Faculty Bibliography

OBJECTIVE:The purpose of this study was to compare image quality and tumor assessment at prostate magnetic resonance imaging (MRI) between reduced field-of-view diffusion-weighted imaging (rFOV-DWI) and standard DWI (st-DWI). METHODS:A total of 49 patients undergoing prostate MRI and MRI/ultrasound fusion-targeted biopsy were included. Examinations included st-DWI (field of view [FOV], 200 × 200 mm) and rFOV-DWI (FOV, 140 × 64 mm) using a 2-dimensional (2D) spatially-selective radiofrequency pulse and parallel transmission. Two readers performed qualitative assessments; a third reader performed quantitative evaluation. RESULTS:Overall image quality, anatomic distortion, visualization of capsule, and visualization of peripheral/transition zone edge were better for rFOV-DWI for reader 1 (P ≤ 0.002), although not for reader 2 (P ≥ 0.567). For both readers, sensitivity, specificity, and accuracy for tumor with a Gleason Score (GS) of 3 + 4 or higher were not different (P ≥ 0.289). Lesion clarity was higher for st-DWI for reader 2 (P = 0.008), although similar for reader 1 (P = 0.409). Diagnostic confidence was not different for either reader (P ≥ 0.052). Tumor-to-benign apparent diffusion coefficient ratio was not different (P = 0.675). CONCLUSIONS:Potentially improved image quality of rFOV-DWI did not yield improved tumor assessment. Continued optimization is warranted.

Prostate MRI is commonly used in the detection of prostate cancer to reduce the detection of clinically insignificant disease; maximize the detection of clinically significant cancer; and better assess disease size, grade, and location. The clinical utility of MRI seems to apply to men with no prior biopsy, who have had a previous negative biopsy, and men who are candidate for active surveillance. In conjunction with traditional clinical parameters and secondary biomarkers, MRI may allow more accurate risk stratification and assessment of need for prostate biopsy.