scholarly journals Synthetic apparent diffusion coefficient for high b-value diffusion weighted MRI in Prostate

2019 ◽  
Author(s):  
Prativa Sahoo ◽  
Russell Rockne ◽  
Jung Alexander ◽  
Pradeep K Gupta ◽  
Rakesh K Gupta

AbstractPurposeIt has been reported that diffusion weighted imaging (DWI) with ultrahigh b-value increases the diagnostic power of prostate cancer. DWI imaging 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 MethodsFifteen patient (7 malignant, 8 benign) with prostate cancer were included in this study retrospectively with the institutional ethical committee approval. All images were acquired at 3T MR scanner. The ADC values were calculated using mono-exponential model. Synthetic ADC (sADC) for higher b-value were 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.ResultsNo 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 lesion (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 (10−3mm2/s).Discussion / ConclusionOur 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 clinician to decide the optimal b-value for prostate lesion identification.

2017 ◽  
Vol 58 (12) ◽  
pp. 1528-1534 ◽  
Author(s):  
Liu Xiaohang ◽  
Zhou Bingni ◽  
Zhou Liangping ◽  
Peng Weijun ◽  
Yang Xiaoqun ◽  
...  

Background Prostate cancer and stromal hyperplasia (SH) in the transition zone (TZ) are difficult to discriminate by conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). Purpose To investigate the apparent diffusion coefficient (ADC) of prostate cancer and SH in the TZ with histogram analysis and the ability of ADC metrics to differentiate between these two tissues. Material and Methods Thirty-three cancer and 29 SH lesions in the TZ of 54 patients undergoing preoperative DWI (b-value 0, 1000 s/mm2) were analyzed. All the lesions on the MR images were localized based on histopathologic correlations. The 10th, 25th, and 50th percentiles, and the mean ADC values were calculated for the two tissues and compared. The efficiencies of the 10th, 25th, and 50th ADC percentiles in differentiating the two tissues were compared with that of the mean ADC with receiver operating characteristic (ROC) analysis. Results The 10th, 25th, and 50th percentiles and mean ADC values (×10−3 mm2/s) were 0.86 ± 0.15, 0.89 ± 0.16, 0.94 ± 0.16, and 1.03 ± 0.17 in SH and 0.64 ± 0.12, 0.69 ± 0.12, 0.72 ± 0.16, and 0.83 ± 0.15 in TZ cancer, respectively. The parameters were all significantly lower in cancer than SH. The 10th ADC percentile yielded an area under the ROC curve (AUC) of 0.87 for the differentiation of carcinomas from SH, which was higher than the mean ADC (0.80) ( P < 0.05), and the AUCs of the 25th (0.82) and 50th (0.83) percentiles exhibited no differences from those of the mean ADC ( P > 0.05). Conclusion Histogram analysis of ADC values may potentially improve the differentiation of prostate cancer from SH in the TZ.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Prativa Sahoo ◽  
Russell C. Rockne ◽  
Alexander Jung ◽  
Pradeep K Gupta ◽  
Ram K. S. Rathore ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Shayan Sirat Maheen Anwar ◽  
Zahid Anwar Khan ◽  
Rana Shoaib Hamid ◽  
Fahd Haroon ◽  
Raza Sayani ◽  
...  

Purpose. To determine association between apparent diffusion coefficient value on diffusion-weighted imaging and Gleason score in patients with prostate cancer. Methods. This retrospective case series was conducted at Radiology Department of Aga Khan University between June 2009 and June 2011. 28 patients with biopsy-proven prostate cancer were included who underwent ultrasound guided sextant prostate biopsy and MRI. MRI images were analyzed on diagnostic console and regions of interest were drawn. Data were entered and analyzed on SPSS 20.0. ADC values were compared with Gleason score using one-way ANOVA test. Results. In 28 patients, 168 quadrants were biopsied and 106 quadrants were positive for malignancy. 89 lesions with proven malignancy showed diffusion restriction. The mean ADC value for disease with a Gleason score of 6 was 935 mm2/s (SD=248.4 mm2/s); Gleason score of 7 was 837 mm2/s (SD=208.5 mm2/s); Gleason score of 8 was 614 mm2/s (SD=108 mm2/s); and Gleason score of 9 was 571 mm2/s (SD=82 mm2/s). Inverse relationship was observed between Gleason score and mean ADC values. Conclusion. DWI and specifically quantitative ADC values may help differentiate between low-risk (Gleason score, 6), intermediate-risk (Gleason score, 7), and high-risk (Gleason score 8 and 9) prostate cancers, indirectly determining the aggressiveness of the disease.


BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Alexey Surov ◽  
Hans Jonas Meyer ◽  
Andreas Wienke

Abstract Background The purpose of the present meta-analysis was to provide evident data about use of Apparent Diffusion Coefficient (ADC) values for distinguishing malignant and benign breast lesions. Methods MEDLINE library and SCOPUS database were screened for associations between ADC and malignancy/benignancy of breast lesions up to December 2018. Overall, 123 items were identified. The following data were extracted from the literature: authors, year of publication, study design, number of patients/lesions, lesion type, mean value and standard deviation of ADC, measure method, b values, and Tesla strength. The methodological quality of the 123 studies was checked according to the QUADAS-2 instrument. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used without any further correction to account for the heterogeneity between the studies. Mean ADC values including 95% confidence intervals were calculated separately for benign and malign lesions. Results The acquired 123 studies comprised 13,847 breast lesions. Malignant lesions were diagnosed in 10,622 cases (76.7%) and benign lesions in 3225 cases (23.3%). The mean ADC value of the malignant lesions was 1.03 × 10− 3 mm2/s and the mean value of the benign lesions was 1.5 × 10− 3 mm2/s. The calculated ADC values of benign lesions were over the value of 1.00 × 10− 3 mm2/s. This result was independent on Tesla strength, choice of b values, and measure methods (whole lesion measure vs estimation of ADC in a single area). Conclusion An ADC threshold of 1.00 × 10− 3 mm2/s can be recommended for distinguishing breast cancers from benign lesions.


2018 ◽  
Vol 10 (12) ◽  
pp. 359-364
Author(s):  
Andrew McPartlin ◽  
Lucy Kershaw ◽  
Alan McWilliam ◽  
Marcus Ben Taylor ◽  
Clare Hodgson ◽  
...  

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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