Background and purpose: It is difficult to anticipate long-term survival in a hyperacute stroke stage. The aim of our study was to investigate whether or not simple probable CBF grading of MR perfusion was useful for anticipating long-term survival probability (SP) in acute stroke patients due to the carotid artery occlusion.
Methods: Included were patients 1) who were admitted to our institution within 24 hours of onset between Jan 2005 and May 2014, 2) who underwent MRA displaying no carotid artery (ICA) in the affected side and 3) who were treated without any reperfusion therapy. We evaluated patients features, CBF grades, any death within 120 days. CBF grade was calculated by using bilateral time-intensity curves (TICs) of MR perfusion. TICs were generated on region of interests set at symmetrical positions of the bilateral MCA territories. According to the time to peak (TP) and the peak signal (PS) comparing the affected side (a) with the contralateral side (c), we regarded the affected-sided PSa divided by TPa as possible CBFa and the contralateral-sided PSc divided by TPc as possible CBFc. CBF grade 1 was defined as CBFa divided by CBFc (CBF%) less than 0.2, grade 2 as CBF% of 0.2 or more and CBF% less than 0.7 and grade 3 as CBF% of 0.7 or more.
Results: Eighty-four patients matched our inclusive criteria. Average age was 77.9 years, median NISS on adm (NIH adm) was 19, DWI-ASPECTS (D-ACT) was 3. There were 27, 32 and 25 in grade 1, 2 and 3. Thirty-eight patients (45.2%) died within 120 days. In grade 1, 2 and 3, 22, 14 and 2 patients died within 120 days, and SP of the Kaplan-Meier method at 120 days was 18.5%,53.9%,92.0% (p<0.001), respectively. In addition, there were significant differences between any two grades (p<0.016).
Conclusion: Simple CBF grading of MR perfusion was useful for anticipating long-term survival provability in the hyperacute stroke stage. Long-term SP in grade 1 patients was very low, whereas that in grade 3 patients was high.