title: Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations.
  
  
  METHODS
  The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations.
  
  
  RESULTS
  At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P < 0.001; ICCs > 0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp.
  
  
  CONCLUSIONS
  SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions.
  
  
  CONCLUSIONS
  • Gadolinium quantification may be useful in patients with contraindication to iodine. • Dual-layer spectral detector CT allows for overall accurate quantification of gadolinium. • Interscan variability of gadolinium quantification using SDCT material decomposition is excellent.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands. R.W.vanHamersvelt-3@umcutrecht.nl.
authors.forename: Robbert W
authors.initials: RW
authors.lastname: van Hamersvelt
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Willemink
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Pim A
authors.initials: PA
authors.lastname: de Jong
authors.affiliation: CT Clinical Science, Philips HealthCare, Best, The Netherlands.
authors.forename: Julien
authors.initials: J
authors.lastname: Milles
authors.affiliation: CT Clinical Science, Philips HealthCare, Brussels, Belgium.
authors.forename: Alain
authors.initials: A
authors.lastname: Vlassenbroek
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Arnold M R
authors.initials: AMR
authors.lastname: Schilham
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
mesh_terms: D005240:Feasibility Studies; D005682:Gadolinium / Q000032:analysis*; D006321:Heart; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D005682:Gadolinium
keywords: Contrast media; Dual-energy CT; Dual-layer spectral detector CT; Gadolinium; Material decomposition