Diagnostic accuracy of digitized dental radiographs

Research Project

Project/Area Number	04671233
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	外科・放射線系歯学
Research Institution	Nagasaki University
Principal Investigator	OHKI Masafumi Nagasaki University, School of Dentistry, Assist.Prof., 歯学部, 講師 (10160441)
Co-Investigator(Kenkyū-buntansha)	IZUMI Masahiro Nagasaki University, School of Dentistry, Instructor, 歯学部, 助手 (40212956) YAMADA Miho Nagasaki University, School of Dentistry, Instructor, 歯学部, 助手 (80200749)
Project Period (FY)	1992 – 1993
Project Status	Completed (Fiscal Year 1993)
Budget Amount *help	¥2,100,000 (Direct Cost: ¥2,100,000) Fiscal Year 1993: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1992: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Radiographic image enhancement / dental radiography / ROC analysis / dental caries / Digital Radiography / ROC / PACS
Research Abstract	A number of factors may determine the diagnostic accuracy of digitized intraoral radiographs. Conventional film radiographs were digitized with three different digitizers, a laser-scanner, a drum-scanner, and a TV camera. Digital images, varying in pixel size and gray level and image processing, were displayd on three different video-monitors and assessed by 10 dentists. The detectability of incipient proximal surface caries was used as an index of the diagnostic accuracy and the effect of the different factors compared by means of receiver operating characteristic analysis. Image digitized by the drum-scanner were found to have the best diagnostic accuracy. Sufficient diagnostic accuracy could be attained on the low-cost video monitor of a personal computer. Digital images with a pixel size of 100mm and 32 gray levels were found to be acceptable for intraoral radiographs, for diagnostic purposes. These results provide a practical guide for establishing a digital image acquiring system for any intraoral radiographs, reducing demands on data storage to a minimum.