Investigations

• Doppler ultrasound to assess kidney size, symmetry, echogenicity, and presence of renal artery stenosis ^b  

Why?

Ultrasonography 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)	ultrasonography	8.0 (6.9 to 9.3)	81%	0.18 (0.16 to 0.21)	9%