الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Renovascular hypertension refers to hypertension caused by renal ischemia and it represents the most common cause of secondary hypertension. It is important to realize that renovascular disease may or may not cause sufficient hypoperfusion to set off the processes that lead to hypertension. Screening options for the diagnosis of renal artery stenosis have a wide range of sensitivity and specificity including conventional angiography, duplex ultrasound, renal scintigraphy, CTA and MRA. Historically, angiography has long been considered the gold standard for the evaluation of the renal arteries; this position has now been seriously challenged by three dimensional CTA. MDCT angiography is increasingly used as it is a fast, non-invasive, easily applicable and available modality for the comprehensive evaluation of the renal vasculature. All cases presented in structural arterial abnormalities like renal artery stenosis, fibromuscular dysplasia, arteriovenous malformations and dissection can be accurately depicted by CTA. MDCT scanners are particularly useful for angiographic applications because they provide larger anatomic coverage, increased contrast enhancement of the arteries, and higher longitudinal spatial resolution, as well as more detailed and sensitive depiction of small renal vasculature. The endovascular treatment with balloon angioplasty and/or stents is almost always the first therapeutic intervention for RAS. The outcome of endovascular treatment and stent lumen patency can be accurately assessed at CTA by using axial and reconstructed images. Various 3D post-processing techniques are employed for obtaining angiographic quality images from the axial CT data including maximum intensity projection, multiplanar reformatting, curve planar reformatting, volume rendering and shaded surface display. Moreover, radiologic follow-up of endovascular treatment of renal artery stenosis with stents can be accurately assessed by MDCTA. In conclusion, MDCT angiography has become a non-invasive alternative imaging modality to catheter renal angiography except when the intervention procedures are needed to correct renal artery pathology. MDCT angiography is a reliable imaging modality in the detection of renal artery stenosis with sensitivity values close up to 100% in diagnosis of the renal artery stenosis.