动态对比增强 MRI 检测前列腺癌：计算机辅助诊断与单一时相灌注参数图比较。

Prostate cancer detection on dynamic contrast-enhanced MRI: computer-aided diagnosis versus single perfusion parameter maps.

机构信息

Department of Radiology, Research Institute of Radiology, Medical Imaging Laboratory, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul, Republic of Korea.

出版信息

AJR Am J Roentgenol. 2011 Nov;197(5):1122-9. doi: 10.2214/AJR.10.6062.

DOI:10.2214/AJR.10.6062

PMID:22021504

Abstract

OBJECTIVE

The purpose of this article is to assess the value of computer-aided diagnosis (CAD) for prostate cancer detection on dynamic contrast-enhanced MRI (DCE-MRI).

MATERIALS AND METHODS

DCE-MRI examinations of 42 patients with prostate cancer were used to generate perfusion parameters, including baseline and peak signal intensities, initial slope, maximum slope within the initial 50 seconds after the contrast injection (slope(50)), wash-in rate, washout rate, time to peak, percentage of relative enhancement, percentage enhancement ratio, time of arrival, efflux rate constant from the extravascular extracellular space to the blood plasma (k(ep)), first-order rate constant for eliminating gadopentetate dimeglumine from the blood plasma (k(el)), and constant depending on the properties of the tissue and represented by the size of the extravascular extracellular space (A(H)). CAD for cancer detection was established by comprehensive evaluation of parameters using a support vector machine. The diagnostic accuracy of single perfusion parameters was estimated using receiver operating characteristic analysis, which determined threshold and parametric maps for cancer detection. The diagnostic performance of CAD for cancer detection was compared with those of T2-weighted imaging (T2WI) and single perfusion parameter maps, using histologic results as the reference standard.

RESULTS

The accuracy, sensitivity, and specificity of CAD were 83%, 77%, and 77%, respectively, in the entire prostate; 77%, 91%, and 64%, respectively, in the transitional zone; and 89%, 89%, and 89%, respectively, in the peripheral zone. Values for k(ep), k(el), initial slope, slope(50), wash-in rate, washout rate, and time to peak showed greater area under the curve values (0.803-0.888) than did the other parameters (0.545-0.665) (p < 0.01) and were compared with values for CAD. In the entire prostate, accuracy was greater for CAD than for all perfusion parameters or T2WI (63-77%); sensitivity was greater for CAD than for T2WI, initial slope, wash-in rate, slope(50), and washout rate (38-77%); and specificity was greater for CAD than for T2WI, k(ep), k(el), and time to peak (59-68%) (p < 0.05).

CONCLUSION

CAD can improve the diagnostic performance of DCE-MRI in prostate cancer detection, which may vary according to zonal anatomy.

摘要

目的

本文旨在评估计算机辅助诊断（CAD）在前列腺癌的动态对比增强磁共振成像（DCE-MRI）中的应用价值。

材料与方法

使用 42 例前列腺癌患者的 DCE-MRI 检查生成灌注参数，包括基线和峰值信号强度、初始斜率、对比剂注射后 50 秒内的最大斜率（斜率（50））、流入率、流出率、达峰时间、相对增强百分比、增强比百分比、到达时间、血管外细胞外空间到血浆的流出率常数（k（ep））、从血浆中消除钆喷替酸二葡甲胺的一级速率常数（k（el））和依赖于组织特性并由血管外细胞外空间大小表示的常数（A（H））。通过支持向量机对参数进行综合评估，建立 CAD 用于癌症检测。使用受试者工作特征分析评估单一生成灌注参数的诊断准确性，确定癌症检测的阈值和参数图。使用组织学结果作为参考标准，比较 CAD 对癌症检测的诊断性能与 T2 加权成像（T2WI）和单一生成灌注参数图的诊断性能。

结果

在整个前列腺中，CAD 的准确性、敏感性和特异性分别为 83%、77%和 77%；在移行带分别为 77%、91%和 64%；在周边带分别为 89%、89%和 89%。k（ep）、k（el）、初始斜率、斜率（50）、流入率、流出率和达峰时间的曲线下面积值（0.803-0.888）大于其他参数（0.545-0.665）（p < 0.01），并与 CAD 进行比较。在整个前列腺中，CAD 的准确性高于所有灌注参数或 T2WI（63-77%）；敏感性高于 T2WI、初始斜率、流入率、斜率（50）和流出率（38-77%）；特异性高于 T2WI、k（ep）、k（el）和达峰时间（59-68%）（p < 0.05）。