Accuracy Of Bladder Stone Detection Using Abdominal X-Ray After Spinal Cord Injury

Abstract

Background: Bladder calculi are a common problern in those with spinal cord injury (SCI). Detection is important to prevent complications.Objective: To determine the accuracy of bladder stone detection by abdominal x-rays.Methods: X-ray reports from individuals with SCI with known bladder stones detected by cystoscopy were reviewed.Main outcome measures: x-ray reports noted the presence or absence of bladder stones. The stone variables evaluated were stone composition (crystallographic analysis) , widest dimension of the largest stone (during cystoscopy) , and the total volume (cm3 ) of the stone mass removed.Results: Sixty-two consecutive x-ray reports from individuals with bladder stones were reviewed. The majority of stones were calcium phosphate (46.8%) or struvite (26.7%). Regarding stone composition, the detection by x-ray was 28.6% for struvite stones and 41 .9% for calcium phosphate stones. Regarding diameter of largest stone, the detection by x-ray was 14% for stones < 0.5 cm, 0% for stones 0.5 cm to 0 .9 cm, 33% for stones 1.0 cm to 1.49 cm, 33% for stones 1.5 cm to 1.9 cm, and 54% for stones 2 2.0 cm. Regarding total volume of stones, the detection by x-ray was 0% forvolumes < 0.2 cm3 , 33% for volumes 0.2 cm3 to 0.39 cm3 , 60% for volumes 0.40 cm3 to 0.5 9 cm3 , 40% for volumes of 0.60 cm3 to 0.79 cm3 , 0% for stones from 0.8 cm3 to 0.99 cm3 , and 57% for volumes 2 1.0 cm3 . Overall, 13/ 62 (20.97%) of stones found during cystoscopy were detected by the x-ray.