Abstract W MP85: MRI Demonstrates Sustained Effect of Early Surgery on Perihematomal Edema
Introduction: The clinical implications of perihematomal edema (PHE) on patients with spontaneous intracerebral hemorrhage (ICH) remains an important question. While several studies describe the natural history of this inflammatory response, progression of PHE in conjunction with ICH evacuation is less understood. We compare CT- the most widely accessible image modality in ICH- with MRI- previously described to be the gold standard for assessing PHE- both to validate the use of CT in PHE measurements and to understand the effect of hematoma evacuation upon PHE mitigation at Day 7.
Methods: We analyzed 43 of 123 patients from MISTIE II (29 surgical, 14 medical). 80 patients were excluded due to missing MRIs at time points T1 (pre-randomization) or T2 (Day 7). MRI edema volume was calculated by manually tracing hyperintense regions on T2-weighted FLAIR sequences and then subtracting the ICH volume measured on the closest CT. CT edema volume was calculated using a semi-automated threshold based approach. A sample set of both MRIs and CTs were assessed by a second blinded reader to assess inter-observer reliability using Pearson correlation.
Results: There was no significant difference between the two treatment cohorts in age, gender, or initial ICH size. The absolute difference in PHE for surgical patients was similar for both MRI, .92cc, and CT, -3.51cc, with a mean difference of 4.44 cc (p-value=.179). For medical patients , the difference between the two time points was MRI, 29.19 cc and CT, 28.74 cc, mean difference of 0.45 cc (p-value=.92). A similar trend exists between ICH removal and edema volume as in previously published work, the less blood removed the greater the amount of edema. Both modalities were robust measures of PHE with inter-reader reliability scores calculated for MRI, .99 (95% CI, .995-.999) and CT .97 (95% CI, .922-.994).
Conclusion: This analysis of a multi-site, international patient population confirms the accuracy of using CT for quantification of PHE in comparison to the previously published gold standard of MRI. In addition, patients receiving minimally invasive surgery plus tissue plasminogen activator continue to show a significant difference in edema formation compared to patients receiving standard of care at the Day 7 time point.
Author Disclosures: W.A. Mould: None. M. Zentar: None. J. Muschelli: None. J.R. Carhuapoma: None. D.F. Hanley: Research Grant; Significant; NINDS sponsored trials, MISTIE II- R01Ns046309 and CLEAR III- 5U01NS062851. Other Research Support; Modest; Donations from Genentech, Inc. and Codman, Inc..
- © 2014 by American Heart Association, Inc.