乳腺实质性病变的MRI定位研究:俯卧位与仰卧位对照

Breast substantial lesion localization on MR imaging: prone posture vs. supine posture

目的:研究MRI检查体位与手术体位乳腺病变相对空间位置变化的影响因素及变化规律。方法:选取81例乳腺MRI检查呈单个实质性病灶的患者,行胸部扫描加仰卧位乳腺扫描。选择乳头为定位参照点,确定与病变中心相关的3条径线,即深度径线A、内外距离径线B和上下距离径线C。研究两个体位时3条径线变化的影响因素。使用配对t检验比较两个体位病变定位时各径线的差异,求各径线的差值;使用单因素方差分析寻找影响各径线差值的因素。结果:患者月经状态、乳腺纤维腺体组成、病灶大小、影像学表现及病理类型对径线变化影响不大。检查体位改为手术体位后,所有病灶的定位径线均发生不同程度的变化,径线A和B的变化程度最大,径线A平均缩小(22.73±13.40)mm,径线B平均增大(12.67±11.85)mm;而径线C相对变化较小,平均增大(8.16±10.87)mm。病变所在位置对病变定位有显著影响(P<0.05),位于乳晕后区的病灶3条径线变化最小,后带及下部病灶偏移较明显。结论:病灶定位径线变化与病灶所在位置密切相关。根据病变所在位置的径线变化规律,纠正体位变化带来的定位偏差可提高病灶切除的准确性。

Objective： To study the influencing factors and rules of changes in relative spatial position of breast lesions from MR examination posture to operation posture. Methods： A total of 81 cases with breast substantial lesion on MR images were chosen, and then breast imaging in supine posture based on chest scan was performed. Nipples were selected as positioning reference point to determine three position lines associated with the lesion center： depth line A, horizontal line B and height line C. The influencing factors of the changes in three position lines in two postures were investigated. Paired t test was used to compare the differences in three lines when positioning lesions in the two postures and the difference values were calculated. Single factor variance analysis was used to find the influencing factors of difference values of three position lines. Results： Menstrual status, fibroglandular tissue, lesion size, imaging manifestations and pathological type did not influence the changes in three position lines. From MR examination posture to operation posture, all position lines changed. The greatest changes took place in line A and line B. Line A averagely decreased （22.73±13.40） mm, and line B averagely increased （12.67±11.85） mm. And line C averagely increased （8.16±10.87） mm. The lesion location had significant effects on lesion positioning （P〈0.05）. Three position lines in the lesions behind nipple areola had the minimal changes, and those in the posterior and lower parts had marked changes. Conclusion： The changes in lesion position lines are closely related to lesion location. According to the rules of changes in lesion position lines, correction of the deviation caused by posture could improve the accuracy of resection of lesions.