Aims and objectives
Recently,
various imaging techniques are used by the development of the X-ray CT apparatus.
Especially,
in the area of dual energy CT using different tube voltages,
computed tomography dose index and a human equivalent body phantom are used for dose evaluation.
However,
defined dose measurement method has not been certain.
The aim of this study was to try to clarify the difference of organ doses between the fast kVp switching dual energy CT (DECT) and the single energy CT (SECT) when the displayed radiation doses...
Methods and materials
The 256-detector row CT system (Revolution CT,
GE Healthcare,
Milwaukee,
USA) was used to scan the trunk (chest apices to symphysis pubis) of an anthropomorphic phantom (Alderson Rando Phantom) (Fig.1).
Thermo-luminescent dosimeters (BeO) inside (n=97) and on the surface (n=57) were positioned at various anatomical organs as per ICRP103 to measure organ doses and effective dose.
The exposure conditions were set to five conditions calculated in GSI Assist,
and five conditions using ATCM in single energy were also used (Table.1).
Results
As the displayed CTDIvol. increased,
the measured doses increased as well.
Among displayed CTDIvol. increased with different exposure conditions,
organ doses and effective dose increased at almost the same ratio between the GSI Assist and the SECT.
The organ dose of the GSI Assist fluctuated within 12.0±3mGy,
and the effective dose within 11.0±2mSv.
However,
using ATCM in SECT,
the organ doses were different by about up to 15% and effective dose by about 10% compared with the GSI Assist,
even if the same CTDIvol. were...
Conclusion
The measured organ doses were different by about up to 15% and effective dose by about 10% between DECT with the GSI Assist and SECT with the ATCM.
Among with the displayed CTDIvol. increased,
the measured doses were fluctuated at almost the same ratio between DECT with the GSI Assist and SECT with the ATCM.Although the same CTDIvol. does not result in the same organ doses in the DECT with the GSI Assist and SECT with the ATCM,
both displayed CTDIvol. have potential to be...
References
Mahmood U,Horvat N,
Horvat JV,
Ryan D et al.
(2018)Rapid switching kVp dual energy CT: Value of reconstructed dual energy CT images and organ dose assessment in multiphasic liver CT exams.Eur Radiol.
102:102-108.