1 Radiological Sciences, University of California, Irvine Medical Center , Orange, CA , USA.
Br J Radiol. 2018 Jul;91(1088):20180091. doi: 10.1259/bjr.20180091. Epub 2018 Jun 21.
The aim of this study is to evaluate the utility of quantitative apparent diffusion coefficient (ADC) measurements and normalized ADC ratios in multiparametric MRI for the diagnosis of clinically significant peripheral zone (PZ) prostate cancer particularly among equivocally suspicious prostate lesions.
A retrospective analysis of 95 patients with PZ lesions by PI-RADSv2 criteria, and who underwent subsequent MRI-US fusion biopsy, was approved by an institutional review board. Two radiologists independently measured ADC values in regions of interest (ROIs) of PZ lesions and calculated normalized ADC ratio based on ROIs in the bladder lumen. Diagnostic performance was evaluated using ROC. Inter observer variability was assessed using intraclass correlation coefficient (ICC).
Mean ADC and normalized ADC ratios for clinically significant and non-clinically significant lesions were 0.763 × 10-3 mm s, 29.8%; and 1.135 × 10-3 mm s, 47.2% (p < 0.001), respectively. Area under the ROC curve (AUC) was 0.880 [95% CI (0.816-0.944) and 0.885 (95% CI (0.814-0.955)] for ADC and ADC ratio, respectively. Optimal AUC threshold for ADC was 0.843 × 10-3 mm s (Sn 70.5%, Sp 88.2%) and for normalized ADC was 33.1% (Sn 75.0%, Sp 95.7%). intraclass correlation coefficient was high at 0.889.
Quantitative ADC measurement in PZ prostate lesions demonstrates excellent diagnostic performance in differentiating clinically significant from non-clinically significant prostate cancer with high inter observer correlation. Advances In knowledge: Quantitative ADC is presented as an additional method to evaluate lesions in mpMRI of the prostate. This technique may be incorporated in new and existing methods to improve detection and discrimination of clinically significant prostate cancer.
本研究旨在评估定量表观扩散系数（ADC）测量值和多参数 MRI 中标准化 ADC 比值在诊断临床显著外周区（PZ）前列腺癌中的效用，特别是在疑似前列腺病变中。
经机构审查委员会批准，回顾性分析了 95 例符合 PI-RADSv2 标准的 PZ 病变患者的资料，这些患者随后接受了 MRI-US 融合活检。两位放射科医生分别在 PZ 病变的感兴趣区域（ROI）中测量 ADC 值，并根据膀胱内腔的 ROI 计算标准化 ADC 比值。使用 ROC 评估诊断性能。使用组内相关系数（ICC）评估观察者间变异性。
临床显著和非临床显著病变的平均 ADC 和标准化 ADC 比值分别为 0.763×10-3mm/s、29.8%和 1.135×10-3mm/s、47.2%（p<0.001）。ADC 和 ADC 比值的 ROC 曲线下面积（AUC）分别为 0.880[95%CI（0.816-0.944）和 0.885（95%CI（0.814-0.955）]。ADC 的最佳 AUC 阈值为 0.843×10-3mm/s（Sn70.5%，Sp88.2%），标准化 ADC 的最佳 AUC 阈值为 33.1%（Sn75.0%，Sp95.7%）。组内相关系数很高，为 0.889。
PZ 前列腺病变的定量 ADC 测量在区分临床显著和非临床显著前列腺癌方面具有出色的诊断性能，且观察者间相关性高。
定量 ADC 被提出作为评估前列腺多参数 MRI 中病变的另一种方法。该技术可应用于新的和现有的方法中，以提高对临床显著前列腺癌的检测和鉴别能力。
