title: A comparison of individual and population-derived vascular input functions for quantitative DCE-MRI in rats.
abstract: Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) can quantitatively and qualitatively assess physiological characteristics of tissue. Quantitative DCE-MRI requires an estimate of the time rate of change of the concentration of the contrast agent in the blood plasma, the vascular input function (VIF). Measuring the VIF in small animals is notoriously difficult as it requires high temporal resolution images limiting the achievable number of slices, field-of-view, spatial resolution, and signal-to-noise. Alternatively, a population-averaged VIF could be used to mitigate the acquisition demands in studies aimed to investigate, for example, tumor vascular characteristics. Thus, the overall goal of this manuscript is to determine how the kinetic parameters estimated by a population based VIF differ from those estimated by an individual VIF. Eight rats bearing gliomas were imaged before, during, and after an injection of Gd-DTPA. K(trans), ve, and vp were extracted from signal-time curves of tumor tissue using both individual and population-averaged VIFs. Extended model voxel estimates of K(trans) and ve in all animals had concordance correlation coefficients (CCC) ranging from 0.69 to 0.98 and Pearson correlation coefficients (PCC) ranging from 0.70 to 0.99. Additionally, standard model estimates resulted in CCCs ranging from 0.81 to 0.99 and PCCs ranging from 0.98 to 1.00, supporting the use of a population based VIF if an individual VIF is not available.
authors.affiliation: Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Hormuth
authors.affiliation: Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA.
authors.forename: Jack T
authors.initials: JT
authors.lastname: Skinner
authors.affiliation: Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Electrical Engineering, Vanderbilt University, Nashville, TN, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Does
authors.affiliation: Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Physics, Vanderbilt University, Nashville, TN, USA; Department of Cancer Biology, Vanderbilt University, Nashville, TN, USA. Electronic address: Thomas.yankeelov@vanderbilt.edu.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Yankeelov
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D005910:Glioma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: DCE; Dynamic contrast; Input function; MRI; Pharmacokinetic modeling; Tumor