|Patient: 2 year 1 month 14 day old male|
|History: 2-year-old boy admitted with hypertensive emergency.|
Renal scintigraphy demonstrated decreased perfusion and function of the smaller left kidney, with progressively increasing renal parenchymal uptake of tracer, but no excretion. In light of the clinical history, the findings are most consistent with high-grade left renal artery stenosis. There is normal right renal function with no evidence of obstruction.
CT angiograhy deminstrated a 6 mm focal stenosis of the left renal artery in its proximal portion. Distal to the stenosis the artery caliber increases to 4 mm in diameter.
|DDx: Unilateral renal artery stenosis|
Unilateral renal vein thrombosis
Unilateral high-grade obstruction
|Diagnosis: Left renal artery stenosis|
General Discussion: |
Long history: 2-year-old boy admitted with hypertensive emergency. At another hospital, ultrasonography demonstrated discrepant kidney size, with the left kidney measuring approximately 2 cm less in length than the right kidney. CT angiogram showed a left renal artery stenosis. He is currently being treated with the nicardipine and nitroprusside. He has not received an ACE inhibitor or an angiotensin receptor blocker. Serum creatinine is 0.3 mg/dL. Evaluate relative renal function.
Radiopharmaceutical: 1.0 mCi Tc-99m MAG3 i.v.
Specific Discussion: Renovascular hypertension (RVH) is the most common cause of surgically correctable hypertension in children. In North America and Western Europe, fibromuscular dysplasia is the most common etiology of pediatric RVH, whereas in Asia and Africa, aortoarteritis is the most common cause. The fibromuscular dysplasia that is observed in the pediatric population does not demonstrate the classic “string of beads” pattern seen in adults. Instead, the stenosis generally appears as discrete narrowing on angiography. |
ACE-inhibited renal scintigraphy is the most specific scintigraphic method for evalauting suspected RVH. In this patient with documented renal artery stenosis, the scintigraphic findings without ACE inhibition are sufficiently characteristic to permit a confident diagnsosis of RVH.
1. Aryce D, Beseth MD. Renal artery aneurysm secondary to fibromuscular dysplasia in a young patient. Ann Vasc Surg. 2005; 19: 605-608.
2. Ziessman HA. The Requisites: Nuclear Medicine. 3rd edition; p230-234.
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Case Number: 96458Owner(s): Xiaoni Hong and Barry Siegel, Prof of RadiologyLast Updated: 12-15-2010 The reader is fully responsible for confirming the accuracy of this content.
The reader is fully responsible for confirming the accuracy of this content.