Prostate Cancer Detection Using Computed Very High b-value Diffusion-weighted Imaging: How High Should We Go?

摘要: Rationale and Objectives The aim of this study was to assess prostate cancer detection using a broad range computed b-values up 5000 s/mm2. Materials Methods This retrospective Health Insurance Portability Accountability Act-compliant approved by an institutional review board with consent waiver. Forty-nine patients (63 ± 8 years) underwent 3T magnetic resonance imaging before prostatectomy. Examinations included diffusion-weighted (DWI) 50 1000 s/mm2. Seven DWI image sets (b-values: 1000, 1500, 2000, 2500, 3000, 4000, 5000 s/mm2) were generated mono-exponential fit. Two blinded radiologists (R1 [attending], R2 [fellow]) independently evaluated diffusion weighted for quality dominant lesion location. A separate unblinded radiologist placed regions interest measure tumor-to-peripheral zone (PZ) contrast. Pathologic findings from prostatectomy served as reference standard. Measures compared between the Jonckheere-Terpstra trend test, Spearman correlation coefficient, generalized estimating equations based on logistic regression correlated data. Results As b-value increased, tumor-to-PZ contrast benign suppression both readers increased (r = +0.65 +0.71, P ≤ 0.001), whereas anatomic clarity, visualization capsule, peripheral-transition edge decreased (r = −0.69 −0.75, P ≤ 0.003). Sensitivity tumor highest R1 at b1500–3000 (84%–88%) b1500–2500 (70%–76%). Sensitivities pathologic outcomes lower b1000 b-values. Gleason >6 (90%–93%) 1500–2500 (78%–80%). positive predictive value similar 4000 (93%–98%) b1500 (88%–94%). Conclusions Computed in 1500–2500 s/mm2 (but not higher) optimal detection; 1000 or 3000–5000 exhibited overall performance.