Diffusely Increased FDG Uptake of the Kidney Caused by Severe Renal Artery Stenosis.

Renal artery stenosis can result in renovascular hypertension and ischemic nephropathy. We describe FDG PET/CT and delayed abdominal FDG PET/MRI findings in a kidney associated with severe renal artery stenosis resulting from renal artery invasion in retroperitoneal alveolar echinococcosis. The renal parenchyma showed diffusely increased activity on both FDG PET/CT and delayed FDG PET/MRI. There was no activity in the renal collecting system on FDG PET/CT and focal urine activity in the renal calyces on delayed FDG PET/MRI. This case indicates that renal artery stenosis should be included in the differential diagnosis of diffuse renal parenchymal FDG uptake.