乳腺良恶性病变的3.0T磁共振扩散加权成像鉴别诊断及b值优化  

Value of Diffusion-weighted Imaging with Different b Values in the Diagnosis of Breast Lesions at 3.0T MRI

作　　者：张雪梅[1] 林江[2] 叶芳[2] 姚秀忠[2] 曾蒙苏[2] 

机构地区：[1]复旦大学附属中山医院青浦分院放射科,复旦大学附属中山医院放射诊断科 [2]复旦大学附属中山医院放射诊断科

出　　处：《中国医学计算机成像杂志》2012年第3期219-223,共5页Chinese Computed Medical Imaging

摘　　要：目的:探讨3.0T扩散加权成像(DWI)在乳腺良恶性病变鉴别诊断中的诊断价值并对b值使用进行优化。方法:34例患者共20个良性和16个恶性乳腺病灶纳入研究,同期20例正常乳腺受检者列为对照组。采用3.0T MR行乳腺DWI成像检查,b值分别取0,750 s/mm2,1000 s/mm2,1250 s/mm2。比较不同b值DWI图像质量,测量病灶的对比噪声比(CNR)以及表观扩散系数(ADC)值,以病理诊断为金标准,计算诊断乳腺癌的敏感度、特异度及准确性,绘制受试者工作特征曲线(ROC)并进行比较。结果:不同b值时DWI图像主观质量评分没有统计学差异(F=3.02,P=0.0516>0.05)。b=750 s/mm2时病灶的CNR明显优于b=1000s/mm2及1250s/mm2时(P值为0.004及0.000),而b=1000s/mm2与1250s/mm2之间没有统计学差异(P=0.800>0.05)。相同b值时,正常乳腺组织的平均ADC值>乳腺良性病变>乳腺恶性病变(P均=0.000)。以各b值恶性病变平均ADC值95%可信区间的上限作为界定乳腺癌ADC的阈值,则b=750 s/mm2、1000 s/mm2、1250s/mm2时,ADC阈值分别为1.33×10-3mm2/s、1.25×10-3mm2/s、1.16×10-3mm2/s。以上述阈值判断乳腺癌的敏感度、特异度及准确性分别为81.25%、87.5%、85.71%,81.25%、77.5%、78.57%及81.25%、82.5%、82.14%。三个b值的ROC曲线下面积无显著性差异(P=0.1925>0.05)。结论:乳腺的3.0T DWI中,以b=750s/mm2时病灶CNR最高,值得推荐应用。应用DWI鉴别乳腺良恶性病变时,需要结合ADC值判断。Purpose： To evaluate the value of diffusion- weighted imaging with different b values in the diagnosis of breast lesions at 3.0T MRI. Methods： Twenty normal controls and 34 patients with 20 benign breast lesions and 16 malignant ones underwent diffusion-weighted imaging at 3.0T MRI with different b values of 0, 750, 1000 and 1250s/mm2. The other conventional sequences （T2WI and T1WI dynamic contrast- enhanced MRI） were performed at 3.0T or 1.5T MRI. Image quality score, contrast-to-noise ratio （CNR） and apparent diffusion coefficient （ADC） of normal breast, benign lesions and malignant ones with the same b value and different b values were compared and analyzed. Sensitivity, specificity and accuracy for the diagnosis of breast cancer with different b values were calculated respectively, as well as the ROC curves. Results： （1） The difference of the image quality score among the different b values was not statistically significant （F=3.02, p=0.0516〉0.05）. （2） The difference of CNR of the breast lesion among the different b values was statistically significant （F=10.69, p=0.0001〈0.01）. Higher CNR was obtained when b value was 750s/mm2 than those when b value was 1000s/mm2 and 1250s/mm2, and the differences were statistically significant （P values were 0.004 and 0.000）, but the difference of CNR between the b value of 1000s/mm2 and 1250s/ram2 was not statistically significant （P=0.800〉0.05）. （3） Average ADC value of normal breast was higher than benign lesion, while that of benign lesion was higher than that of malignant ones at the same b value. Among them the differences were statistically significant （P values were all 0.000）. （4） The cutoff ADC value was 1.33x10 3mm2,1.25x10 3mm2/s, and 1.16x10 3mm2/s when b value was 0,750s/mm2, 0,1000 and 0,1250s/mm2. Sensitivity, specificity and accuracy for diagnosis of breast cancer was 81.25%, 87.5%, 85.71%~ 81.25%, 77.5%, 78.57% and 81.25%, 82.5%, 82.14% respectively. And the area under ROC curve （AUC） was 0.8

关 键 词：磁共振成像 扩散加权成像 乳腺肿瘤 

分 类 号：R445.2[医药卫生—影像医学与核医学] R737.9[医药卫生—诊断学]