Clinical MRI Interpretation for Outcome Prediction in Cardiac Arrest
Neurocritical Care , 05/14/2012
Greer D et al. – The qualitative evaluation of imaging abnormalities by stroke physicians in comatose cardiac arrest patients is a highly sensitive method of predicting poor outcome, but with limited specificity.Methods
- The authors analyzed 80 consecutive MRIs from patients in coma following cardiac arrest.
- Each study was graded as “normal” or “abnormal restricted diffusion” in pre–specified brain regions by two blinded stroke neurologists.
- Poor outcome was defined as a modified Rankin Scale (mRS) score >4 at 3months.
- Formal interpretations of neuroimaging by non–blinded neuroradiologists were compared with the blinded reviews by the stroke neurologists.
- DWI abnormalities were highly sensitive (98.5 %) but only modestly specific (46.2 %) for predicting poor neurological outcome.
- Inter–observer reliability was moderate (kappa=0.49±0.32), with 91 % agreement between study observers, and no significant differences in study observers’ interpretations (p=0.125).
- There were, however, significant differences between the study observers and the clinical neuroradiologists in identifying studies showing evidence of global hypoxic–ischemic injury (p=0.001).