What are the CT and MRI findings of adrenal hemorrhage/hematoma?
Adrenal hemorrhage/hematoma is rare. Eighty percent occurs unilaterally, more commonly on the right than on the left. It is often asymptomatic, but it may be associated with acute adrenal insufficiency (Addison’s disease) when bilateral.
A masslike abnormality or diffuse thickening of the adrenal gland with maintenance of its normal inverted-Y or inverted-V configuration is seen, typically with high attenuation (30 to 70 HU) on CT. On MRI, low signal intensity on T1-weighted and T2-weighted images is seen in acute hemorrhage, whereas high signal intensity on T1-weighted images is seen in subacute hemorrhage. There is often associated infiltration of the surrounding fat and fascial planes by hemorrhagic fluid. Solid enhancing components or intralesional calcifications, when visualized, are suggestive of presence of an underlying adrenal neoplasm. Over time, adrenal hemorrhage/hematoma will decrease in size, decrease in attenuation, develop very low signal intensity components on T1-weighted and T2-weighted images secondary to hemosiderin or ferritin, and may either fully resolve, lead to adrenal pseudocyst formation, or lead to adrenal gland calcification.