Abstract
Hypertension is a serious health problem for millions of Americans. A small portion of these cases result from renal artery stenosis. Angiography continues to be the gold standard for diagnosing renal vascular disease. However, as a result of the high cost and possible risks associated with this invasive method, duplex sonography has emerged as an inexpensive and noninvasive alternative diagnostic tool that, in many cases, can accurately detect renal vascular disease. According to the literature, there are numerous techniques using Doppler waveforms to show renal artery stenosis. These include renal artery to aortic ratio, acceleration index, acceleration time, end diastolic ratio, and the tardus-parvus waveform. Several studies have been conducted to evaluate duplex sonography as a diagnostic tool for detection of renal artery stenosis and the overall accuracy of ultrasound compared with angiography. The accurcy of duplex ultrasound largely depends on the blood flocriteria being used to evaluate renal vasculature, patient preparation, the time allowed to perform the ultrasound examination, and the technical expertise of the sonographer performing the study.