Biomaterial Database

Evaluation of rare earth intensifying screens in cephalometric radiography. 1990

V Stathopoulos, and D R Poulton

University of the Pacific, School of Dentistry, San Francisco, CA 94115.

Accuracy of cephalometric landmark location was determined in 20 pairs of headfilms, measuring differences in 18 points in two planes of each, using five independent observers. Each pair had one film taken with a conventional (calcium tungstate) intensifying screen system and one taken with a rare earth system. Statistically significant differences in accuracy were found in only six of the 36 measurements. Three of the differences favored the accuracy of the rare earth system (Pogonion Y, S Pogonion X and Y), while the other three favored the conventional system (ANS-X, Nasion-Y, Pt.A-Y). The least reproducible point in both systems in the horizontal axis was condylion. Since these findings showed no landmark accuracy preference of one screen system over the other, the 96 percent reduction in patient radiation with the rare earth system would mandate this be used in cephalometric radiography.

UI	MeSH Term	Description	Entries
D008674	Metals, Rare Earth	A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition, they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.	Rare Earth Metal,Rare Earth Metals,Earth Metal, Rare,Earth Metals, Rare,Metal, Rare Earth
D011856	Radiographic Image Enhancement	Improvement in the quality of an x-ray image by use of an intensifying screen, tube, or filter and by optimum exposure techniques. Digital processing methods are often employed.	Digital Radiography,Image Enhancement, Radiographic,Radiography, Digital,Enhancement, Radiographic Image,Enhancements, Radiographic Image,Image Enhancements, Radiographic,Radiographic Image Enhancements
D011857	Radiographic Image Interpretation, Computer-Assisted	Computer systems or networks designed to provide radiographic interpretive information.	Computer Assisted Radiographic Image Interpretation,Computer-Assisted Radiographic Image Interpretation,Radiographic Image Interpretation, Computer Assisted
D002508	Cephalometry	The measurement of the dimensions of the HEAD.	Craniometry
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014414	Tungsten	A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.	Wolfram
D014962	X-Ray Film	A film base coated with an emulsion designed for use with x-rays.	Film, X-Ray,Radiographic Film,Film, Radiographic,Xray Film,Film, X Ray,Film, Xray,Films, Radiographic,Films, X-Ray,Films, Xray,Radiographic Films,X Ray Film,X-Ray Films,Xray Films
D014963	X-Ray Intensifying Screens	Screens which absorb the energy in the x-ray beam that has penetrated the patient and convert this energy into a light pattern which has as nearly as possible the same information as the original x-ray beam. The more light a screen produces for a given input of x-radiation, the less x-ray exposure and thus shorter exposure time are needed to expose the film. In most film-screen systems, the film is sandwiched between two screens in a cassette so that the emulsion on each side is exposed to the light from its contiguous screen.	Film-Screen Systems, X-Ray,Radiographic Intensifying Screens,Screen-Film Systems, X-Ray,X-Ray Film-Screen Systems,Screens, Radiographic Intensifying,Xray Intensifying Screens,Film Screen Systems, X Ray,Film-Screen System, X-Ray,Intensifying Screen, Radiographic,Intensifying Screen, X-Ray,Intensifying Screen, Xray,Intensifying Screens, Radiographic,Intensifying Screens, X-Ray,Intensifying Screens, Xray,Radiographic Intensifying Screen,Screen Film Systems, X Ray,Screen, Radiographic Intensifying,Screen, X-Ray Intensifying,Screen, Xray Intensifying,Screen-Film System, X-Ray,Screens, X-Ray Intensifying,Screens, Xray Intensifying,System, X-Ray Film-Screen,System, X-Ray Screen-Film,Systems, X-Ray Film-Screen,Systems, X-Ray Screen-Film,X Ray Film Screen Systems,X Ray Intensifying Screens,X-Ray Film-Screen System,X-Ray Intensifying Screen,X-Ray Screen-Film System,X-Ray Screen-Film Systems,Xray Intensifying Screen
D017610	Calcium Compounds	Inorganic compounds that contain calcium as an integral part of the molecule.	Compounds, Calcium