Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room C-278, New York, NY 10065, USA.
Radiology. 2011 Jun;259(3):775-84. doi: 10.1148/radiol.11102066. Epub 2011 Mar 24.
To assess the incremental value of diffusion-weighted (DW) magnetic resonance (MR) imaging over T2-weighted MR imaging at 3 T for prostate cancer detection and to investigate the use of the apparent diffusion coefficient (ADC) to characterize tumor aggressiveness, with whole-mount step-section pathologic analysis as the reference standard.
The Internal Review Board approved this HIPAA-compliant retrospective study and waived informed consent. Fifty-one patients with prostate cancer (median age, 58 years; range, 46-74 years) underwent T2-weighted MR imaging and DW MR imaging (b values: 0 and 700 sec/mm(2) [n = 20] or 0 and 1000 sec/mm(2) [n = 31]) followed by prostatectomy. The prostate was divided into 12 regions; two readers provided a score for each region according to their level of suspicion for the presence of cancer on a five-point scale, first using T2-weighted MR imaging alone and then using T2-weighted MR imaging and the ADC map in conjunction. Areas under the receiver operating characteristic curve (AUCs) were estimated to evaluate performance. Generalized estimating equations were used to test the ADC difference between benign and malignant prostate regions and the association between ADCs and tumor Gleason scores.
For tumor detection, the AUCs for readers 1 and 2 were 0.79 and 0.76, respectively, for T2-weighted MR imaging and 0.79 and 0.78, respectively, for T2-weighted MR imaging plus the ADC map. Mean ADCs for both cancerous and healthy prostatic regions were lower when DW MR imaging was performed with a b value of 1000 sec/mm(2) rather than 700 sec/mm(2). Regardless of the b value used, there was a significant difference in the mean ADC between malignant and benign prostate regions. A lower mean ADC was significantly associated with a higher tumor Gleason score (mean ADCs of [1.21, 1.10, 0.87, and 0.69] × 10(-3) mm(2)/sec were associated with Gleason score of 3 + 3, 3 + 4, 4 + 3, and 8 or higher, respectively; P = .017).
Combined DW and T2-weighted MR imaging had similar performance to T2-weighted MR imaging alone for tumor detection; however, DW MR imaging provided additional quantitative information that significantly correlated with prostate cancer aggressiveness.
评估在 3T 下弥散加权（DW）磁共振成像（MR）相对于 T2 加权 MR 成像在前列腺癌检测中的附加价值，并研究表观扩散系数（ADC）在肿瘤侵袭性特征中的应用，以全器官切片病理分析为参考标准。
本 HIPAA 兼容的回顾性研究经内部审查委员会批准，且免除了知情同意。51 例前列腺癌患者（中位年龄 58 岁；范围：46-74 岁）行 T2 加权 MR 成像和 DW MR 成像（b 值：0 和 700 sec/mm(2)[n = 20]或 0 和 1000 sec/mm(2)[n = 31]），随后行前列腺切除术。前列腺被分为 12 个区域；两位读者根据他们对每个区域存在癌症的怀疑程度，在五个等级上对每个区域进行评分，首先单独使用 T2 加权 MR 成像，然后使用 T2 加权 MR 成像和 ADC 图联合评分。使用受试者工作特征曲线下面积（AUCs）来评估性能。使用广义估计方程来检验良性和恶性前列腺区域之间 ADC 的差异，以及 ADC 与肿瘤 Gleason 评分之间的相关性。
对于肿瘤检测，读者 1 和 2 的 AUC 分别为 T2 加权 MR 成像的 0.79 和 0.76，T2 加权 MR 成像联合 ADC 图的 0.79 和 0.78。当使用 b 值为 1000 sec/mm(2)而不是 700 sec/mm(2)进行 DW MR 成像时，癌性和健康前列腺区域的平均 ADC 均降低。无论使用何种 b 值，恶性和良性前列腺区域之间的平均 ADC 均存在显著差异。较低的平均 ADC 与较高的肿瘤 Gleason 评分显著相关（平均 ADCs 分别为[1.21、1.10、0.87 和 0.69]×10(-3)mm(2)/sec 与 Gleason 评分 3+3、3+4、4+3 和 8 或更高分别相关；P =.017）。
DW 和 T2 加权 MR 成像联合应用与单独 T2 加权 MR 成像相比，在肿瘤检测方面具有相似的性能；然而，DW MR 成像提供了与前列腺癌侵袭性显著相关的额外定量信息。
