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 (ktrans, ve) at each RT. 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: RT did not affect sensitivity (R1all: 69.0%–72.4%, all Padj = 1.000; R1GS≥4 + 3: 83.3–91.7%, all Padj = 1.000; R2all: 60.3–69.0%, all Padj = 1.000; R2GS≥4 + 3: 58.3%–79.2%, all Padj = 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; Padj = 0.029). No other tumor conspicuity pairwise comparison reached significance (R1all: 2.98–3.43, all Padj ≥ 0.205; R2all: 2.57–3.19, all Padj ≥ 0.059; R1GS≥4 + 3: 3.46–4.29, all other Padj ≥ 0.156; R2GS≥4 + 3: 2.92–3.71, all Padj ≥ 0.439). There was no effect of RT on reader confidence (R1all: 3.17–3.34, all Padj = 1.000; R2all: 2.83–3.19, all Padj ≥ 0.801; R1GS≥4 + 3: 3.79–4.21, all Padj = 1.000; R2GS≥4 + 3: 3.13–3.79, all Padj = 1.000). ktrans and ve of tumor and benign tissue did not differ across RT (all adjusted P values [Padj] = 1.000). RT did not significantly affect area under the curve (AUC) of Ktrans or ve for differentiating tumor from benign (all Padj = 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. Level of Evidence: 3. J. MAGN. RESON. IMAGING 2017;45:1464–1475.
- dynamic-contrast enhanced MRI
- tumor detection
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging