title: Multi-modal registration of speckle-tracked freehand 3D ultrasound to CT in the lumbar spine.
abstract: A method for registration of speckle-tracked freehand 3D ultrasound (US) to preoperative CT volumes of the spine is proposed. We register the US volume to the CT volume by creating individual US "sub-volumes", each consisting of a small section of the entire US volume. The registration proceeds incrementally from the beginning of the US volume to the end, registering every sub-volume, where each sub-volume contains overlapping images with the previous sub-volume. Each registration is performed by generating simulated US images from the CT volume. As a by-product of our registration, the significant drift error common in speckle-tracked US volumes is corrected for. Results are validated through a phantom study of plastic spine phantoms created from clinical patient CT data as well as an animal study using a lamb cadaver. Results demonstrate that we were able to successfully register a speckle-tracked US volume to CT volume in four out of five phantoms with a success rate of greater than 98%. The final error of the registered US volumes decreases by over 50 percent from the speckle tracking error to consistently below 3 mm. Studies on the lamb cadaver showed a mean registration error consistently below 2 mm.
authors: Department of Electrical and Computer Engineering, Queen's University, Kingston, Ontario, Canada.
authors: Andrew
authors: A
authors: Lang
authors: Parvin
authors: P
authors: Mousavi
authors: Sean
authors: S
authors: Gill
authors: Gabor
authors: G
authors: Fichtinger
authors: Purang
authors: P
authors: Abolmaesumi
mesh_terms: D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D010363:Pattern Recognition, Automated / Q000379:methods*; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D013382:Subtraction Technique; D025321:Surgery, Computer-Assisted / Q000379:methods