Radiation Dose from Computed Tomography Scanning in Patients at Songklanagarind Hospital: Diagnostic Reference Levels
Keywords:
computed tomography, CT dose index, dose length product, diagnostic imaging, diagnostic reference level, radiation doseAbstract
Objective: To determine diagnostic reference levels (DRLs) of computed tomography (CT) radiation doses in terms of CT dose index volume (CTDIvol) and dose length product (DLP) of CT scans of the head, chest and abdomen for patients at Songklanagarind Hospital, Thailand.
Material and Methods: This was a retrospective analysis of 463 randomly selected head, chest and abdominal CT stuides from 416 patients enrolled from July 1st to 31st 2017. The CTDIvol, DLP and clinical indication for each CT study were conducted. The median and third quartile values were analysed and compared to the standard international DRLs. The DRL was defined as the third quartile value.
Results: The DRLs for CTDIvol, and DLP of head, chest and whole abdominal CT were 57.5, 11.6 and 13.1 milliGray (mGy), and 1,102.6, 474.7 and 624.4 milliGray x centimetre (mGy.cm), respectively. The most common clinical indications were stroke (29.1%) for head CT and malignancy for both chest (73.6%) and abdominal CTs (49.6%).
Conclusion: The DRLs of each CT region were mostly below standard international DRLs of Australia, Europe, Japan, the United Kingdom and the United States. The clinical indication for malignancy had significant difference in the DLP values than other clinical indications in head and chest CT.
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