Imaging in Renovascular Hypertension: State of the Art

Renovascular hypertension (RVH) results from activation of the renin-angiotensin system by renal arterial stenosis (RAS). RAS can result from either intrinsic narrowing or extrinsic compression. Intrinsic narrowing may be caused by atherosclerosis, fibromuscular dysplasia, vasculitis, dissection, thrombus, aneurysm, arteriovenous fistula, neurofibromatosis type 1, or midaortic syndrome. Extrinsic compression can be from retroperitoneal fibrosis, neoplasm, or subcapsular hematoma or fluid. Diagnostic evaluation for RVH is triggered by either a high index of suspicion in a patient with hypertension or incidental detection of RAS at noninvasive imaging. Renal US, primarily with Doppler, is a common modality used for initial screening of RVH, especially when renal function is decreased. US can be used to evaluate hemodynamically significant RAS, including in stents, and also for parenchymal evaluation. MR angiography (MRA) is an excellent modality for RVH evaluation, typically used following US. In patients with decreased renal function, MRA can be performed without contrast material or with ferumoxytol, but group 2 gadolinium-based contrast agents are safe. CT angiography offers excellent spatial resolution that is ideal for the evaluation of distal small renal arterial branches and for assessment of in-stent stenosis following intervention. Conventional angiography is the reference standard, now reserved only for interventional procedures. Imaging also plays an important role in excluding other causes of secondary hypertension and evaluating complications of RVH. The management of RVH depends on the cause and involves a combination of medical treatment and surgical or interventional procedures. Interventional options include angioplasty, stent placement, and embolization. ^©RSNA, 2025 Supplemental material is available for this article.