外周带前列腺癌：3T体线圈多体素^1H MRS的ROC曲线分析

目的应用ROC曲线分析3T场强下采用体线圈行前列腺氢质子磁共振波谱（H-1 magnetic resonance spectroscopy, ^1H MRS）对外周带前列腺癌的诊断效能。方法40名临床可疑前列腺癌患者于3T场强下仅用体线圈行前列腺MRS检查。结合穿刺病理及T2WI分区将外周带体素分为正常、癌灶体素，计算各体素（胆碱＋肌酸）／枸橼酸（Cho＋Cr）／Cit]。分析比较外周带正常及癌灶体素（Cho＋Cr）／Cit，绘制用于诊断外周带癌的接受者操作特征曲线（ROC曲线）。结果所有病人均顺利完成检查。经系统穿刺活检病理证实前列腺癌18例，外周带59分区有癌灶；不典型增生或前列腺上皮内瘤4例；前列腺增生15例；前列腺炎2例；前列腺结核1例。正常外周带体素（Cho＋Cr）／Cit比值为0．50±0．12，外周带癌灶体素（Cho＋Cr）／Cit比值均数为1．57，两者间有统计学差异（t=16．58，P〈0．001），确定外周带前列腺癌ROC曲线下面积的Az为0．968，其切点值为0．67（敏感度90％，特异度89％，P〈0．001）。结论3T场强下仅采用体线圈采集^1H MRS能反映外周带癌灶代谢变化，对外周带前列腺癌有较高的诊断效能。

Analysis of ROC curve in proton MRS of prostate cancer in peripheral zone at 3T MR

Objective To evaluate the value of ^1HMRS of the prostate with body coil at 3T in diagnosis of prostate cancer in peripheral zone. Methods 40 suspicious prostate cancer patients aeeepted 1HMRS data acquisition with 3T MR using only body coil. The voxels in peripheral zone were divided as normal and cancer tissue. Ratios of （Cho＋Cre）/Cit were calculated in useful voxels, and were compared. Area under the receiver operating eharaeteristie curves （Az） values were used to assess the accuracy of discrimination of cancer from healthy tissues in peripheral zone. Results All patients completed the exam. Proved by biopsy, there were 18 prostate cancer with lesions in 59 divisions of peripheral zone, 15 benign prostatic hyperplasia, 4 prostatic intraepithelial neoplasia, 2 prostatitis, and 1 prostate tuberculosis. The ratio of （Cho＋Cre）/Cit in normal voxels of peripheral zone wag 0.50 ＋ 0.12 and the mean ratio in the lesion was 1.57, which had statistieally difference. The sensitivity and specificity was 90% and 89% （P〈 0.001） respectively with Az of 0.968 and the eut point ratio of 0.67 to determine cancer tissue from healthy tissue in the peripheral zone. Conclusion Metabolites changes in prostate cancer in peripheral zone could be accessed by ^1H MRS of the prostate with body coil at 3T MR and has good value in prostate eaneer diagnosis.