【正文】 增強時均勻一致強化也是腎上腺腺瘤的特征，腎上腺腺瘤小的，圓點狀信號強度改變可能是由于囊變，出血或血供的差異。囊腫出血，破裂或感染時出現急性癥狀。 Figure 11. (a–c) Axial T1weighted inphase MR image , outofphase MR image , and threedimensional GRE contrastenhanced MR image with VIBE show a pheochromocytoma (arrow). The pheochromocytoma shows the typical features of no loss of signal intensity on the outofphase image and intense enhancement on the contrastenhanced image. Photograph of sections of the resected specimen shows a typical, homogeneous, wellcircumscribed, tanpink lesion, an appearance typical of pheochromocytoma. 七 : Adreniform Adrenal Masses 1，腎上腺皮質增生 腎上腺皮質增生常見于 Cushing綜合癥。 Figure 15. (a, b) Axial T1weighted inphase and outofphase MR images show bilateral lymphomatous deposits. The deposits have low signal intensity, and the signal intensity does not decrease on the outofphase pared with the inphase image. 3，轉移 轉移病變是腎上腺最常見的惡性腫瘤，尸檢發(fā)現 27%患惡性上皮腫瘤有腎上腺轉移。 MRI在顯示腫塊上臂 CT有優(yōu)勢，在于 MRI高軟組織分辨率，多方位成像，以及能清楚顯示腫瘤成分。增強后強化。較大腎上腺皮質腺癌能夠侵犯腎上腺靜脈和下腔靜脈。因為一部分嗜鉻細胞瘤也表現出中等信號。巨大髓樣脂肪瘤要和腹膜后像脂肪肉瘤鑒別。在化學位移成像上信號減低能夠 在脂 —水交界處發(fā)現，腫塊邊緣具有代表性。 腎上腺實質由周邊的皮質和中央的髓質兩部分構成，兩者在發(fā)生、結構和功能上均不相 同，皮質來自中胚層，髓質來自外胚層。內側面依次為腎上腺上 ﹑ 中 ﹑ 下動脈，分別起源于膈下動脈，腹主動脈，腎動脈。 腎上腺腺瘤出血少見，出血不同時期有不同 MRI表現 ，急性期 T1WI和肌肉信號相近， T2WI低信號。 1， 單純囊腫 內皮囊腫是腎上腺囊腫最常見的亞型。腎上腺皮質增生可以是彌漫性和結節(jié)性，常發(fā)生于兩側。 原發(fā)部位一般有：肺，腸道，乳腺，胰腺。 Figure 17. (a, b) Coronal unenhanced T1weighted MR image and axial T2weighted MR image obtained with inversion recovery show a right adrenal tumor. The tumor is predominantly hypointense on the T1weighted image and has areas of highsignalintensity hemorrhage (arrow in a). The tumor is hyperintense on the T2weighted image. ，節(jié)細胞神經母細胞瘤 其潛在惡性度介于神經母細胞瘤和節(jié)細胞神經瘤之間。 神經母細胞瘤 T1WI上不均勻低信號和 T2WI上不均勻高信號。 腎上腺皮質腺癌可以有點狀細胞內脂肪，在 outofphase上信號減低。 Figure 10. Coronal T1weighted, threedimensional, GRE MR image obtained with VIBE shows a lymphangioma, which has the typical appearance of a wellcircumscribed area of low signal intensity. Photograph of the specimen shows