Purpose:To analyze the diffusion and perfusion parameters of central gland (CG) prostate cancer, stromal hyperplasia (SH), and glandular hyperplasia (GH) and to determine the role of these parameters in the differentiation of CG cancer from benign CG hyperplasia. Materials and Methods:In this institutional review board-approved (with waiver of informed consent), HIPAA-compliant study, 38 foci of carcinoma, 38 SH nodules, and 38 GH nodules in the CG were analyzed in 49 patients (26 with CG carcinoma) who underwent preoperative endorectal magnetic resonance (MR) imaging and radical prostatectomy. All carcinomas and hyperplastic foci on MR images were localized on the basis of histopathologic correlation. The apparent diffusion coeffi cient (ADC), the contrast agent transfer rate between blood and tissue (K trans ), and extravascular extracellular fractional volume values for all carcinoma, SH, and GH foci were calculated. The mean, standard deviation, 95% confi dence interval (CI), and range of each parameter were calculated. Receiver operating characteristic (ROC) and multivariate logistic regression analyses were performed for differentiation of CG cancer from SH and GH foci. Results:The average ADCs ( 3 10 2 3 mm 2 /sec) were 1.05 (95% CI: 0.97, 1.11), 1.27 (95% CI: 1.20, 1.33), and 1.73 (95% CI: 1.64, 1.83), respectively, in CG carcinoma, SH foci, and GH foci and differed signifi cantly, yielding areas under the ROC curve (AUCs) of 0.99 and 0.78, respectively, for differentiation of carcinoma from GH and SH. Perfusion parameters were similar in CG carcinomas and SH foci, with K trans yielding the greatest AUCs (0.75 and 0.58, respectively). Adding K trans to ADC in ROC analysis to differentiate CG carcinoma from SH increased sensitivity from 38% to 57% at 90% specifi city without noticeably increasing the AUC (0.79). Conclusion:ADCs differ signifi cantly between CG carcinoma, SH, and GH, and the use of them can improve the differentiation of CG cancer from SH and GH. Combining K trans with ADC can potentially improve the detection of CG cancer.

Purpose: To retrospectively determine the incremental value of diffusion-weighted MR-imaging (DW-MRI) to T2-weighted (T2w) images in diagnosis of internal fistulas (IFs) and sinus tracts (STs). Materials and Methods:Fourteen patients with 25 IFs and STs arising from the small bowel (20), colon (4) and biliary tract (1) were included. Two independent observers reviewed T2w images, T2wþDW-MRI images and T2wþcontrast enhanced T1-weighted (CE T1w) images at three sessions to detect IF/ST based on a confidence scale of five. Sensitivity and confidence score of each session was compared.Results: 10/25 (40%) and 9/25 (36%) IFs and STs were detected on T2w images by observer 1 and 2, respectively. Both observers detected 19/25 (76%) and 24/25(96%) IFs and STs on T2wþDW-MRI and T2wþCE T1w images, respectively. Detection rate and confidence score improved significantly by combining T2w images with DW-MRI or CE T1w images (reader 1 þ 2: P 0.01). There was no significant difference between the IF/ST detection rate of T2wþDW-MRI and T2wþCE T1 image combinations. Confidence scores with T2wþCE T1w images were significantly greater than DW-MRIþT2w images (reader 1:P ¼ 0.01; reader 2: P ¼ 0.03).Conclusion: DW-MRI showed additional value to T2w imaging for diagnosis of IF and ST. DW-MRI can be a useful adjunct, especially for patients with renal failure.

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Liver metastases are not a homogenous group of lesions with uniform DW-MRI features. Hypervascular metastases demonstrate significantly lower ADC values compared to hypovascular metastases. DW-MRI improved detection of hypervascular metastases compared to T2-w images alone and is a useful adjunct to T2-w images for their detection.