Diagnostic ionizing radiation exposure in a population-based cohort of patients with inflammatory bowel disease.
OBJECTIVE
For diagnosis, assessing disease activity, complications and extraintestinal manifestations, and monitoring response to therapy, patients with inflammatory bowel disease undergo many radiological studies employing ionizing radiation. However, the extent of radiation exposure in these patients is unknown.


METHODS
A population-based inception cohort of 215 patients with inflammatory bowel disease from Olmsted County, Minnesota, diagnosed between 1990 and 2001, was identified. The total effective dose of diagnostic ionizing radiation was estimated for each patient. Linear regression was used to assess the median total effective dose since symptom onset.


RESULTS
The number of patients with Crohn's disease and ulcerative colitis was 103 and 112, with a mean age at diagnosis of 38.6 and 39.4 yr, respectively. Mean follow-up was 8.9 yr for Crohn's disease and 9.0 yr for ulcerative colitis. Median total effective dose for Crohn's disease was 26.6 millisieverts (mSv) (range, 0-279) versus 10.5 mSv (range, 0-251) for ulcerative colitis (P < 0.001). Computed tomography accounted for 51% and 40% of total effective dose, respectively. Patients with Crohn's disease had 2.46 times higher total effective dose than ulcerative colitis patients (P= 0.001), adjusting for duration of disease.


CONCLUSIONS
Annualizing our data, the radiation exposure in the inflammatory bowel disease population was equivalent to the average annual background radiation dose from naturally occurring sources in the U.S. (3.0 mSv). However, a subset of patients had substantially higher doses. The development of imaging management guidelines to minimize radiation dose, dose-reduction techniques in computed tomography, and faster, more robust magnetic resonance techniques are warranted.
Department of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Joanna M
JM
Peloquin
Darrell S
DS
Pardi
William J
WJ
Sandborn
Joel G
JG
Fletcher
Cynthia H
CH
McCollough
Beth A
BA
Schueler
James A
JA
Kofler
Felicity T B
FT
Enders
Sara J
SJ
Achenbach
Edward V
EV
Loftus
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy; D003424:Crohn Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data