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TU‐E‐110‐03: Inverse Geometry X‐Ray Fluoroscopy Using Scanning‐Beam Digital X‐Ray Technology
Author(s) -
Speidel M
Publication year - 2011
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3613205
Subject(s) - collimator , fluoroscopy , optics , tomosynthesis , detector , physics , dosimetry , tracking (education) , x ray detector , nuclear medicine , mammography , medicine , psychology , pedagogy , cancer , breast cancer , nuclear physics
Scanning‐beam digital x‐ray (SBDX) is an inverse geometry x‐ray fluoroscopic system using a sequentially illuminated array of focal spot positions, CdTe photon‐counting detector array, and real‐time image reconstructor. 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 entrance field area. SBDX also has a unique real‐time tomosynthesis capability that enables 3D catheter tracking, fiducial tracking, and 3D vessel dimension analysis during procedures. Recently, image intensity equalization via adaptive reduction of beam‐on time in more transmissive patient regions has been investigated. These advanced fluoroscopic capabilities stem from a radically different x‐ ray source design. SBDX has a large‐area transmission‐style tungsten target bonded to a water‐cooled beryllium plate. A multihole collimator positioned beyond the target defines a series of narrow overlapping x‐ray beams. As the focal spot is electronically deflected from one collimator hole to the next, detector images are simultaneously acquired. Images of the scanning field‐of‐view are reconstructed in real time at up to 30 Hz. Design challenges include achieving sufficient x‐ray source output, fast readout rates in the detector, and the need for real‐time image reconstruction. This lecture will present the principles of the SBDX system and inverse geometry fluoroscopy. Applications of SBDX tomosynthesis and techniques used to increase signal‐to‐noise ratio and reduce heat loading in the x‐ray source will be discussed. This research was supported by NIH Grant R01 HL084022, NovaRay Medical, Inc., and Triple Ring Technologies, Inc. Learning Objectives: 1. Understand how inverse geometry x‐ray fluoroscopy design improves dose efficiency 2. Understand the operating principles of the scanning‐beam digital x‐ray system 3. Understand applications of real‐time tomosynthesis in fluoroscopically‐guided procedures