单纯体表线圈磁共振波谱成像诊断前列腺癌

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

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。

Objective To study the value of magnetic resonance spectroscopic imaging （MRSI） with only surface coils in diagnosing prostate cancer. Methods A total of 48 elderly patients with surgery or biopsy-confirmed benign prostatic hyperplasia or prostate cancer were preoperatively examined by surface coils for three-dimensional simple multi-voxel magnetic resonance spectroscopy scans, and the voxel （choline[,Cho] ＋creatine[-Cr]）/citrate（Cit） values were calculated. According to the pathological findings, the voxels were divided into prostate cancer and non-cancer. The voxel （Choff-Cr）/Cit values of prostate central zone and prostate peripheral zone were analyzed. The voxel nature of （Cho＋Cr）/Cit value was used as the gold standard receiver to plot characteristic curve （ROC curve） and to calculate the area under the curve; the maximal Youden index was used as the standard to obtain the cut-off value and the corresponding sensitivity and specificity. Results The voxel （Cho＋ Cr）/Cit values of different natures were significantly different （P〈0. 001）. When the area under the ROC curve of （Cho＋Cr）/ Cit value was used for diagnosis of prostate cancer, the central zone was 0. 652, and the peripheral zone was 0. 821. For the cut- off value, the central zone was （Cho＋Cr）/Cit=0. 645, with the corresponding sensitivity and specificity being 0. 512 and 0.71, respectively; the peripheral zone was （Choq-Cr）/Cit= 0. 815, with the corresponding sensitivity and specificity being 0.72 and 0.84, respectively. Conclusion Surface coil alone can successfully complete the three-dimensional proton spectroscopic imaging of prostate, and （Choq-Cr）/Cit=0. 815 for the cut-off value has a high diagnostic value for DeriDheral zone prostate cancer.