Geographic variation in administered radiation dose for myocardial perfusion imaging

Objectives As part of support of the Image Wisely Initiative, the SNMMI urges nuclear medicine providers to optimize studies to obtain the best image quality with the lowest radiation dose. The imaging community is poorly informed on radiation dose used in current practice. The aim of this study was to determine geographic patterns associated with elevated radiation dose for myocardial perfusion imaging in the United States.

Methods Reports from 612 facilities applying for accreditation in 2012 by the Intersocietal Accreditation Commission (IAC) were evaluated. Three to five reports from each facility were used to determine the total administered radiation dose per US Census defined region (Northeast, South, Midwest and West) and state. States were also ranked based on average effective radiation dose. States with average administered dose ≥ 20 mSv were compared to obesity prevalence by state. The percent of doses ≥ 20 mSv was determined.

Results 2992 patient reports were reviewed. There was a significant association (p=.008) between geographic area and frequency of use of radiation dose ≥ 20 mSv with the West (14.8%) and South (13.8%) having the highest percentage. Facilities in the Northeast (6.9%) and Midwest (4.0%) have a lower frequency of doses ≥ 20 mSv. Alabama, Missouri and Georgia had the highest average effective radiation dose ≥ 20 mSv. Kentucky, Rhode Island and Pennsylvania demonstrated lowest average effective radiation dose of ≤ 13 mSv. For states demonstrating an average radiation dose ≥ 20 mSv, there was no correlation between percentage of doses >20 mSv and prevalence of obesity.

Conclusions There is considerable geographic variance in average effective radiation dose. States in the West and South had a significantly higher percentage of doses ≥ 20 mSv, but there was no correlation with obesity and thus no apparent reason for increased regional radiation dose.