Answer is A (Magnetic Resonance Angiography (MRA) Magnetic Resonance Angiography (MRA) has now emerged as the most sensitive and specific screening test for Renovascular hypeension. Note: Harrison 16'h edition (old) mentions Spiral CT scan as the most sensitive and specific screening test for Renovascular Hypeension, however most recent textbooks now prefer MRA as the screening test of choice with similar or even better sensitivity and specificity than spiral CT Angiography. Screening Test Test Sensitivity (%) Specificity (%) Magnetic resonance angiography (MRA) 100 96 Spiral computerized tomography 98 94 Captopril renogram 70-93 95 Duplex Doppler ultrasonography 69-96 86-90 IVP --75 --85 Renovascular Hypeension Test Sensitivity Specificity Conventional Renal Angiography >99% >99%