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Nitanda A, Iwawaki A, Otaka Y, Tamatsu Y, Ishii T, Ochiai A, Otomo Y, Kito S, Saka H. Fundamental research for dose control during supine dental panoramic radiography. J Oral Biosci 2023; 65:365-370. [PMID: 37717634 DOI: 10.1016/j.job.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 09/07/2023] [Accepted: 09/10/2023] [Indexed: 09/19/2023]
Abstract
OBJECTIVE This study aimed to control radiation doses when using a portable supine dental panoramic radiography system by measured the scattered doses. METHOD The study used LPX7007 (Asahi Roentgen) for the panoramic radiography system. The subjects comprised a cylinder phantom (QualitA) and a RANDO Phantom (Alderson). The semiconductor dosimeter was an X2 survey sensor (RaySafe). The phantom was set at a height of 1 m from the floor, and the sensor was set at 1 m from the floor at the genital level and 1.5 m at the lens level. Measurements were taken at 30°intervals clockwise from 0°at distances of 0.5 m and 1 m in radius around the phantom. The occupational exposure range was defined as 0 ± 30° and the public exposure range was defined as the occupational exposure range and 30° to 150° and 210° to 330° as the public exposure range. RESULT The highest doses were observed in the 120° and 240° directions, and the lowest in 0° ± 30° range. The lowest limit number of images taken in the occupational exposure range was 130 images at a distance of 0.5 m, 452 images at 1 m at the lens level for the cylinder phantom, and 320 images at 0.5 m and 1098 images at 1 m for the RANDO Phantom. In the public exposure range at the genital level, there was one image at 0.5 m and six images at 1 m for the cylinder phantom, and two images at 0.5 m and eight images at 1 m for the RANDO Phantom. CONCLUSION We found that radiation exposure can be reduced by keeping a distance from the subject, avoiding working at 120° and 240° and staying within 0° ± 30° behind the panoramic radiography system.
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Affiliation(s)
- Atsuharu Nitanda
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan.
| | - Atsushi Iwawaki
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Yusei Otaka
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan; Forensic Odontology Center, Meikai University School of Dentistry, Saitama, Japan
| | - Yuichi Tamatsu
- Department of Gross Anatomy and Forensic Dentistry, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Takeru Ishii
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Akihiro Ochiai
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Yuko Otomo
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Shinji Kito
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Hideki Saka
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan; Forensic Odontology Center, Meikai University School of Dentistry, Saitama, Japan
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Iwawaki A, Otaka Y, Asami R, Ishii T, Kito S, Tamatsu Y, Aboshi H, Saka H. Comparison of air dose and operator exposure from portable X-ray units. Leg Med (Tokyo) 2020; 47:101787. [PMID: 32992157 DOI: 10.1016/j.legalmed.2020.101787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/29/2020] [Accepted: 09/06/2020] [Indexed: 10/23/2022]
Abstract
This study was aimed at investigating and comparing exposure dose of workers and the surrounding workers. In addition, worker's exposure was also measure about lens and finger. Four intraoral portable X-ray units were evaluated. The stray radiations were measured using Pitman 37D and ionization chamber (Pitman). MyDosemini (ALOKA) was used for measurement of the finger exposure dose. Without the shield became high in anterior 0.5 m. Comparing the air dose for the four models used in this study showed a high tendency for the two NOMAD models. And using the shields, the images could be taken 4.6 times of the baseline at a maximum and 3.6 times on average. The finger radiation exposure dose was low with both of the NOMAD models, with no significant difference found. By setting the baseline value without a shield, finger radiation exposure when using a shield was lower than the detection limit for the D3000, and was reduced by approximately 94-96% for other three models. All models can photograph around 100 bodies, so it is considered that it is not necessary to switch out the operator considering the operation limit. But even if it does not reach the operation limit, the stochastic effects of radiation exposure can be increased as well as the deterministic effects of the operation limit. The operator and the surrounding workers seek to protect themselves. It is important to perform exposure management that takes into account the stochastic effects to the operator and the surrounding workers.
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Affiliation(s)
- Atsushi Iwawaki
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan.
| | - Yusei Otaka
- Division of Dental Radiology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Ruri Asami
- Division of Oral Anatomy, Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan
| | - Takeru Ishii
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Shinji Kito
- Division of Dental Radiology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Yuichi Tamatsu
- Department of Gross Anatomy and Forensic Dentistry, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Hirofumi Aboshi
- Department of Legal Medicine, Nihon University School of Dentistry, Tokyo, Japan
| | - Hideki Saka
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan; Forensic Odontology Center, Meikai University School of Dentistry, Saitama, Japan
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Otaka Y, Harata Y, Izawa M, Iwawaki A, Ishii T, Saka H, Kito S. Reduction of operator exposure by rectangular collimation in portable intraoral radiography. Radiol Phys Technol 2020; 13:312-320. [PMID: 32607711 DOI: 10.1007/s12194-020-00573-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 06/13/2020] [Accepted: 06/22/2020] [Indexed: 11/29/2022]
Abstract
Portable intraoral X-ray units are frequently used for home-visit dental treatment and personal dental identification. Therefore, the reduction of operator exposure is crucial. Rectangular collimation is effective at reducing patient exposure and operator exposure; however, its effects are not known. We investigated the reduction of operator exposure through rectangular collimation by measuring the backscattered dose in relation to the operator exposure dose. Using a portable intraoral X-ray unit, a head phantom for CT dose measurement as the object, a dosimeter, and stainless-steel rectangular collimator, a 1-cm ambient dose equivalent was measured in intervals of 15° in horizontal and vertical planes with the radii of 50 and 100 cm. The backscattered dose decreased to approximately one-third when a rectangular collimator was attached to the cone tip. This may have been due to the reduction of the volume of scattered X-rays generated in the phantom by rectangular collimation. We clarified that rectangular collimation is effective at reducing the operator exposure and is useful for protecting the operators of portable intraoral X-ray units during home-visit dental treatment and personal dental identification.
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Affiliation(s)
- Yusei Otaka
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan.
| | - Yasuo Harata
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Maki Izawa
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Atsushi Iwawaki
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Takeru Ishii
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Hideki Saka
- Division of Forensic Odontology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan.,Forensic Odontology Center, Meikai University School of Dentistry, Saitama, Japan
| | - Shinji Kito
- Division of Dental Radiology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
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Iwawaki A, Otaka Y, Asami R, Ozawa T, Izawa M, Saka H. The study of protection of operators and surrounding workers at the time of using portable intraoral X-ray unit. Leg Med (Tokyo) 2018; 33:66-71. [PMID: 29933235 DOI: 10.1016/j.legalmed.2018.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/14/2018] [Accepted: 05/26/2018] [Indexed: 10/14/2022]
Affiliation(s)
- Atsushi Iwawaki
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan.
| | - Yusei Otaka
- Division of Dental Radiology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan
| | - Ruri Asami
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan
| | - Tomonori Ozawa
- Division of Dental Radiology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan
| | - Maki Izawa
- Division of Dental Radiology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan
| | - Hideki Saka
- Division of Forensic Odontology, Department of Diagnostic & Therapeutic Sciences, Meikai University School of Dentistry, Japan; Forensic Odontology Center, Meikai University School of Dentistry, Japan
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