Department of Radiology, NYU School of Medicine, 660 First Ave, New York, NY 10016, USA.
AJR Am J Roentgenol. 2013 Sep;201(3):W471-8. doi: 10.2214/AJR.12.9737.
The objective of this study was to compare the performance of different methodologies for interpretation of dynamic contrast-enhanced MRI (DCE-MRI) in localization of peripheral zone prostate cancer.
Forty-three men (mean age, 59±8 years) with biopsy-proven prostate cancer who underwent prostate MRI including DCE-MRI before prostatectomy were included. Two observers independently reviewed DCE-MRI data using three methodologies: qualitative, in which kinetic curves of signal intensity versus time were generated for foci showing rapid enhancement on subtracted contrast-enhanced images; semiquantitative, in which a biexponential heuristic model was used to generate color-coded maps depicting maximum slope and washout of contrast enhancement; and quantitative, in which a Tofts model was used to generate color-coded influx rate transfer constant (Ktrans) and efflux rate transfer constant (Kep) maps. Findings were stratified by whether suspicious foci showed evidence of washout with each method and compared with histopathologic results in each sextant.
There was similar accuracy for the semiquantitative and quantitative models for both observers irrespective of requiring evidence of washout. For the more experienced observer, requiring washout resulted in lower sensitivity and higher specificity for the qualitative and semiquantitative models. Also for the more experienced observer, use of either a semiquantitative or quantitative model provided greater sensitivity compared with a qualitative model when requiring washout. There was no association between tumor detection and Gleason score for any DCE-MRI methodology for either reader.
For the experienced reader, sensitivity for peripheral zone tumor was increased by use of either a semiquantitative or quantitative model compared with a qualitative model and decreased by requiring washout. We failed to identify a difference in performance between semiquantitative and quantitative models.
本研究旨在比较不同方法在定位外周区前列腺癌中的动态对比增强 MRI（DCE-MRI）解读性能。
本研究共纳入 43 名经前列腺 MRI（包括 DCE-MRI）检查并经前列腺穿刺活检证实为前列腺癌的患者，这些患者均接受了前列腺切除术。两名观察者分别使用三种方法独立评估 DCE-MRI 数据：定性法，为在减影对比增强图像上显示快速增强的病灶生成信号强度与时间的动力学曲线；半定量法，使用双指数启发式模型生成描绘对比增强最大斜率和洗脱的彩色编码图；定量法，使用 Tofts 模型生成彩色编码的流入率转移常数（Ktrans）和流出率转移常数（Kep）图。根据每种方法是否显示洗脱的可疑病灶，对结果进行分层，并与每个六区的组织病理学结果进行比较。
无论是否需要洗脱证据，两名观察者的半定量和定量模型的准确性均相似。对于更有经验的观察者，定性和半定量模型的敏感性降低，特异性提高。对于更有经验的观察者，当需要洗脱时，与定性模型相比，使用半定量或定量模型提供了更高的敏感性。对于任何 DCE-MRI 方法，肿瘤检测与 Gleason 评分之间均无相关性。
对于经验丰富的观察者，与定性模型相比，使用半定量或定量模型可提高外周区肿瘤的敏感性，而要求洗脱则会降低敏感性。我们未能确定半定量和定量模型之间的性能差异。
