乳腺腺病瘤MRI表现特征分析

Analysis of MRI Features of Breast Adenosis Tumor

目的分析乳腺腺病瘤MRI平扫、动态增强(DCE)和扩散加权成像(DWI)表现特征,提高对腺病瘤的认识和术前诊断准确率。方法搜集2008年10月至2013年11月期间行乳腺MRI检查并经手术病理证实的8例患者9个乳腺腺病瘤,依据美国放射学会提出的乳腺影像报告和数据系统磁共振成像(BI-RADS-MRI)标准,回顾性分析病变MRI表现,包括形态学、平扫T1WI及T2WI信号、DCE表现及时间-信号强度曲线(TIC)类型、DWI信号及ADC值。结果 9个腺病瘤中8个表现为肿块,1个表现为非肿块。8个肿块型腺病瘤中,6个呈圆形或卵圆形,所有病变均边界清楚,6个边缘不规则;于平扫T1WI均呈等信号,脂肪抑制T2WI呈等或稍高信号;DCE-MRI扫描均于早期时相明显强化,早期强化率平均值为(173.2±52.8)%,4个腺病瘤内部呈不均匀强化;7个TIC呈流出型;于DWI上呈高或稍高信号,b值为500 s/mm2时,平均ADC值为(1.4±0.3)×10-3mm2/s,b值为1000 s/mm2时,平均ADC值为(1.2±0.3)×10-3mm2/s。1例非肿块型腺病瘤呈区域性分布,呈不均匀强化,TIC呈Ⅰ型。结论腺病瘤DEC-MRI扫描TIC类型和DWI上ADC值表现与乳腺癌相似,但其形态上多呈良性病变特点,MRI检查有助于乳腺腺病瘤的诊断,但确诊仍需依靠组织病理学。

Objective To analyze MRI features of breast adenosis tumor,including plain MRI,dynamic contrast-enhanced MRI（ DCE-MRI） and diffusion weighted imaging（ DWI）,in order to improve the understanding of adenosis tumor and the preoperative diagnostic accuracy.Methods A total of 8 patients with pathologically-proved breast adenosis tumor（ 9 lesions in total）,who were encountered at authors’ hospital during the period from Oct.2008 to Nov 2013,were enrolled in this study.Breast MRI examination was performed in all patients.According to Breast Imaging and Reporting Data System Magnetic Resonance Imaging（ BI-RADS-MRI） standard,which was proposed by American Radiological Society,the MRI manifestations,including morphology,signal intensity on plain T1 WI and T2 WI,DCE-MRI findings,the pattern of time-signal intensity curve（ TIC）,DWI signal and ADC values,were retrospectively analyzed.Results Of the 9 lesions,8 was characterized by a mass and one was non-mass type.Among the 8 breast adenosis tumors of mass type,6 were round or oval and 6 had an irregular margin; all the lesions showed a clear border.All the lesions were iso-intensity on T1 WI,and were iso-intensity or slight hyper-intensity on FS T2 WI.All lesions showed early and obvious enhancement on DCE-MRI,the mean early phase enhancement rate was（ 173.2 ± 52.8） %.Heterogeneous enhancement was observed in 4lesions.TIC of type Ⅲ（ washout pattern） was seen in 7 lesions,which showed hyper-intensity or slightly hyper-intensity signal on DWI,the mean ADC value was（ 1.4 ± 0.3） × 10- 3mm2/ s when b = 500 s / mm2,and the mean ADC value was（ 1.2 ± 0.3） × 10- 3mm2/ s when b = 1000 s / mm2.In one case of non-mass type,the lesion was regional distribution,showing inhomogeneous enhancement and type I TIC.Conclusion The TIC type on DCE-MRI and the ADC value on DWI of breast adenosis tumors are similar to those of breast cancers.But,its morphology usually has benign lesion characteristics.MRI is helpful for the diagnosis of breast adenosis tumor,although the confirmation of the diagnosis relies on pathological examination.