STIR对诊断乳腺肿块的临床应用研究

目的 探讨低场强MR机STIR对诊断乳腺肿块的临床应用价值。方法 对25例共26个临床可扪及的乳腺肿块患者行T1WI和STIR横断及矢状面扫描，逐个记录肿块的MRI形态和信号特征，重点观察肿块的形态、边缘、纵横比、内部信号、周围腺体及皮肤改变、腋窝淋巴结肿大等表现，密切结合临床和MRI特点对乳腺肿块性质进行判断。结果 乳腺囊肿于T1WI信号特异，乳腺实性肿块于T1WI信号无特征性，但可以显示肿块形态及与腺体下脂肪垫的关系。STIR可清晰显示乳腺肿块的形态和信号特征，并可同时显示肿块同腺体、皮肤及腋窝淋巴结肿大的关系。良恶性肿块间在形态、边缘、纵横比及内部信号特征方面具有显著性差异。结合STIR所显示的乳腺肿块的形态和信号特点及临床触诊，MRI诊断乳腺肿块的灵敏度为92．3％,符合率为81％。结论 低场强MR机STIR是显示乳腺肿块的理想序列，对诊断乳腺囊肿、乳腺炎和典型的浸润性导管癌及乳腺纤维腺瘤效果明显。

Research on clinical application of STIR in the diagnoses of breast masses

Objective: To evaluate the clinical application of STIR in the diagnosis of breast masses by using low field MR unit. Methods: Twenty-six clinically palpable breast masses in 25 cases were examined routinely in transverse T 1WI and STIR and saggital STIR. The MR appearances of the masses were carefully recorded according to their specific shape and signal. More attention was paid to the shape, boundary, depth to width ratio, texture of the signal inside the mass, the nearby skin and glandular tissue changes as well as the axillary lymphnode enlargement. A prospective diagnosis was made according to the combination of the clinical manifestation and MRI appearance, and the diagnostic result was correlated with the result of operation and pathologic examination. Finally the diagnostic accuracy of the breast masses was calculated. Results: Cysts of the breast had characteristic signal in T 1WI. Although different solid masses had no special signal in T 1WI the shape of the masses and the subglandular fat pad were clearly manifested but by using T 1WI. STIR could reveal clearly the characteristics of both the shape and the texture of the breast masses. Other changes of the nearby glandular tissue, skin and axillary lymphnode enlargement relative to the breast masses were also clearly showed in STIR. There were significant differences between infiltrative ductal carcinoma and other benign breast masses in their shape regularity, edge, depth to width ratio and texture of internal signal intensity. By using the subjective method of judgement according to the combination of the specific shape, texture of the masses in STIR and the clinical palpation, the MRI diagnostic sensitivity is 92.3%, and agreement rate 81%. Conclusion: STIR in low field MR unit is a promising sequence in the diagnosis of palpable breast masses, especially of cysts, inflammations, typical breast carcinomas and fibroadenomas.