肾上腺解剖与肾上腺腺瘤快速排泄性CT和MRI化学移位特点

1、肾上腺解剖与肾上腺腺瘤快速排泄性CT和MRI化学移位特点2022-3-7肾上腺左右各一，位于肾的上方，共同为肾筋膜和脂肪组织所包裹。左肾上腺呈半月形，右肾上腺为三角形。肾上腺两侧共重约30g。从侧面观察，腺体分肾上腺皮质和肾上腺髓质两部分，周围部分是皮质，内部是髓质。两者在发生、结构与功能上均不相同，实际上是两种内分泌腺。2022-3-7球状带：醛固酮束状带：皮质醇网状带：性激素髓质：肾上腺素、去甲肾上腺素adenomas contain abundant intracytoplasmic lipid, and thus approximately 70%- 10 HUAdrenal Aden

2、oma approximately 30% of adrenal adenomas are lipid-poor- greater than 10 HUWashout CT characterizes these lipid-poor adenomas with sensitivity of almost 100%Chemical-shift MRI is also useful in characterizing adrenal adenomasthe sensitivity for more than 30 HU is poor for differentiating adenomas f

3、rom nonadenomasWashout CT examinationsTwo-phase contrast-enhanced CT performed at 1 minute (early contrast-enhanced CT) and 15 minutes (delayed contrast-enhanced CT) after administration of contrast material73-year-old woman with history of breast cancer and left adrenal lipid-poor adenoma Unenhance

4、d CT scan shows left adrenal mass that measured 29 H Enhanced CT scan shows left adrenal mass that measured 73 HDelayed enhanced CT scan shows left adrenal mass that measured 44 HEnhancement washout = 29 H (73 H 44 H)enhancement = 44 H (73 H 29 H)Percentage enhancement washout = 66%(enhancement wash

5、out / enhancement) = (29 / 44) 100增强后定量参数：Mean EnhancementEnhancement Washout平均增强排泄率肾上腺富脂，乏脂腺瘤和非腺瘤增强参数比较直方图肾上腺富脂，乏脂腺瘤和非腺瘤增强参数比较富脂乏脂非腺瘤Chemical-shift MRIFor all masses identified on MR images, the adrenal-to-spleen ratio (ASR) was calculated as ASR =(SIAO / SISO) / (SIAI / SISI), where SIAO was the s

6、ignal tensity of the adrenal mass on opposed-phase images, SISO was the signal intensity of the spleen on opposed-phase images, SIAI was the signal intensity of the adrenal mass on in-phase images, and SISI was the signal intensity of the spleen on in-phase images. The signal intensity index (SII) w

7、as calculated as SII = (SIAI SIAO)100 / SIAI.2022-3-7ASR and SII of lipid-poor adenomas ranged from 0.35 to 1.33 (0.79 0.24) and from 38.7%(24,000/620) to 71.8% (11,700/163) (30.8 25.5%), SII was better than ASR for characterizing adenomasGraph shows MRI sensitivity for lipid-poor adenomas随着腺瘤CT值增加M

8、RI敏感性逐渐下降MRI sensitivity for lipid-poor adenomas measuring greater than 10 HU and 20 HU or less on unenhanced CT is 100% , whereas sensitivities for lipid-poor adenomas measuring greater than 20, greater than 30, and greater than 40 HU decreases to 64.0% , 61.5% , and 40% , respectivelyGraph shows C

9、T and MRI sensitivities for lipid-poor adenomas直方图显示乏脂类腺瘤MRI和CT诊断灵敏性 Unenhanced 20HU 平扫16 HU早期50HU延迟期19 HU 同相位反相位Lipid-poor adenoma in 77-year-old manAdrenal-to-spleen ratio and signal intensity index of lesion are 0.463 and 50.1%, respectively, consistent with adenomaLipid-poor adenoma in 70-year-o

10、ld 平扫34 HU123HU延迟期45 HU 同相位反相位Adrenal-to-spleen ratio and signal intensity index of lesion are 1.139 and 10.3%, respectively, which are not consistent with adenoma2022-3-77O-year-old man with adrenal adenoma.-5HU On initial enhanced 52HU15-mm delayed enhanced CT 10HU2022-3-72022-3-7Exclusion of Pheo

11、chromocytoma Using CT Attenuation and Washout Criteria2022-3-71、plasma and urinary metanephrines or catecholamines血浆和尿肾上腺素和儿茶酚胺2、1-minute enhanced attenuation minus unenhanced attenuationpheochromocytoma3、No adenoma was more than 85-HU enhancing in the arterial phase. Morethan one half (7/12, 58%) o

12、f pheochromocytomas exceeded 110 HU in the arterial phase,the same number exceeding 110 HU in the venous phase. 2022-3-7 unenhanced CT (35 HU) 1-minute contrast-enhanced CT (221 HU) 15-minute contrast-enhanced CT (93 HU). Mass was histologically confirmed pheochromocytoma 2022-3-755-year-old man wit

13、h lipid-rich adenoma.-3HU 30 HU in arterial phase 62 HU in venous phase2022-3-754-year-old man with pathologically proven pheochromocytoma.121 HU in arterial phase and 113 HU in venous phase. This enhancement level and pattern were seen with 25% (3/12) of pheochromocytomas and no adenoma.2022-3-751-

14、year-old woman with 2.6-cm functioningadenoma in right adrenal arterial phase (A) enhancement of 81 HU and venous phase (B) enhancement of 133 HU. Venous phase enhancement greaterthan 110 HU was identified in 7% (3/41) of adenomas.2022-3-7 arterial phase enhancement of 42 HU and venous phase enhance

15、ment of68 HU. This pattern was seen with 42% (5/12) of pheochromocytomas and 85% (35/41)of adenomas.66-year-old man with 3.2-cm homogeneous-appearing left adrenal pheochromocytoma that mimics adenoma enhancement levels and pattern2022-3-7adrenal metastasis 90% of adenomas exhibit a homogeneous or ri

16、ng enhancement pattern and60% of malignant lesions have a heterogeneous pattern.chemical shift imaging (CSI)2022-3-72022-3-7 adrenal adenomaadrenal metastasis In conclusion washout CT is more accurate than chemical-shift MRI for lipid-poor adenoma characterizationMRI is quivalent to CT in characterizing adenomas measuring 1020 HU on unenhanced CTCT i