Fogging effect on MR in subacute cerebral infarct: Report of 2 cases

ABSTRACT

In acute phase, cerebral infartion is usually hypodense on CT and hyperintense on T2-weighted MR image. This hyperintensity on T2-weighted MR image gradually approaches an isointensity stage after 2 or 3 weeks of onset. In the later stage, cerebral infarction is observed hyperintense on T2-weighted MR image. This sequential phenomenon is so-called "fogging effect". We experienced two cases of "fogging effect". The first case did not show abnormal signal intensity on TI or T2 weighted MR images taken after 14 days of onset and the second case also did not show abnormal signal intensity after 17 days of onset. Each case revealed hyperintense in T2-weighted image with contrast enhancement taken after 20 weeks and 8 weeks of onset, respectively. We present two cases with MRI and brief review of literatures.