LAUSR

level of 469 U/L, mild leukocytosis (18.41×10 9 /L) with 84.5% neutrophils, and slight renal dysfunction (creatinine μmol/L, urea nitrogen 7.32 mmol/L). However, the C-reactive protein (CRP) level was normal. No hematuria or proteinuria was detected in the spot urine, and urinalysis was negative. He had no past medical history and no urinary symptoms. He had been smoking approximately 10 cigarettes a day for 10 years. His bowel sounds were normal. A B-ultrasound examination showed bilateral small renal stones, and after analgesic treatment, no obvious relief of the lower back pain was achieved. Thus, we began to suspect acute renal colic. Computed tomography angiography (CTA) of the aorta and renal arteries showed dissection at the distal end of the main right renal artery, the formation of a dissecting aneurysm, and occlusion of the posterior branch of the right renal artery, including the branches supplying the lower level of the posterior right