title: Reproducibility and comparison of DCE-MRI and DCE-CT perfusion parameters in a rat tumor model.
abstract: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and computed tomography (DCE-CT) provide independent measures of biomarkers related to tumor perfusion. We compared the reproducibilities and absolute values of DCE-MRI and DCE-CT biomarkers in the same tumors in an animal model, to investigate the physiologic validity of both approaches. DCE-MRI and DCE-CT were each performed sequentially on three consecutive days in each of twelve rats bearing C6 glioma xenografts. DCE-MRI yielded endothelial transfer constant (K(trans)), extracellular, extravascular space volume fraction (v(e)), and contrast agent reflux rate constant (k(ep)); and DCE-CT, blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) using Tofts and deconvolution physiological models, with 6.6 and 0.4 seconds temporal resolutions, respectively. Variability in DCE-CT and DCE-MRI were evaluated by variance components analysis. Intra-rat coefficients of variation for DCE-CT parameters BF, BV, MTT and PS were 25%, 22%, 18% and 23%; and for DCE-MRI parameters K(trans), k(ep) and v(e) were 23%, 16% and 20%, respectively. Mean (±SD) BF, BV, MTT and PS were: 44.6 (±13.7) ml min(-1) 100 g(-1), 5.7 (±1.5) ml 100 g(-1), 10.8 (±2.3) seconds, and 14.6 (±4.7) ml min(-1) 100 g(-1), respectively. Mean (±SD) K(trans), k(ep) and v(e) were: 0.21 (±0.05) min(-1), 0.68 (±0.14) min(-1), and 0.29 (±0.06), respectively. Permeability estimates from DCE-MRI (K(trans)) were 44% higher than from DCE-CT (PS), despite application of appropriate corrections. DCE-MRI and DCE-CT biomarkers of tumor perfusion have similar reproducibilities suggesting that they may have comparable utility, but their derived parameter values are not equivalent.
authors.affiliation: Department of Radiology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA. cng@mdanderson.org
authors.forename: Chaan S
authors.initials: CS
authors.lastname: Ng
authors.forename: John C
authors.initials: JC
authors.lastname: Waterton
authors.forename: Vikas
authors.initials: V
authors.lastname: Kundra
authors.forename: David
authors.initials: D
authors.lastname: Brammer
authors.forename: Murali
authors.initials: M
authors.lastname: Ravoori
authors.forename: Lin
authors.initials: L
authors.lastname: Han
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Sherry
authors.initials: S
authors.lastname: Klumpp
authors.forename: Valen E
authors.initials: VE
authors.lastname: Johnson
authors.forename: Edward F
authors.initials: EF
authors.lastname: Jackson
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D003287:Contrast Media; D005910:Glioma / Q000175:diagnosis*; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D055420:Perfusion Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D051381:Rats; D011923:Rats, Nude; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D015415:Biomarkers; D003287:Contrast Media