of emphysema. Randomly connecting two or four pairs of airways per generation (in generations 19–25) led to a 40 and 142% increase, respectively, in effective diffusion coefficient cumulated over the time interval of 0.2–5 s. Finally, we also used a system of two coupled multiple branch-point models to simulate diffusive attenuation over a 50-s interval in cases of purely acinar tagging (i.e., the initial gas concentration = 1 in one acinus and 0 in the other) and of partial tagging astride on two acini. It is shown that, in the latter case, the decay rate cannot be approximated by a mono-exponential with a several-fold faster decay for times below 10 s due to intra-acinar diffusion. We conclude that both the characteristic biphasic time dependence of simulated effective diffusion and its sensitivity to intra-acinar structural change mimic experimental ADC behavior. Additional simulations of combined inter- and intra-acinar diffusion strongly suggest that neglecting intra-acinar branching would in fact lead to considerable error of simulated ADC.
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Sumikawa, Tetsuo, Hidetake Yabuuchi, Chiharu Sumikawa, Yoshiteru Nakashima e Gouji Miura. "Influence of blade width and magnetic field strength on the ADC on PROPELLER DWI in head and neck". Neuroradiology Journal 33, n. 1 (13 agosto 2019): 39–47. http://dx.doi.org/10.1177/1971400919870178.
Abstract (sommario):
Purpose The purpose of this study was to investigate the influence of blade width and magnetic field strength on apparent diffusion coefficient values of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging in the head and neck at 1.5 and 3.0 T magnetic resonance imaging. Methods Fifteen healthy volunteers (eight men and seven women; mean age 36.4 ± 10.1 years) underwent PROPELLER diffusion-weighted imaging using four blade widths at 3.0 T and three blade widths at 1.5 T. For the multigroup comparison of apparent diffusion coefficient values, we performed analysis of variance and Tukey–Kramer tests. The apparent diffusion coefficient values in each organ were compared among the different blade widths and magnetic field strengths by a t test. Inter and intra-observer agreements regarding apparent diffusion coefficient value measurements were evaluated using the intraclass correlation coefficient. Results No significant differences were observed in apparent diffusion coefficient values of the cerebellum in each blade width at both field strengths. The apparent diffusion coefficient values of the right parotid glands were significantly lower for blade width 32 than for blade width 16 at 3.0 T (1.16 × 10–3 mm2/s vs. 1.01 × 10–3 mm2/s; P < 0.05). The apparent diffusion coefficient values of bilateral parotid glands were significantly higher at 1.5 T than at 3.0 T. Intraclass correlation coefficients were almost perfect to substantial in the cerebellum, whereas they showed moderate agreement in the parotid glands. Conclusion The largest blade width 32 at 3.0 T and high magnetic field strength lowered the apparent diffusion coefficient values of parotid glands of PROPELLER diffusion-weighted imaging. The apparent diffusion coefficient values in the parotid glands of PROPELLER diffusion-weighted imaging may be affected for blade width and magnetic field strength.
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Ignjatovic, Jelena, Dragan Stojanov, Vladimir Zivkovic, Srdjan Ljubisavljevic, Nebojsa Stojanovic, Ivan Stefanovic, Daniela Benedeto-Stojanov et al. "Apparent diffusion coefficient in the evaluation of cerebral gliomas malignancy". Vojnosanitetski pregled 72, n. 10 (2015): 870–75. http://dx.doi.org/10.2298/vsp140229073i.
Abstract (sommario):
Background/Aim. Magnetic resonance imaging (MRI) is a key modality not only for lesion diagnosis, but also to evaluate the extension, type and grade of the tumor. Advanced MRI techniques provide physiologic information that complements the anatomic information available from conventional MRI. The aim of this study was to determine whether there is a correlation between apparent diffusion coefficient (ADC) maps of intracranial glial tumors and histopathologic findings and whether ADCs can reliably distinguish lowgrade from high-grade gliomas. Methods. This retrospective study included 25 patients with MRI examination up to seven days before surgery, according to the standard protocol with the following sequences: T1WI, T2WI, FLAIR, DWI and post contrast T1WI. Data obtained from DW MRI were presented by measuring the value of ADC. The ADC map was determined by utilizing Diffusion-Perfusion (DP) Tools software. All the patients underwent surgical resection of the tumor. Histological diagnosis of tumors was determined according to the World Health Organization (WHO) classification. The ADC values were compared with the histopathologic findings according to the WHO criteria. Results. The ADC values of astrocytomas grades I (0.000614 ? 0.000032 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000436 ? 0.000016 mm2/s) and the ADC values of glioblastomas multiforme (0.000070 ? 0.000008 mm2/s). The ADC values of astrocytomas grades II (0.000530 ? 0.000114 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000436 ? 0.000016 mm2/s) and glioblastomas multiforme (0.000070 ? 0.000008 mm2/s). The ADC values of anaplastic astrocytomas (0.000436 ? 0.000016 mm2/s) were significantly higher (< 0.001) than the ADC values of glioblastomas multiforme (0.000070 ? 0.000008 mm2/s). The ADC values in the cystic part of the tumor for astrocytomas grades I (0.000775 ? 0.000023 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000119 ? 0.000246 mm2/s) and glioblastomas multiforme (0.000076 ? 0.000004 mm2/s). The ADC values astrocytomas grades II (0.000511 ? 0.000421 mm2/s) were significantly higher (< 0.001) than the ADC values of glioblastomas multiforme (0.000076 ? 0.000004 mm2/s). Concluson. DWI with calculation of ADC maps can be regarded as a reliable useful diagnostic tool, which indirectly reflects the proliferation and malignancy of gliomas. The ADCs maps can both predict the results of histopathological tumor and distinguish between low- and high-grade gliomas, and provide significant information for presurgical planning, treatment and prognosis for patients with highgrade astrocytomas.
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Usuda, Katsuo, Shun Iwai, Aika Yamagata, Yoshihito Iijima, Nozomu Motono, Mariko Doai, Munetaka Matoba, Keiya Hirata e Hidetaka Uramoto. "How to Discriminate Lung Cancer From Benign Pulmonary Nodules and Masses? Usefulness of Diffusion-Weighted Magnetic Resonance Imaging With Apparent Diffusion Coefficient and Inside/Wall Apparent Diffusion Coefficient Ratio". Clinical Medicine Insights: Oncology 15 (gennaio 2021): 117955492110148. http://dx.doi.org/10.1177/11795549211014863.
Abstract (sommario):
Background: Although diffusion-weighted imaging (DWI) is useful for differential diagnosis between lung cancers and benign pulmonary nodules and masses (BPNMs), it is difficult to differentiate pulmonary abscesses from lung cancers because pulmonary abscesses show restricted diffusion. With this research we will present how to assess the total apparent diffusion coefficient (ADC) and inside/wall ADC ratio for these pulmonary nodules and masses (PNMs). Methods: The pulmonary lesions were divided into next 3 groups. There were 40 lung cancers, 41 inflammatory benign PNMs (mycobacteria disease 13, pneumonia 12, pulmonary abscess 10, other 6) and 7 noninflammatory benign PNMs. Definitions were as follows: wall ADC = ADC value in outer one-third of the lesion; inside ADC = ADC value in central two-thirds of the lesion: inside/wall ADC ratio = ratio of inside ADC/wall ADC. Results: Mean total ADC (1.26 ± 0.32 × 10−3 mm2/s) of the lung cancers was remarkably lower than that (1.53 ± 0.53) of the BPNMs. The mean total ADC values were 1.26 ± 0.32 in lung cancer, 1.45 ± 0.47 in inflammatory BPNM and 2.04 ± 0.63 in noninflammatory BPNM, and there were significant differences among them. The mean inside ADC value (1.33 ± 0.32) of the lung cancers was remarkably higher than that (0.94 ± 0.42) of the pulmonary abscesses. The mean inside/wall ADC ratio (1.20 ± 0.28) of the lung cancers was remarkably higher than that (0.74 ± 0.14) of the pulmonary abscesses. Conclusions: Although ADC of DWI could differentiate lung cancer from BPNM, the inside/wall ADC ratio of DWI is efficient for differentiation between lung cancer and lung abscess. The inside/wall ADC ratio of DWI strengthens a weak point of DWI.
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Wang, Rui, Weidong Liu, Fang Ren e Jing Ren. "Comparative study of diagnostic value between IVIM and DWI for prostate cancer at 3.0 T magnetic resonance". Chinese Journal of Academic Radiology 4, n. 3 (19 agosto 2021): 186–93. http://dx.doi.org/10.1007/s42058-021-00079-x.
Abstract (sommario):
Abstract Objective To quantitatively compare the diagnostic and differential diagnostic value of intra-voxel incoherent motion imaging (IVIM) and diffusion weighted imaging (DWI) for prostate cancer (PCa) and benign prostatic hyperplasia (BPH). Methods 68 cases of prostate confirmed by pathology, including 33 cases of PCa and 35 cases of BPH were analyzed retrospectively. All patients were underwent T1WI, T2WI, DWI and IVIM sequences to obtain the apparent diffusion coefficient (ADC), pure apparent diffusion coefficient (Pure-ADC/D), standard apparent diffusion coefficient (standard-ADC/Ds), fast apparent diffusion coefficient (fast-ADC/D*), fraction of fast apparent diffusion coefficient (f) values. All the multiple parameters were statistically analyzed for the differential diagnosis of BPH and PCa. P < 0.05 was considered as statistically significant. Results The differences in D, Ds, f and ADC values between BPH and PCa groups were statistically significant (all P values < 0.001), respectively. Among them, D value in the IVIM model had the highest diagnostic efficiency for PCa, the area under the curve (AUC) was 0.967, and the AUC combined with the ADC value and D value reaches 0.973. Conclusion The diagnostic efficacy of multiple parameters in the IVIM model for PCa was higher than the ADC value of the quantitative parameter of DWI. D value had the highest diagnostic efficiency. The combined diagnosis of ADC and D value was more effective, more advantageous in the diagnosis and differential diagnosis of PCa.
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Kanamoto, Hirohito, Masaki Norimoto, Yawara Eguchi, Yasuhiro Oikawa, Sumihisa Orita, Kazuhide Inage, Koki Abe et al. "Evaluating Spinal Canal Lesions Using Apparent Diffusion Coefficient Maps with Diffusion-Weighted Imaging". Asian Spine Journal 14, n. 3 (30 giugno 2020): 312–19. http://dx.doi.org/10.31616/asj.2019.0266.
Abstract (sommario):
Study Design: Observational study.Purpose: To evaluate healthy volunteers and patients with spinal canal lesions using apparent diffusion coefficient (ADC) maps with diffusion-weighted imaging.Overview of Literature: Decompression surgery for lumbar spinal stenosis (LSS) is selected on the basis of subjective assessment and cross-sectional magnetic resonance imaging (MRI). However, there is no objective standard for this procedure.Methods: We performed 3T MRI in 10 healthy volunteers and 13 patients with LSS. The ADC values in the spinal canal were evaluated at 46 vertebrae (L4/5 and L5/S1 for each participant), and the reduced and conventional fields of view were compared.Results: The ADC values were 2.72±0.12 at L4/5 in healthy volunteers, 2.76±0.19 at L5/S1 in healthy volunteers, 1.77±0.58 at L4/5 in patients with LSS, and 2.35±0.29 at L5/S1 in patients with LSS. The ADC value at L4/5 in patients with LSS was significantly lower than that at L5/S1 in patients with LSS and that at L4/5 and L5/S1 in healthy volunteers (<i>p</i> <0.05). With an ADC cutoff value of 2.46 to identify LSS, this approach provided an area under the curve of 0.81, sensitivity of 0.92, and specificity of 0.76 (<i>p</i> <0.05).Conclusions: Preoperative examination using ADC maps permits visualization and quantification of spinal canal lesions, thus proving the utility of ADC maps in the selection of decompression surgery for LSS.
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Basirjafari, Sedigheh, Masoud Poureisa, Babak Shahhoseini, Mohammad Zarei, Saeideh Aghayari Sheikh Neshin, Sheida Anvari Aria e Masoud Nouri-Vaskeh. "Apparent diffusion coefficient values and non-homogeneity of diffusion in brain tumors in diffusion-weighted MRI". Acta Radiologica 61, n. 2 (2 luglio 2019): 244–52. http://dx.doi.org/10.1177/0284185119856887.
Abstract (sommario):
Background The values that have been received from apparent diffusion coefficient (ADC) maps of diffusion-weighted magnetic resonance imaging (DW-MRI) might play a vital role in evaluating tumors and their grading scale. Purpose To investigate the predictive role of this heterogeneity in brain tumor pathologies and its correlation with Ki-67. Material and Methods A total of 124 patients with brain tumors underwent brain MRI with gadolinium injection. ADC and standard deviation of each lesion have been obtained from manual localization of the region of interest on the ADC map. A receiver operating characteristic analysis was conducted to determine the minimum cut-off values of the mean ADC and mean standard deviation of ADC maps having the highest sensitivity and specificity to differentiate high-grade and low-grade tumors. Results Mean ADC values in the region of interest were significantly lower for malignant tumors (grade IV and metastasis) than grade I brain tumors, while a higher mean standard deviation was observed. In a more detailed comparison of tumor groups, the mean standard deviation of the ADC for glioblastoma multiform was significantly higher than meningioma grade I ( P < 0.001) and metastasis was significantly higher than grade III and IV astrocytic tumors ( P = 0.004). The analysis of Ki-67 proliferation index and mean ADC values in gliomas showed a significant inverse correlation between the parameters (r = –0.0429, P < 0.001) and direct correlation between Ki-67 and mean standard deviation of the ADC (r = 0.551, P < 0.001). As an index for the ADC to differentiate high-grade and low-grade tumors, the cut-off values of 1.40*10−3 mm2/s for mean ADC and 45*10−3 mm2/s for mean standard deviation have the highest combination of sensitivity, specificity, and area under the curve. Conclusion The mean value and standard deviation of the ADC could be considered for differentiating between low-grade and high-grade brain tumors, as two available non-invasive methods.
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Sahoo, Prativa, Russell C. Rockne, Alexander Jung, Pradeep K. Gupta, Ram K. S. Rathore e Rakesh K. Gupta. "Synthetic Apparent Diffusion Coefficient for High b-Value Diffusion-Weighted MRI in Prostate". Prostate Cancer 2020 (10 febbraio 2020): 1–7. http://dx.doi.org/10.1155/2020/5091218.
Abstract (sommario):
Purpose. It has been reported that diffusion-weighted imaging (DWI) with ultrahigh b-value increases the diagnostic power of prostate cancer. DWI with higher b-values is challenging as it commonly suffers from low signal-to-noise ratio (SNR), distortion, and longer scan time. The aim of our study was to develop a technique for quantification of apparent diffusion coefficient (ADC) for higher b-values from lower b-value DW images. Materials and Methods. Fifteen patients (7 malignant and 8 benign) were included in this study retrospectively with the institutional ethical committee approval. All images were acquired at a 3T MR scanner. The ADC values were calculated using a monoexponential model. Synthetic ADC (sADC) for higher b-value was computed using a log-linear model. Contrast ratio (CR) between prostate lesion and normal tissue on synthetic DWI (sDWI) was computed and compared with original DWI and ADC images. Results. No significant difference was observed between actual ADC and sADC for b-2000 in all prostate lesions. However, CR increased significantly (p=0.002, paired t-test) in sDWI as compared to DWI. Malignant lesions showed significantly lower sADC as compared to benign lesions (p=0.0116, independent t-test). Mean (±standard deviation) of sADC of malignant lesions was 0.601 ± 0.06 and for benign lesions was 0.92 ± 0.09 (10−3 mm2/s). Discussion/Conclusion. Our initial investigation suggests that the ADC values corresponding to higher b-value can be computed using log-linear relationship derived from lower b-values (b ≤ 1000). Our method might help clinicians to decide the optimal b-value for prostate lesion identification.
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Gwak, Dong-Seok, WooChan Choi, Dong-Hyun Shim, Yong-Won Kim, Dong-Hun Kang, Wonsoo Son e Yang-Ha Hwang. "Role of Apparent Diffusion Coefficient Gradient Within Diffusion Lesions in Outcomes of Large Stroke After Thrombectomy". Stroke 53, n. 3 (marzo 2022): 921–29. http://dx.doi.org/10.1161/strokeaha.121.035615.
Abstract (sommario):
Background and Purpose: The outcome of endovascular treatment in stroke patients with a large ischemic core is not always satisfactory. We evaluated whether the severity of baseline diffusion-weighted imaging abnormalities, as assessed by different apparent diffusion coefficient (ADC) thresholds, correlates with the clinical outcome in these patients after successful endovascular treatment. Methods: In 82 consecutive patients with a large vessel occlusion in the anterior circulation admitted ≤24 hours after onset, a baseline diffusion lesion volume (ADC ≤620×10 −6 mm 2 /s [ADC 620 ]) ≥50 mL and successful recanalization by endovascular treatment were retrospectively investigated. Lesion volumes of 3 ADC thresholds (ADC 620 , ADC ≤520×10 −6 mm 2 /s [ADC 520 ], and ADC ≤540×10 −6 mm 2 /s [ADC 540 ]) were measured using an automated Olea software program. The performance of the ADC 520 /ADC 620 and ADC 540 /ADC 620 ratios in predicting the functional outcome was assessed by receiver operating characteristic curve analysis. The ADC ratio with optimal threshold showing better receiver operating characteristic performance was dichotomized at its median value into low versus high subgroup and its association with the outcome subsequently evaluated in a multivariable logistic regression model. Results: The median baseline diffusion lesion volume was 80.8 mL (interquartile range, 64.4–105.4). A good functional outcome (modified Rankin Scale score, ≤2) was achieved in 35 patients (42.7%). The optimal threshold for predicting the functional outcome was identified as ADC 540 /ADC 620 (area under the curve, 0.833) and dichotomized at 0.674. After adjusting for age, baseline National Institutes of Health Stroke Scale score, intravenous tissue-type plasminogen activator, baseline diffusion lesion volume, and onset-to-recanalization time, a low ADC 540 /ADC 620 was independently associated with a good functional outcome (adjusted odds ratio, 10.72 [95% CI, 3.06–37.50]; P <0.001). Conclusions: A low ADC 540 /ADC 620 , which may reflect less severe ischemic stress inside a diffusion lesion, may help to identify patients who would benefit from endovascular treatment despite having a large ischemic core.
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Park, Ga Eun, Sung Hun Kim, Eun Jeong Kim, Bong Joo Kang e Mi Sun Park. "Histogram analysis of volume-based apparent diffusion coefficient in breast cancer". Acta Radiologica 58, n. 11 (27 febbraio 2017): 1294–302. http://dx.doi.org/10.1177/0284185117694507.
Abstract (sommario):
Background Breast cancer is a heterogeneous disease. Recent studies showed that apparent diffusion coefficient (ADC) values have various association with tumor aggressiveness and prognosis. Purpose To evaluate the value of histogram analysis of ADC values obtained from the whole tumor volume in invasive ductal cancer (IDC) and ductal carcinoma in situ (DCIS). Material and Methods This retrospective study included 201 patients with confirmed DCIS (n = 37) and IDC (n = 164). The IDC group was divided into two groups based on the presence of a DCIS component: IDC–DCIS (n = 76) and pure IDC (n = 88). All patients underwent preoperative breast magnetic resonance imaging (MRI) with diffusion-weighted images at 3.0 T. Histogram parameters of cumulative ADC values, skewness, and kurtosis were calculated and statistically analyzed. Results The differences between DCIS, IDC–DCIS, and pure IDC were significant in all percentiles of ADC values, in descending order of DCIS, IDC–DCIS, and pure IDC. IDC showed significantly lower ADC values than DCIS, and ADC50 was the best indicator for discriminating IDC from DCIS, with a threshold of 1.185 × 10–3 mm2/s (sensitivity of 82.9%, specificity of 75.7%). However, multivariate analysis of obtained ADC values showed no significant differences between DCIS, IDC–DCIS, and pure IDC ( P > 0.05). Conclusion Volume-based ADC values showed association with heterogeneity of breast cancer. However, there was no additional diagnostic performance in histogram analysis for differentiating between DCIS, IDC–DCIS, and pure IDC.
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Xing, Da, Nikolaos G. Papadakis, Christopher L. H. Huang, Vee Meng Lee, T. Adrian Carpenter e Laurance D. Hall. "Optimised diffusion-weighting for measurement of apparent diffusion coefficient (ADC) in human brain". Magnetic Resonance Imaging 15, n. 7 (gennaio 1997): 771–84. http://dx.doi.org/10.1016/s0730-725x(97)00037-4.
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Hruşcã, Adrian, Andreea Liana Rãchişan, Siegfried Rödl e Erich Sorantin. "Can Apparent Diffusion Coefficient Predict the Clinical Outcome in Drowned Children?" Canadian Association of Radiologists Journal 68, n. 2 (maggio 2017): 217–23. http://dx.doi.org/10.1016/j.carj.2016.12.001.
Abstract (sommario):
Introduction Pediatric cerebral hypoxic-ischemic injury frequently results in severe neurological outcome. Imaging with diffusion-weighted magnetic resonance imaging (DWi) demonstrates that the acute cerebral injury and apparent diffusion coefficient (ADC) allow the assessment of the severity of brain damage. The main objective was to examine if spatial distribution of reductions in ADC values is associated with clinical outcome in drowned children. Methods This is a retrospective study of 7 children (7 examinations) suffering from a hypoxic-ischemic event who underwent DWi. Seven subjects with normal DWi served as controls. The mean patient age was 4.88 ± 2.93 years and the male-to-female ratio was 5:2. The neurological outcome was divided into 2 categories: 4 children with Apallic syndrome and 3 deaths. We analysed the differences between the drowned children and the control group regarding clinical data, DWi abnormalities, and ADC values. Results The ADC values in the occipital and parietal grey matter were significantly different between the drowned children (765.14 ± 65.47 vs 920.95 ± 69.62; P = .003) and the control group (670.82 ± 233.99 vs 900.66 ± 92.72; P = .005). The ADC showed low values in the precentral area also ( P = .044). Conclusion The ADC reduction may be useful to predict the poor outcome in drowned children and can be a valuable tool for clinical assessment.
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Utomo, Sri Andreani, Abdul Hafid Bajamal, Yuyun Yueniwati Prabowowati Wadjib, Irwan Barlian Immadoel Haq, Vivid Umu Varidha e Dyah Fauziah. "The role of apparent diffusion coefficient in differentiating typical from atypical meningioma". Bali Medical Journal 11, n. 1 (30 aprile 2022): 455–59. http://dx.doi.org/10.15562/bmj.v11i1.3244.
Abstract (sommario):
Background: Differentiation of typical from atypical meningiomas would greatly improve surgical planning and further treatment options. Appparent diffusion coefficient (ADC) has the potential to characterize meningioma subtypes. This study aimed to assess the value of ADC in differentiating typical and atypical meningiomas. Method: A retrospective study was conducted using medical records at RSUD Dr. Soetomo Surabaya in January 2019 – September 2021. ADC values were obtained by placing three ROIs on tumors. We used receiver operating curve (ROC) analysis to determine the optimal cut-off ADC value to differentiate meningioma grading and Mann-Whitney U test to evaluate the difference in ADC values between the two groups. In addition, Chi-square was used to assess the correlation between ADC values and the type of meningioma. Results: The ADC values in typical meningiomas ranged from 1.12 - 2.47 × 10-3 mm2/s with an average of 1.45 ± 0.38 × 10-3 mm2/s, while in atypical meningiomas ranged from 0.64 – 1.12 × 10-3 mm2/s with an average of 0.81 ± 0.20 × 10-3 mm2/s. Based on ROC analysis to distinguish typical and atypical meningiomas, the cut-off mean ADC value is 1.12 × 10-3 mm2/s with a sensitivity of 100%, specificity of 96.87%, and area under the curve (AUC) of 0.996. The cut-off difference in the ADC value and the relationship between the ADC value and meningioma type based on histopathology were significant. Conclusion: Typical meningiomas have higher ADC values than atypical cases. ADC value can help differentiate typical from atypical meningiomas.
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Klose, Uwe, Marion Batra e Thomas Nägele. "Parameterization of the Age-Dependent Whole Brain Apparent Diffusion Coefficient Histogram". BioMed Research International 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/373716.
Abstract (sommario):
Purpose. The distribution of apparent diffusion coefficient (ADC) values in the brain can be used to characterize age effects and pathological changes of the brain tissue. The aim of this study was the parameterization of the whole brain ADC histogram by an advanced model with influence of age considered.Methods. Whole brain ADC histograms were calculated for all data and for seven age groups between 10 and 80 years. Modeling of the histograms was performed for two parts of the histogram separately: the brain tissue part was modeled by two Gaussian curves, while the remaining part was fitted by the sum of a Gaussian curve, a biexponential decay, and a straight line.Results. A consistent fitting of the histograms of all age groups was possible with the proposed model.Conclusions. This study confirms the strong dependence of the whole brain ADC histograms on the age of the examined subjects. The proposed model can be used to characterize changes of the whole brain ADC histogram in certain diseases under consideration of age effects.
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Evans, Andrea, David G. McCormack, Giles Santyr e Grace Parraga. "Mapping and quantifying hyperpolarized 3He magnetic resonance imaging apparent diffusion coefficient gradients". Journal of Applied Physiology 105, n. 2 (agosto 2008): 693–99. http://dx.doi.org/10.1152/japplphysiol.00178.2008.
Abstract (sommario):
We measured hyperpolarized 3He magnetic resonance imaging (MRI) apparent diffusion coefficients (ADC) and quantified ADC gradients in each three-by-three voxel region of interest (ROI). Such local ADC gradients can be represented in vector maps showing the magnitude (| G3×3|) and direction of ADC gradients, providing a qualitative visualization tool and quantitative measurement of airway and air space heterogeneity. Twenty-four subjects (15 male, mean age = 67 ± 7 yr) with global initiative for chronic obstructive lung disease (GOLD) stage II ( n = 9, mean age 68 ± 6 yr), GOLD stage III chronic obstructive pulmonary disease (COPD; n = 7, mean age 67 ± 8 yr), and age-matched healthy volunteers ( n = 8, mean age 67 ± 6 yr) were enrolled based on their age and spirometry results. Hyperpolarized 3He MRI was performed on a whole body 3.0 Tesla system. Mean 3He ADC and ADC standard deviation were calculated for the center coronal slice, and the mean magnitude and direction of the ADC gradient vectors were calculated for each three-by-three voxel matrix (| G3×3|). While the 3He ADC standard deviation was not significantly different, mean | G3×3| was significantly different between subjects with stage II (0.14 ± 0.03 cm/s) and stage III COPD (0.19 ± 0.03 cm/s; P < 0.005) and between healthy subjects (0.12 ± 0.03 cm/s) and those with stage II COPD ( P < 0.02). The second order statistic | G3×3| may provide a sensitive measure of ADC heterogeneity for ROI representing 9.4 × 9.4 × 30 mm or 2.6 cm3 of lung tissue.
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Bušić, Marija, Zoran Rumboldt, Dora Čerina, Željko Bušić e Krešimir Dolić. "Prognostic Value of Apparent Diffusion Coefficient (ADC) in Patients with Diffuse Gliomas". Cancers 16, n. 4 (6 febbraio 2024): 681. http://dx.doi.org/10.3390/cancers16040681.
Abstract (sommario):
This study aimed to evaluate potential posttreatment changes in ADC values within the tissue surrounding the enhancing lesion, particularly in areas not exhibiting MRI characteristics of involvement. Additionally, the objective was to investigate the correlations among ADC values, treatment response, and survival outcomes in individuals diagnosed with gliomas. This retrospective study included a total of 49 patients that underwent either stereotactic biopsy or maximal surgical resection. Histologically confirmed as Grade III or IV gliomas, all cases adhered to the 2016 and 2021 WHO classifications, with subsequent radio-chemotherapy administered post-surgery. Patients were divided into two groups: short and long survival groups. Baseline and follow-up MRI scans were obtained on a 1.5 T MRI scanner. Two ROI circles were positioned near the enhancing area, one ROI in the NAWM ipsilateral to the neoplasm and another symmetrically in the contralateral hemisphere on ADC maps. At follow-up there was a significant difference in both ipsilateral and contralateral NAWM between the two groups, −0.0857 (p = 0.004) and −0.0607 (p = 0.037), respectively. There was a weak negative correlation between survival and ADC values in ipsilateral and contralateral NAWM at the baseline with the correlation coefficient −0.328 (p = 0.02) and −0.302 (p = 0.04), respectively. The correlation was stronger at the follow-up. The findings indicate that ADC values in normal-appearing white matter (NAWM) may function as a prognostic biomarker in patients with diffuse gliomas.
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Lucarelli, Nicola Maria, Ilaria Villanova, Nicola Maggialetti, Sara Greco, Francesca Tarantino, Roberto Russo, Senia Maria Rosaria Trabucco, Amato Antonio Stabile Ianora e Arnaldo Scardapane. "Quantitative ADC: An Additional Tool in the Evaluation of Prostate Cancer?" Journal of Personalized Medicine 13, n. 9 (15 settembre 2023): 1378. http://dx.doi.org/10.3390/jpm13091378.
Abstract (sommario):
Prostate cancer is one of the most common tumors among the male population. Magnetic resonance imaging (MRI), standardized by the PI-RADS version 2.1 scoring system, has a fundamental role in detecting prostate cancer and evaluating its aggressiveness. Diffusion-weighted imaging sequences and apparent diffusion coefficient values, in particular, are considered fundamental for the detection and characterization of lesions. In 2016 the International Society of Urological Pathology introduced a new anatomopathological 5-grade scoring system for prostate cancer. The aim of this study is to evaluate the correlation between quantitative apparent diffusion coefficient values (ADC) derived from diffusion-weighted imaging (DWI) sequences and the International Society of Urological Pathology (ISUP) and PI-RADS groups. Our retrospective study included 143 patients with 154 suspicious lesions, observed on prostate magnetic resonance imaging and compared with the histological results of the biopsy. We observed that ADC values can aid in discriminating between not clinically significant (ISUP 1) and clinically significant (ISUP 2-5) prostate cancers. In fact, ADC values were lower in ISUP 5 lesions than in negative lesions. We also found a correlation between ADC values and PI-RADS groups; we noted lower ADC values in the PI-RADS 5 and PI-RADS 4 groups than in the PI-RADS 3 group. In conclusion, quantitative apparent diffusion coefficient values can be useful to assess the aggressiveness of prostate cancer.
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Gihr, Georg, Diana Horvath-Rizea, Elena Hekeler, Oliver Ganslandt, Hans Henkes, Karl-Titus Hoffmann, Cordula Scherlach e Stefan Schob. "Diffusion weighted imaging in high-grade gliomas: A histogram-based analysis of apparent diffusion coefficient profile". PLOS ONE 16, n. 4 (15 aprile 2021): e0249878. http://dx.doi.org/10.1371/journal.pone.0249878.
Abstract (sommario):
Purpose Glioblastoma and anaplastic astrocytoma represent the most commonly encountered high-grade-glioma (HGG) in adults. Although both neoplasms are very distinct entities in context of epidemiology, clinical course and prognosis, their appearance in conventional magnetic resonance imaging (MRI) is very similar. In search for additional information aiding the distinction of potentially confusable neoplasms, histogram analysis of apparent diffusion coefficient (ADC) maps recently proved to be auxiliary in a number of entities. Therefore, our present exploratory retrospective study investigated whether ADC histogram profile parameters differ significantly between anaplastic astrocytoma and glioblastoma, reflect the proliferation index Ki-67, or are associated with the prognostic relevant MGMT (methylguanine-DNA methyl-transferase) promotor methylation status. Methods Pre-surgical ADC volumes of 56 HGG patients were analyzed by histogram-profiling. Association between extracted histogram parameters and neuropathology including WHO-grade, Ki-67 expression and MGMT promotor methylation status was investigated due to comparative and correlative statistics. Results Grade IV gliomas were more heterogeneous than grade III tumors. More specifically, ADCmin and the lowest percentile ADCp10 were significantly lower, whereas ADCmax, ADC standard deviation and Skewness were significantly higher in the glioblastoma group. ADCmin, ADCmax, ADC standard deviation, Kurtosis and Entropy of ADC histogram were significantly correlated with Ki-67 expression. No significant difference could be revealed by comparison of ADC histogram parameters between MGMT promotor methylated and unmethylated HGG. Conclusions ADC histogram parameters differ significantly between glioblastoma and anaplastic astrocytoma and show distinct associations with the proliferative activity in both HGG. Our results suggest ADC histogram profiling as promising biomarker for differentiation of both, however, further studies with prospective multicenter design are wanted to confirm and further elaborate this hypothesis.
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McPartlin, Andrew, Lucy Kershaw, Alan McWilliam, Marcus Ben Taylor, Clare Hodgson, Marcel van Herk e Ananya Choudhury. "Changes in prostate apparent diffusion coefficient values during radiotherapy after neoadjuvant hormones". Therapeutic Advances in Urology 10, n. 12 (11 ottobre 2018): 359–64. http://dx.doi.org/10.1177/1756287218798748.
Abstract (sommario):
Background: Changes in prostate cancer apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (MRI) provide a noninvasive method for assessing radiotherapy response. This may be attenuated by neoadjuvant hormone therapy (NA-HT). We investigate ADC values measured before, during and after external beam radiotherapy (EBRT) following NA-HT. Methods: Patients with ⩾T2c biopsy-proven prostate cancer receiving 3 months of NA-HT plus definitive radiotherapy were prospectively identified. All underwent ADC-MRI scans in the week before EBRT, in the third week of EBRT and 8 weeks after its completion. Imaging was performed at 1.5 T. The tumour, peripheral zone (PZ) and central zone (CZ) of the prostate gland were identified and median ADC calculated for each region and time point. Results: Between September and December 2014, 15 patients were enrolled (median age 68.3, range 57–78) with a median Gleason score of 7 (6–9) and prostate-specific antigen (PSA) at diagnosis 14 (3–197) ng/ml. Median period of NA-HT prior to first imaging was 96 days (69–115). All patients completed treatment. Median follow up was 25 months (7–34), with one patient relapsing in this time. Thirteen patients completed all imaging as intended, one withdrew after one scan and another missed the final imaging. PZ and CZ could not be identified in one patient. Median tumour ADC before, during and post radiotherapy was 1.24 × 10−3 mm2/s (interquartile range 0.16 × 10−3 mm2/s), 1.31 × 10−3 mm2/s (0.22 × 10−3 mm2/s), then 1.32 × 10−3 mm2/s (0.13 × 10−3 mm2/s) respectively ( p > 0.05). There was no significant difference between median tumour and PZ or CZ ADC at any point. Gleason score did not correlate with ADC values. Conclusions: Differences in ADC parameters of normal and malignant tissue during EBRT appear attenuated by prior NA-HT. The use of changes in ADC as a predictive tool in this group may have limited utility.
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Elysanti Dwi Martadiani, I Wayan Juli Sumadi, I Wayan Gede Artawan Eka Putra, Jonathan Andryanto, Anak Agung Gede Agung Priyastana e Felicia Nike. "Characteristics and Role of Apparent Diffusion Coefficient (ADC) Value in Musculoskeletal Soft Tissue Tumor". Indonesia Journal of Biomedical Science 17, n. 2 (8 dicembre 2023): 289–94. http://dx.doi.org/10.15562/ijbs.v17i2.512.
Abstract (sommario):
Introduction: Musculoskeletal soft tissue tumors (STTs) consist of a group of malignant and benign tumors that present challenges in diagnosis and therapy. Adding diffusion-weighted imaging and apparent diffusion coefficient (DWI/ADC) provides tissue characteristics that are different from those obtained by conventional MR techniques. Quantitative examination of the diffusion of water molecules in tissue is expressed as ADC value, which is expected to be more helpful in differentiating malignant and benign soft tissue masses. This study was carried out to determine the characteristics and role of ADC values in musculoskeletal STTs. Methods: This research was conducted retrospectively. Analysis was performed using MRI results of patients with musculoskeletal STTs who met the inclusion and exclusion criteria. Three regions of interest (ROI) were assessed in the tumor area with the strongest contrast enhancement for DWI mapping, ADC, and ROI ADC value placement. An Independent T-test test was performed to determine the mean difference of ADC in each tumor category. Receiver Operating Characteristics (ROC) were generated to find the optimal cut-off value. Then, a diagnostic test was carried out to determine the sensitivity, specificity, PPV, and NPV of the ADC value. Results: There were 41 research subjects with musculoskeletal STTs with male predominance, in which 75.61% of cases were malignant. DWI/ADC showed that 78.05% of patients with musculoskeletal soft tissue tumors had restricted diffusion areas. In this study, the ADC cutoff value to differentiate benign and malignant musculoskeletal STT is 0,84 x 10-3mm2/s with 77.4% sensitivity and 90% specificity, 96% positive predictive value and 56.3% negative predictive value. Conclusion: In differentiating malignant and benign musculoskeletal STTs, the ADC value provides fair sensitivity, very good specificity, good positive predictive value, and low negative predictive value.
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Barham, Majd, Masahiro Kuroda, Yuuki Yoshimura, Kentaro Hamada, Abdullah Khasawneh, Kohei Sugimoto, Kohei Konishi et al. "Evaluation of calculation processes of apparent diffusion coefficient subtraction method (ASM) imaging". PLOS ONE 18, n. 2 (27 febbraio 2023): e0282462. http://dx.doi.org/10.1371/journal.pone.0282462.
Abstract (sommario):
A number of restricted diffusion (RD) imaging techniques, such as diffusion kurtosis (DK) imaging and Q space imaging, have been developed and proven to be useful for the diagnosis of diseases, including cerebral gliomas and cerebrovascular infarction. In particular, apparent diffusion coefficient (ADC) subtraction method (ASM) imaging has become available recently as a novel RD imaging technique. ASM is based on the difference between the ADC values in an image pair of two ADC maps, ADC basic (ADCb) and ADC modify (ADCm), which are created from diffusion-weighted images taken using short and long effective diffusion times, respectively. The present study aimed to assess the potential of different types of ASM imaging by comparing them with DK imaging which is the gold-standard RD imaging technique. In the present basic study using both polyethylene glycol phantom and cell-containing bio-phantom, three different types of ASM images were created using different calculation processes. ASM/A is an image calculated by dividing the absolute difference between ADCb and ADCm by ADCb several times. By contrast, ASM/S is an image created by dividing the absolute difference between ADCb and ADCm by the standard deviation of ADCb several times. As for positive ASM/A image (PASM/A), the positive image, which was resultant after subtracting ADCb from ADCm, was divided by ADCb several times. A comparison was made between the types of ASM and DK images. The results showed the same tendency between ASM/A in addition to both ASM/S and PASM/A. By increasing the number of divisions by ADCb from three to five times, ASM/A images transformed from DK-mimicking to more RD-sensitive images compared with DK images. These observations suggest that ASM/A images may prove useful for future clinical applications in RD imaging protocols for the diagnosis of diseases.
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Ranabhat, Kajan, Suresh Bishokarma, Pratyush Shrestha, Rajesh Panth e Ram Kumar Ghimire. "Role of Quantitative Apparent Diffusion Coefficient in Predicting Genetic Subtypes of Gliomas". Nepal Journal of Neuroscience 17, n. 3 (27 novembre 2020): 4–11. http://dx.doi.org/10.3126/njn.v17i3.33115.
Abstract (sommario):
Introduction: Magnetic resonance morphologic features are widely used in characterising gliomas for predicting grades and thereby aiding in preoperative management planning. We aim to find out if Magnetic Resonance Imaging (MRI) morphologic characters and quantitative apparent diffusion coefficient (ADC) measurements can predict genetic subtypes of high-grade gliomas.
Methods and Materials: Preoperative MRI examinations of histopathologically proven gliomas were retrospectively studied for qualitative tumor characteristics, including location, extent, cortical involvement, margin sharpness, cystic component, mineralization or hemorrhage, and contrast enhancement. Quantitative diffusion metrics were also assessed. Chi-square test, students t-test and multivariate regression analysis were used to evaluate the relationship between MRI features and Isocitrate Dehydrogenase (IDH) mutational status.
Results: The final study population included 23 patients (sixteen males and seven females, mean age 40 years ± 14.4, age range 13–66 years). Nine tumors were IDH mutant and fourteen were IDH wild type. IDH wild-type tumors showed patchy to diffuse diffusion restriction and a lower apparent diffusion coefficient (ADC) compared to IDH mutant types. T2/FLAIR high signal and maximum ADC values were associated with IDH mutational status. Contrast enhancement, hemorrhage and necrosis were significantly higher in IDH wild type gliomas. There was no statistical difference in the age, gender, tumor burden, location, site and edema between the IDH-mutant and wild-type tumors.
Conclusions: Magnetic resonance morphometric parameters that include T2/FLAIR signal character, contrast enhancement pattern, hemorrhage and necrosis and quantitative mean ADC /normalized ADC can support preoperatively the distinction of genetic subtypes of gliomas.
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Mustofa, Ali, Anggraini Dwi Sensusiati, Muhaimin Muhaimin, Sri Andreani Utomo e Risalatul Latifah. "ANALYSIS OF FRACTIONAL ANISOTROPY (FA) VALUES AND APPARENT DIFFUSION COEFFICIENT (ADC) VALUES IN ISCHEMIC STROKE DISEASES OF MRI GE 3 TESLA". Journal Of Vocational Health Studies 2, n. 3 (6 maggio 2019): 107. http://dx.doi.org/10.20473/jvhs.v2.i3.2019.107-111.
Abstract (sommario):
Background: Diffusion Weighted Imaging and Diffusion Tensor Imaging is an advanced technique in MRI that shows the diffusion in brain of ischemic stroke disease. Diffusion Weighted Imaging (DWI) shows the lesions without gadolinium contrast agent and produce Apparent Diffusion Coefficient values. Whereas, Diffusion Tensor Imaging (DTI) shows connectivity’s of central nervous system that cannot be seen by using conventional MRI. Diffusion Tensor Imaging produces Fractional Anisotropy values. Purpose:This study has aim to analyze the Apparent Diffusion Coefficient values and Fractional Anisotropy values in Stroke Ischemic disease. Methods: Total samples used are 14 samples, consist of 7 (50%) man and 7 (50%) woman with ischemic stroke disease. Each sample deals by Diffusion Weighted Imaging and Diffusion Tensor Imaging sequences. The Region of Interest (ROI) is placed in ischemic stroke lesions and contra lateral side of lesions. Results: The result shows that 9 samples of brain tissue lesions located in the right side and 5 samples in the left side. Right lesions have the average ADC stroke: 0.001748; normal ADC: 0.000954; FA stroke: 0.144522; and normal FA: 0.426111. While, left lesions have the average ADC strokes 0.000979; normal ADC: 0.000835; FA stroke: 0.2556; and normal FA 0.4324. Conclusion: So, the conclusion of this study is Apparent Diffusion Coefficient (ADC) values in case of ischemic stroke can decreases or increases depend on the age of stroke. While, the Fractional Anisotropy (FA) values will decrease without being affected by age of stroke.
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Na, Sa-Ra, Kwan-Woo Choi, No-Hyun Koo, Beong-Gyu Yoo e Soon-Yong Son. "A Change of Apparent Diffusion Coefficient in Diffusion Weighted Imaging Applied with Rectangular FOV Technique". Journal of the Korean Society of Radiology 10, n. 7 (30 novembre 2016): 545–50. http://dx.doi.org/10.7742/jksr.2016.10.7.545.
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Olsen, Ø. E., e N. J. Sebire. "Apparent diffusion coefficient maps of pediatric mass lesions with free-breathing diffusion-weighted magnetic resonance: feasibility study". Acta Radiologica 47, n. 2 (marzo 2006): 198–204. http://dx.doi.org/10.1080/02841850500479651.
Abstract (sommario):
Purpose: To assess the technical feasibility of apparent diffusion coefficient (ADC) mapping based on free-breathing diffusion-weighted magnetic resonance (DW-MR) outside the CNS in children. Material and Methods: Twelve children with mass lesions of varied histopathology were scanned with short- tau inversion recovery (STIR), contrast-enhanced T1-weighted (CE-T1W), and diffusion-weighted (b = 0, 500 and 1000 s/mm2) sequences. ADC maps were calculated. Lesion-to-background signal intensity ratios were measured and compared between STIR/CE-T1W/ADC overall (Friedman test) and between viable embryonal tumors and other lesions (Kruskal-Wallis test). Results: ADC maps clearly depicted all lesions. Lesion-to-background signal intensity ratios of STIR (median 3.7), CE-T1W (median 1.4), and ADC (median 1.6) showed no overall difference (chi-square = 3.846; P = 0.146), and there was no difference between viable embryonal tumors and other lesions within STIR/CE-T1W/ADC (chi-square 1.118/0.669/<0.001; P = 0.290/0.414/1.000, respectively). Conclusion: ADC mapping is feasible in free-breathing imaging of pediatric mass lesions outside the CNS using standard clinical equipment.
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Ristic-Balos, Dragana, Svetlana Gavrilovic, Slobodan Lavrnic, Brankica Vasic, Marija Macvanski, Dusan Damjanovic e Tatjana Stosic-Opincal. "Proton magnetic resonance spectroscopy and apparent diffusion coefficient in evaluation of solid brain lesions". Vojnosanitetski pregled 70, n. 7 (2013): 637–44. http://dx.doi.org/10.2298/vsp110223044r.
Abstract (sommario):
Background/Aim. Advanced magnetic resonance techniques can provide insight in physiological changes within pathological canges and contribute to better distinquishing between different tumor types and their discrimination from non-neoplastic lesions. The aim of this study was to evaluate the role of proton magnetic resonance spectroscopy (1H-MRS) and apparent diffusion coefficients (ADC) in distinguishing intracranial glial tumors from tumor like nonneoplastic lesions, as well as for differentiating high- from low-grade gliomas. Methods. This retrospective study included 47 patients with solid brain lesions (25 nonneoplastic, 14 low-grade and 8 anaplastic glial tumors). In all patients 1H-MRS (at a TE of 135 ms and 30 ms) and diffusion- weighted imaging (DWI) were performed. The choline to creatine (Cho/Cr), choline to N-acetyl aspartate (Cho/NAA), N-acetyl aspartate to creatine (NAA/Cr) and myoinositol to creatine (mIn/Cr) ratios and the apparent diffusion coefficient (ADC) were determined. Results. The Cho/Cr ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.008) and in glial tumors grade III than in non-neoplastic lesions (p = 0.001). The Cho/NAA ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.037). ?ADC/ADC between glial tumors grade II and glial tumors grade III showed a statistical significance (p = 0.023). Conclusion. Our study showed that 1H-MRS and apparent diffusion coefficients can help in evaluation and differentiation of solid brain lesions.
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Ustabasioglu, Fethi Emre, Cesur Samanci, Deniz Alis, Nilay Sengul Samanci, Osman Kula e Deniz Cebi Olgun. "Apparent Diffusion Coefficient Measurement in Mediastinal Lymphadenopathies: Differentiation between Benign and Malignant Lesions". Journal of Clinical Imaging Science 7 (6 marzo 2017): 12. http://dx.doi.org/10.4103/jcis.jcis_84_16.
Abstract (sommario):
Objectives:We aimed to prospectively assess the diagnostic value of apparent diffusion coefficient (ADC) measurement in the differentiation of benign and malignant mediastinal lymphadenopathies.Materials and Methods:The study included 63 consecutive patients (28 women, 35 men; mean age 59.3 years) with 125 mediastinal lymphadenopathies. Echoplanar diffusion-weighted magnetic resonance imaging of the mediastinum was performed with b-factors of 0 and 600 mm2/s before mediastinoscopy and mediastinotomy, and ADC values were measured. The ADC values were compared with the histological results, and statistical analysis was done.P< 0.05 was considered statistically significant.Results:The mean ADC value of malignant mediastinal lymphadenopathy (1.030 ± 0.245 × 10−3mm2/s) was significantly lower (P< 0.05) when compared to benign lymphadenopathies (1.571 ± 0.559 × 10−3mm2/s). For differentiating malignant from benign mediastinal lymphadenopathy, the best result was obtained when an ADC value of 1.334 × 10−3mm2/s was used as a threshold value; area under the curve 0.848, accuracy 78.4%, sensitivity 66%, specificity of 86%, positive predictive value 76.7%, and negative predictive value of 79.2%. Interobserver agreement was excellent for ADC measurements.Conclusions:ADC measurements could be considered an important supportive method in differentiating benign from malignant mediastinal lymphadenopathies.
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Dudhe, Sakshi, Gaurav Mishra, Pratapsingh Parihar, Dhananjay Shinde e Anjali Kumari. "MRI based evaluation of carcinoma gallbladder using apparent diffusion coefficient (ADC) and diffusion weighted imaging (DWI)". F1000Research 13 (29 aprile 2024): 414. http://dx.doi.org/10.12688/f1000research.143953.1.
Abstract (sommario):
Background Carcinoma of the gallbladder is a malignant neoplasm, which is associated with a poor prognosis due to its often-asymptomatic nature and late-stage diagnosis. Non-invasive imaging techniques play a key role in the early detection and characterization of gallbladder carcinoma. This thesis presents a comprehensive analysis of the utility of Diffusion-Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping in the magnetic resonance imaging (MRI) evaluation of carcinoma of the gallbladder. The primary objective of this research was to investigate the exact diagnostic accuracy and potential clinical applications of DWI and ADC in assessing carcinoma of the gallbladder and related tumour aggressiveness. A systematic review of existing literature was conducted to establish a foundation for this study with efforts to acquire relevant imaging data. The results of this study demonstrate the efficacy of DWI and ADC in the detection of carcinoma of the gallbladder when compared to conventional MRI sequences. These advanced imaging techniques hold promise in increasing the accuracy of diagnosis, ultimately leading to improved patient outcomes and more informed clinical decision making. The potential of Diffusion-Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping in the evaluation of gallbladder cancer using magnetic resonance imaging (MRI) is thoroughly analysed in this thesis. Methods A descriptive prospective study will be done at Acharya Vinoba Bhave Rural Hospital, Sawangi, involving 20 patients with clinically suspected carcinoma gallbladder, who are referred to the department of Radiodiagnosis. These patients will be subjected to study-purposive sampling. Conclusion After an appropriate statistical analysis, we expect to assess the role of Diffusion-Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping in the magnetic resonance imaging (MRI) evaluation of carcinoma of the gallbladder. CTRI registration This trial has been submitted to Clinical Trials Registry-India (CTRI) for Review. Registration Number: REF/2023/09/072780 Registration date:01/05/2023 URL of trial: https://www.ctri.nic.in/
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Rulseh, Aaron Michael, e Josef Vymazal. "Whole brain apparent diffusion coefficient measurements correlate with survival in glioblastoma patients". Journal of Neuro-Oncology 146, n. 1 (3 dicembre 2019): 157–62. http://dx.doi.org/10.1007/s11060-019-03357-y.
Abstract (sommario):
Abstract Introduction Glioblastoma (GBM) is the most common malignant primary brain tumor, and methods to improve the early detection of disease progression and evaluate treatment response are highly desirable. We therefore explored changes in whole-brain apparent diffusion coefficient (ADC) values with respect to survival (progression-free [PFS], overall [OS]) in a cohort of GBM patients followed at regular intervals until disease progression. Methods A total of 43 subjects met inclusion criteria and were analyzed retrospectively. Histogram data were extracted from standardized whole-brain ADC maps including skewness, kurtosis, entropy, median, mode, 15th percentile (p15) and 85th percentile (p85) values, and linear regression slopes (metrics versus time) were fitted. Regression slope directionality (positive/negative) was subjected to univariate Cox regression. The final model was determined by aLASSO on metrics above threshold. Results Skewness, kurtosis, median, p15 and p85 were all below threshold for both PFS and OS and were analyzed further. Median regression slope directionality best modeled PFS (p = 0.001; HR 3.3; 95% CI 1.6–6.7), while p85 was selected for OS (p = 0.002; HR 0.29; 95% CI 0.13–0.64). Conclusions Our data show tantalizing potential in the use of whole-brain ADC measurements in the follow up of GBM patients, specifically serial median ADC values which correlated with PFS, and serial p85 values which correlated with OS. Whole-brain ADC measurements are fast and easy to perform, and free of ROI-placement bias.
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Schlaug, G., B. Siewert, A. Benfield, R. R. Edelman e S. Warach. "Time course of the apparent diffusion coefficient (ADC) abnormality in human stroke". Neurology 49, n. 1 (1 luglio 1997): 113–19. http://dx.doi.org/10.1212/wnl.49.1.113.
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Walker-Samuel, Simon, Matthew Orton, Lesley D. McPhail e Simon P. Robinson. "Robust estimation of the apparent diffusion coefficient (ADC) in heterogeneous solid tumors". Magnetic Resonance in Medicine 62, n. 2 (7 aprile 2009): 420–29. http://dx.doi.org/10.1002/mrm.22014.
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Colombo, Alberto, Giulia Saia, Alcide A. Azzena, Alice Rossi, Fabio Zugni, Paola Pricolo, Paul E. Summers et al. "Semi-Automated Segmentation of Bone Metastases from Whole-Body MRI: Reproducibility of Apparent Diffusion Coefficient Measurements". Diagnostics 11, n. 3 (11 marzo 2021): 499. http://dx.doi.org/10.3390/diagnostics11030499.
Abstract (sommario):
Using semi-automated software simplifies quantitative analysis of the visible burden of disease on whole-body MRI diffusion-weighted images. To establish the intra- and inter-observer reproducibility of apparent diffusion coefficient (ADC) measures, we retrospectively analyzed data from 20 patients with bone metastases from breast (BCa; n = 10; aged 62.3 ± 14.8) or prostate cancer (PCa; n = 10; aged 67.4 ± 9.0) who had undergone examinations at two timepoints, before and after hormone-therapy. Four independent observers processed all images twice, first segmenting the entire skeleton on diffusion-weighted images, and then isolating bone metastases via ADC histogram thresholding (ADC: 650–1400 µm2/s). Dice Similarity, Bland-Altman method, and Intraclass Correlation Coefficient were used to assess reproducibility. Inter-observer Dice similarity was moderate (0.71) for women with BCa and poor (0.40) for men with PCa. Nonetheless, the limits of agreement of the mean ADC were just ±6% for women with BCa and ±10% for men with PCa (mean ADCs: 941 and 999 µm2/s, respectively). Inter-observer Intraclass Correlation Coefficients of the ADC histogram parameters were consistently greater in women with BCa than in men with PCa. While scope remains for improving consistency of the volume segmented, the observer-dependent variability measured in this study was appropriate to distinguish the clinically meaningful changes of ADC observed in patients responding to therapy, as changes of at least 25% are of interest.
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Abd-Alhamid, Tarek, Ahmed G. Khafagy, Hesham Al Sersy, Anas Askora, Tahany M. Rabie, Mohamed S. Taha, Amal Ebrahim e Hoda M. El Sayed. "Certainty of pretreatment apparent diffusion coefficient in the characterization of thyroid gland pathologies". Egyptian Journal of Otolaryngology 33, n. 2 (aprile 2017): 495–501. http://dx.doi.org/10.4103/1012-5574.206019.
Abstract (sommario):
Abstract Introduction One of the most recent techniques in imaging tumors is the diffusion-weighted MRI. It provides information regarding the metabolic, molecular, and pathophysiological aspects of tumors, especially thyroid gland cancer. Diffusion-weighted imaging (DWI) has also been proposed as a sensitive marker for monitoring treatment response in head and neck cancers. The biophysical mechanism of DWI is based on the translational motion of water molecules in tissues. The magnitude of this motion is characterized by its apparent diffusion coefficient (ADC) values. Objective The aim of the present study was to evaluate the certainty of ADC value in differentiating between benign and malignant thyroid lesions. Materials and methods Neck MRI with several sequences including DWI in the axial plane were carried out for 49 patients who presented with thyroid masses either benign or malignant. ADC maps were calculated by using the MRI machine software. Results A total of 49 patients (77.6%) were included in the present study. There were 11 men (22.4%) and 38 women patients (77.6%), with a mean age of 44.4 years. The lesions were benign in 31 cases (63.3%) and malignant in 18 cases (36.7%). The ADC values were significantly different (P<0.001) between benign and malignant lesions. Conclusion ADC value is a promising noninvasive imaging tool that can be used for characterization and differentiation of thyroid nodules.
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Surov, Alexey, Lisa Paul, Hans Meyer, Stefan Schob, Cornelius Engelmann e Andreas Wienke. "Apparent Diffusion Coefficient Is a Novel Imaging Biomarker of Myopathic Changes in Liver Cirrhosis". Journal of Clinical Medicine 7, n. 10 (15 ottobre 2018): 359. http://dx.doi.org/10.3390/jcm7100359.
Abstract (sommario):
Diffusion weighted imaging can provide information regarding tissue composition and can quantitatively characterize different pathological changes by means of apparent diffusion coefficient (ADC). The study comprised of 114 patients with liver cirrhosis—22 women and 92 men with a mean age of 56.5 ± 9.0 years. In all patients, the Model for End Stage-Liver Disease (MELD) score was calculated. Furthermore, 12 healthy persons (5 women, 7 men), mean age, 42.1 ± 16.2 years, were investigated as a control group. In all cases, magnetic resonance imaging of the liver/trunk was performed using different 3T scanners and diffusion weighted images were obtained with a multi-shot SE-EPI sequence. In all cases, polygonal regions of interest were manually drawn on the ADC maps along the contours of the iliopsoas and paravertebral muscles. The comparison of ADC values in groups was performed by Mann-Whitney-U tests. The association between ADC and MELD score was calculated by Spearman’s rank correlation coefficient. ADC values of the skeletal musculature were statistically much higher in comparison to those in the control group: 1.85 ± 0.46 × 10−3 mm2 s−1 vs. 1.23 ± 0.12 × 10−3 mm2 s−1, p = 0.001. ADC values showed statistically significant correlation with the MELD score (r = 0.473, p = 0.0001). Furthermore, ADC values differed between the subgroups with different values of the MELD score. ADC values correlated slightly with lactate dehydrogenase (LDH) (r = 0.381, p = 0.0001) and tended to correlate with C-reactive protein (CRP) (r = 0.171, p = 0.07) and alanine aminotransferase (ALAT) (r = −0.167, p = 0.076). ADC can reflect muscle changes in liver cirrhosis and shows statistically significant correlation with the MELD score. Therefore, ADC can be used as an imaging biomarker of myopathic changes in liver cirrhosis.
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Marissa, Risa, Rachmi Fauziah Rahayu, Hari Wujoso, Subandi Subandi, Prasetyo Sarwono Putro e Widiastuti Soewondo. "The diagnostic value of apparent diffusion coefficient to differentiate benign and malignant meningiomas". Universa Medicina 40, n. 2 (26 luglio 2021): 141–50. http://dx.doi.org/10.18051/univmed.2021.v40.141-150.
Abstract (sommario):
BACKGROUNDMeningiomas are the most common primary extra-axial non-glial intracranial tumors. The severe grade of meningioma, according to WHO, has the highest recurrence rate accompanied by high morbidity and mortality rates. Therefore, it is imperative to perform pre-operative assessments so the clinician can give prompt treatment to gain a better prognosis. It is a novel alternative way of predicting meningioma’s malignancy by calculating the tumor’s apparent diffusion coefficient (ADC) value. The objective of the study was to determine the value of ADC for differentiating benign and malignant meningiomas. METHODSThis cross-sectional study involved 32 subjects with clinically diagnosed or histologically verified meningioma (21 benign and 11 malignant). They underwent a head-magnetic resonance imaging (MRI) examination and biopsy. We calculated the ADC value by creating regions of interest (ROIs) on the solid part of the tumor, guided by contrast and fluid-attenuated inversion recovery (FLAIR) sequence. We analyzed the ADC value with independent t-test and Bland-Altman graphs, calculated the average difference, CI 95%, limit of agreement between observers, and ROC. RESULTSMean ADC of malignant meningiomas (0.877 ± 0.167 x 10-3 mm2/s) was significantly lower than that of benign meningiomas (0.990 ± 0.105 x 10-3 mm2/s) (p<0.05). The ADC threshold is 0.886 x 10-3 mm2/s with sensitivity 63.6%, specificity 85.7%, positive predictive value 70% and negative predictive value 81.8%. CONCLUSIONThe ADC value measurement provides a discriminative feature to differentiate between benign and malignant meningiomas. However, the clinical applicability still needs to be elucidated, as histopathological confirmation remains the mainstay of definitive diagnosis.
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Iqbal, Bushra, Nadia Gul, Khalid Mehmood, Sobia Jawwad, Kanza Afzal e Muhammad Yousaf. "Diagnostic Accuracy of Apparent Diffusion Coefficient Value in Differentiating Benign and Malignant Brain Lesions Keeping Histopathology as Gold Standard". Life and Science 4, n. 2 (14 aprile 2023): 06. http://dx.doi.org/10.37185/lns.1.1.299.
Abstract (sommario):
Objective: The purpose of this study was to assess the competence of preoperative Apparent Diffusion Coefficient (ADC) values in predicting brain tumors as benign or malignant, keeping histopathology as the gold standard.Study Design: Cross-sectional study.Place and Duration of Study: The study was carried out at the Department of Diagnostic Radiology, POF Hospital, Wah Cantt, Pakistan, from December 12th 2020 to June 9th 2021.Materials and Methods: The apparent diffusion coefficient (ADC) sequence is based on the diffusion properties of water molecules within tissues and correlates with tissue cellularity. ADC may have a role in predicting tumor grade for gliomas and may in turn, assist in identifying tumor biopsy sites.A total of 140 patients were enrolled in the study. In all the images, the slice thickness was taken as 3mm, and the slice gap of 10. The mean age of the patients was 46.5±14.0 years. Males were predominant. The mean BMI was 26.8±5.5 kg/m2, and the mean duration of symptoms was 2.0±1.4 months.Results: The mean age of the patients enrolled in the study was 46.5±14.0 years. Males were predominant; there were 85 males (60.7%) and 55 females (39.3%). The mean duration of symptoms was 2.0±1.4 months. A history of chronic headache was found in 100 patients (71.4%), a history of seizures in 20 (14.3%), and a history of focal deficit was present in 111 patients (79.3%). Apparent diffusion coefficient (ADC) value in differentiating benign and malignant brain lesions showed sensitivity 77.5%, specificity 91.6%, PPV 92.5%, NPV 75.3% and diagnostic accuracy 83.5%.Conclusion: Overall, malignant brain lesions display lower ADC values than benign ones. Apparent diffusion coefficient (ADC) values improved our abilities to differentiate benign from malignant brain lesions.
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Chen, Peiqian, Bing Dong, Chunye Zhang, Xiaofeng Tao, Pingzhong Wang e Ling Zhu. "The histogram analysis of apparent diffusion coefficient in differential diagnosis of parotid tumor". Dentomaxillofacial Radiology 49, n. 5 (luglio 2020): 20190420. http://dx.doi.org/10.1259/dmfr.20190420.
Abstract (sommario):
Objectives: Use apparent diffusion coefficient (ADC) histogram to investigate whether the parameters of ADC histogram can distinguish between benign and malignant tumors and further differentiate the tumor subgroups. Methods and materials: This study retrospectively enrolls 161 patients with parotid gland tumors. Histogram parameters including mean, inhomogeneity, skewness, kurtosis and 10th, 25th, 50th, 75th, 90th percentiles are derived from ADC mono-exponential model. Mann–Whitney U test is used to compare the differences between benign and malignant groups. Kruskal–Wallis test with post-hoc Dunn–Bonferroni method is used for subgroup classification, then receiver operating characteristic curve analysis is performed in mean ADC value to obtain the appropriate cutoff values. Results: Except for kurtosis and 90th percentile, there are significant differences in all other ADC parameters between benign and malignant groups. In subgroup classification of benign tumors, there are significant differences in all ADC parameters between pleomorphic adenoma and Warthin’s tumor (area under curve 0.988; sensitivity 93.8%; specificity 94.7%; all ps < 0.05). Pleomorphic adenoma has high value in mean than basal cell adenoma (area under curve 0.819; sensitivity 76.9%; specificity 76.9%; p < 0.05). Basal cell adenoma has high values in mean (area under curve 0.897; sensitivity 92.3%; specificity 78.9%; all ps < 0.05) and 10th, 25th, 50th percentiles than Warthin’s tumor. In subgroup classification of malignant tumors, low-risk parotid carcinomas have higher values than hematolymphoid tumors in mean (area under curve 0.912; sensitivity 84.6%; specificity 100%, all ps < 0.05) and 10th, 25th percentiles. Conclusion: ADC histogram parameters, especially mean and 10th, 25th percentiles, can potentially be an effective indicator for identifying and classifying parotid tumors.
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Taffel, Myles T., Lyndon Luk, Justin M. Ream e Andrew B. Rosenkrantz. "Exploratory Study of Apparent Diffusion Coefficient Histogram Metrics in Assessing Pancreatic Malignancy". Canadian Association of Radiologists Journal 70, n. 4 (novembre 2019): 416–23. http://dx.doi.org/10.1016/j.carj.2019.07.001.
Abstract (sommario):
Purpose To evaluate whole-lesion 3D-histogram apparent diffusion coefficient (ADC) metrics for assessment of pancreatic malignancy. Methods Forty-two pancreatic malignancies (36 pancreatic adenocarcinoma [PDAC], 6 pancreatic neuroendocrine [PanNET]) underwent abdominal magnetic resonance imaging (MRI) with diffusion-weighted imaging before endoscopic ultrasound biopsy or surgical resection. Two radiologists independently placed 3D volumes of interest to derive whole-lesion histogram ADC metrics. Mann-Whitney tests and receiver operating characteristic analyses were used to assess metrics’ diagnostic performance for lesion histology, T-stage, N-stage, and grade. Results Whole-lesion ADC histogram metrics lower in PDACs than PanNETs for both readers ( P ≤ .026) were mean ADC (area under the curve [AUC] = 0.787-0.792), mean of the bottom 10th percentile (mean0-10) (AUC = 0.787-0.880), mean of the 10th-25th percentile (mean10-25) (AUC = 0.884-0.917) and mean of the 25th-50th percentile (mean25-50) (AUC = 0.829-0.829). For mean10-25 (metric with highest AUC for identifying PDAC), for reader 1 a threshold > 0.94 × 10−3 mm2/s achieved sensitivity 94% and specificity 83%, and for reader 2 a threshold > 0.82 achieved sensitivity 97% and specificity 67%. Metrics lower in nodal status ≥ N1 than N0 for both readers ( P ≤ .043) were mean0-10 (AUC = 0.789-0.822) and mean10-25 (AUC = 0.800-0.822). For mean10-25 (metric with highest AUC for identifying N0), for reader 1 a threshold <1.17 achieved sensitivity 87% and specificity 67%, and for reader 2 a threshold <1.04 achieved sensitivity 87% and specificity 83%. No metric was associated with T-stage ( P > .195) or grade ( P > .215). Conclusion Volumetric ADC histogram metrics may serve as non-invasive biomarkers of pancreatic malignancy. Mean10-25 outperformed standard mean for lesion histology and nodal status, supporting the role of histogram analysis.
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OĞUZMAN, Mehmet, Cüneyt ÇALIŞIR e Ulukan İNAN. "DIFFUSION WEIGHTED IMAGING OF SOFT TISSUE MASSES: CAN APPARENT DIFFUSION COEFFICIENT MEASUREMENT DIFFERENTIATE BETWEEN MALIGNANT AND BENIGN LESIONS ?" Kocatepe Tıp Dergisi 24, n. 4 (26 febbraio 2023): 481–87. http://dx.doi.org/10.18229/kocatepetip.1122866.
Abstract (sommario):
AMAÇ: Yumuşak doku tümörlerinin değerlendirilmesinde di-füzyon ağırlıklı görüntüleme (DAG) yöntemi ile elde olunan gö-rünür difüzyon katsayısı (apparent diffusion coefficient, ADC) haritalamasının benign ve malign lezyonların ayrımında etkinli-ğini değerlendirmek ve bu lezyonların ayrımında kullanılabile-cek niceliksel ADC eşik değeri oluşturmak.GEREÇ VE YÖNTEM: Bu retrospektif çalışmaya yumuşak doku kitleleri nedeniyle DAG yapılan ve histopatolojik sonuçları mevcut olan toplam 34 hasta dahil edildi. Patolojik sonuçlarına göre hastalar benign ve malign lezyonlara sahip olarak katego-rize edildi. Ölçümler serbest el ilgi bölgesi tekniği kullanılarak yapıldı. Değerlendirilen parametrelerde herhangi bir fark olup olmadığı araştırıldı (boyut, yaş, cinsiyet, minimum, ortalama ve maksimum ADC değerleri). DAG’de değerlendirilen parametre-ler için kesim değeri Alıcı işlem karakteristikleri (ROC), Receiver Operating Characteristic) analizi ile belirlendi. BULGULAR: Minimum ADC değeri ortalaması benign yumuşak doku kitlelerinde 1,28x10-³mm²/s, malign yumuşak doku kit-lelerinde 1,00x10-³mm²/s ölçüldü. Minimum ADC değerleri iki grup arasında istatistiksel olarak anlamlı farklılık göstermekte-dir (p=0,007). Minimum ADC için ≤1,01x10-³mm²/s eşik değerini kullanarak %78,95 duyarlılık ve %73,33 özgüllük ile yumuşak doku kitlelerini karakterize edilmesini sağladık. Ortalama ve maksimum ADC değerleri iki grup arasında istatistiksel olarak anlamlı farklılığa sahip değildir (sırasıyla p=0,319; 0,960). SONUÇ: DAG yumuşak doku kitlelerin değerlendirilmesinde benign ve malign ayrımında etkili bir yöntemdir ve minimum ADC hesaplamasında ≤1,01x10-³mm²/s eşik değerinin kullanımı klinik yararlılığı artıracaktır.
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Vora, Zainab, Smita Manchanda, Raju Sharma, Chandan Jyoti Das, Smriti Hari, Sandeep Mathur, Sunesh Kumar, Garima Kachhawa e Maroof Ahmad Khan. "Normalized apparent diffusion coefficient: a novel paradigm for characterization of endometrial and subendometrial lesions". British Journal of Radiology 94, n. 1117 (1 gennaio 2021): 20201069. http://dx.doi.org/10.1259/bjr.20201069.
Abstract (sommario):
Objectives: To assess the role of normalized apparent diffusion coefficient (ADC) in characterization of endometrial and subendometrial masses, measured as a ratio of the mean ADC of the pathology to mean ADC of two different internal controls, normal myometrium and gluteus maximus muscle, referred to as nADCm and nADCg respectively. Methods: 55 females with pathologically proven endometrial and subendometrial lesions, including 27 cases of endometrial carcinoma, and 28 cases of benign masses were enrolled in this prospective study and assessed with single-shot echoplanar diffusion-weighted imaging. The normalized and absolute ADC of the lesions, measured by two radiologists, were compared in different pathologies and receiver operating characteristics (ROC) performed to distinguish benign and malignant endometrial masses. In the endometrial carcinoma group, the ADC values were further compared with tumor grade and subtype. Results: There was good interobserver agreement (>0.800) for both internal controls, however it was higher for myometrium [intraclass correlation coefficient-0.92; confidence interval (0.86–0.95)] than gluteus maximus muscle [ICC-0.84; CI (0.72–0.90)]. There were statistically significant differences in absolute ADC (p-0.02), nADCm (p-0.02) and nADCg (p < 0.0001) of benign and malignant endometrial masses. Conclusion: Normalized ADC is useful to distinguish benign and malignant masses with comparable accuracy as absolute ADC. Advances in knowledge: Normalized ADC represents an easily measurable quantitative parameter which limits the influence of endogenous and exogenous factors that affect its reproducibility.
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Ripp, V. O., P. E. Menshchikov, D. A. Kupriyanov, P. A. Bulanov, K. A. Sergunova, D. S. Semenov, T. P. Berezovskaya, S. A. Ivanov e A. D. Kaprin. "Possibilities of Using DWIBS for Clinical Tasks with the Measurement of the Apparent Diffusion Coefficient". Meditsinskaya Fizika 94, n. 2 (12 luglio 2022): 76–84. http://dx.doi.org/10.52775/1810-200x-2022-94-2-76-84.
Abstract (sommario):
Additional suppression of the background signal in diffusion-weighted images (DWIBS) allows to get more contrast images to highlight areas with restricted diffusion, for example, in many malignant primary and metastatic tumors. Due to fundamental differences in DWIBS and DWI acquisition, the apparent diffusion coefficient (ADC) values may differ, which could negatively affect attempts to compare with the available literature data or with conventional DWI studies. Purpose. Evaluation of the correctness of the calculation of the ADC values based on DWIBS images, compared to regular DWI. Material and methods. A comparative analysis of the ADC values obtained using DWIBS and conventional DWI on an MR-compatible phantom and on 20 healthy volunteers was carried out. Free breathing DWIBS as well as DWI with breath synchronization were acquired using 1.5 T MRI scanner. Results and discussion. ADC values measured with DWIBS and DWI were found to coincides well both for the phantom and for the volunteers in all the areas (vertebra, kidney, spleen), except for the liver, where the ADC values obtained from DWIBS images were 11 % lower than with standard DWI (1.06 vs 0.92 mm2/s). This may be due to the greater displacement of the liver during respiratory movements. The advantages of the DWIBS technique include a significant decrease in scan time (1.5-2 times with a 10 % decrease in signal-to-noise ratio compared to routine DWI), which allows for a quantitative analysis of ADC values in a whole-body scan in a comfortable timing for the patient. Conclusion. DWIBS can be recommended for calculating ADC values, however, a comparative analysis of ADC values in organs and tissues exposed to strong respiratory movements require additional assessments of repeatability and reproducibility directly when comparing areas with a strongly pronounced diffusion restriction.
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Xue, Jun Lai, Meng Chao Zhang, Mao Hua Zhang, Dong Tong e Wu Qiang. "Study of Multi-b-Value Diffusion-Weighted Imaging at 3.0 T for Measuring Renal Function of Patients with Chronic Renal Failure". Advanced Materials Research 998-999 (luglio 2014): 320–24. http://dx.doi.org/10.4028/www.scientific.net/amr.998-999.320.
Abstract (sommario):
To investigate the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted imaging (DWI) on a 3.0T MR unit and glomerular filtration rate (GFR) determined by renal imaging using Nuclear Medicine 99 Tcm-DTPA. 3.0T MRI DWI and 99 Tcm-DTPA renal imaging were simultaneously performed in 30 patients with chronic renal failure. The b values set for DWI imaging were 0, 200, 400, 600, 800 and 1000 s/mm2 and the ADC values of renal cortex were measured. 60 kidneys from the patients were classified into three groups according to the measurements of GFR: mildly impaired renal function, moderately impaired renal function and severely impaired renal function. ADC values of the three groups were compared to determine whether there existed statistic difference and the correlation between ADC values and GFR was also measured. Statistical difference was found in ADC values of the three groups and a positive correlation was identified between ADC values and GFR (r = 0.623). Multi-b-value diffusion-weighted MR imaging at 3.0 T can be used to assess renal filtration function.Abbreviation used: DWI, diffusion-weighted imaging; ADC, apparent diffusion coefficient; GFR, glomerular filtration rate; NEX, number of excitation.
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Endo, Toshiki, Shinsuke Suzuki, Akihiro Utsunomiya, Hiroshi Uenohara e Teiji Tominaga. "Prediction of Neurological Recovery Using Apparent Diffusion Coefficient in Cases of Incomplete Spinal Cord Injury". Neurosurgery 68, n. 2 (1 febbraio 2011): 329–36. http://dx.doi.org/10.1227/neu.0b013e3182031ce7.
Abstract (sommario):
Abstract BACKGROUND: Magnetic resonance imaging is useful in evaluating acute spinal cord injury. Apparent diffusion coefficient (ADC) values obtained by diffusion-weighted imaging can differentiate cytotoxic edema from vasogenic edema through microscopic motion of water protons. OBJECTIVE: To determine whether ADC values in the cervical spinal cord match neurological grades and thus predict functional recovery in patients suffering from cervical spinal cord injury. METHODS: Diffusion-weighted images were obtained using 15 axial slices covering the cervical spinal cord from 16 consecutive patients. ADC values were determined for both gray and white matter. All patients were treated surgically. Patient neurological status was evaluated preoperatively and postoperatively with the Frankel classification and neurosurgical cervical spine scale. One patient had complete spinal cord injury and showed no recovery. Using 15 patients with incomplete injury, we analyzed correlations between preoperative ADC values and neurological grading, degree of postoperative recovery, or cavity formation in follow-up magnetic resonance images. For comparison, ADC values of 11 healthy volunteers were also calculated. RESULTS: There was significant correlation between ADC values and degree of postoperative recovery (P = .02). ADC values of patients showing cavity formation were significantly lower than those of patients without cavity formation (0.70 vs 0.96 × 10−3 mm2/s; P = .01). The cutoff ADC value of 0.80 × 10−3 mm2/s resulted in 75% sensitivity and 81.8% specificity for predicting cavity formation. CONCLUSION: Low ADC values in acute spinal cord injury may indicate postoperative cavity formation in the injured spinal cord and predict poor functional recovery.
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Georgiev, Aleksandar, Lyubomir Chervenkov, Mladen Doykov, Katya Doykova, Petar Uchikov e Silvia Tsvetkova. "Surveillance Value of Apparent Diffusion Coefficient Maps: Multiparametric MRI in Active Surveillance of Prostate Cancer". Cancers 15, n. 4 (10 febbraio 2023): 1128. http://dx.doi.org/10.3390/cancers15041128.
Abstract (sommario):
Background: This study aims to establish the value of apparent diffusion coefficient maps and other magnetic resonance sequences for active surveillance of prostate cancer. The study included 530 men with an average age of 66, who were under surveillance for prostate cancer. We have used multiparametric magnetic resonance imaging with subsequent transperineal biopsy (TPB) to verify the imaging findings. Results: We have observed a level of agreement of 67.30% between the apparent diffusion coefficient (ADC) maps, other magnetic resonance sequences, and the biopsy results. The sensitivity of the apparent diffusion coefficient is 97.14%, and the specificity is 37.50%. According to our data, apparent diffusion coefficient is the most accurate sequence, followed by diffusion imaging in prostate cancer detection. Conclusions: Based on our findings we advocate that the apparent diffusion coefficient should be included as an essential part of magnetic resonance scanning protocols for prostate cancer in at least bi-parametric settings. The best option will be apparent diffusion coefficient combined with diffusion imaging and T2 sequences. Further large-scale prospective controlled studies are required to define the precise role of multiparametric and bi-parametric magnetic resonance in the active surveillance of prostate cancer.
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Mihailovic, Jelena, Danica Grujicic, Slobodan Lavrnic e Marko Dakovic. "The application of the local histograms of apparent difusion coefficient in differentiation of brain astrocytomas". Vojnosanitetski pregled 76, n. 4 (2019): 385–91. http://dx.doi.org/10.2298/vsp161215103m.
Abstract (sommario):
Background/Aim. Microstructural diversity of brain astrocytomas makes their diagnostics and differentiation by using the diffusion weighted imaging (DWI) difficult. In this study we used the histogram-based positioning of regions of interests on the apparent diffusion coefficient (ADC) maps in order to restrict the determination of diffusion parameters to regions of interest (ROI) corresponding to maximum cellularity. Success of ADC standard deviation (?ADC) and kurtosis (K) in differentiation of brain astrocytomas was evaluated. Methods. The thirtyone patients (16 women and 15 men, median age 37 years, age range 6?72 years) with suspected supratentorial astrocytomas were included in the retrospective study. The magnetic resonance imaging (MRI) examinations were performed using the 1.5 T MR system (Avanto; Siemens, Erlangen, Germany) and 8-channel phased array head coil. The DWI images were acquired in three orthogonal directions for the b-values 0, 500 and 1000 s mm-2. The histogram calculations and determination of diffusion parameters were performed using the MIPAV software package and the statistical analysis was done in the Openstat software. Results. The ADC values enabled differentiation of diffuse astrocytomas (DA) from a high-grade astrocytoma (HGA), but not between the classes of HGA. In addition, the ?ADC value provided discrimination between the anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) with 100% of sensitivity and 89% of specificity . The kurtosis value can also differentiate between the grades AA and GBM although with the lower sensitivity and specificity. Conclusion. The histogram analysis of tumor region on the ADC maps can provide a guidance for an appropriate choice of the ROIs. The parameters which characterize diffusion of such defined ROIs, as well as their combination can improve differentiation of brain astrocytomas.
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Ragheb, Ahmad Sabry, Hossam Mansour Abdel Rahman, Ahmed A. Azeem Ismail e Nashwa Nawar. "Can diffusion weighted image and apparent diffusion coefficient (ADC) differentiate benign from malignant cervical adenopathy?" Egyptian Journal of Radiology and Nuclear Medicine 45, n. 2 (giugno 2014): 377–86. http://dx.doi.org/10.1016/j.ejrnm.2014.01.016.
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Prokhorov, S. N., N. V. Kochergina, A. D. Ryzhkov, A. S. Krylov e A. B. Bludov. "The Apparent Diffusion Coefficient in the Diagnosis of Metastatic Lesions of Skeletal Bones". MEDICAL RADIOLOGY AND RADIATION SAFETY 68, n. 6 (dicembre 2023): 80–85. http://dx.doi.org/10.33266/1024-6177-2023-68-6-80-85.
Abstract (sommario):
Aim: To evaluate the possibilities of absolute and relative values of the apparent diffusion coefficient (ADC) in the diagnosis of metastatic lesions of skeletal bones. Material and methods: The study included 12 patients with metastatic bone lesions, before any treatment was applied. The age of the patients ranged from 38 to 73 years, 3 men, 9 women. Among the morphological forms of tumors were presented: cancers of the breast (3), prostate (1) glands, colon (1), lung (2), body (1) and cervix (1) uterus, thyroid (1) and pancreas (2). The detected changes were classified on the basis of Bone scan, SPECT/CT and standard MRI. The ADC values of unchanged bone marrow (n=360), divided by anatomical zones, metastatic foci (n=117), as well as benign changes of various nature (n=19) were analyzed. The ratio of the ADC values of each of the metastatic and benign focal formations to the normal values for each of the localizations was calculated. Results: Unchanged bone marrow, depending on anatomical localization (cervical, thoracic, lumbar spine, pelvic bones, shoulder blades, collarbones, sternum, ribs, proximal humerus and femur bones) from the point of view of ADC, showed statistically significant heterogeneity. Statistical analysis has shown that there is no connection between the groups of ADC indicators in the foci of metastatic lesions, combined depending on the anatomical localization. With a similar comparison, but by belonging to the primary tumor, an even greater intergroup difference was found. ADC values in the foci of metastatic lesions turned out to be dependent on the morphological type of the primary tumor and significantly differ both from metastases of other morphological affiliation and from normal red bone marrow parameters. The use of relative values allowed to increase the specificity from 15 to 19 %. Conclusion: This study showed that knowledge of the range of reference ADC values for unchanged red bone marrow and anomalies of various genesis is important in differential diagnosis. The differentiation of the skeleton into separate anatomical zones probably makes it possible to increase the effectiveness of the isolated application of the technique when it comes to absolute values. The morphological affiliation of metastatic foci is important in the formation of ADC values, rather than the bone marrow microenvironment, which is also supported by the low efficiency of the use of relative values.
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Wouters, Anke, Lauranne Scheldeman, Sam Plessers, Ronald Peeters, Sarah Cappelle, Philippe Demaerel, Wim Van Paesschen et al. "Added Value of Quantitative Apparent Diffusion Coefficient Values for Neuroprognostication After Cardiac Arrest". Neurology 96, n. 21 (9 aprile 2021): e2611-e2618. http://dx.doi.org/10.1212/wnl.0000000000011991.
Abstract (sommario):
ObjectiveTo test the prognostic value of brain MRI in addition to clinical and electrophysiologic variables in patients post–cardiac arrest (CA), we explored data from the randomized Neuroprotect Post-CA trial (NCT02541591).MethodsIn this trial, brain MRIs were prospectively obtained. We calculated receiver operating characteristic (ROC) curves for the average apparent diffusion coefficient (ADC) value and percentage of brain voxels with an ADC value <650 × 10−6 mm2/s and <450 × 10−6 mm2/s. We constructed multivariable logistic regression models with clinical characteristics, EEG, somatosensory evoked potentials (SSEP), and ADC value as independent variables to predict good neurologic recovery.ResultsIn 79/102 patients, MRI data were available and in 58/79 patients all other data were available. At 180 days post-CA, 25/58 (43%) patients had good neurologic recovery. In univariable analysis of all tested MRI measures, average ADC value in the postcentral cortex had the highest accuracy to predict good neurologic recovery, with an area under the ROC curve (AUC) of 0.78. In the most optimal multivariable model, which also included corneal reflexes and EEG, this measure remained an independent predictor of good neurologic recovery (AUC 0.96, false-positive 27%). This model provided a more accurate prediction compared to the most optimal combination of EEG, corneal reflexes, and SSEP (p = 0.03).ConclusionsAdding information on brain MRI in a multivariable model may improve the prediction of good neurologic recovery in patients post-CA.Classification of EvidenceThis study provides Class III evidence that MRI ADC features predict neurologic recovery in patients post-CA.