title: AN INVESTIGATION INTO CT RADIATION DOSE VARIATIONS FOR HEAD EXAMINATIONS ON MATCHED EQUIPMENT.
abstract: This study investigated radiation dose and image quality differences for computed tomography (CT) head examinations across centres with matched CT equipment. Radiation dose records and imaging protocols currently employed across three European university teaching hospitals were collated, compared and coded as Centres A, B and C from specification matched CT equipment models. Patient scans (n = 40) obtained from Centres A and C were evaluated for image quality, based on the visualisation of Commission of European Community (CEC) image quality criteria using visual grading characteristic (VGC) analysis, where American Board of Radiology examiners (n = 11) stated their confidence in identifying anatomical criteria. Mean doses in terms of CT dose index (CTDIvol-mGy) and dose length product (DLP-mGy cm) were as follows: Centre A-33.12 mGy and 461.45 mGy cm; Centre B -101 mGy (base)/32 mGy (cerebrum) and 762 mGy cm and Centre C-71.98 mGy and 1047.26 mGy cm, showing a significant difference (p ≤ 0.05) in DLP across centres. VGC analysis indicated better visualisation of CEC criteria on Centre C images (VGCAUC0.225). All three imaging protocols are routinely used clinically, and image quality is acceptable in each centre. Clinical centres with identical model CT scanners have variously customised their protocols achieving a range of dose savings and still resulting in clinically acceptable image quality.
authors.affiliation: Faculty of Health Sciences, Department of Radiography, University of Malta, Msida, Malta francis.zarb@um.edu.mt.
authors.forename: Francis
authors.initials: F
authors.lastname: Zarb
authors.affiliation: Diagnostic Imaging, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland.
authors.forename: Shane
authors.initials: S
authors.lastname: Foley
authors.affiliation: CONRAD-Radiographic Research Center, University College Lillebaelt, Blangstedgaardsvej 4, 5220 Odense, Denmark.
authors.forename: Susanne
authors.initials: S
authors.lastname: Holm
authors.affiliation: Diagnostic Imaging, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland.
authors.forename: Rachel
authors.initials: R
authors.lastname: Toomey
authors.affiliation: American Board of Radiology, 5441 East Williams Boulevard, Suite 200, Tucson, AZ, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Evanoff
authors.affiliation: Diagnostic Imaging, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland.
authors.forename: Louise
authors.initials: L
authors.lastname: Rainford
mesh_terms: D006257:Head / Q000000981:diagnostic imaging*; D006785:Hospitals, University; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000379:methods*