Aims and objectives
Japan is the only country in the world where atomic bombs were dropped in 1945.
Furthermore,
during the Tohoku Region Pacific Offshore Earthquake,
the environmental pollution brought by the radioactive plume released in TEPCO Fukushima Daiichi Nuclear Power Plant accident is observed in 2011.
This resulted in the citizens’ increasing interest on radiation exposure,
and several issues remaining on the risk communication with patients during an examination using medical equipment with radiation,
which requires dose optimization and dose management with dose reports.
For example,
in...
Methods and materials
Study Population
A total of 126 people who underwent Xp and CT lung cancer screening from April 1,
2016 to March 31,
2018 were included in this study.The collected data were dose [mAs] of Xp,
CTDIvol,
and body mass index (BMI).
Calculation of SSDE
SSDE was calculated according totheAAPM report No.
204 and was set as SSDE(Calc.,
CT)(the upper portion in Fig. 1).
SSDE(Calc.,
CT)= CTDIvol×CF(CT Axi.)
CF(CT Axi.)was calculated based on the body thickness measured using the axial CT image.
The effective diameter was...
Results
Fig. 2 shown the regression analysis results between the BMI and dose.
In the chest Xp (left),
the correlation between BMI and dose [mAs] has the slope value of 0.250,
intercept of −2.307,
and correlation coefficient of R = 0.771 (p < 0.01).
In the CT examination (right),
the correlation between BMI and CTDIvolhas the slope value of 0.275,
intercept of −3.053,
and correlation coefficient of R = 0.815 (p < 0.01),
both of which showed a strong positive correlation.
Fig. 3 shown the regression...
Conclusion
The correlation between BMI and dose was clarified by collecting and analyzing DICOM information.The findings suggest that CTDIvoland SSDE can be predicted from Xp examination.From analysis based on the output data of the device,
the reliable dose estimation was possible without requiring simulation software.
Personal information
Tomoko Oikawa,
RT
1-21-1 Toyama Shinjuku Tokyo,
Japan
Center Hospital of National Center for Global Health and Medicine
Tel: +81-3- 3202-7181
E-mail:
[email protected]
[email protected]
References
International Electrotechnical Commission.
"International Standard IEC 60601-2-2.1: Medical Electrical Equipment,
Part 2-44: Particular Requirements for the Safety of X-ray Equipment for Computed Tomography."Geneva,
Switzerland: International Electrotechnical Commission(2002).
International Electrotechnical Commission.
"Medical electrical equipment–Exposure index of digital X-ray imaging systems-Part 1: Definitions and requirements for general radiography."IEC,
Geneva,
Switzerland(2008): 62494-1.
Boone,
J.
M.,
et al.
"AAPM Report No.
204."Size-Specific Dose Estimates (SSDE) in Pediatric and Adult Body CT Examinations204 (2011).