Imaging in Chronic Kidney Disease

Abstract

Imaging in patients with reduced kidney function (glomerular filtration rate) raises three problems. (1) The imaging procedures (e.g., renography, CT urography, MR urography), where excretion of contrast media/isotopes is an integrated part of the examination, cannot give useful images in patients with <~30 ml/min/1.73 m²; all other procedures can be done. (2) Administration of iodine-based contrast media may cause a temporary (in most cases) decrease in kidney function (contrast nephropathy). (3) Injection of gadolinium-based contrast media may induce nephrogenic systemic fibrosis. Awareness of these issues is of utmost importance, when one takes care of patients with a glomerular filtration rate below 60 ml/min/1.73 m². One should never deny a patient a clinically well-indicated imaging examination due to fear of contrast nephropathy or nephrogenic systemic fibrosis; denying may cause one overlooking, e.g., a tumor at a time where it might be removed. In patients with moderate or severe renal insufficiency, the relative low risk of nephrogenic systemic fibrosis against the relative high risk of intermittent contrast nephropathy should be taken into consideration before enhanced imaging; contrast nephropathy is seen after all agents, whereas nephrogenic systemic fibrosis does not occur after all agents.