title: Variable compensation chest radiography performed with a computed radiography system: design considerations and initial clinical experience.
abstract: The authors describe a variable compensation (VC) technique in which an x-ray equalizer and a computed radiography system are used. The VC technique allows retrospective alteration of equalized chest appearance with maintenance of improved signal-to-noise ratio in dense regions. Two imaging plates are used: one upstream of the patient to record the incident beam profile and one down-stream to record the equalized image. Subtraction of a weighted version of the upstream image from the down-stream image permits alteration of the appearance of the VC image, from the extremes of stimulated-unequalized to highly equalized. VC image appearance was optimized with a real-time workstation. The quality of VC images obtained in 33 patients was evaluated by three chest radiologists. Mediastinal appearance was better on VC equalized images than on conventional screen-film images. The stimulation of the appearance of a conventional radiograph with VC proved useful in interpretation of lung appearances on equalized radiographs.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710.
authors.forename: J T
authors.initials: JT
authors.lastname: Dobbins
authors.forename: J J
authors.initials: JJ
authors.lastname: Rice
authors.forename: P C
authors.initials: PC
authors.lastname: Goodman
authors.forename: E F
authors.initials: EF
authors.lastname: Patz
authors.forename: C E
authors.initials: CE
authors.lastname: Ravin
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D013679:Technology, Radiologic; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*