单纯体表线圈磁共振波谱成像诊断前列腺癌

目的 探讨单纯采用体表线圈进行磁共振波谱成像检查对前列腺癌的诊断价值.方法 对48例手术或穿刺病理证实为前列腺良性增生或前列腺癌的老年男性患者术前单纯采用体表线圈进行三维多体素磁共振波谱成像扫描,获取各体素[胆碱类化合物(Cho)+肌酸(Cr)]/枸橼酸盐(Cit)值.参考病理结果,将前列腺各体素性质分为癌与非癌,分别分析前列腺中央带与外周带各体素(Cho+Cr)/Cit值,并对(Cho+Cr)/Cit值以体素性质为金标准描画接受者操作特性(ROC)曲线,计算曲线下面积,并以Youden指数最大为标准求得阈值及相应敏感度与特异度.结果 不同性质体素(Cho+Cr)/Cit值差异有统计学意义(P＜0.001).(Cho+ Cr)/Cit值诊断前列腺癌的ROC曲线下面积:中央带为0.652,外周带为0.821;阈值:中央带(Cho+ Cr)/Cit值为0.645,相应敏感度、特异度为0.512、0.71;外周带(Cho+ Cr)/Cit值为0.815,相应敏感度、特异度为0.72、0.84.结论 仅用体表线圈可以顺利完成前列腺三维质子波谱成像,以(Cho+ Cr)/Cit值0.815为阈值对外周带前列腺癌具有较高的诊断价值.

Magnetic resonance spectroscopic imaging with only surface coils for diagnosing prostate cancer

Objective: To study the methods and values of magnetic resonance spectroscopy imaging (MRSI) with only surface coils for diagnosing prostate cancer. Methods:48 aged male,who had undergone 3D-MRSIwith only surface coils in order to acquire the (Cho + Cr) / Cit ratio of each prostate voxel,were confirmed benign prostate hyperplasia(BPH) or cancer by pathology.Then each the voxel was classified as positive or negative voxel under pathological results.According to voxel localizing in central gland or in peripheral zone, analysis of variance for the (Cho+Cr)/Cit ratio between positive and negative voxels were performed and the receiver operating characteristic curves (ROC curves) were drawn, respectively. With the ROC curves, the diagnosis thresholds were calculated under condition of maximizing the Youden index (YI), thus the sensitivity and specificity were also acquired.Results: There was significantly difference (P <0.001) of the (Cho+Cr)/Cit ratio between positive and negative voxels. The area under the ROC curves were 0.652 and 0.821 for prostate central gland and prostate peripheral zone, respectively. The diagnosis threshold for central gland was (Cho+Cr)/Cit =0.645, with sensitivity=0.512 and specificity =0.71, while the threshold for peripheral zone was (Cho+Cr)/Cit=0.815, with sensitivity=0.72 and specificity=0.84.Conclusion: It is feasible to perform prostate 3D-MRSI with only surface coils. And this kind of MRSI is valuble for diagnosing peripheral prostate cancer.