Abstract TP46: ASPECTS Performance in a Series of Patients Undergoing CT and MRI: Reader Agreement, Modality Agreement, and Outcome Prediction
Objective: To compare the performance of pre-treatment Alberta Stroke Program Early CT scoring (ASPECTS) using NCCT and MRI in a large endovascular therapy cohort.
Methods: This is a DEFUSE 2 substudy. Prospectively enrolled patients underwent baseline CT, MRI and started endovascular therapy within 12 hours of stroke onset. Inclusion criteria for this analysis were evaluable pre-treatment NCCT, diffusion-weighted MRI (DWI) and 90-day modified Rankin Scale (mRS) score. Two expert readers graded ischemic change on NCCT and DWI using the ASPECTS and were blinded to all clinical information except stroke side. ASPECTS scores were analyzed either full scale, trichotomized (0-4 vs. 5-7 vs. 8-10), or dichotomized (0-7 vs. 8-10). Good functional outcome was defined as a 90 day mRS of 0-2. Infarct volumes were calculated using rapid processing of perfusion and diffusion (RAPID) software.
Results: 71 patients fulfilled our study criteria. Their mean age was 68±15 years, median NIHSS score was 17 (IQR 12-20), and 49% were female. There were 31 (44%) right-sided strokes. Reader and modality agreement are presented in the Table. Median (IQR) time between NCCT and MRI was 1.62 (1.14-2.38) hours. There was greater correlation of DWI ASPECTS with DWI volume (p<0.001) and functional outcome (p=0.001) than NCCT ASPECTS. DWI ASPECTS correlated with 90 day mRS with OR (95%) of: 12.3 (1.4-105) 8-10 vs.0-4; 4.0 (1.2-13.2) 8-10 vs. 5-7; 3.1 (0.3-30) 5-7 vs. 0-4; and 5.4 (1.8-16.2) 8-10 vs.0-7. NCCT ASPECTS did not correlate with mRS with OR (95%) of: 1.4(0.2-8.3) 8-10 vs. 0-4, 1.02(0.4-2.8) 8-10 vs. 5-7, 1.4(0.2-8.5) 5-7 vs. 0-4, and 1.1(0.4-2.9) 8-10 vs. 0-7.
Conclusion: Inter-rater agreement on NCCT ASPECTS, as well agreement between NCCT and DWI ASPECTS, ranged from slight to moderate. DWI ASPECTS outperformed NCCT ASPECTS in correlation with DWI volume and predicting functional outcome at 90 days. These results may be influenced by differences in acquisition times for NCCT and MRI.
- © 2012 by American Heart Association, Inc.