OBJECTIVES: To assess the cross-centre consistency of iodine enhancement, contrast-to-noise ratio and radiation dose in a multicentre perfusion CT trial of colorectal cancer. MATERIALS AND METHODS: A cylindrical water phantom containing different iodine inserts was examined on seven CT models in 13 hospitals. The relationship between CT number (Hounsfield units, HU) and iodine concentration (milligrams per millilitre) was established and contrast-to-noise ratios (CNRs) calculated. Radiation doses (CTDIvol, DLP) were compared across all sites. RESULTS: There was a linear relationship between CT number and iodine density. Iodine enhancement varied by a factor of at most 1.10, and image noise by at most 1.5 across the study sites. At an iodine concentration of 1 mg ml(-1) and 100 kV, CNRs ranged from 3.6 to 4.8 in the 220-mm phantom and from 1.4 to 1.9 in the 300-mm phantom. Doses varied by a factor of at most 2.4, but remained within study dose constraints. Iterative reconstruction algorithms did not alter iodine enhancement but resulted in reduced image noise by a factor of at most 2.2, allowing a potential dose decrease of at most 80% compared to filtered back projection (FBP). CONCLUSIONS: Quality control of CT performance across centres indicates that CNR values remain relatively consistent across all sites, giving acceptable image quality within the agreed dose constraints. KEY POINTS: Quality control is essential in a multicentre setting to enable CT quantification. CNRs in a body-sized phantom had the recommended value of at least 1.5. CTDIs and DLPs varied by factors of 1.8 and 2.4 respectively.
OBJECTIVES: To assess the cross-centre consistency of iodine enhancement, contrast-to-noise ratio and radiation dose in a multicentre perfusion CT trial of colorectal cancer. MATERIALS AND METHODS: A cylindrical water phantom containing different iodine inserts was examined on seven CT models in 13 hospitals. The relationship between CT number (Hounsfield units, HU) and iodine concentration (milligrams per millilitre) was established and contrast-to-noise ratios (CNRs) calculated. Radiation doses (CTDIvol, DLP) were compared across all sites. RESULTS: There was a linear relationship between CT number and iodine density. Iodine enhancement varied by a factor of at most 1.10, and image noise by at most 1.5 across the study sites. At an iodine concentration of 1 mg ml(-1) and 100 kV, CNRs ranged from 3.6 to 4.8 in the 220-mm phantom and from 1.4 to 1.9 in the 300-mm phantom. Doses varied by a factor of at most 2.4, but remained within study dose constraints. Iterative reconstruction algorithms did not alter iodine enhancement but resulted in reduced image noise by a factor of at most 2.2, allowing a potential dose decrease of at most 80% compared to filtered back projection (FBP). CONCLUSIONS: Quality control of CT performance across centres indicates that CNR values remain relatively consistent across all sites, giving acceptable image quality within the agreed dose constraints. KEY POINTS: Quality control is essential in a multicentre setting to enable CT quantification. CNRs in a body-sized phantom had the recommended value of at least 1.5. CTDIs and DLPs varied by factors of 1.8 and 2.4 respectively.
Authors: Christopher H Cagnon; Dianna D Cody; Michael F McNitt-Gray; J Anthony Seibert; Philip F Judy; Denise R Aberle Journal: Acad Radiol Date: 2006-11 Impact factor: 3.173
Authors: K A Miles; T-Y Lee; V Goh; E Klotz; C Cuenod; S Bisdas; A M Groves; M P Hayball; R Alonzi; T Brunner Journal: Eur Radiol Date: 2012-02-26 Impact factor: 5.315
Authors: James P B O'Connor; Eric O Aboagye; Judith E Adams; Hugo J W L Aerts; Sally F Barrington; Ambros J Beer; Ronald Boellaard; Sarah E Bohndiek; Michael Brady; Gina Brown; David L Buckley; Thomas L Chenevert; Laurence P Clarke; Sandra Collette; Gary J Cook; Nandita M deSouza; John C Dickson; Caroline Dive; Jeffrey L Evelhoch; Corinne Faivre-Finn; Ferdia A Gallagher; Fiona J Gilbert; Robert J Gillies; Vicky Goh; John R Griffiths; Ashley M Groves; Steve Halligan; Adrian L Harris; David J Hawkes; Otto S Hoekstra; Erich P Huang; Brian F Hutton; Edward F Jackson; Gordon C Jayson; Andrew Jones; Dow-Mu Koh; Denis Lacombe; Philippe Lambin; Nathalie Lassau; Martin O Leach; Ting-Yim Lee; Edward L Leen; Jason S Lewis; Yan Liu; Mark F Lythgoe; Prakash Manoharan; Ross J Maxwell; Kenneth A Miles; Bruno Morgan; Steve Morris; Tony Ng; Anwar R Padhani; Geoff J M Parker; Mike Partridge; Arvind P Pathak; Andrew C Peet; Shonit Punwani; Andrew R Reynolds; Simon P Robinson; Lalitha K Shankar; Ricky A Sharma; Dmitry Soloviev; Sigrid Stroobants; Daniel C Sullivan; Stuart A Taylor; Paul S Tofts; Gillian M Tozer; Marcel van Herk; Simon Walker-Samuel; James Wason; Kaye J Williams; Paul Workman; Thomas E Yankeelov; Kevin M Brindle; Lisa M McShane; Alan Jackson; John C Waterton Journal: Nat Rev Clin Oncol Date: 2016-10-11 Impact factor: 66.675