双侧乳腺同时磁共振扫描序列及扫描方位选择

The selection of sequence and position:MRI of the bilateral breasts

目的探讨双侧乳腺同时MR扫描的序列及扫描方位在乳腺病变MRI诊断中的作用。方法30例乳腺病变常规SPGR序列T1WI、FSE序列T2WI及脂肪抑制分别行轴位、矢状位和冠状位平扫。注射Gd-DTPA后采用3D-FSPGR序列行双侧乳腺矢状位同时动态增强扫描。结果SPGR序列T1WI平扫信噪比好,时间短,但病变与正常组织的对比分辨率不及FSE序列T2WI。动态增强3D-FSPGR序列显示病变最敏感,可以显示平扫不能显示或显示不明确的病变,而且可根据病变的增强特点及时间-信号强度曲线进行定性分析。FSE序列T2WI冠状位压脂对腋窝区淋巴结的显示较敏感。结论双侧乳腺3D-FSPGR序列是乳腺病变中最有价值的检查序列,轴位及矢状位是乳腺检查中的基本位置,冠状位可以良好地显示腋窝淋巴结。

Objective To investigate the magnetic resonance imaging（MRI） of bilateral breasts with various sequences and positions and evaluate those imaging in the diagnosis of the breast disorders. Methods MRI using SPGR-T1-weighted imaging（T1WI） and FSE T2-weight imaging（T2WI） with fat suppression on axial, sagittal and coronal sections was performed in 30 cases of breast disorders. After the Gd-DTPA was given, dynamic enhancement with 3D-FSPGR sequence was done on bilateral breasts on sagittal slices. Results Non-enhanced T1WI using SPGR sequence had higher SNR and quicker than FSE T2WI ,but the contrast of the signal between the lesions and normal tissue was poor compared with FSE T2WI. 3D-FSPGR sequence with chemical saturation had the highest sensitivity for detecting the breast lesions among all 3 sequences and demonstrated the occult lesions that could not be found on the non-contrast enhanced scan. Additionally, with the characteristics of the lesions during enhancement and time-intensity curve, a qualitative evaluation of the disorder could be made. Coronal FSE with T2WI fat suppression had higher sensitivity for auxiliary lymphadenpathy. Conclusion 3D-FSPG is the most valuable sequence in the evaluation of the breast disorders. Axial and sagittal slices are the routine projections in the imaging of the breast disorder. The coronal imaging is superior in assessing auxiliary lymphadenopathy.