肝脏实性占位磁共振成像定量指标与病灶性质的相关研究

目的:研究病灶?肝脏信号强度比(SIR)、信噪比(SNR)、对比噪声比(CNR)在区分肝脏实质性小占位的性质方面的价值。方法:随机选择经确诊的肝细胞癌、肝转移瘤和肝血管瘤共67例(101个病灶),行前瞻性磁共振成像(0.5T)研究。计算病灶的SIR,SNR,CNR,并进行统计学分析。结果:T1W图像及质子加权像上,三种定量指标对区分肝血管瘤和肝细胞癌、肝转移瘤无价值。T2W图像上,肝转移瘤与肝细胞癌的SIR,SNR,CNR值均显著小于血管瘤的SIR,SNR,CNR值,TE=60ms时SIR,SNR,CNR区分肝血管瘤和肝细胞癌的诊断正确率分别为72%,72%,83%;TE=90ms时诊断正确率分别为74%,80%,84%;TE=120ms时诊断正确率分别为75%,86%,88%。结论:T1W图像及质子加权像上,三种定量指标对区分肝脏实质性占位的性质无明确价值,T2W图像上测得的SIR,SNR,CNR值可用于区分肝血管瘤与肝细胞癌,且TE=120ms时诊断正确率最高。

Correlative study between identifications and the quantitative indexes using magnetic resonance imaging in the small solid hepatic lesions

Objective:To determine the value of magnetic resonance imaing(MRI)quantitative indexes in characterizing small solid hepatic lesions.These quantitative indexes included,lesion?liver signal intensity ratio(SIR),signal noise ratio(SNR),contrast to noise ratio(CNR).Methods:Sixty-seven patients with101solid hepatic lesions were prospectively performed mag-netic resonance imaging at0.5T.The SIR,SNR and CNR of hepatocellular carcinomas,metastases and hemangiomas were calculated.Results:In T 1 -weighted imaging and proton-density imaging,the values of SIR,SNR and CNR had no value for characterizing hepatic lesions,the values of SIR,SNR and CNR for hepatocellular carcinomas and metastases were significantly lower than those for hemangiomas in T 2 -weighted imaging.Using SIR,SNR,CNR to distinguish hemangiomas from hepato-cellular carcinomas,the accuracy was72%,72%,83%respectively at60ms TE,and was74%,80%,84%respectively at90ms TE,and was75%,86%,88%respectively at120ms TE.Conclusions:In T 1 -weighted imaging and proton-density imaging,the three quantitative indexes had no value for characterizing hepatic lesions,the values of SIR,SNR,CNR can be used to dis-tinguish hemangiomas from hepatocellular carcinomas in T 2 -weighted imaging.The accuracy was highest at120ms TE.