Gaurav Kumar Thawait MD, Presenter: Nothing to Disclose

Lew Schon MD, Abstract Co-Author: Royalties, DJO, LLC Royalties, Arthrex, Inc Royalties, DARCO International, Inc Royalties, Gerson Lehrman Group, Inc Royalties, Zimmer Holdings, Inc Royalties, Reed Elsevier Speakers Bureau, Tornier, Inc Speakers Bureau, Biomet, Inc Speakers Bureau, Zimmer Holdings, Inc Speakers Bureau, BioMimetic Therapeutics, Inc Consultant, Biomet, Inc Consultant, BioMimetic Therapeutics, Inc Consultant, Guidepoint Global, LLC Consultant, Gerson Lehrman Group, Inc Consultant, Tornier, Inc Consultant, Wright Medical Technology, Inc Consultant, Zimmer Holdings, Inc Consultant, Royer Medical, Inc Consultant, Carestream Health, Inc Stockholder, Tornier, Inc Stockholder, Royer Medical, Inc Stockholder, Bioactive Surgical, Inc Stockholder, HealthpointCapital Research support, Royer Medical, Inc Research support, Zimmer Holdings, Inc Research support, Tornier, Inc Research support, Arthrex, Inc Research support, SpineSmith LP Research support, Biomet, Inc Research support, BioMimetic Therapeutics, Inc Support, Bioactive Surgical, Inc Support, Educational Concepts in Medicine, LLC Support, Smith & Nephew plc Support, OrthoHelix Surgical Designs, Inc Support, Chesapeake Surgical Biocomposites Support, Olympus Corporation Support, Omega Surgical

Grace Jianan Gang, Abstract Co-Author: Nothing to Disclose

Wojciech Zbijewski PhD, Abstract Co-Author: Research Grant, Carestream Health, Inc

John Yorkston PhD, Abstract Co-Author: Employee, Carestream Health, Inc

John A. Carrino MD, MPH, Abstract Co-Author: Consultant, BioClinica, Inc Consultant, Pfizer Inc Advisory Board, General Electric Company

Jeffrey H. Siewerdsen PhD, Abstract Co-Author: Research Grant, Siemens AG Consultant, Siemens AG Research Grant, Carestream Health, Inc Royalties, Elekta AB

Shadpour Demehri MD, Abstract Co-Author: Nothing to Disclose

A prototype cone-beam CT (CBCT) scanner has been developed with capability for imaging of the weight-bearing (or non-weight-bearing) lower extremities. This work reports the first investigation of image quality and dose in relation to imaging of the foot and ankle.

The technical performance of the new clinical CBCT scanner was assessed in terms of spatial resolution, soft-tissue contrast resolution, and radiation dose. Clinical performance in imaging of the foot and ankle was assessed in a prospective IRB-approved study of 11 patients (8 female, 3 male; 32-62 yo, mean 43 yo) with ankle pathologies including fracture, tendonitis, osteoarthritis, and rheumatoid arthritis. Image quality was evaluated by a musculoskeletal radiologist and orthopedic surgeon in visualization tasks pertinent to each pathology. Patients with foot and/or ankle fracture were imaged longitudinally to characterize fracture healing, detect non-union, and quantify bone remodeling patterns in high-resolution 3D images.

The scanner exhibited spatial resolution of ~15-17 lp/cm (~0.5 mm) and contrast resolution sufficient for visualization of cartilage, ligament, tendons, and muscles. Radiation dose was less than that measured in conventional multi-detector CT protocols (CTDIw = 9 mGy, SSDE = 13 mGy for an 8 cm diameter ankle, compared to 25 mGy, SSDE = 35 mGy). The images provided clear visualization of numerous pathologies in the foot and ankle, including cartilage loss, soft tissue edema, bone cysts, erosions, subtle fractures, and non-union. The high spatial resolution enabled quantification of fracture healing patterns, including bridging trabeculae and cortical remodeling.

The prototype scanner exhibited spatial and contrast resolution sufficient for a broad range of diagnostic imaging tasks in the foot and ankle. The capability for weight-bearing imaging could offer a valuable tool for diagnosis and treatment assessment in various ankle pathologies including flat foot, osteoarthritis, and fracture nonunion.

CBCT of the foot and ankle can provide functional information and precise morphological analysis in cross sectional imaging not achieved by radiographs.

Thawait, G, Schon, L, Gang, G, Zbijewski, W, Yorkston, J, Carrino, J, Siewerdsen, J, Demehri, S, 3D Imaging of the Foot and Ankle Using a Dedicated Extremity Cone-Beam CT Scanner.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015491.html