Figure 6. (a, b) Axial T1-weighted MR images obtained without fat suppression and with fat suppression show typical MR imaging features of right adrenal myelolipoma. The fatty component of the myelolipoma (arrow in a) shows a decrease in signal intensity on the fat-suppressed image. Photomicrograph (original magnification, 100; H-E stain) shows the typical microscopic appearance of myelolipoma. There is fat and a maturing marrow element on the right side and an otherwise normal adrenal cortex on the left.
2,髓样脂肪瘤 髓样脂肪瘤是不常见的良性肿瘤。由成熟脂肪组织和造血组织构成。大部分是 在偶然时发现。在非压脂T1WI上脂肪成分为高信号,压脂脂肪成信号减低能够 帮助诊断。 髓样脂肪瘤根据MR信号特征分为三类: 1)以脂肪成分为主型:T1WI均匀高信号,T2WI中等信号。 2)脂肪和髓样成分混合型:T2WI和T1WI增强上脂肪信号混杂高信号区域。 3)髓样成分为主型:相对于肝脏,T1WI低信号,T2WI高信号,增强有强化。 髓样脂肪瘤可以很大,并有症状,可以继发出血。巨大髓样脂肪瘤要和腹膜后 像脂肪肉瘤鉴别。
Figure 7. (a, b) Coronal T1-weighted in-phase and T2-weighted half-Fourier RARE MR images show an oval, well-circumscribed, right adrenal cyst (arrow in b) with a thin wall (arrowhead in b). The cyst has a typical appearance, showing low signal intensity at T1-weighted imaging and high signal intensity at T2-weighted imaging. Photomicrograph (original magnification, 100; H-E stain) shows a cystic lesion with a simple cuboidal mesothelial lining.