摘要目的 通过比较联合应用弥散加权成像(DWI)与2D二维动态对比增强磁共振(2DDCE MRI)检查和仅2D DCE MRI方法 对慢性肝病基础上肝细胞肝癌(HCC)小病灶的检出敏感性,评价DWI对肝癌小病灶检出的价值.方法 复旦大学附属中山医院54例患者共74个HCC病灶(≤3cm)被纳入研究,所有患者均一次同时进行DWI和常规T1>WI、T2WI和2D DCE MRI,DWI成像采用mSENSE-DWI(SE-EPI)序列和b值500 s/mm2,在15～17 s内完成20～24层扫描;两位有10年腹部MRI阅片资历的医生独立随机分析仅2D DCE MRI检查图像和联合DWI/2D DCE MRI的图像,两种阅片方式对肝癌小病灶和微小肝癌(≤1 cm micro-HCC)的诊断能力行受试者工作曲线(ROC)分析,并统计病灶的检出敏感性和阳性预测值.结果 对所有≤3 cm小病灶和≤1 cm MHCC病灶,两位阅片者ROC曲线下平均面积联合DWI的方法 (0.948,0.860)均高于仅2D DCE MRI(0.86,0.64),并且差异有统计学意义(P<0.01),对所有≤3 cm小病灶和≤1 cmMHCC病灶,联合DWI的方法 对病灶检出的敏感性均高于仅2D DCE MRI方法 (P<0.05).对于MHCC病灶,联合DWI方法 和仅用2DDCE MRI敏感性分别为95.8%～96.0%,62.5%～68.0%;对MHCC病灶,联合DWI的方法 的阳性预测值(95.8%～96.0%)要高于仅2D DCE MRI(94.1%～94.4%),差异有统计学意义(P<0.05);对所有肝癌小病灶,联合DWI方法 和仅2D DCE MRI方法 的阳性预测值分别为98.6%～98.7%,95.5%～95.7%,差异无统计学意义.结论 在2D DCE基础上,应用屏气DWI有助于提高慢性肝病基础上的肝癌小病灶检出的敏感性,而且可以补充提供有价值的鉴别诊断信息.

abstractsObjective To evaluate the added value of single breath-hold diffusion-weighted imaging (DWI) in detection of small HCC lesions (≤3 cm) in patients with chronic liver disease, by comparing the detection sensitivity of DWI/conventional dynamic contrast enhancement (DCE) MRI and that of conventional DCE MRI alone. Methods A total of 54 patients with chronic liver diseases underwent abdominal MRI at 1.5T, including T1 -weighted (T1WI), T2-weighted (T2WI), and 2 D conventional DCE. For each patient study, axial DWI was performed with a single-shot echo-planar imaging (EPI) sequence using modified sensitivity encoding (mSENSE) with b-value of 500 seconds/mm2. A total of 20-24 slices were obtained during a 15-17-second breath-hold. Two observers independently interpreted the combined DWI/conventional DCE MRI images and the conventional DCE MRI images in random order. For all small HCC lesions and micro-hepatocellular carcinoma(smaller than 10 mm MHCC), the diagnostic performance using each imaging techniques were evaluated by ROC analysis. Sensitivity and positive predictive values were also calculated. Results The mean areas under the ROC curve (Az) of combined DWI/conventional DCE MRI images (0.945,0.86) were statistically higher than those of conventional DCE MRI alone (0.86, 0.64) for all small HCC lesions and MHCC (micro hepatocellular carcinoma) lesions (P<0.01). The lesion detection sensitivities using the combined technique of both observers were significantly higher than those using the conventional DCE MRI alone for all small lesions and for MHCC (P<0.01). For MHCC, the sensitivities using the combined technique and the conventional DCE MRI alone were 95.8%-96.0% and 62.5% -68.0%, respectively. The positive predictive values for MHCC using the combined imaging technique (95.8%-96.0%) were higher than those using the conventional DCE MRI alone (94.1%-94. 4%) (P<0.05). For all small HCC lesions, the positive predictive values using the combined imaging technique and the conventional DCE MRI alone were 98.6%-98.7% and 95.5%-95.7%, respectively and there was no statistical difference. Conclusion Combined use of Breath-hold DWI with conventional DCE MRI helped to provide higher sensitivities than conventional DCE MRI alone in the detection of small HCC lesions in patients with chronic liver disease. Furthermore, DWI could provide additional valuable information that benefits the differential diagnosis.