磁共振扩散加权成像对乳腺炎性病变的诊断价值探讨

目的 探讨磁共振扩散加权成像(diffusion weighted imaging,DWI)对乳腺炎性病变的诊断价值.方法 收集经活检或手术病理证实的乳腺炎性病变33例(其中12例炎症伴脓肿形成).全部病例行磁共振短TI反转恢复序列(STIR)压脂及DWI检查,DWI采用3组b值扫描(b为400、800、1 000 s·mm-2).分析炎性病变的STIR及DWI表现,测量其ADC值并进行统计学分析.结果 (1) 81.82%(27/33)炎性渗出在STIR上表现为散在的斑片状及点条状高信号影,18.18%(6/33)表现为等-略低信号;75.75%(25/33)炎性渗出在DWI上也表现为散在点片状或条状高信号,但信号强度低于STIR,且显示的炎性渗出范围均较STIR要小,24.24%(8/33)的等信号.脓肿在DWI及STIR上均表现为境界较清晰的结节状均匀高信号影.(2) 同一b值下,脓肿与邻近炎性渗出、炎性渗出与正常腺体及脓肿与正常腺体之间ADC差异均有统计学意义(P<0.05);炎性渗出及脓肿在3个b值下的ADC值差异均具有统计学意义,且b值越小,ADC值越大.随b值的增大,100%(25/25)炎性渗出DWI信号强度呈现逐渐减低,84%(21/25)呈现面积逐渐减小;而83.33%(10/12)脓肿的信号强度表现为无明显变化,66.67%(8/12)的面积无明显变化.结论 STIR及DWI相结合是乳腺炎性病变重要的补充检查手段,DWI对脓肿的显示具有重要价值.

Value of MR diffusion-weighted imaging in diagnosing the inflammatory lesions of breast

Objective: To investigate the diagnostic value of diffusion-weighted magnetic resonance imaging(DWI) in patients with inflammatory lesions of breast.Methods: Thirty-three female patients(including twelve inflammatory lesions with abscess formation) pathologically proven mastitis were all examined with MR diffusion-weighted imaging(MR-DWI) and short T1 inversion recovery(STIR).All patients were scanned with different b values(b=400 s·mm-2,800 s·mm-2,1 000 s·mm-2 respectively) in DWI.Then the ADC value was calculated and the findings of lesions in DWI and STIR were analyzed.Results:(1) 81.82% inflammatory exudation mostly manifested patchy or dot-linear high signal intensity and 18.18% manifested equal-low signal in STIR,75.75% manifested scatter dot-linear high intensity in DWI and the signal intensity was lower than in STIR and the scape of the exudation was all smaller than in STIR,24.24% manifested equal signal.All abscess manifested homegenious high signal intensity with well-defined margin in STIR and DWI.All abscess were well shown with b value increasing due to the exudation sharply lowered.(2) 100% inflammatory exudation were lower in signal intensity and the 84% decreased in area of exudation with the b value increasing,but most of the signal intensity and area of abscess had no change,they were respectively 83.33% and 66.67%.(3) Under the same b value,all the ADC values had significant differences between the abscess and the inflammatory exudation,the inflammatory exudation and the normal breast tissue,the abscess and the normal breast tissue(P<0.05).(4) There were significant differences among the ADC value of different values of the inflammatory exudation and the abscess.The lower the b value,the higher the ADC value.Conclusion: The combination of STIR and DWI is an important supplemental method for diagnosing inflammatory lesions.DWI can play an important role in demonstrating the abscess.