Vascular Disease USMLE Step 1 Practice Question
A 64-year-old woman with a 15-year history of hypertension and type 2 diabetes mellitus presents to the emergency department with acute onset left flank pain and gross hematuria. Blood pressure is 168/94 mmHg, heart rate 92 bpm, respirations 16/min, temperature 37°C, and oxygen saturation 98% on room air. Laboratory studies show serum creatinine 1.8 mg/dL (baseline 0.9 mg/dL), BUN 38 mg/dL, and urinalysis with 3+ blood and no proteinuria or casts. CT angiography of the abdomen demonstrates severe stenosis of the left renal artery with thrombus at the site of stenosis. The left kidney measures 7 cm in length, compared to the right kidney at 10.5 cm. Which of the following best explains the reduction in left kidney size?
Answer choices
- AAcute tubular necrosis from contrast-induced nephropathy during CT angiography
- BChronic ischemic injury from prolonged renal artery stenosis causing nephron lossCorrect answer
- CAcute pyelonephritis with suppurative destruction of renal parenchyma
- DDiabetic glomerulosclerosis with progressive proteinuric kidney disease
- EReflux nephropathy from vesicoureteral reflux causing chronic pyelonephritis
- FAutosomal dominant polycystic kidney disease with cyst-induced atrophy
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