定量研究表观扩散系数与T2值在肝局灶性小病变中的应用价值

目的通过对表观扩散系数（ADC）与T2值的定量对比研究,探讨ADC值与T2值在肝脏局灶性小病变定性诊断中的价值. 资料与方法对临床发现有肝脏局灶性小病变患者73例（其中包括原发性肝细胞癌22例22个病灶,肝转移瘤16例26个病灶,肝海绵状血管瘤27例38个病灶,肝囊肿8例11个病灶）分别行磁共振扩散加权成像（DWI）和常规快速自旋回波（FSE）T2WI,然后测量计算各病变的ADC值及T2值,进行统计学分析,对比两种量化方法（ADC值和T2值）对肝脏良恶性病变的诊断准确性. 结果肝脏恶性病变的ADC值明显低于良性病变（P＜0.01）,其诊断准确性为93.8%;肝脏恶性病变的T2值也低于良性病变（P＜0.05）,但两者数值重叠较多,其诊断准确性为77.3%,有明显统计学差异（P＜0.05）. 结论利用ADC值在定性方面优于T2值,对肝脏局灶性小病变的诊断更具临床价值.

Quantitative Study of ADCs and T2 Value in the Diagnosis of Small Focal Hepatic Lesions

Objective To evaluate the value of the ADCS and T_2 value in the diagnosis of small focal hepatic lesions.Materials and Methods 73 patients suspected of hepatic lesions(hepatic carinoma 22, metastasis 26, hemangioma 38, hepatic cyst 11) were examined with diffusion weighted single-shot echoplanar MR imaging and fast spin-echo T_2-weighted sequences. ADCs and T_2 value were measured in all hepatic masses and correlation analysis was used to determine the relation among the lesions, then the accuracy of malignant lesions was compared between T_2 and ADC value.Results The average apparent diffusion coeffecient of malignant masses was significantly lower than that of benign lesions (P<0.01), and the accuracy of differentiating malignant with benign lesions was 93.8%. There was also statistical value for T_2 value (P<0.05) between malignant and benign masses, T_2 value was lower in malignant masses than that in benign lesions, but a amount of overlap in T_2 value were existed among malignant tumors, hemangiomas, and cysts, and the accuracy (77.3%) was significantly lower than that of ADCs (P<0.05).Conclusion ADCs is superior to T2 value in qualitatively diagnosis of the lesion, and may be useful for diagnosis of Small Focal Hepatic Lesions.