title: Improved accuracy and precision of tracer kinetic parameters by joint fitting to variable flip angle and dynamic contrast enhanced MRI data.
abstract: To improve the accuracy and precision of tracer kinetic model parameter estimates for use in dynamic contrast enhanced (DCE) MRI studies of solid tumors.
  
  
  
  Quantitative DCE-MRI requires an estimate of precontrast T1 , which is obtained prior to fitting a tracer kinetic model. As T1 mapping and tracer kinetic signal models are both a function of precontrast T1 it was hypothesized that its joint estimation would improve the accuracy and precision of both precontrast T1 and tracer kinetic model parameters.
  
  
  
  Accuracy and/or precision of two-compartment exchange model (2CXM) parameters were evaluated for standard and joint fitting methods in well-controlled synthetic data and for 36 bladder cancer patients. Methods were compared under a number of experimental conditions.
  
  
  
  In synthetic data, joint estimation led to statistically significant improvements in the accuracy of estimated parameters in 30 of 42 conditions (improvements between 1.8% and 49%). Reduced accuracy was observed in 7 of the remaining 12 conditions. Significant improvements in precision were observed in 35 of 42 conditions (between 4.7% and 50%). In clinical data, significant improvements in precision were observed in 18 of 21 conditions (between 4.6% and 38%).
  
  
  
  Accuracy and precision of DCE-MRI parameter estimates are improved when signal models are fit jointly rather than sequentially. Magn Reson Med 76:1270-1281, 2016. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK. ben.dickie@postgrad.manchester.ac.uk.|Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK. ben.dickie@postgrad.manchester.ac.uk.
authors.forename: Ben R
authors.initials: BR
authors.lastname: Dickie
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, Centre for Imaging Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
authors.forename: Anita
authors.initials: A
authors.lastname: Banerji
authors.affiliation: Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK.|Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Kershaw
authors.affiliation: Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.|Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: McPartlin
authors.affiliation: Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.|Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK.
authors.forename: Ananya
authors.initials: A
authors.lastname: Choudhury
authors.affiliation: Institute of Cancer Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
authors.forename: Catharine M
authors.initials: CM
authors.lastname: West
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, Centre for Imaging Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Rose
mesh_terms: D000368:Aged; D000465:Algorithms; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: DCE-MRI; accuracy; heterogeneity; joint estimation; precision; tracer kinetic modeling; two-compartment exchange model