常规磁共振影像特征对前列腺外周带良恶性病变的鉴别诊断价值探讨

目的 探讨常规磁共振序列(T1WI、T2WI及增强T1WI)影像特征对前列腺外周带良恶性病变的鉴别诊断价值,提高对前列腺良恶性疾病的诊断准确性。 方法 回顾性分析46例前列腺癌患者及25例良性前列腺疾病患者(共28个病灶)的常规磁共振增强扫描的影像学特征。运用χ2检验对各观察指标进行筛选,绘制ROC曲线,并行判别分析,对所得判别式的诊断准确性进行新样本验证。 结果 T2WI均匀低信号、病变形状、外科包膜消失、前列腺包膜中断破坏、病变均匀强化和病变侧外周带大小改变等6个指标在前列腺良恶性病变组中差异有统计学意义(P<0.05),T2WI均匀低信号、病变均匀强化和患侧外周带大小改变3个指标的ROC曲线下面积均在0.7以上,高于其他指标,进入判别式,利用判别式对新样本判断准确率:前列腺增生组为83%,前列腺癌组为77%。 结论 T2WI均匀低信号、强化方式及患侧外周带体积改变等征象对前列腺良恶性病变的鉴别诊断具有重要价值。

The Diagnostic Value of Conventional MRI in the Differentiation of Malignant Tumor from Benign Lesion in Prostatic Peripheral Zone

Objective To evaluate the diagnostic capabilities of conventional MRI (T1WI, T2WI and Gd-enhancement T1WI) for differentiating prostate cancer from benign prostatic disorders in prostatic peripheral zone (PZ). Methods Respectively analyze the characteristics of conventional MRI in 46 cases of prostate cancer and 25 cases of benign prostatic disorders (with 28 lesions). Six indexes were initially screened by χ2-test, and receiver operating characteristic curves (ROC) of these indexes were depicted, then Bayes discriminator was applied to discriminate all the lesions according to the indexes with statistic meaning. The discriminant function was evaluated with new sample validation. Results The indexes showing statistics meaning between prostate cancer and benign prostatic disorders were uniform low SI on T2WI, shape, pseudocapsule extension, prostate-capsule extension, size change of PZ with lesion and enhancement style. Furthermore, uniform low SI on T2WI, enhancement style and size change of PZ with lesion were consist of the function after discrimination, AUC of these 3 indexes were all above 0.7, which were wider than that of the other 3 indexes. The discriminating accuracy rates of the new sample for benign prostatic disorders and prostate cancer were 83% and 77%. Conclusion The importance of uniform low SI on T2WI, enhancement style and size change of PZ with lesion should be highlighted in the differentiation of prostate cancer and benign prostatic disorders in PZ.