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FIG 3. 71-year-old man with left hemiparesis. The first MR examination (left column) was performed 15 hours after the onset of symptoms, the second MR examination (middle column) was performed on the second day, and the third MR examination (right column) 1 week after stroke.
Top row, Unenhanced T1-weighted images (600/14/1) show progressing low signal mass effect of the infarcted tissue. Hemorrhagic transformation is detected as areas of increased signal intensity on the second day and at 1 week.
Middle row, Contrast-enhanced T1-weighted images (600/14/1) show intravascular enhancement over the infarct on the first and second days. Moderate cortical and subcortical enhancement are detected on the second day. Intense parenchymal enhancement is detected in the infarct at 1 week.
Bottom row, Diffusion-weighted trace images (4000/103/1, in raw image acquisition) show the extent of infarcted tissue as areas of increased signal intensity in the territory of the right middle cerebral artery. Hemorrhagic transformation is detected as dark areas due to the susceptibility effect of the breakdown products of hemoglobin.
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