T1 in subacute and chronic brain infarctions. Time-dependent development.
OBJECTIVE
Time-dependent behavior of T1 in brain infarcts and in brain tissue of the contralateral hemisphere was studied in the subacute and early chronic stages of stroke.


METHODS
T1 was measured from magnetic resonance images (MRIs) of 29 patients as a function of infarct location and age. Another group of 11 patients was studied with consecutive MRI studies during the first 5 weeks after the onset of infarct, and the distribution of T1 in the infarctions was analyzed from T1 maps using a histographic method.


RESULTS
During the first 2 months after a stroke, T1 was longer in the infarcted gray matter than in the infarcted white matter (P = .002), and prolonged linearly in both. The histographic analysis showed a component arising from tissue breakdown products that could be identified for up to 5 weeks. A transient lengthening in T1 of the contralateral hemisphere, reaching a maximum at 3 weeks, also was observed.


CONCLUSIONS
These characteristics of recent infarctions differentiate them from older, gliotic lesions. The lengthening of T1 in the contralateral hemisphere may reflect remote flow and metabolic effects of brain infarctions.
Lundbom
N
N
Department of Diagnostic Radiology, University of Turku, Finland.
Katevuo
K
K
Komu
M
M
Kurki
T
T
Kormano
M
M
D000208:Acute Disease; D000367:Age Factors; D001921:Brain / Q000473:pathology; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000453:epidemiology; D002908:Chronic Disease; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D011446:Prospective Studies; D012189:Retrospective Studies; D012737:Sex Factors; D013997:Time Factors