The reliability of radiation dose display of a computed tomography scanner

V. Forss, H. Yli-Ollila, J. Vatanen, P. Kölhi, V. P. Poutanen, A. Palomäki

Research output: Contribution to journalArticleScientificpeer-review

5 Downloads (Pure)


Background: Internationally, the typical allowed difference between the measured radiation dose and dose reported by a computed tomography (CT) scanner is ±20 %. The objective is to describe a method in order to analyse this difference in a CT scanner in the Emergency Department of Kanta-Häme Central Hospital, and to calculate a correction factor for more comparable radiation dose values in further studies. Methods: Ten intra-day radiation dose measurements were performed with undisturbed setting. Measurement reports on differences between measured and displayed dose were gathered from the vendor maintenance and supervising authority over a 12-year period. Additionally, two in-house measurements were made. A total of 18 datapoints were collected, with some differences in measurement settings. Data were also analysed against imaging parameters, ambient air pressure and time to identify trends or associations in the variation of the discrepancy. Results: Measured doses were generally lower than displayed doses. Differences between displayed and measured doses varied between −3.46 and −0.10 %, with a mean of −1.26 % in the intra-day measurements, and between +4.65 and −17.3 %, with a mean of −7.53 % in the long-term data. There were no trends nor connections in the variations. Conclusion: Since the acceptable difference between the radiation dose display and the measured dose is relevant, the average difference for every CT scanner should be determined before radiation dose studies, especially when comparing multiple scanners.

Original languageEnglish
Article number100345
JournalEuropean Journal of Radiology Open
Publication statusPublished - 2021
Publication typeA1 Journal article-refereed


  • Computer tomography
  • CTDIvol
  • DLP
  • Emergency department
  • Radiation dose

Publication forum classification

  • Publication forum level 1

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'The reliability of radiation dose display of a computed tomography scanner'. Together they form a unique fingerprint.

Cite this