title: Digital breast tomosynthesis: studies of the effects of acquisition geometry on contrast-to-noise ratio and observer preference of low-contrast objects in breast phantom images.
abstract: The effect of acquisition geometry in digital breast tomosynthesis was evaluated with studies of contrast-to-noise ratios (CNRs) and observer preference. Contrast-detail (CD) test objects in 5 cm thick phantoms with breast-like backgrounds were imaged. Twelve different angular acquisitions (average glandular dose for each ~1.1 mGy) were performed ranging from narrow angle 16° with 17 projection views (16d17p) to wide angle 64d17p. Focal slices of SART-reconstructed images of the CD arrays were selected for CNR computations and the reader preference study. For the latter, pairs of images obtained with different acquisition geometries were randomized and scored by 7 trained readers. The total scores for all images and readings for each acquisition geometry were compared as were the CNRs. In general, readers preferred images acquired with wide angle as opposed to narrow angle geometries. The mean percent preferred was highly correlated with tomosynthesis angle (R = 0.91). The highest scoring geometries were 60d21p (95%), 64d17p (80%), and 48d17p (72%); the lowest scoring were 16d17p (4%), 24d9p (17%) and 24d13p (33%). The measured CNRs for the various acquisitions showed much overlap but were overall highest for wide-angle acquisitions. Finally, the mean reader scores were well correlated with the mean CNRs (R = 0.83).
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Mitchell M
authors.initials: MM
authors.lastname: Goodsitt
authors.forename: Heang-Ping
authors.initials: HP
authors.lastname: Chan
authors.forename: Andrea
authors.initials: A
authors.lastname: Schmitz
authors.forename: Scott
authors.initials: S
authors.lastname: Zelakiewicz
authors.forename: Santosh
authors.initials: S
authors.lastname: Telang
authors.forename: Lubomir
authors.initials: L
authors.lastname: Hadjiiski
authors.forename: Kuanwong
authors.initials: K
authors.lastname: Watcharotone
authors.forename: Mark A
authors.initials: MA
authors.lastname: Helvie
authors.forename: Chintana
authors.initials: C
authors.lastname: Paramagul
authors.forename: Colleen
authors.initials: C
authors.lastname: Neal
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Christodoulou
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Larson
authors.forename: Paul L
authors.initials: PL
authors.lastname: Carson
mesh_terms: D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008327:Mammography / Q000295:instrumentation*; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed