Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Biomedical Engineering, Tokai University School of Engineering, Kanagawa, Japan.
J Magn Reson Imaging. 2017 Aug;46(2):490-496. doi: 10.1002/jmri.25593. Epub 2017 Feb 2.
To investigate the value of computed (c) diffusion-weighted imaging (DWI) in assessing prostate cancer aggressiveness.
Fifty-five patients with peripheral zone prostate cancer who underwent prebiopsy 1.5T magnetic resonance imaging (including native DWI at b-values of 0 and 1000 s/mm ) were included. cDWI signal intensities of peripheral zone prostate cancer and nonmalignant prostate tissue were measured. Association between changes in monoexponentially calculated cDWI signals according to different b-values and primary Gleason grades were assessed.
The cDWI signal intensity of prostate cancer was lower at b = 0 s/mm and higher at b = 1000 s/mm compared to nonmalignant prostate tissue. The b-value at which the signal intensities of prostate cancer and nonmalignant prostate tissue were equal was defined as the "iso-b-value." On multivariate analysis, only the iso-b-value was a significant predictor of primary Gleason grade 4/5 cancer (P = 0.001). The area under the curve (AUC) of the iso-b-value for diagnosing primary Gleason grade 4/5 cancer was 0.94, and significantly higher than that of the tumor apparent diffusion coefficient (ADC) value with an AUC of 0.68 (P < 0.001).
cDWI with iso-b-value-based semiquantitative analysis was found to be useful for predicting the aggressiveness of prostate cancer and may potentially outperform tumor ADC measurements in this setting.
3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:490-496.
探究计算扩散加权成像（cDWI）在评估前列腺癌侵袭性方面的价值。
本研究共纳入 55 例经穿刺活检证实的外周带前列腺癌患者，所有患者均在术前 1.5T 磁共振成像检查（包括 b 值为 0 和 1000 s/mm 的弥散加权成像）。测量外周带前列腺癌和正常前列腺组织的 cDWI 信号强度。评估不同 b 值下单指数计算的 cDWI 信号变化与原发性 Gleason 分级之间的关系。
与正常前列腺组织相比，前列腺癌在 b 值为 0 s/mm 时的 cDWI 信号强度较低，在 b 值为 1000 s/mm 时的信号强度较高。将前列腺癌和正常前列腺组织的信号强度相等时的 b 值定义为“等 b 值”。多变量分析显示，只有等 b 值是预测原发性 Gleason 分级 4/5 肿瘤的独立预测因子（P=0.001）。等 b 值诊断原发性 Gleason 分级 4/5 肿瘤的曲线下面积（AUC）为 0.94，明显高于肿瘤表观扩散系数（ADC）值的 AUC（0.68，P<0.001）。
基于等 b 值的半定量 cDWI 分析有助于预测前列腺癌的侵袭性，在这种情况下，其可能优于肿瘤 ADC 值的测量。
3 级 技术效果：2 级 J. MAGN. RESON. IMAGING 2017；46：490-496
