Dynamic Contrast -Enhanced MRI of the Prostate: An Intraindividual Assessment of the Effect of Temporal Resolution on Qualitative Detection and Quantitative Analysis of Histopathologically Proven Prostate Cancer

Purpose: To assess the effects of temporal resolution (RT) in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on qualitative tumor detection and quantitative pharmacokinetic parameters in prostate cancer. Materials and Methods: This retrospective Institutional Review Board (IRB)-approved study included 58 men (64 7 years). They underwent 3T prostate MRI showing dominant peripheral zone (PZ) tumors (24 with Gleason > 4 + 3), prior to prostatectomy. Continuously acquired DCE utilizing GRASP (Golden-angle RAdial Sparse Parallel) was retrospectively reconstructed at RT of 1.4 sec, 3.7 sec, 6.0 sec, 9.7 sec, and 14.9 sec. A reader placed volumes-of-interest on dominant tumors and benign PZ, generating quantitative pharmacokinetic parameters (k(trans), ve) at each R-T. Two blinded readers assessed each RT for lesion presence, location, conspicuity, and reader confidence on a 5-point scale. Data were assessed by mixed-model analysis of variance (ANOVA), generalized estimating equation (GEE), and receiver operating characteristic (ROC) analysis. Results: R-T did not affect sensitivity (R1(all): 69.0%-72.4%, all P-adi = 1.000; R1(G5 >= 4+3): 83.3-91.7%, all P-adi= 1.000; R2a1: 60.3-69.0%, all P-adi = 1.000; R2(Gs)>= 4+3: 58.3%-79.2%, all P-adi = 1.000). R1 reported greater conspicuity of GS > 4 + 3 tumors at RT of 1.4 sec vs. 14.9 sec (4.29 1.23 vs. 3.46 +/- 1.44; P-adi = 0.029). No other tumor conspicuity pairwise comparison reached significance (R1a11: 2.98-3.43, all Padi > 0.205; R2(all) 2.57-3.19, all P-adi > 0.059; R105>4_3: 3.46-4.29, all other P-adi > 0.156; R2Gs-,4+ 3: 2.92-3.71, all P-adi > 0.439). There was no effect of RT on reader confidence (Riau: 3.173.34, all P-adj 1.000; R2(all): 2.83-3.19, all P-adi > 0.801; R1(Gs)>4 + 3: 3.79-4.21, all P-adi = 1.000; R2(Gs >= 4+3): 3.13-3.79, all P-adi 1.000). k(trans) and ve of tumor and benign tissue did not differ across RT (all adjusted P values [Padi] 1.000). RT did not significantly affect area under the curve (AUC) of K-trans or ve for differentiating tumor from benign (all Pad' 1.000). Conclusion: Current PI-RADS recommendations for RT of 10 seconds may be sufficient, with further reduction to the stated PI-RADS preference of RT < 7 seconds offering no benefit in tumor detection or quantitative analysis.