Diagnostic Approach to Renal Hypertension

Initial Clinical Assessment

The American College of Radiology recommends considering high clinical suspicion based on specific features such as new-onset hypertension in patients <35 years or sudden onset/worsening after age 50 2
The American College of Radiology suggests considering treatment resistance, refractory hypertension despite multiple medications, as a criterion for high clinical suspicion 2, 5
The American College of Radiology recommends considering medication response, deterioration of renal function after starting ACE inhibitors or ARBs, as a criterion for high clinical suspicion 2
The American College of Radiology suggests considering associated conditions, generalized atherosclerotic disease with hypertension, flash pulmonary edema, as a criterion for high clinical suspicion 1, 6
The American College of Radiology recommends considering physical findings, abdominal bruits, asymmetric kidney size on imaging, as a criterion for high clinical suspicion 6

For patients with normal renal function (eGFR ≥30 mL/min/1.73 m²), the American College of Radiology recommends CT angiography (CTA) or MR angiography (MRA) as the preferred imaging modalities, with CTA and MRA showing sensitivities of 88-100% and specificities of 71-100% for detecting renal artery stenosis 1, 2
For patients with severely impaired renal function (eGFR <30 mL/min/1.73 m²), the American College of Radiology recommends duplex Doppler ultrasound as the preferred initial screening examination 3, 4
The American College of Radiology suggests that contrast-enhanced CTA has a sensitivity of 88-100% and specificity of 71-100% for detecting renal artery stenosis >50% 1, 2
The American College of Radiology recommends that gadolinium-enhanced MRA has a sensitivity of 97% and specificity of 85% in meta-analysis of 25 studies 1

The European Heart Journal recommends obtaining serum creatinine and eGFR (using race-free CKD-EPI equation) before imaging 10
The European Heart Journal and Hypertension recommend obtaining urinalysis with albumin-to-creatinine ratio before imaging 10, 6
Hypertension recommends obtaining basic metabolic profile (sodium, potassium) before imaging 5
Hypertension recommends obtaining morning plasma aldosterone and plasma renin activity (to screen for primary aldosteronism) before imaging 5

The American College of Radiology recommends avoiding using serum creatinine alone rather than eGFR for risk assessment—eGFR is superior for determining baseline renal function 3
The American College of Radiology suggests avoiding ordering ultrasound at centers without dedicated, experienced technologists—this highly operator-dependent technique requires expertise 1, 2
Praxis Medical Insights recommends avoiding failing to hydrate patients with borderline renal function before contrast administration 8
The American College of Radiology recommends avoiding relying on captopril scintigraphy in patients with bilateral disease or impaired renal function where accuracy is significantly reduced 1
The American College of Radiology suggests avoiding performing renal vein renin sampling as a screening test given its poor specificity and high false-positive rate 3, 4