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MO‐A‐M100J‐02: Performance Evaluation for New‐Technology CT Systems: 256‐Channel C
Author(s) -
Geleijns J
Publication year - 2007
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 - 10.1118/1.2761190
Subject(s) - scanner , imaging phantom , dosimetry , ionization chamber , image quality , absorbed dose , channel (broadcasting) , nuclear medicine , medical physics , beam (structure) , medical imaging , optics , physics , computer science , medicine , ionization , computer vision , artificial intelligence , telecommunications , image (mathematics) , ion , quantum mechanics
Medical physicists are challenged to assess image quality and patient dose for 256‐channel CT scanners. Whereas current concepts for measurement of image quality still remain valid for 256‐channel scanners, concepts for CT dosimetry will have to change fundamentally. Current methodology for CT dosimetry, e.g. assessment of CTDI with a 10 cm CT ionization chamber and standard CT dose phantoms, is not compatible with the x‐ray beam geometry of the new 256‐channel CT scanner. The beam width exceeds the length of the CT ionization chamber and, at the exit surface of the phantom; the beam width even exceeds the length of the body phantom. Several options to overcome dosimetric problems of cone beam CT scanners will be considered. Educational Objectives: 1. Understand the design and operation concepts a new 256‐channel axial CT scanner. 2. Understand concepts for specifying and measuring absorbed dose for a new 256‐channel axial CT scanner. 3. Understand shortcomings in current concepts for assessment of absorbed dose and and patient dose for the new 256‐channel axial CT scanner.