MRI-DRAGON score is an adaptation of CT DRAGON score to predict 3 month outcome in acute anterior circulation stroke patients who had MRI as initial diagnostic workup and were treated with IV t-PA within 4.5 hours.
One point each is given for M1 occlusion, DWI ASPECTS ≤ 5, prestroke mRS >1, Age 65-79, Glucose level >8mmol/l prior to t-PA, Onset to treat time >90 min and NIHSS 5-9 prior to IV t-PA. Two points each is given for age ≥ 80 and NIHSS 10-15. Patients with NIHSS>15 get 3 points. With MRI-DRAGON score total of 10 points is possible.
Among 228 patients evaluated with the MRI-DRAGON score in the study all patients with total score ≤ 2 (n=22) had a good outcome (mRS 0-2) while those with score ≥ 8 (n=11) had poor outcome (mRS 5-6). Poor outcome was significantly associated with all parameters considered in the MRI-DRAGON score except onset to treat time and prestroke mRS>1 which only had a nonsignificant trend towards poor outcome.
It is well known from previous studies that the odds of good outcome is higher for those patients treated within 90 min of symptom onset compared to those treated in 90-180 min and 180-270min of symptom onset. However it is interesting to note in this study that onset to treat time>90min had only a nonsignificant trend for association with poor outcome.
This tool incorporates only information that is available prior to IV t-PA administration. Therefore it may be helpful in selecting patients for therapeutic interventions in clinical trials, for example, excluding patients with higher MRI-DRAGON score (≥ 8) due to increased probability of poor outcome at 3 months in these patients.