naa a22 4500 510807062 CHVBK 20180411083423.0 cr unu---uuuuu 180411e20131101xx s 000 0 eng 10.1007/s11548-013-0837-3 doi (NATIONALLICENCE)springer-10.1007/s11548-013-0837-3 Preliminary evaluation of an MRI-based technique for displaying and quantifying bony deformities in cam-type femoroacetabular impingement [Elektronische Daten] [Xiumei Kang, Honglin Zhang, Donald Garbuz, David Wilson, Antony Hodgson] Purpose: Characterizing aspheric deformities of the femoral head-neck junction in cam-type femoroacetabular impingement (FAI) requires representing the location, size, or extent of the bony lesion. The objectives of this work are to (1) assess the feasibility of creating 3D models of cam deformities from MRI sets, (2) present a standardized 2D visualization of the lesion, and (3) present and evaluate the potential utility of summary metrics in distinguishing between FAI patients and control subjects. Methods: Using MRIs from five subjects with diagnosed cam-type FAI and four healthy subjects, we developed a technique based on subtracting an estimated normal surface from each subject's actual bone surface in order to generate a subject-specific 2D "diagnosis graph” that characterized the femoral deformity. The models from three control subjects were combined to create the baseline model. Results: The RMS fitting error between the surface models of individual control subjects and their corresponding baseline models was 1.05 mm across the head and the head-to-neck transition region. In the anterosuperior region of the 2D diagnosis graphs, the mean height of the detected cam deformities relative to the estimated baseline normal shape was 17.9% of the head radius for the five FAI subjects (95% CI 8.5-27.3%) and 7.0% (95% CI 2.9-11.1%) for the four control subjects. A binary logistic regression analysis indicated that an h/r ratio larger than a threshold of $$\varepsilon $$ = 10.7% (equivalent to approximately 2.3 mm in height) yielded the best discrimination between cam-type FAI subjects and normal subjects. Conclusions: Our 2D diagnosis graph qualitatively enabled the cam-type lesions in four of our five diagnosed patients to be clearly visualized on MRI-derived models. We believe this visualization tool may be helpful in better characterizing cam-type lesions for diagnosis and for developing more precise plans for surgical treatment. CARS, 2013 Hip nationallicence Femoroacetabular impingement nationallicence Alpha angle nationallicence Computer-assisted diagnosis nationallicence Magnetic resonance imaging nationallicence Kang Xiumei Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, V6T 1Z4, Vancouver, BC, Canada aut Zhang Honglin Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Orthopaedics, University of British Columbia, 7/F, 2635 Laurel Street, V5Z 1M9, Vancouver, BC, Canada aut Garbuz Donald Division of Lower Limb Reconstruction and Oncology, Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada aut Wilson David Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Orthopaedics, University of British Columbia, 7/F, 2635 Laurel Street, V5Z 1M9, Vancouver, BC, Canada aut Hodgson Antony Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, V6T 1Z4, Vancouver, BC, Canada aut International Journal of Computer Assisted Radiology and Surgery Springer Berlin Heidelberg 8/6(2013-11-01), 967-975 1861-6410 8:6<967 2013 8 11548 https://doi.org/10.1007/s11548-013-0837-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11548-013-0837-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kang Xiumei Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, V6T 1Z4, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Zhang Honglin Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Orthopaedics, University of British Columbia, 7/F, 2635 Laurel Street, V5Z 1M9, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Garbuz Donald Division of Lower Limb Reconstruction and Oncology, Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Wilson David Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Orthopaedics, University of British Columbia, 7/F, 2635 Laurel Street, V5Z 1M9, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- Hodgson Antony Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, V6T 1Z4, Vancouver, BC, Canada aut NATIONALLICENCE 773 0- International Journal of Computer Assisted Radiology and Surgery Springer Berlin Heidelberg 8/6(2013-11-01), 967-975 1861-6410 8:6<967 2013 8 11548 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer