Prognostic Values of the Gray-to-White Matter Ratio on Brain Computed Tomography Images for Neurological Outcomes after Cardiac Arrest: A Meta-Analysis

Abstract

Background and Purpose. The gray-to-white matter ratio (GWR) on brain computed tomography (CT) is associated with neurological outcomes after cardiac arrest (CA); however, the prognostic value of GWR in CA patients has yet to be confirmed. Therefore, we conducted a meta-analysis of related studies to investigate the prognostic value of GWR on brain CT for neurological outcomes after CA. Materials and Methods. The PubMed, ScienceDirect, Web of Science, and China National Knowledge Infrastructure databases were searched for all relevant articles published before March 31, 2020, without any language restrictions. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random-effects model using Stata 14.0 software. Result. A total of 24 eligible studies with 2812 CA patients were recruited in the meta-analysis. The pooled result showed that decreased GWR was correlated with poor neurological outcomes after CA ( OR = 11.28 , 95% CI: 6.29–20.21, and P < 0.001 ) with moderate heterogeneity ( I 2 = 71.5 % , P < 0.001 ). The pooled sensitivity and specificity were 0.58 (95% CI: 0.47–0.68) and 0.95 (95% CI: 0.87–0.98), respectively. The area under the curve (AUC) of GWR was 0.84 (95% CI: 0.80–0.87). Compared with GWR (cerebrum) and GWR (average), GWR using the basal ganglion level of brain CT had the highest AUC of 0.87 (0.84–0.90). Subgroup analysis indicated that heterogeneity may be derived from the time of CT measurement, preset specificity, targeted temperature management, or proportion of cardiac etiology. Sensitivity analysis indicated that the result was stable, and Deeks’ plot showed no possible publication bias ( P = 0 .64 ). Conclusion. Current research suggests that GWR, especially using the basal ganglion level of brain CT, is a useful parameter for determining neurological outcomes after CA.

Analysis of Cerebral CT Based on Supervised Machine Learning as a Predictor of Outcome After Out-of-Hospital Cardiac Arrest

“…The prognostic power of GWR described in the literature varies considerably (AUCs ranging between 0.59 and 0.95) depending on the study design, timing of imaging, and ROIs selected. 9,13 Consequently, the identification of suitable regions and the correct manual positioning of the measuring points are crucial for determining the GWR. Regarding suitable regions, determining the GWR at the level of the basal ganglia, as also performed in our study, seems to be the most reliable approach.…”

“…7 The most common, accessible, and guideline-recommended imaging modality after OHCA is cerebral CT (CCT). For outcome prediction, commonly, the gray-white matter ratio (GWR) is determined in several brain regions of interest (ROIs) prone to hypoxia [8][9][10] to visualize and quantify secondary brain injury 3 indicated by a loss of gray matter (GM)/ white matter (WM) differentiation.…”

“…Although a reduced GWR has been reported to have high specificity for predicting poor neurologic outcomes after resuscitation from cardiac arrest, its sensitivity seems to depend on the time interval between circulatory arrest and imaging, with limited and inconsistent evidence regarding the appropriate timing of imaging. [9][10][11][12][13] In emergencies, the timing of cerebral imaging is often determined by the clinical course and routines, with the determination of an ideal time for imaging playing a rather subordinate role.…”

Can Optic Nerve Sheath Images on a Thin-Slice Brain Computed Tomography Reconstruction Predict the Neurological Outcomes in Cardiac Arrest Survivors?

“…As the GWR decreases over time in patients with a severe hypoxic-ischemic brain injury, its dis-criminative performance and sensitivity increase over time [35][36][37][38]. Thus, a GWR that is determined within this time window may not be a good outcome predictor [6,39].…”

Outcome prediction of cardiac arrest with automatically computed gray-white matter ratio on computed tomography images

“…Recent guidelines have proposed brain noncontrast CT as an early prognostic tool to be utilized within 24-72 h after ROSC [6][7][8][9][10][11]. During the early postcardiac arrest period, the gray-white matter ratio (GWR) emerges as one of the important indicators of hypoxicischemic encephalopathy [12][13][14][15][16]. However, emergency or intensive care physicians cannot perform the quantitative measurement of the GWR using a bedside imaging system.…”