Investigations

• if renal artery stenosis suspected:
• gadolinium-enhanced MR angiography ^b
• CT angiography ^b

  Less helpful tests include

  • captopril scintigraphy  ^b 
  • captopril test. ^b

Why?

Gadolinium-enhanced MR angiography and CT angiography helps diagnose renal artery stenosis

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected renovascular hypertension b   (pre-test probability: 35%)	renal artery stenosis (> 50%) (interarterial X-ray angiography)	gadolinium-enhanced MR angiography	16 (10 to 26)	90%	0.019 (0.0062 to 0.059)	1%
		CT angiography	26 (16 to 41)	93%	0.037 (0.020 to 0.068)	2%
		captopril renal scintigraphy	4.5 (3.9 to 5.2)	71%	0.19 (0.15 to 0.23)	9%
		captopril test	2.8 (1.9 to 3.9)	60%	0.69 (0.58 to 0.81)	27%