title: Quantitative evaluation of free-form deformation registration for dynamic contrast-enhanced MR mammography.
abstract: In this paper, we present an evaluation study of a set of registration strategies for the alignment of sequences of 3D dynamic contrast-enhanced magnetic resonance breast images. The accuracy of the optimal registration strategies was determined on unseen data. The evaluation is based on the simulation of physically plausible breast deformations using finite element methods and on contrast-enhanced image pairs without visually detectable motion artifacts. The configuration of the finite element model was chosen according to its ability to predict in vivo breast deformations for two volunteers. We computed transformations for ten patients with 12 simulated deformations each. These deformations were applied to the postcontrast image to model patient motion occurring between pre- and postcontrast image acquisition. The original precontrast images were registered to the corresponding deformed postcontrast images. The performance of several registration configurations (rigid, affine, B-spline based nonrigid, single-resolution, multi-resolution, and volume-preserving) was optimized for five of the ten patients. The images were most accurately aligned with volume-preserving single-resolution nonrigid registration employing 40 or 20 mm control point spacing. When tested on the remaining five patients the optimal configurations reduced the average mean registration error from 1.40 to 0.45 mm for the whole breast tissue and from 1.20 to 0.32 mm for the enhancing lesion. These results were obtained on average within 26 (81) min for 40 (20) mm control point spacing. The visual appearance of the difference images from 30 patients was significantly improved after 20 mm volume-preserving single-resolution nonrigid registration in comparison to no registration or rigid registration. No substantial volume changes within the region of the enhancing lesions were introduced by this nonrigid registration.
authors.affiliation: Centre of Medical Image Computing at University College London, Gower Street, London WC1IE 6BT, United Kingdom. c.tanner@ucl.ac.uk
authors.forename: Christine
authors.initials: C
authors.lastname: Tanner
authors.forename: Julia A
authors.initials: JA
authors.lastname: Schnabel
authors.forename: Derek L G
authors.initials: DL
authors.lastname: Hill
authors.forename: David J
authors.initials: DJ
authors.lastname: Hawkes
authors.forename: Andreas
authors.initials: A
authors.lastname: Degenhard
authors.forename: Martin O
authors.initials: MO
authors.lastname: Leach
authors.forename: D Rodney
authors.initials: DR
authors.lastname: Hose
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Hall-Craggs
authors.forename: Sasha I
authors.initials: SI
authors.lastname: Usiskin
mesh_terms: D000465:Algorithms; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008327:Mammography / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013382:Subtraction Technique
chemical_list: D003287:Contrast Media