Evaluation of the dose distribution according to tube voltage in pediatric head ct examination. (September 2016)

• Record Type: Journal Article
• Authors: Noguchi, K.; Gotanda, R.; Sato, H.; Nakajima, E.; Gotanda, T.; Akagawa, T.; Tanki, N.; Kuwano, T.; Katsuda, T.
• Is Part Of: Physica medica. Volume 32(2016)Supplement 3
• Page Start: 310
• Publication Date: 2016-09
• Subjects: Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2016.07.176
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract : Introduction: In pediatric computed tomography (CT) examination, CT scanning with low tube voltage is suggested for increase the contrast enhancement. When the tube voltage is lowered, the tube current is raised to keep the image quality. Additionally, the dose distribution varies according to tube voltage and patient size. Purpose: In this study, the dose distributions according to tube voltage were evaluated using developed phantoms and radiochromic film for CT dose dosimetry. Materials and methods: The phantom shape was cylindrical and diameters were 100 and 140 mm. The dose distributions in the phantom were measured by GAFCHROMIC XR-QA2 film. The scanning tube voltages of CT (Supria; Hitachi Medical Corporation) were 80, 100, 120 and 140 kV. The tube currents were set based on CTDIvol (48.8 mGy) displayed on the CT console. Results: In 100 mm phantom, the maximum doses of center or peripheral at 80 and 140 kV were 90.0 or 109.5, and 66.7 or 84.8 mGy, respectably. The maximum dose areas were at the surface in all tube voltage. However, the mean center dose was larger than mean peripheral dose. Additionally, the ratios of center to peripheral were increased according to increase tube voltage. Conclusion: The results indicated the dose distribution in pediatric head CT become complex according to tube voltage and phantom size. Furthermore, tube current is important factor in determining the maximum dose. To appreciate the radiation risk, the pediatric CT dose should be evaluated by the dose distributions for each patient size and tube voltage. Disclosure: We have no disclosure and financial support.