腎上腺腫塊mr的特征及診斷-展示頁(yè)
2025-06-04 18:14本頁(yè)面
【正文】 ，組織學(xué)及解剖學(xué) 腎上腺位于腎的上方，右側(cè)腎上腺呈人字形，左側(cè)呈半月形，右側(cè)較左側(cè)稍高。腎上腺占位可根據(jù)細(xì)胞內(nèi)脂質(zhì)，肉眼可見(jiàn)的脂肪，出血和囊變，血供情況和腫瘤形態(tài)進(jìn)行分類(lèi) 。這些特征可用于大部分腎上腺占位：腺瘤，增生，單純或復(fù)雜囊腫，淋巴管瘤，髓樣脂肪瘤，嗜鉻細(xì)胞瘤 ,腎上腺出血，皮質(zhì)腺癌，神經(jīng)母細(xì)胞瘤，淋巴瘤和轉(zhuǎn)移瘤。成人的每側(cè)腎上腺重 4～ 5g。 腎上腺實(shí)質(zhì)由周邊的皮質(zhì)和中央的髓質(zhì)兩部分構(gòu)成，兩者在發(fā)生、結(jié)構(gòu)和功能上均不相 同，皮質(zhì)來(lái)自中胚層，髓質(zhì)來(lái)自外胚層。 髓質(zhì)主要由排列成索或團(tuán)的髓質(zhì)細(xì)胞組成，髓質(zhì)細(xì)胞又稱(chēng)為嗜鉻細(xì)胞 (chromaffin cell)。 腎上腺的血管分布：腎上腺上面有膈下動(dòng)脈的終末分支，經(jīng)腎上腺靜脈出腎上腺。髓質(zhì)內(nèi)的小靜脈匯合成一條中央靜脈，最后匯入腎上腺靜脈，右側(cè)直接引入下腔靜脈，左側(cè)先與膈下靜脈會(huì)合，爾后引入左腎靜脈。 hematoxylineosin [HE] stain) of a normal adrenal gland specimen shows an outer capsule (C) and the cortical layers: zona glomerulosa (G), fasciculata (F), and reticularis (R). The medulla (M) is present centrally. 二，正常腎上腺 MRI表現(xiàn)： 在軸位及冠狀位 MRI圖像上，右側(cè)腎上腺直接位于下腔靜脈后方，右腎上極上方，呈線狀，倒 V或 Y形。正常腎上腺 26mm厚， 24 cm長(zhǎng)。 it has a triangular, inverted Y, or V configuration. Normal adrenal glands range from 2 to 6 mm in thickness and from 2 to 4 cm in length. Figure 3. Coronal T1weighted, threedimensional, GRE MR image obtained with VIBE shows the normal inverted Y shape of the right adrenal gland (arrow 三 MRI檢查技術(shù)： 腎上腺成像最重要的是化學(xué)位移成像，可以通過(guò)擾相 GRE的 inphase and outofphase來(lái)完成。 四：含脂肪腎上腺腫塊 Fatcontaining Adrenal Masses Fatcontaining adrenal masses can be classified into two main types: those that contain intracellular fat (eg, adenoma) and those with macroscopic fat (eg, myelolipoma). Adrenal masses that contain intracellular fat have been shown to lose signal intensity on chemical shift outofphase images pared with inphase images owing to the presence of intracellular lipid. Adrenal lesions that contain macroscopic fat demonstrate a loss of signal intensity on fatsaturated images. A loss of signal intensity at chemical shift imaging can be seen at fatwater interfaces, typically at the borders of such lesions 含脂肪腎上腺腫塊分為兩類(lèi)：細(xì)胞內(nèi)脂質(zhì)（如腺瘤），肉眼可見(jiàn)脂肪 （如髓樣脂肪瘤）。在化學(xué)位移成像上信號(hào)減低能夠 在脂 —水交界處發(fā)現(xiàn)，腫塊邊緣具有代表性。腎上腺腺瘤最重要的特征是細(xì)胞內(nèi)脂質(zhì)，化學(xué)位移成像是腎上腺腺瘤最可靠的檢查手段。 Figure 4. (a, b) Axial inphase and outofphase MR images show an adrenal adenoma (arrow), which exhibits the typical decrease in signal intensity on the outof phase image. Photograph
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