title: Detection and registration of ribs in MRI using geometric and appearance models.
abstract: Magnetic resonance guided high intensity focused ultrasound (MRgHIFU) is a new type of minimally invasive therapy for treating malignant liver tissues. Since the ribs on the beam path can compromise an effective therapy, detecting them and tracking their motion on MR images is of great importance. However, due to poor magnetic signal emission of bones, ribs cannot be entirely observed in MR. In the proposed method, we take advantage of the accuracy of CT in imaging the ribs to build a geometric ribcage model and combine it with an appearance model of the neighbouring structures of ribs in MR to reconstruct realistic centerlines in MRIs. We have improved our previous method by using a more sophisticated appearance model, a more flexible ribcage model, and a more effective optimization strategy. We decreased the mean error to 2.5 mm, making the method suitable for clinical application. Finally, we propose a rib registration method which conserves the shape and length of ribs, and imposes realistic constraints on their motions, achieving 2.7mm mean accuracy.
authors.forename: Golnoosh
authors.initials: G
authors.lastname: Samei
authors.forename: Gábor
authors.initials: G
authors.lastname: Székely
authors.forename: Christine
authors.initials: C
authors.lastname: Tanner
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012272:Ribs / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods