Magnetization transfer imaging in the evolution of cerebral infarction

MAGNETIZATION TRANSFER IMAGING (MTI) IN THE EVOLUTION OFCEREBRAL INFARCTIONŞEBNEM KARASUPurposeTo determine whether MTI can play a role in screening the evolution of cerebralarterial infarction.Material and methodBetween April 2005 and June 2006, 34 (21 men, 13 women) patients with strokemean age of 68.8 (40-83), underwent MTI and diffusion weighted imaging (DWI)studies in a 1.5 T magnetic resonance (MR) unit. Magnetization transfer ratios (MTR)and apparent diffusion coefficients (ADC) were measured from both the infarctlesions and the opposite cerebral hemisphere and compared with each other. Themean MTR and ADC values of 8 lesions, which were evaluated at 3 stages ofinfarction, were compared with respect to their stages. p<0.05 was accepted to besignificant.ResultsFifty-five lesions were found and 75 scans have been done. The mean MTR valuesfor the lesions in acute, subacute and chronic stages were 48.2±7.2%, 44.4±8.6%,23.3±15.2%, and the mean ADC values were 0.4±0.1x10-5, 1.0±0.4x10-5 and2.0±0.6x10-5 cm2/sn respectively. These parameters for the opposite hemispherewere 55.6±4.7% and 0.8±0.1x10-5 cm2/sn. At each stage, there was a significantdifference between the lesions and the opposite hemisphere for both parameters.There was no correlation between these parameters for the acute stage. A negativecorrelation in the subacute and chronic stages was observed. For the 8 lesionsscreened at all stages of infarction, there was no difference between the mean MTRvalues at the acute-subacute stages, but the differences were significant between theother stages.ConclusionMTI is a useful method for determining the age of cerebral infarcts.