Helmut Rumpel1, Ling Ling Chan. 1. Department of Diagnostic Radiology, Singapore General Hospital, Outram Rd, Singapore 169608. helmut.rumpel@pacific.net.sg
Abstract
BACKGROUND: Most MRI protocols for stroke trials comprise 2 successive fluid-attenuated inversion-recovery (FLAIR) imaging acquisitions in which the first scan is done pre-Gd-DTPA contrast while the second is within the contrast clearance window. SUMMARY OF REPORT: A 68-year-old male was diagnosed as having hyperacute right middle cerebral artery infarct and a subacute chronic small left occipital cortical infarct. The latter turned from hypointense to strikingly hyperintense on the second FLAIR image, resembling the picture of an acute-on-chronic infarction or hemorrhage. However, the second DWI and CT refuted either of these. CONCLUSIONS: Image contrast using FLAIR in acute stroke trial imaging may also be affected by T1 effects of Gd-DTPA in chronic infarcts.
BACKGROUND: Most MRI protocols for stroke trials comprise 2 successive fluid-attenuated inversion-recovery (FLAIR) imaging acquisitions in which the first scan is done pre-Gd-DTPA contrast while the second is within the contrast clearance window. SUMMARY OF REPORT: A 68-year-old male was diagnosed as having hyperacute right middle cerebral artery infarct and a subacute chronic small left occipital cortical infarct. The latter turned from hypointense to strikingly hyperintense on the second FLAIR image, resembling the picture of an acute-on-chronic infarction or hemorrhage. However, the second DWI and CT refuted either of these. CONCLUSIONS: Image contrast using FLAIR in acute stroke trial imaging may also be affected by T1 effects of Gd-DTPA in chronic infarcts.