title: Dual-energy imaging of the chest: optimization of image acquisition techniques for the 'bone-only' image.
abstract: Experiments were conducted to determine optimal acquisition techniques for bone image decompositions for a prototype dual-energy (DE) imaging system. Technique parameters included kVp pair (denoted [kVp(L)/kVp(H)]) and dose allocation (the proportion of dose in low- and high-energy projections), each optimized to provide maximum signal difference-to-noise ratio in DE images. Experiments involved a chest phantom representing an average patient size and containing simulated ribs and lung nodules. Low- and high-energy kVp were varied from 60-90 and 120-150 kVp, respectively. The optimal kVp pair was determined to be [60/130] kVp, with image quality showing a strong dependence on low-kVp selection. Optimal dose allocation was approximately 0.5-i.e., an equal dose imparted by the low- and high-energy projections. The results complement earlier studies of optimal DE soft-tissue image acquisition, with differences attributed to the specific imaging task. Together, the results help to guide the development and implementation of high-performance DE imaging systems, with applications including lung nodule detection and diagnosis, pneumothorax identification, and musculoskeletal imaging (e.g., discrimination of rib fractures from metastasis).
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada.
authors.forename: N A
authors.initials: NA
authors.lastname: Shkumat
authors.forename: J H
authors.initials: JH
authors.lastname: Siewerdsen
authors.forename: S
authors.initials: S
authors.lastname: Richard
authors.forename: N S
authors.initials: NS
authors.lastname: Paul
authors.forename: J
authors.initials: J
authors.lastname: Yorkston
authors.forename: R
authors.initials: R
authors.lastname: Van Metter
mesh_terms: D000465:Algorithms; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D006801:Humans; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique