scholarly journals A nonstandard smoothing in reconstruction of apparent diffusion coefficient profiles from diffusion weighted images

2008 ◽  
Vol 2 (2) ◽  
pp. 205-224 ◽  
Author(s):  
Yunmei Chen ◽  
◽  
Weihong Guo ◽  
Qingguo Zeng ◽  
Yijun Liu ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Apparent Diffusion

Prostate Cancer: Comparison of Tumor Visibility on Trace Diffusion-Weighted Images and the Apparent Diffusion Coefficient Map

2011 ◽  
Vol 196 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Andrew B. Rosenkrantz ◽  
Xiangtian Kong ◽  
Benjamin E. Niver ◽  
Douglas S. Berkman ◽  
Jonathan Melamed ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Apparent Diffusion

scholarly journals Role of MR Morphology and Diffusion-Weighted Imaging in the Evaluation of Meningiomas: Radio-Pathologic Correlation

2019 ◽  
Vol 57 (215) ◽  
Author(s):  
Kajan Ranabhat ◽  
Suresh Bishokarma ◽  
Prity Agrawal ◽  
Pratyush Shrestha ◽  
Ram Kumar Ghimire ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Histological Grade ◽  
Cross Sectional ◽  
Who Grade ◽  
Adc Value ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Brain Interface

Introduction: Preoperative differentiation of benign, atypical and malignant meningiomas would significantly help in surgical planning and treatment. The aim of this study is to look at radio- morphologic behavior of various histopathological types and grades of meningiomas and their diffusion characteristics.Methods: We performed an analytical cross-sectional study including all patients operated on for meningiomas at our hospital during January 2016 to July 2018. We studied 38 meningiomas in 38 patients aged 14 to 73 years old. All patients underwent MRI prior to surgery, including diffusion- weighted sequences, in a 1.5T scanner. Signal intensity in T2-weighted images, diffusion-weighted images (b=0, 90 and 1,000), and Apparent Diffusion Coefficient maps within the tumors and in the normal parietal white matter as a reference were evaluated. Results: There was female predilection with male:female ratio of 1:2.4. Most meningiomas were supratentorial with most common origin being parafalcine and convexity. Of the 38 meningiomas, 31 were WHO grade I, 6 were WHO grade II (apalstic) and one was WHO grade III (anaplastic). Similarly, tumors showing pial invasion, breached tumor-brain interface, no capsular enhancement and parenchyma invasion showed significantly low NADC. Mean ADC value was 0.722±7.7x10-3 mm2/s (normalized ADC 0.9±0.1) in the atypical group and 0.876±24.56x10-3 mm2/s (normalized ADC 1.11±0.31) in the typical group. No statistically significant differences of ADC/NADC were found between histologic subtypes. Two subtypes of typical meningiomas, metaplastic and angiomatous meningioma had the highest values in the ADC maps.Conclusions: MR morphology like pial invasion, breached tumors brain interface, parenchymal invasion can predict aggressiveness and atypical nature of meningiomas. Meningioma shows moderately restricted diffusion. The signal on the ADC map is associated with tumors cellularity and aggressiveness suggesting its usefulness for predicting the histological grade. Keywords: apparent diffusion coefficient; atypical; histopathology; meningioma; MR morphology.

scholarly journals Semi-Automated Segmentation of Bone Metastases from Whole-Body MRI: Reproducibility of Apparent Diffusion Coefficient Measurements

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 499
Author(s):  
Alberto Colombo ◽  
Giulia Saia ◽  
Alcide A. Azzena ◽  
Alice Rossi ◽  
Fabio Zugni ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Bone Metastases ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Whole Body ◽  
Whole Body Mri ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Apparent Diffusion

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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