Imaging Science in Dentistry

Korean Academy of Oral and Maxillofacial Radiology (대한영상치의학회)
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Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

3차원 안모분석을 위한 저선량 Multi-detector CT 영상의 유효선량 및 화질 평가

  • Chung, Gi-Chung (Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University) ;
  • Han, Won-Jeong (Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University) ;
  • Kim, Eun-Kyung (Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University)
  • 정기정 (단국대학교 치과대학 구강악안면방사선학교실) ;
  • 한원정 (단국대학교 치과대학 구강악안면방사선학교실) ;
  • 김은경 (단국대학교 치과대학 구강악안면방사선학교실)
  • Received : 2010.01.15
  • Accepted : 2010.02.10
  • Published : 2010.03.31
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Abstract

Purpose : This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. Materials and Methods : 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Results : Effective doses in ${\mu}Sv$ ($E_{2007}$) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. Conclusion : From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

Keywords

References

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