DTPA scan of hypeensive young lady is normal, USG shows small kidney on left side. Next investigation will be ?

Ans. is 'c' ie. Digital Subtraction angiography Hypeension in a young female is most probably due to renal aery stenosis (cause fibromuscular dysplasia) DTPA scan which shows the GFR* comes to be normal because of increased renin activity. Digital subtraction angiography or Doppler U/S will show the stenosis. Now MRA (Magnetic resonance angiography) has replaced all previous modalities as the most sensitive (>95%) and specific test (95%) for the diagnosis of renal aery stenosis. But the most definitive diagnostic procedure is bilateral aeriography with repeated bilateral renal vein and systemic renin determinations.