摘要目的 评价磁共振扩散加权成像(DWI)在鉴别良恶性胆囊息肉样病变中的价值.方法 回顾性分析2007年11月至2014年5月张家港市第一人民医院收治的经手术病理证实的胆囊息肉样病变患者的临床资料,包括10例良性(其中5例息肉、3例腺肌瘤和2例腺瘤)和13例恶性(腺癌)病变,分别由2名高年资医师根据DWI表现将其分为等信号、高信号和很高信号三级进行视觉定性评判,并测量病灶的表观扩散系数(ADC值)进行定量分析,采用SPSS 19.0软件通过Fisher确切概率法及Mann-Whitney秩和检验分别进行统计学分析,根据受试者操作特性(ROC)曲线分析确定鉴别诊断的ADC阈值.结果 定性分析显示10例良性息肉样病变中,3例为等信号,5例为高信号,2例为很高信号,而13例恶性息肉样病变中,4例为高信号,9例为很高信号,差异有统计学意义(P=0.036).恶性息肉样病变的平均ADC值[(1.13 ±0.28)×10-3 mm2/s]明显低于良性息肉样病变[(2.22±0.42)×10-3mm2/s](P＜0.01),设定ADC阈值为1.5×10-3 mm2/s时,其敏感度、特异度和准确度分别为92％、100％和96％.结论 DWI有助于良恶性胆囊息肉样病变的鉴别.

abstractsObjective To evaluate the efficiency of diffusion-weighted MRI in differentiating between benign and malignant polypoid gallbladder lesions.Methods The study population consisted of 10 benign (5 polyps, 3 adenomyomatosis and 2 adenomas) and 13 malignant (all adenocarcinomas) polypoid gallbladder lesions treated in hospital from November 2007 to May 2014.DWI was evaluated by two observers.Qualitatively, the signal intensity of the lesions on DWI was visually evaluated and categorized as iso, high, or very high signal.Quantitatively, the ADC values of the lesions were measured from ADC maps.Statistical analysis was performed using a two-tailed Fisher's exact test and the Mann-Whitney test, respectively.The cut-off values were determined by receiver operating characteristic analysis.Results Qualitative analysis revealed a statistical difference (P =0.036).In the 10 benign lesions, three were categorized as iso, 5 as high, and 2 as very high signal.Four of the 13 malignant lesions were categorized as high, and the remaining 9 were categorized as very high signal.The mean ADC value of the malignant lesions [(1.13 ±0.28) × 10-3mm2/s] was significantly lower than that of benign lesions [(2.22 ±0.42) × 10-3 mm2/s,P＜0.01].The cut-off value between cancer and the benign lesions was 1.5 × 10-3mm2/s, the sensitivity, specificity, and accuracy were 92％, 100％ and 96％, respectively.Conclusion Diffusionweighted MRI may be useful in differentiating between benign and malignant polypoid gallbladder lesions.