Unenhanced ultrafast computerized tomography for the evaluation of patients with acute flank pain

Abstract

Objective : To determine the value of unenhanced ultrafast computerized tomography (CT) in the diagnosis of acute flank pain in 43 patients evaluated for suspected stone disease. Material and Method : Noncontrasted ultrafast CT was performed in 43 consecutive patients seen in the emergency department to evaluate acute flank pain. All CT studies were reviewed for the presence of ureteral and renal calculi, perinephric and periureteral stranding, presence and degree of pelvicalicectasis or other radiological findings. If necessary, an excretory urogram was performed to confirm the presence or absence of urinary stone. Patients were followed to determine clinical outcome including the need for urological intervention. Results : Of the 28 patients determined to have stones 16 (57.14%) had spontaneous stone passage, 7 (25%) had improved symptoms without documented stone passage and 4 (14.29%) required surgical intervention. In 6 of 14 patients (42.86%) with negative CT readings for stone disease a diagnosis was established by other intra-abdominal findings. In 7 patients (50%) no clinical diagnosis could be established, and 1 scan in a patient with a ureteral calculus was interpreted as falsely negative. These findings yielded a sensitivity of 96.63 per cent, Specificity 92.85 per cent and overall accuracy 95.24 per cent for diagnosing ureteral stones. Conclusions : Unenhanced ultrafast CT is an accurate, safe and rapid imaging modality for the detection of urinary tract calculi and obstruction. The majority of patients required no further imaging to determine the need for urological intervention. Ultrafast CT could be used as the stan-dard method to evaluate patients with acute flank pain.