Outcome Prediction in Patients After Cardiac Arrest: A Simplified Method for Determination of Gray–White Matter Ratio in Cranial Computed Tomography

• Published in: Clinical neuroradiology (Munich) Vol. 25; no. 1; pp. 49 - 54
• Main Authors: Gentsch, A., Storm, C., Leithner, C., Schroeder, T., Ploner, C. J., Hamm, B., Wiener, E., Scheel, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2015; Springer; Springer Nature B.V
• Subjects: Aged; Analysis; Brain - diagnostic imaging; Brain damage; Cardiac arrest; Cardiac patients; Cardiopulmonary resuscitation; Care and treatment; CPR; CT imaging; Defibrillators; Female; Gray Matter - diagnostic imaging; Heart Arrest - complications; Heart Arrest - diagnostic imaging; Humans; Hypoxia-Ischemia, Brain - diagnostic imaging; Hypoxia-Ischemia, Brain - etiology; Male; Medicine; Medicine & Public Health; Methods; Middle Aged; Neurology; Neuroradiology; Neurosurgery; Original Article; Patient outcomes; Prognosis; Radiographic Image Interpretation, Computer-Assisted - methods; Reproducibility of Results; Risk Assessment; Sensitivity and Specificity; Tomography; Tomography, X-Ray Computed - methods; White Matter - diagnostic imaging; Hypoxic ischemic encephalopathy; Prognosis; Computed tomography; Cardiac arrest; Gray–white matter ratio; Hypothermia
• ISSN: 1869-1439; 1869-1447
• DOI: 10.1007/s00062-013-0281-3

Purpose
Out-of-hospital cardiac arrest is a frequent cause of death in Europe. Hypoxic ischemic encephalopathy (HIE) often develops in initial survivors, and the question of treatment limitation arises in severely affected patients. To establish a poor prognosis with a high level of certainty, the use of a combination of prognostic parameters such as neurological examination, somatosensory evoked potentials, and neuron-specific enolase is common practice. A few recent studies suggest that gray–white matter ratio (GWR) determined from cranial computed tomography (CT) scans is an additional reliable predictor of poor prognosis. The standard GWR determination method involves measurements of 16 different regions of interest (ROIs). We tested whether a simplified method to obtain GWR has equivalent reliability for poor outcome prediction.
Materials and Methods
We retrospectively analyzed 98 patients after cardiac arrest who had been treated with hypothermia. CT scans were obtained within the first 7 days after cardiac arrest. Neurological outcome was determined at intensive care unit discharge. Four different methods to obtain GWR were compared in a receiver-operating characteristic curve analysis with respect to their prognostic value for poor outcome prediction.
Results
The simplest method using only four ROIs (putamen and internal capsule bilaterally) had the same prognostic value compared with the standard method using 16 ROIs. The simplified GWR predicted poor outcome with a sensitivity of 44 % at 100 % specificity.
Conclusion
Our results indicate that for poor outcome prediction in survivors of cardiac arrest, a simplified GWR determination is feasible and has the same reliability as the complex standard procedure.