Ona Wu1, Kenneth K. Kwong1, William A. Copen2, Thomas Benner1, Timothy G. Reese1, Megan M. Aleardi3, Pamela W. Schaefer2, Aneesh B. Singhal3
1Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 3Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
Oxygen extraction fraction (OEF) increases in tissue at risk of infarction. Since R2 is related to OEF, we investigated the utility of measuring R2 with an asymmetric spin echo sequence in stroke patients imaged within 48 hours of onset. We found that R2 was very heterogeneous, decreasing in some patients (most notably those imaged post-thrombolysis), while increasing in others. Increased R2appears to be associated with subsequent infarction, while decreased R2is associated with both good and poor outcome. R2may be useful for predicting tissue fate in combination with cerebral blood flow and cerebral blood volume.