磁共振扩散加权成像对乳腺炎性病变的诊断价值探讨

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

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。

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 intensitv 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.