title: A fast nonlinear regression method for estimating permeability in CT perfusion imaging.
abstract: Blood-brain barrier damage, which can be quantified by measuring vascular permeability, is a potential predictor for hemorrhagic transformation in acute ischemic stroke. Permeability is commonly estimated by applying Patlak analysis to computed tomography (CT) perfusion data, but this method lacks precision. Applying more elaborate kinetic models by means of nonlinear regression (NLR) may improve precision, but is more time consuming and therefore less appropriate in an acute stroke setting. We propose a simplified NLR method that may be faster and still precise enough for clinical use. The aim of this study is to evaluate the reliability of in total 12 variations of Patlak analysis and NLR methods, including the simplified NLR method. Confidence intervals for the permeability estimates were evaluated using simulated CT attenuation-time curves with realistic noise, and clinical data from 20 patients. Although fixating the blood volume improved Patlak analysis, the NLR methods yielded significantly more reliable estimates, but took up to 12 × longer to calculate. The simplified NLR method was ∼4 × faster than other NLR methods, while maintaining the same confidence intervals (CIs). In conclusion, the simplified NLR method is a new, reliable way to estimate permeability in stroke, fast enough for clinical application in an acute stroke setting.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: Bennink
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Riordan
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Horsch
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Dankbaar
authors.forename: Birgitta K
authors.initials: BK
authors.lastname: Velthuis
authors.forename: Hugo W
authors.initials: HW
authors.lastname: de Jong
mesh_terms: D001812:Blood-Brain Barrier / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002199:Capillary Permeability / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D017711:Nonlinear Dynamics; D012044:Regression Analysis; D020521:Stroke / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data*