title: The infarct core is well represented by the acute diffusion lesion: sustained reversal is infrequent.
abstract: Diffusion-weighted imaging (DWI) is commonly used to assess irreversibly infarcted tissue but its accuracy is challenged by reports of diffusion lesion reversal (DLR). We investigated the frequency and implications for mismatch classification of DLR using imaging from the EPITHET (Echoplanar Imaging Thrombolytic Evaluation Trial) and DEFUSE (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution) studies. In 119 patients (83 treated with IV tissue plasminogen activator), follow-up images were coregistered to acute diffusion images and the lesions manually outlined to their maximal visual extent in diffusion space. Diffusion lesion reversal was defined as voxels of acute diffusion lesion that corresponded to normal brain at follow-up (i.e., final infarct, leukoaraiosis, and cerebrospinal fluid (CSF) voxels were excluded from consideration). The appearance of DLR was visually checked for artifacts, the volume calculated, and the impact of adjusting baseline diffusion lesion volume for DLR volume on perfusion-diffusion mismatch analyzed. Median DLR volume reduced from 4.4 to 1.5 mL after excluding CSF/leukoaraiosis. Visual inspection verified 8/119 (6.7%) with true DLR, median volume 2.33 mL. Subtracting DLR from acute diffusion volume altered perfusion-diffusion mismatch (T(max)>6 seconds, ratio>1.2) in 3/119 (2.5%) patients. Diffusion lesion reversal between baseline and 3 to 6 hours DWI was also uncommon (7/65, 11%) and often transient. Clinically relevant DLR is uncommon and rarely alters perfusion-diffusion mismatch. The acute diffusion lesion is generally a reliable signature of the infarct core.
authors.affiliation: Department of Medicine and Neurology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia. bruce.campbell@mh.org.au
authors.forename: Bruce C V
authors.initials: BC
authors.lastname: Campbell
authors.forename: Archana
authors.initials: A
authors.lastname: Purushotham
authors.forename: Soren
authors.initials: S
authors.lastname: Christensen
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Desmond
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Nagakane
authors.forename: Mark W
authors.initials: MW
authors.lastname: Parsons
authors.forename: Maarten G
authors.initials: MG
authors.lastname: Lansberg
authors.forename: Michael
authors.initials: M
authors.lastname: Mlynash
authors.forename: Matus
authors.initials: M
authors.lastname: Straka
authors.forename: Deidre A
authors.initials: DA
authors.lastname: De Silva
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Olivot
authors.forename: Roland
authors.initials: R
authors.lastname: Bammer
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Albers
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Donnan
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Davis
mesh_terms: D000368:Aged; D020520:Brain Infarction / Q000188:drug therapy / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011446:Prospective Studies; D015912:Thrombolytic Therapy / Q000379:methods*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator