MR导引的乳腺病变定位方法及其病变特征分析

MRI-guided breast lesion localization and lesion analysis

目的探讨乳腺病变MR导引定位的适应证、技术可行性，以及病灶特点。方法在1．5TMR扫描仪上利用特制的活检穿刺定位架，对43例在MRI上显示有可疑病灶，而临床触诊、乳腺X线和超声检查未显示有病灶的患者行MR导引的双钩针定位。观察技术操作可行性和定位准确性，并观察病灶特征，采用Fisher精确检验分析定位病灶的影像特征与病理结果的关系。结果43例中，37例（86．0％）共38个病灶定位成功。取消定位6例，其中4例病灶在定位时不明显，2例摆位困难。38个病灶呈肿块样强化17个，非肿块样强化20个，混合性病灶1个。恶性肿瘤11个（28．9％）。非肿块样强化的内部强化特征在良恶性病变间分布差异有统计学意义（P=0．028），其余形态特征在良、恶性肿瘤问差异无统计学意义（P〉0．05）。结论对仅在MRI上显示的可疑病灶，MR导引的定位是一种准确而安全的方法，这些病灶影像上的形态特征在良恶性乳腺肿瘤间的差异不明显。

Objective To analyze the indications, techniques of MR-guided localization and the imaging features of breast lesion. Methods Hook wire localization was performed in 43 patients whose lesions were only detected by MRI, based on a 1.5 T MR scanner and a special MR biopsy positioning frame. The feasibility of operation and accuracy of localization were explored. Lesion features and pathologic findings were analyzed using Fisher exact test. Results A total of 37 patients （ 86. 0% ） with 38 lesions underwent MR-guided localization. Of the 6 patients canceled, the lesions were not obvious in 4 patients, and the positioning was difficult in 2 cases. Of the 38 lesions, 17 were masses,20 were non-mass enhancement lesions,and one lesion was undetermined enhancement. There were 11 （28.9%） malignant lesions. The distribution of internal enhancement pattern was different between benign and malignant non-mass lesions （P = 0. 028）, while the other morphological features between benign and malignant were not significantly different （P 〉 0. 05 ）. Conclusions MR-guided localization provides an accurate and safe method for localizing the suspicious lesions on MRI. The morphological findings of these lesions are not characteristic for the differentiation of benign and malignant lesions.