title: A study of the apparent diffusion coefficient of grey and white matter in human ischaemic stroke.
abstract: We examined whether there was any difference in the value, and temporal evolution, of the apparent diffusion tensor trace (ADC) in acute and subacute grey and white matter lesions. Thirty-seven patients underwent diffusion imaging once (up to 3 days), 15 patients were scanned twice (up to 7 days), and seven patients were scanned three times (up to 14 days) after stroke. Values of the ratio of ischaemic to contralateral ADC (ADCr) were reduced on average by 30% (p<0.001) in the whole hyperintense region up to 7 days post-ictus. No difference was seen between ADCr values of grey and white matter in individual subjects within the patient groups scanned up to 7 days. However, in the subgroup of patients scanned beyond 7 days, ADCr for grey matter rose significantly (p=0.02) from ADCr approximately 0.7 (< 7 days) to 0.95 (> or = 10 days). This increase did not occur in white matter whose ADCr remained fairly constant (ADCr approximately 0.7) over the time course of the study.
authors.affiliation: Department of Medical and Radiological Sciences (Medical Physics), University of Edinburgh, Western General Hospital.
authors.forename: M E
authors.initials: ME
authors.lastname: Bastin
authors.forename: A K
authors.initials: AK
authors.lastname: Rana
authors.forename: J M
authors.initials: JM
authors.lastname: Wardlaw
authors.forename: P A
authors.initials: PA
authors.lastname: Armitage
authors.forename: S L
authors.initials: SL
authors.lastname: Keir
mesh_terms: D000208:Acute Disease; D000368:Aged; D001834:Body Water / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004058:Diffusion; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D011859:Radiography; D020521:Stroke / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D013997:Time Factors