TY - JOUR
T1 - Method for determining the half-value layer in computed tomography scans using a real-time dosimeter
T2 - Application to dual-source dual-energy acquisition
AU - Matsubara, Kosuke
AU - Nagata, Hiroji
AU - Okubo, Rena
AU - Takata, Tadanori
AU - Kobayashi, Masanao
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number 15K09887 . We would like to thank Dr. Takehiro Kuroda of Toyo Medic Co., Ltd for his technical support with regard to the AccuGold multifunction digitizer module, Dr. Shuji Koyama of Nagoya University for advice and discussion regarding the lead-covered case method, Dr. Atsushi Fukuda of Shiga Medical Center for Children for his fruitful advice, and Enago ( www.enago.jp ) for the English language review.
PY - 2017/12
Y1 - 2017/12
N2 - Purpose We have proposed a method for determining the half-value layers (HVL) in dual-source dual-energy computed tomography (DS-DECT) scans without the need for the X-ray tubes to be fixed. Methods A custom-made lead-covered case and an ionizing chamber connected with a multi-function digitizer module (a real-time dosimeter) were used. The chamber was placed in the center of the case, and aluminum or copper filters were placed in front of the aperture. The HVL was measured using aperture widths of 1.0, 2.0, and 3.0 cm for tube potentials of 80, 120, and 150 kV in single-source single-energy CT (SS-SECT) scans and was calculated from the peak air kerma rate (peak method) and the integrated air kerma rate (integrating method); the obtained values were compared with those from a conventional non-rotating method performed using the same procedure. The HVL was then measured using an aperture width of 1.0 cm for tube potential combinations of 70/Sn150 kV and 100/Sn150 kV in DS-DECT scans using the peak method. Results In the SS-SECT scans, the combination of a 1.0-cm aperture and the peak method was adequate due to the small differences in the HVL values obtained for the conventional non-rotating method. The method was also found to be applicable for the DS-DECT scans. Conclusions Our proposed method can determine the HVL in SS-SE and DS-DECT scans to a good level of accuracy without the need for the X-ray tubes to be fixed. The combination of a 1.0-cm aperture and the peak method was adequate.
AB - Purpose We have proposed a method for determining the half-value layers (HVL) in dual-source dual-energy computed tomography (DS-DECT) scans without the need for the X-ray tubes to be fixed. Methods A custom-made lead-covered case and an ionizing chamber connected with a multi-function digitizer module (a real-time dosimeter) were used. The chamber was placed in the center of the case, and aluminum or copper filters were placed in front of the aperture. The HVL was measured using aperture widths of 1.0, 2.0, and 3.0 cm for tube potentials of 80, 120, and 150 kV in single-source single-energy CT (SS-SECT) scans and was calculated from the peak air kerma rate (peak method) and the integrated air kerma rate (integrating method); the obtained values were compared with those from a conventional non-rotating method performed using the same procedure. The HVL was then measured using an aperture width of 1.0 cm for tube potential combinations of 70/Sn150 kV and 100/Sn150 kV in DS-DECT scans using the peak method. Results In the SS-SECT scans, the combination of a 1.0-cm aperture and the peak method was adequate due to the small differences in the HVL values obtained for the conventional non-rotating method. The method was also found to be applicable for the DS-DECT scans. Conclusions Our proposed method can determine the HVL in SS-SE and DS-DECT scans to a good level of accuracy without the need for the X-ray tubes to be fixed. The combination of a 1.0-cm aperture and the peak method was adequate.
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U2 - 10.1016/j.ejmp.2017.10.020
DO - 10.1016/j.ejmp.2017.10.020
M3 - Article
C2 - 29111386
AN - SCOPUS:85032214531
VL - 44
SP - 227
EP - 231
JO - Physica Medica
JF - Physica Medica
SN - 1120-1797
ER -