Figure 8a. Partially thrombosed renal artery aneurysm with rim calcification in a 67-year-old man with hypertension. (a) Axial unenhanced CT scan shows a large, lobulated, masslike lesion with soft-tissue attenuation and rim calcifications (arrows) in the right renal sinus. (b) Axial contrast-enhanced CT scan shows that the lesion is vascular (arrows) with a nonenhancing area suggestive of thrombus (T). (c) Direct right renal arteriogram shows the large, saccular, bilobed aneurysm.