Ultrasound of Renal Artery Fibromuscular Dysplasia—A Case Study and Review

ABSTRACT Fibromuscular dysplasia (FMD) is a rare vascular disease that is idiopathic, segmental, non‐atherosclerotic and non‐inflammatory. FMD primarily affects women between 20 and 60 but can occur in patients of all genders and all age groups. It most commonly affects the renal and carotid arteries but can occur in any arteries in the body. Renal artery stenosis (RAS) is the narrowing of the lumen of an artery or arteries supplying blood to the kidneys. RAS can result from either intrinsic narrowing or extrinsic compression, and is the most common cause of secondary hypertension. RAS resulting from intrinsic narrowing is predominantly caused by atherosclerotic renovascular disease. However, FMD can also cause narrowing of the renal arteries and accounts for 10%–20% of all cases of RAS. Renal artery Doppler ultrasound is commonly used as a screening tool for the screening of secondary hypertension and providing initial diagnosis of FMD and related RAS. CTA, MR angiography (MRA) and digital subtraction angiography (DSA) can also be used to detect RAS caused by FMD, with DSA remaining the standard for the confirmation and identification of RAS and renal artery occlusion. Additional knowledge of FMD and renal Doppler ultrasound can help sonographers to make the correct diagnosis in clinical settings.