MRI scans are helpful in differentiating between adrenal adenoma, carcinoma, and metastatic lesions. Due to the multi-planar capability of MRI, direct invasion of adjacent organs may be better shown. Inferior vena cava invasion has been reported in 9% to 19% of cases at presentation.

• Adrenocortical carcinomas are usually large and appear as heterogeneous masses on both T1- and T2-weighted images owing to the presence of internal hemorrhage and necrosis.^[1]
• Adrenocortical carcinoma may contain foci of intra-cytoplasmic lipid, which results in a loss of signal intensity on out-of-phase images.^[2]
• Large adrenal carcinomas tend to invade the adrenal vein and inferior vena cava.^[1]

• On MRI, ACCs appear iso-intense to hypo-intense relative to liver parenchyma on T1-weighted images and hyper-intense relative to liver parenchyma on T2-weighted images.^[3]

• On chemical-shift MRI, the presence of intracellular lipid can cause regions of signal loss on out-of-phase images relative to in-phase images.^[4]

• Inferior vena cava invasion has been reported in 9% to 19% of cases at presentation.
• Due to the multi-planar capability of MRI, direct invasion of adjacent organs may be better shown.

Source: Case courtesy of Radswiki, Radiopaedia.org, rID: 11176