论文部分内容阅读
目的:探讨脂肪坏死的MR表现、演变规律及其病理基础。方法:采用射频消融技术在5只实验用猪(约克夏)项背部浅表脂肪层内制作脂肪坏死模型。于造模后1周开始,在不同时间点(7 d～6个月)对脂肪坏死区域进行MR扫描。MR成像序列包括T1WI、T2WI、T2STIR、灌注成像及常规T1WI增强扫描。分析病灶的MR表现,并与病理结果对照。结果:5只猪共成功制作出22个脂肪坏死病灶模型,依据病理特征将脂肪坏死演变过程分为早、中、晚期。全部病灶早期在T1WI及T2WI均呈不均匀稍低信号,边缘可见环形低信号。随时间推移,病灶T1WI及T2WI信号均逐渐减低,T1WI部分病灶内可见点片状高信号。所有时间点病灶T2STIR均呈明显高信号,信号强度随时间推移略有降低。灌注曲线表现为逐渐上升型及平台型,未见速升速降型。强化特点早期以环形强化为主,中后期以不均匀轻度强化为主。病理显示病灶早期边缘主要是由纤维母细胞、吞噬脂质的泡沫细胞及混合性炎症细胞组成,内见脂肪崩解后残存的空泡状轮廓,中后期纤维成分逐渐增多,直至完全替代坏死的脂肪细胞。结论:不同时期脂肪坏死MR表现具有一定的特征性,能够反映其病理特征。
Objective: To investigate the manifestation, evolution and pathology of MR in fat necrosis. METHODS: Fat necrosis models were made in the superficial fat layer of the back of 5 experimental pigs (Yorkshire) using radiofrequency ablation. At 1 week after modeling, MR scanning of the fat necrosis area was performed at different time points (7 days to 6 months). MR imaging sequence includes T1WI, T2WI, T2STIR, perfusion imaging and conventional T1WI enhanced scan. The MR findings of the lesions were analyzed and compared with the pathological findings. Results: Twenty-two fat necrosis lesions were successfully produced in 5 pigs. According to the pathological features, the process of fat necrosis was divided into early, middle and late stages. All lesions early in T1WI and T2WI showed uneven slightly lower signal, the edge of the ring can be seen low signal. Over time, the lesion T1WI and T2WI signals were gradually reduced, T1WI lesions can be seen some flaky high signal. The T2STIR of all the time points showed obviously high signal, and the signal intensity decreased slightly with the passage of time. Perfusion curve showed a gradual increase and platform type, no speed-down type. Reinforcement characteristics of early ring-based enhancement, in the latter part of non-uniform mild enhancement based. Pathology showed that the early edge of the lesion is mainly composed of fibroblasts, phagocytic lipid foam cells and mixed inflammatory cells, see the collapse of fat after the collapse of the vacuolar contour, the fiber content gradually increased in the late until completely replace the necrosis Adipocytes. Conclusion: The MR manifestations of fat necrosis in different periods have certain characteristics and can reflect the pathological features.