THE MAGNETIZATION-TRANSFER EFFECT IN CEREBRAL INFARCTION

To estimate the age of cerebral infarcts using magnetization transfer. METHODS: Twelve patients with radiographically and clinically documen ted cortical and subcortical cerebral infarctions underwent MR imaging on a 0.1T magnet. Magnetization transfer contrast images were generat ed by application of off-resonance pulses to every other repetition ti me on intermediate-weighted images. The magnetization transfer effect was calculated by obtaining an intensity value in the region of intere st within the infarcted area. RESULTS: The data show a pattern in whic h the magnetization transfer effect decreases as the chronicity of the infarct increases. Infarcts less than 1 week old had an average magne tization transfer effect of 0.35. Those more than 1 week and less than 1 month old average 0.30. Infarcts more than 1 month and specifically those more than 1 year old averaged 0.16 or less. CONCLUSION: Magneti zation transfer offers the potential to estimate the age of cerebral i nfarcts.