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A web-based CT dose calculator


About WAZA-ARIv2

Recently, X-ray CT (Computed Tomography) is very popular as helpful diagnostics. But its high exposure dose as compared with simple roentgenography should be assessed on a clinical basis as an input to the justification and the optimization. The IAEA has called for enhanced Radiation Protection of Patients (RPoP).

The number of CT scanners in Japan, about 13,000, has been acknowledged to be the largest over the world, as published in the reports from the OECD (Organization for Economic Co-operation and Development) in 2014. And the number of CT scanners per million populations is about 92; this is by far the largest. On the other hand, the number of CT scanners in America is the second largest and is comparable with Japan, but it per million populations is about 32. In Japan these situation urges the patient dose assessment on a clinical basis as an input to the justification and the optimization.

WAZA-ARI is the web-based open system for CT dose calculator, which has been developed by Oita University of Nursing and Health Sciences and the Japan Atomic Energy Agency (JAEA) . From Dec. 2012, it has installed in the web server of NIRS, and opened to the public for trial use. In this version, users can select 3 phantoms (adult male and female and 4 years old girl) for a dose calculation.

To consider patient’s age and body type, we installed the simulation data of organ doses and effective doses for several phantoms on WAZA-ARI system. And we added the database function of storing the calculation results in each facility in order to check the exposure levels of the CT examination in each medical facility in japan. We developed WAZA-ARIv2 associated with improvement of above functions. WAZA-ARIv2 was opened to the public on Jan. 31, 2015. And corresponding homepage was made and uploaded onto the NIRS web server.

Report and Paper

  • NIRS annual Report 2014-2015, pp.96-97.
    8. Reserch on Evaluation of Medical Exposure
  • WAZA-ARI - A web-based CT dose calculator - ,URL:
  • Takahashi F, Sato K, Endo A, Ono K, Ban N, Hasegawa T, Katsunuma Y, Yoshitake T, Kai M. Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System. Health Phys., 109(2), 104-112, 2015.
  • Ban N, Takahashi, Ono K, Hasegawa T, Yoshitake T, Katsunuma Y, Sato K, Endo A and Kai M. Development of a web-based CT dose calculator: WAZA-ARI. Radiat. Prot. Dosim., 147, 333-337, 2011.


WAZA-ARI Development Group

Privacy PolicyWAZA-ARI v2

Privacy Policy

User ManualWAZA-ARI v2

WAZA-ARI v2 UserManual
Appendix: Parameters