title: Receiver operating characteristic analysis of fracture and pneumonia detection: comparison of laser-digitized workstation images and conventional analog radiographs.
abstract: Forty pneumonia and 40 fracture cases were matched by patient age and gender with normal cases. Pediatric cases constituted 25% of this sample. All 160 examinations were laser-digitized at a spot size of 210 microns, a contrast resolution of 12 bits, and a spatial resolution of 2.35 line pairs per millimeter. The digitized images were transmitted 5 miles over a dedicated telephone line at a T1 rate from Francis Scott Key Hospital to Johns Hopkins Hospital (both in Baltimore, Md). At Johns Hopkins Hospital, eight radiologists interpreted the original analog radiograph and corresponding soft-copy display (1,280 x 1,024 pixels). Findings, confidence ratings, and image quality were reported for each reading. A receiver operating characteristic (ROC) analysis was conducted to compare observer performance under the analog and digital reading conditions. The overall sensitivity of the analog method was 89% versus 78% for the digital method (P < .001), while the specificity values were 96% and 92%, respectively (P > .20). ROC analysis similarly indicated a statistically significant difference in favor of analog radiographs (P = .028).
authors.affiliation: Department of Radiology, Johns Hopkins Hospital, Baltimore, MD 21287.
authors.forename: S J
authors.initials: SJ
authors.lastname: Ackerman
authors.forename: J N
authors.initials: JN
authors.lastname: Gitlin
authors.forename: R W
authors.initials: RW
authors.lastname: Gayler
authors.forename: C D
authors.initials: CD
authors.lastname: Flagle
authors.forename: R N
authors.initials: RN
authors.lastname: Bryan
mesh_terms: D002648:Child; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000000981:diagnostic imaging*; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D011873:Radiology Information Systems; D012680:Sensitivity and Specificity