Are stone protocol computed tomography scans mandatory for children with suspected urinary calculi?

Abstract

Objective: To examine the clinical utility of noncontrast-enhanced computed tomography (NCCT) in pediatric patients with urolithiasis who progressed to surgery. Although NCCT is routine for the evaluation of adult patients with suspected urolithiasis, its routine use in the pediatric population is tempered by concern about radiation exposure. Methods: We conducted a retrospective chart review of all pediatric patients who had undergone surgery for urinary stones from 2003 to 2008 at our institution. The imaging modalities used, surgery type, stone composition, 24 -hour urinalyses, and relevant predisposing conditions were characterized. Results: A total of 42 pediatric patients (24 males and 18 females) were treated during the 6-year period. The average age was 11.3 ± 5.3 years (range 2.7 -25.4), and the most common treatment modalities were shock wave lithotripsy (28%) and ureteroscopy (22%). A discernible risk factor or cause of urolithiasis was absent in 21 patients (47%). A review of imaging studies found 38 with stones visible on ultrasonography and/or abdominal plain film. A total of 21 patients underwent NCCT, in addition to ultrasonography and/or abdominal plain film. Of these, only 5 patients required NCCT for the diagnosis or management of their stone. Conclusion: Nearly 90% of pediatric patients treated for symptomatic urolithiasis could have completed their evaluation and treatment without undergoing NCCT. For children who present with signs and symptoms suggesting urinary calculi, an initial evaluation and imaging with ultrasonography and abdominal plain film might suffice, avoiding the radiation of NCCT. Editorial CommentWhile non-contrast CT scans have become the gold standard for imaging of urinary tract stones in the adult population, legitimate concerns have been raised regarding the widespread use of CT scans in the pediatric population. These authors performed a retrospective review of their pediatric stone patients over a five year period of time to determine the usefulness of CT scans compared with ultrasound and/or KUB. They were able to identify 42 patients during the study period and found that 90% of the stones were visible on ultrasound and/or KUB.

Use of and Regional Variation in Initial CT Imaging for Kidney Stones

“…The rationale for using ultrasound as the initial screening modality for children with suspected nephrolithiasis is that ultrasound accurately localizes most clinically important stones in children 17,18 and CT can be reserved for children with a nondiagnostic ultrasound for whom the clinical suspicion for stones remains high. Passerotti et al 18 observed that the sensitivity and specificity of ultrasound for 50 children with suspected nephrolithiasis were 70% and 100%, respectively, when compared with CT. Of the stones not visualized on ultrasound, 25% were in the ureter and the remainder were nonobstructive stones in the kidney.…”

Place of non-contrast computed tomography for evaluation of flank pain and suspected urinary stone in emergency service

“…Interestingly, non-calcified urinary stones those are radiolucent on AXR can also seen as calcified urinary stones on non-contrast CT. To differentiate calcified and noncalcified urinary stones according to their appearance is not possible. Degree of accuracy in interpreting a non-contrast CT in a case with urinary stone increases in accordance with the severity of urinary obstruction [14][15][16].…”

Urinary Stones in Children

“…Taşlı çocukların büyük çoğunluğunda ciddi radyasyon riski nedeniyle bilgisayarlı tomografi (BT) çekmeye gerek yoktur (20). Ender olarak, taş tanısı kesin değilse, anatomik bilgi şüpheliyse veya retrorenal kolon şüphesi varsa BT yararlı olabilir ve çekilecekse düşük-doz kontrastsız BT çekilmelidir.…”