Radiation Dose from Diagnostic Computed Tomography in Saskatchewan

Objective: To calculate the effective dose from diagnostic computed tomography (CT) scans in Saskatchewan, Canada, and compare with other reported dose levels. Methods: Data from CT scans were collected from 12 scanners in 7 cities across Saskatchewan. The patient age, scan type, and selected technique parameters including the dose length product and the volume computed tomography dose index were collected for a 2-week period. This information then was used to calculate effective doses patients are exposed to during CT examinations. Data from 2,061 clinically indicated CT examinations were collected, and of them 1,690 were eligible for analysis. Every examination during a 2-week period was recorded without selection. Results: The average provincial estimated patient dose was as follows: head, 2.7 mSv (638 scans; standard deviation [SD], +/- 1.6); chest, 11.3 mSv (376 scans; SD, +/- 8.9); abdomen-pelvis, 15.5 mSv (578 scans; SD, +/- 10.0); abdomen, 11.7 mSv (80 scans; SD, +/- 11.48), and pelvis, 8.6 mSv (18 scans; SD, +/- 6.04). Significant variation in dose between the CT scanners was observed (P = .049 for head, P = .001 for chest, and P = .034 for abdomen-pelvis). Conclusions: Overall, the estimated dose from diagnostic CT examinations was similar to other previously published Canadian data from British Columbia. This dose varied slightly from some other published standards, including being higher than those found in a review conducted in the United Kingdom in 2003.