磁共振成像与多层CT对肝脏局灶性病变定性的比较研究

Characterization of focal liver lesions: comparison of MRI and MSCT

目的比较综合MRI(1.5T或3T)多种序列与MSCT(16或64层)动态增强扫描对肝脏局灶性病变定性的价值。方法回顾性分析行腹部MSCT与MRI检查(两种检查间隔时间不超过1个月)且发现肝脏局灶性病变的41例患者(75个病灶)的诊断结果。结果MSCT鉴别诊断良恶性病灶的敏感度为80.77%(21/26),特异度为68.42%(26/38)。MRI鉴别诊断良恶性病灶的敏感度为93.33%(28/30),特异度为97.56%(40/41)。两者敏感度之间的差异无统计学意义(P=0.311),MRI的特异度高于MSCT(P<0.001)。对于具体的各类病灶,MRI的总体诊断准确率(86.36%,57/66)高于(P=0.004)MSCT(64.41%,38/59)。结论MRI对肝脏局灶性病变的定性能力优于MSCT。

Objective To compare the efficacy of plain and contrast enhancement MRI （1.5T or 3T） and dynamic contrast enhanced MSCT （16- or 64-slice） for characterization of focal liver lesions. Methods A retrospective analysis was performed on 41 patients who underwent MSCT and MRI within one month period for evaluation of focal liver lesions. Triple-phase or dual-phase dynamic contrast enhancement was performed on a 16- or 64-slice MSCT. MRI sequences included transverse T1-weighted images acquired as fast spoiled gradient （FSPGR） in-phase and out-of-phase dual-echo, transverse T2-weighted images with respiratory triggering acquired as fat-suppressed fast spin echo （FSE） or fast recovery fast spin echo （FRFSE）, and breath-hold coronal T2-weighted images acquired as single shot fast spin echo （SSFSE） or fast imaging employing steady-state acquisition （FIESTA）. Additional dynamic gadolinium enhancement imaging was performed on 20 patients. A total of 75 lesions （32 malignant and 43 benign） were finally confirmed either by histopathology or combined clinical data, typical imaging features and follow-up for a period of at least one year. Chi-Square tests were used to compare the performances of MSCT and MRI in characterization of lesions, respectively. Results The sensitivity and specificity in differentiation of benign from malignant lesions on MSCT were 80.77% （21/26）, 68.42% （26/38） and on MRI were 93.33% （28/30）, 97.56% （40/41）, respectively. There was no significant difference in sensitivity between two imaging techniques （P=0.311）, but the specificity of MRI was significantly higher than that of MSCT （P〈0.001）. The diagnostic accuracy of MRI based on lesion types （86.36%, 57/66） was significantly better （P=0.004） than that of MSCT （64.41%, 38/59）. Conclusion MRI was superior to MSCT for characterization of focal liver lesions.