Operator Dose Measurements and Image Quality Assessment in Computed Tomography Fluoroscopy Using Bismuth Sheet
| Autor: | Tsukasa Yoshida, Yoshihiro Nakaya, Kenichi Hirosawa, Takahiro Ito, Keisuke Takiguchi, Atsushi Urikura |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Image quality chemistry.chemical_element Dose profile Radiation Dosage Imaging phantom 030218 nuclear medicine & medical imaging Bismuth 03 medical and health sciences Radiation Protection 0302 clinical medicine Contrast-to-noise ratio Occupational Exposure medicine Humans Fluoroscopy medicine.diagnostic_test Phantoms Imaging business.industry General Medicine Torso equipment and supplies medicine.anatomical_structure chemistry 030220 oncology & carcinogenesis Tomography Tomography X-Ray Computed Nuclear medicine business |
| Zdroj: | Japanese Journal of Radiological Technology. 72:1137-1143 |
| ISSN: | 1881-4883 0369-4305 |
| Popis: | Objective The purpose of this study was to assess the dose reduction and the image quality using bismuth sheets during the computed tomography fluoroscopy (CTF). Materials and methods The bismuth sheets of 1-mm thick were put on the upper mylar ring to reduce the frontal X-ray. The dose rates of an operator were measured using a torso phantom in the patient position during the CTF. The torso phantom was set on the gantry rotation center (center) and the lower position from the center (off-center). The image quality of the CTF image was assessed using an original phantom that mimics the normal liver parenchyma and the low attenuation lesions. The image contrast and contrast-to-noise ratio (CNR) were compared with and without the bismuth sheets. Results The bismuth sheets reduced the dose rate of the operator, regardless of whether the torso phantom was set at the center or the off-center. The reduction rate of exposure at the center and the off-center were 42.3% and 34.5%, respectively. There were no significant differences in the image contrast and the CNR, although the bismuth sheets increased the CT values of the liver parenchyma and the low attenuation lesions. Conclusion The bismuth sheets were effective for the reduction of exposure to the operator without degrading the image quality of CTF images. |
| Databáze: | OpenAIRE |
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