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Renal artery stenosis (RAS) (plural: stenoses) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin.
Doppler ultrasound. can be technically difficult and only completed in 60% of patients. normal peak systolic velocity is 150-180 cm/s and elevation beyond this may indicate renal artery stenosis of >60% 4. normal renal arterial resistive index (RI) is ≈ 0.60.
Venous compression syndromes (anterior and posterior nutcracker syndrome) can be symptomatic and can be diagnosed with a combination of radiologic features. Renal artery stenosis is commonly atherosclerotic and is diagnosed with Doppler US, CT angiography, or MR angiography.
Renal artery stenosis (RAS) is a potentially treatable cause of hypertension in pediatric patients. Imaging of RAS is challenging in children because of the small caliber of the renal artery and potential involvement of even smaller intrarenal arteries.
Renal artery stenosis (RAS) refers to a fixed narrowing of the renal artery which can lead to renin-mediated renovascular hypertension (RVH) and ischemic nephropathy (IN). It is the most common cause of secondary hypertension and accounts for 1–4 % of all patients with hypertension [ 6 ].
The renal arteries (RAs) are important vessels that usually arise from the abdominal aorta and supply the kidneys; thus, these arteries play a vital role in physiologic functions such as hemofiltration and blood pressure regulation.
Detecting renal artery stenosis is particularly important for ensuring that this potentially curable form of hypertension is identified and treated properly.
Complete renal vascular Doppler assessment involves determining the patency and waveform of the main renal artery and vein; the waveform of the arcuate and interlobar arteries in the upper, interpolar, and lower pole regions; and their associated resistive index (RI).
Renal angiography provides a better quantification of the degree of stenosis and an opportunity to determine the physiologic significance of a stenosis. A clinically and hemodynamically significant RAS occurs when the renal artery lumen is narrowed enough to reduce flow and perfusion to the affected kidney.
Being a non-invasive, cost-effective and radiation-free examination method with good sensitivities and specificities (approximately 90 %), CCDS is well suited to the diagnosis of RAS. An intrastenotic PSV > 180− 200 cm/s represents the most accurate stenosis criterion for stenosis > 50 %.