前列腺癌磁共振动态增强扫描与波谱分析的比较研究

目的在1．5T场强下评价MRI动态增强扫描（DCE．MRI）和磁共振波谱（MRS）诊断前列腺癌的能力。方法2011年4月-2012年12月，根据前列腺穿刺活检结果，在36例患者的MRJ图像中测得216个感兴趣区，其中癌肿组131个，良性组85个，对测得的DCE．MRJ和MRS数据进行统计学分析，并利用受试者工作特征（ROC）曲线对两种方法进行比较。结果癌肿组和良性组在枸橼酸盐（Cit）积分（integral）、胆碱复合物（Cho）积分、（肌酸＋CHo）／Crt比值（CC／Cit）、时间信号曲线类型、达峰时间、时间差、初始值、强化速率、强化比率之间的差异有统计学意义。根据ROC曲线，CC／Cit和强化速率的曲线下面积（AUC）分别为0．853和0．719，达峰时间、时间差、强化比率和Cit积分的AUC〈0．400，CC／Cit的最佳工作点为0．775，其特异度为0．85，灵敏度为0．79，AUC为0．853。强化速率的最佳工作点为60．89，其特异度为0．66，灵敏度为0．71，AUC为0．719。结论在1．5T场强下，波谱分析诊断前列腺癌比DCE．MRI具有更高的特异度和灵敏度，但也容易受到干扰因素影响，而DCE．MRI常常能弥补这些不足。

A Comparative Study between Dynamic Contrast-enhancement MRI and Magnetic Resonance Spectroscopy in Diagnosing Prostate Cancer

Objective To compare the effectiveness of magnetic resonance spectroscopy （MRS） and Dynamic Contrast-enhancement （DCE-MRI） with 1.5 T MR scanner in diagnosing prostate cancer. Methods From April 2011 to December 2012, based on the results of biopsy, we measured 216 regions of interest （ROIs） in images of MRS and DCE-MRI, comprised of 131 ROIs from cancer zone and 85 ROIs from non-cancer zone. The data were analyzed with statistical methods, including receiver operating characteristic （ROC） curve. Results There were significant differences between the malignant group and the benign group （P 〈 0.05） in Cit integral, Cho integral, CC/Cit ratio, the type of time- signal intensity curve, initial value, enhancement rate and ratio of enhancement. According to ROC curve, the area under curve （AUC） of CC/Cit and enhancement rate was 0.853 and 0.719, respectively. AUC of time to peak, time difference, enhancement rate and Cit integral was lower than 0.400. The optimal operating point （OOP） of CC/Cit was 0.775, with a specificity of 0.85 and a sensitivity of 0.79, and the AUC was 0.853. The OOP of the ratio of enhancement was 60.89, with a specificity of 0.66 and a sensitivity of 0.71, and the AUC was 0.719. Conclusions MRS is more sensitive and specific than DCE-MRI to diagnose prostate cancer when an 1.5 T MR scanner is used. On the other hand, MRS is susceptible to interference, but DCE-MRI can make up for these deficiencies.