title: The effects of CT drift on xenon/CT measurement of regional cerebral blood flow.
abstract: A systematic increase in computed tomography (CT) number of approximately 0.13 Hounsfield unit per scan (HU/scan) was observed when serial DeltaScan 2020 CT scans of a uniform water phantom were equally spaced at 0.5, 1.0, or 2.0 min and a shaped aluminum beam-hardening filter was employed. Much smaller drifts (less than 0.06 HU/scan) were observed with flat aluminum or shaped beryllium oxide filters. This machine drift, which was not associated with a rise in water phantom temperature and did not consistently correlate with estimated x-ray tube heat, could result in a significant overestimation of regional cerebral blood flow (rCBF) for a xenon/CT rCBF protocol involving 5-7 sequential scans obtained at 1-min interscan intervals.
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D006801:Humans; D008961:Models, Structural; D014057:Tomography, X-Ray Computed; D014978:Xenon
chemical_list: D014978:Xenon