Medical Physics Seminar – Friday, July 13, 2012
SPECIAL SEMINAR - Inverse Geometry X-ray Fluoroscopy: New SBDX Technology for Cardiac Interventional Procedures
Dr. Michael A. Speidel
Assistant Scientist, Department of Medical Physics, UW-School of Medicine & Public Health, Madison, WI USA
Scanning-beam digital x-ray (SBDX) is an inverse geometry x-ray fluoroscopic technology using a sequentially illuminated array of focal spot positions, CdTe photon-counting detector array, and digital tomosynthesis image reconstruction. The system design substantially improves the dose efficiency of fluoroscopy by minimizing image degrading x-ray scatter, maintaining high primary detection efficiency at high kVp, and increasing skin entrance field area. The unique ability to perform depth-resolved tomosynthesis at fluoroscopic frame rates (15-30 fps) also supports new interventional tools including 3D catheter tip tracking from a single gantry view, and calibration-free vessel dimension analysis. Recently, a Next-Generation SBDX detector was constructed to increase image signal-to-noise ratio to a level comparable to conventional cine angiography. A regional dose reduction capability has also been added which modulates x-ray output from each focal spot position. This lecture will describe current SBDX research, including phantom and animal studies evaluating Next-Generation SBDX system performance, and studies of SBDX 3D catheter tracking accuracy and precision.