title: Efficacy of quantitative digital subtraction radiography using radiographs exposed in a multicenter trial.
abstract: Digital subtraction radiography (DSR) has been shown to be a sensitive and specific method for the detection of small bony changes in periodontitis. The purpose of this study was to perform a multicenter validation of the DSR in human subjects. Seventeen subjects were enrolled at 3 centers. Feather-edged hydroxyapatite chips (approximately 1, 7 and 10 mg) were used to simulate osseous lesions. Bilateral radiographs were taken with and without chips. Geometry was standardized using a cephalostat and the order of radiographs was determined using a randomization plan. Radiographs were subtracted, lesions isolated, and quantified at a single center without knowledge of the randomization code or location of the chips used in each subject. The overall sensitivity and specificity in detecting 1 mg changes was 87.8% and 100%, respectively. Sensitivity and specificity in detecting 7 mg and 10 mg chips was 100%. A strong linear relationship between actual lesion mass and calculated mass was observed (R2 = 0.94, slope = 0.98, p < 0.0001). No significant differences were observed by center. These data indicate that the DSR is a valid technique for the assessment of alveolar bone changes in multicenter trials.
authors.affiliation: Department of Periodontics, University of Alabama School of Dentistry, Birmingham 35294, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Jeffcoat
authors.forename: M S
authors.initials: MS
authors.lastname: Reddy
authors.forename: I
authors.initials: I
authors.lastname: Magnusson
authors.forename: B
authors.initials: B
authors.lastname: Johnson
authors.forename: M P
authors.initials: MP
authors.lastname: Meredith
authors.forename: P F
authors.initials: PF
authors.lastname: Cavanaugh
authors.forename: R W
authors.initials: RW
authors.lastname: Gerlach
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011856:Radiographic Image Enhancement; D016300:Radiography, Bitewing / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013382:Subtraction Technique / Q000379:methods*