Evaluation of effective energy for QA and QC: Measurement of half-value layer using radiochromic film density

T. Gotanda, T. Katsuda, R. Gotanda, A. Tabuchi, K. Yamamoto, T. Kuwano, H. Yatake, Yoshihiro Takeda

Research output: Contribution to journalArticle

18 Citations (Scopus)


The effective energy of diagnostic X-rays is important for quality assurance (QA) and quality control (QC). However, the half-value layer (HVL), which is necessary to evaluate the effective energy, is not ubiquitously monitored because ionization-chamber dosimetry is time-consuming and complicated. To verify the applicability of GAFCHROMIC XR type R (GAF-R) film for HVL measurement as an alternative to monitoring with an ionization chamber, a single-strip method for measuring the HVL has been evaluated. Calibration curves of absorbed dose versus film density were generated using this single-strip method with GAF-R film, and the coefficient of determination (r2) of the straight-line approximation was evaluated. The HVLs (effective energies) estimated using the GAF-R film and an ionization chamber were compared. The coefficient of determination (r2) of the straight-line approximation obtained with the GAF-R film was more than 0.99. The effective energies (HVLs) evaluated using the GAF-R film and the ionization chamber were 43.25 keV (5.10 mm) and 39.86 keV (4.45 mm), respectively. The difference in the effective energies determined by the two methods was thus 8.5%. These results suggest that GAF-R might be used to evaluate the effective energy from the film-density growth without the need for ionization-chamber measurements.

Original languageEnglish
Pages (from-to)26-29
Number of pages4
JournalAustralasian Physical and Engineering Sciences in Medicine
Issue number1
Publication statusPublished - Mar 2009



  • Effective energy
  • Half-value layer
  • Quality assurance
  • Quality control
  • Radiochromic film

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

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