Radiation From Kidney-Ureter-Bladder Radiographs Is Not Trivial.

OBJECTIVE

To estimate effective dose of kidney-ureter-bladder (KUB) radiographs in a contemporary population of patients with urolithiasis.

METHODS

A retrospective review was performed to identify patients visiting a urology clinic for urolithiasis where a KUB was obtained and whom had a recent computed tomography (CT). Effective dose for KUBs was estimated using a Monte Carlo based simulation program and for CT utilizing the reported dose-length-product. Age, gender, body mass index, and abdominal diameter were analyzed for association with effective dose. KUBs performed at outside facilities in referred patient were compared to those obtained locally when available.

RESULTS

Fifty-four patients were identified meeting criteria. The majority (92.6%) of KUBs contained multiple radiographs. Mean effective dose was 2.15 mSv ± 1.67 mSv. Only 26% of examinations effective dose was under 1 mSv. Body mass index, abdominal thickness, and image count were all associated with an increase in dose (P < .01 each). Similar to local KUBs, 88% of outside examinations contained multiple images.

CONCLUSION

KUB examinations in this contemporary setting are associated with a 2-fold higher effective dose then is often referenced. Increased effective dose is associated with increased patient size and number of images acquired. Nearly 1 in 5 patient's KUB effective dose was similar to a low-dose CT. KUBs role should be re-examined given its limited sensitivity, specificity, associated radiation, and other available imaging options.