磁共振减影技术在乳腺良恶性肿瘤鉴别诊断中的应用

摘要

Objective: To evaluate dynamic contrast-enhanced MRI in conjunction with MR subtraction in the differential diagnosis of benign and malignant breast tumors at 3 Tesla. n Methods: A total of 78 patients with breast tumors enrolled in this study, including 45 malignant lesions and 33 benign lesions verified by histopathology. Dynamic MR contrast enhanced imaging was done by T1 high resolution isotropic volume excitation sequence. MR subtraction was used to retrospectively analyze the MR dynamic image. A dynamic phase subtraction (DPS) map is a map image with pixel-by-pixel subtraction of an early-phase image from a delayed maximum enhancement phase image obtained in a dynamic study. The sensitivity and speciifcity were calculated with or without subtraction in the diagnosis of benign and malignant breast tumors. Results: The sensitivity of benign breast masses increased from 0.879 to 0.939, and the specificity increased from 0.818 to 0.909 with reference to the DPS map. There was statistical difference between with or without DPS (Z=2.023,P=0.043). The sensitivity of breast malignant masses increased from 0.889 to 0.933, and the specificity increased from 0.867 to 0.911 with reference to the DPS map, with statistical difference between with or without DPS map (Z=2.294, P=0.021). The pattern of TIC changed from continuous to a plateau in 8 patients, from a plateau to washout in 10, and from continuous to washout in 5. No changes were observed in the other 55 patients. n Conclusion: MR Subtraction is a simple and useful technique to identify breast lesions. It helps to accurately set the location of the ROI TIC and improve the detection rate of benign and malignant breast tumors.%目的：评价3.0T磁共振动态增强结合减影技术对乳腺良恶性肿瘤鉴别诊断的意义。方法：收集78例经病理确诊的乳腺肿瘤患者，恶性45例，良性33例，采用三维容积内插快速扰相梯度回波序列进行动态扫描，使用磁共振减影技术回顾性分析MR动态增强图像，减影图由延时期强化最显著的图像减除早期增强图像获得，分别计算使用减影图与不使用减影图诊断乳腺良恶性肿瘤的敏感度和特异度。结果：参考减影图，乳腺癌诊断敏感度由0.889提高到0.933，特异度由0.867提高到0.911，使用与不使用减影图的两次诊断结果有显著差异(Z=2.023，P=0.043)；乳腺良性肿瘤诊断敏感度由0.879提高到0.939，特异度由0.818提高到0.909，使用与不使用减影图的两次诊断结果有显著差异(Z=2.294，P=0.021)。参考减影图后重新设置感兴趣区(ROI)，病灶动态增强时间信号曲线(TIC)由流入型到平台型8例，由平台型到流出型10例，5例由流入型变为流出型。55例TIC曲线无显著改变。结论：MR减影技术简便易行，有助于精确设定TIC曲线ROI的位置，可提高乳腺良恶性肿瘤的检出率。