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Radiation exposure from CT examinations in Japan
Yoshito Tsushima1, Ayako Taketomi-Takahashi, Hiroyuki Takei
1Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Hospital 3-39-22 Showa-machi, Maebashi, Gunma, Japan. tyoshito@showa.gunma-u.ac.jp
BMC Medical Imaging
|November 4, 2010
Summary
Computed tomography (CT) scans are a major source of medical radiation. This study found significant variations in CT radiation exposure across Japanese institutions, highlighting the need for standardized protocols to manage cancer risk.
Area of Science:
- Medical Imaging
- Radiology
- Public Health
Background:
- Computed tomography (CT) represents the largest source of medical radiation exposure for the general population.
- CT use is a potential contributor to increased cancer risk.
- Understanding CT utilization patterns and radiation dose variations is crucial for public health.
Purpose of the Study:
- To assess the current landscape of CT utilization in Japan.
- To investigate institutional and scanner-based variations in radiation exposure from CT examinations.
- To identify factors contributing to dose discrepancies in CT procedures.
Main Methods:
- A survey was conducted across hospitals and clinics in Gunma prefecture, Japan, with CT scanners.
- Data on patient CT examinations (June 2008) and institutional scan protocols were collected.
- Analysis focused on age/sex patterns, radiation dose variations, and contributing factors.
Main Results:
- An estimated 235.4 individuals per 1,000 population annually undergo CT scans.
- Significant variations in effective dose were observed, particularly for lower abdominal CT (2.6-19.0 mSv).
- Chest and upper abdomen CT scans accounted for 73.2% of the collective radiation dose.
Conclusions:
- Substantial variations in radiation exposure from CT examinations exist among different institutions.
- CT scans of the chest and upper abdomen are the primary drivers of collective radiation dose.
- Standardization of CT protocols may be necessary to mitigate radiation risks.
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