title: Calibration-Free Coronary Artery Measurements for Interventional Device Sizing using Inverse Geometry X-ray Fluoroscopy:In VivoValidation.
abstract: Proper sizing of interventional devices to match coronary vessel dimensions improves procedural efficiency and therapeutic outcomes. We have developed a novel method using inverse geometry x-ray fluoroscopy to automatically determine vessel dimensions without the need for magnification calibration or optimal views. To validate this methodin vivo, we compared results to intravascular ultrasound (IVUS) and coronary computed tomography angiography (CCTA) in a healthy porcine model. Coronary angiography was performed using Scanning-Beam Digital X-ray (SBDX), an inverse geometry fluoroscopy system that performs multiplane digital x-ray tomosynthesis in real time. From a single frame, 3D reconstruction of the arteries was performed by localizing the depth of vessel lumen edges. The 3D model was used to directly calculate length and to determine the best imaging plane to use for diameter measurements, where out-of-plane blur was minimized and the known pixel spacing was used to obtain absolute vessel diameter. End-diastolic length and diameter measurements were compared to measurements from CCTA and IVUS, respectively. For vessel segment lengths measuring 6 mm to 73 mm by CCTA, the SBDX length error was -0.49 ± 1.76 mm (SBDX - CCTA, mean ± 1 SD). For vessel diameters measuring 2.1 mm to 3.6 mm by IVUS, the SBDX diameter error was 0.07 ± 0.27 mm (SBDX - minimum IVUS diameter, mean ± 1 SD). Thein vivoagreement between SBDX-based vessel sizing and gold standard techniques supports the feasibility of calibration-free coronary vessel sizing using inverse geometry x-ray fluoroscopy.
authors.affiliation: Dept. of Medical Physics, University of Wisconsin, Madison, WI, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Tomkowiak
authors.affiliation: Dept. of Medicine, University of Wisconsin, Madison, WI, USA.
authors.forename: Amish N
authors.initials: AN
authors.lastname: Raval
authors.affiliation: Dept. of Medical Physics, University of Wisconsin, Madison, WI, USA ; Dept. of Medicine, University of Wisconsin, Madison, WI, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Van Lysel
authors.affiliation: Triple Ring Technologies, Inc, Newark, CA, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Funk
authors.affiliation: Dept. of Medical Physics, University of Wisconsin, Madison, WI, USA ; Dept. of Medicine, University of Wisconsin, Madison, WI, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Speidel
keywords: cardiac interventions; inverse geometry; quantitative coronary angiography; x-ray fluoroscopy