title: Computed tomography assessment of cerebral perfusion using a distributed parameter tracer kinetics model: validation with H(2)((15))O positron emission tomography measurements and initial clinical experience in patients with acute stroke.
abstract: We describe a distributed parameter (DP) model for tracer kinetic analysis in brain and validate the derived perfusion values with positron emission tomography (PET) scans. The proposed model is applied on actual clinical cases of hemispheric stroke. Nine patients with experienced transient ischaemic attack or minor stroke and a stenosis of the internal carotid artery were referred for computed tomography (CT) and PET imaging. The applicability of the DP model in clinical practice was tested in seven patients with acute stroke who received a baseline perfusion CT study and a noncontrast follow-up CT study after 2.4+/-1.8 days. The mean blood flow (F) value for all patients with carotid stenosis in the pooled data (54 regions of interest (ROIs)) was 37.9+/-11.2 mL/min per 100 g in perfusion CT and 35.6+/-9.8 mL/min per 100 g in perfusion PET imaging [r=0.77 (P=0.00)]. Regression analysis of the pooled ROIs for every patient revealed significant correlation between F values in seven patients [r=0.50 to 0.79 (r(2)-values ranged from 0.45 to 0.79), (0.01 < or = P < or = 0.05)]. Parametric maps that corresponded to all physiologic parameters were generated for every perfusion CT in the patients with acute stroke using the DP model. The ischaemic area was better delineated in F, intravascular blood volume and lag time (t(lag)) maps. The correlation coefficient comparing the visually outlined regions of abnormality between the t(lag) parametric map and the follow-up CT scans was 0.81 (P=0.003). In conclusion, DP physiological model using more realistic pharmacokinetics is feasible in dynamic contrast-enhanced CT of the brain in patients with acute and chronic cerebrovascular disease.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University Hospital, Frankfurt, Germany. sbisdas@med.uni-frankfurt.de
authors.forename: Sotirios
authors.initials: S
authors.lastname: Bisdas
authors.forename: Frank
authors.initials: F
authors.lastname: Donnerstag
authors.forename: Georg
authors.initials: G
authors.lastname: Berding
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: Choon Hua
authors.initials: CH
authors.lastname: Thng
authors.forename: Tong San
authors.initials: TS
authors.lastname: Koh
mesh_terms: D000208:Acute Disease; D000368:Aged; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D016893:Carotid Stenosis / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D020521:Stroke / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals