J Stroke.  2016 Jan;18(1):80-86. 10.5853/jos.2015.01298.

Gray-Matter Volume Estimate Score: A Novel Semi-Automatic Method Measuring Early Ischemic Change on CT

• Song D
• Lee K
• Kim EH
• Kim YD
• Lee HS
• Kim J
• Song TJ
• Ahn SS
• Nam HS
• Heo JH

• KMID: 2223639
• DOI: http://doi.org/10.5853/jos.2015.01298

Abstract

BACKGROUND AND PURPOSE
We developed a novel method named Gray-matter Volume Estimate Score (GRAVES), measuring early ischemic changes on Computed Tomography (CT) semi-automatically by computer software. This study aimed to compare GRAVES and Alberta Stroke Program Early CT Score (ASPECTS) with regards to outcome prediction and inter-rater agreement.
METHODS
This was a retrospective cohort study. Among consecutive patients with ischemic stroke in the anterior circulation who received intra-arterial therapy (IAT), those with a readable pretreatment CT were included. Two stroke neurologists independently measured both the GRAVES and ASPECTS. GRAVES was defined as the percentage of estimated hypodense lesion in the gray matter of the ipsilateral hemisphere. Spearman correlation analysis, receiver operating characteristic (ROC) comparison test, and intra-class correlation coefficient (ICC) comparison tests were performed between GRAVES and ASPECTS.
RESULTS
Ninety-four subjects (age: 68.7+/-10.3; male: 54 [54.9%]) were enrolled. The mean GRAVES was 9.0+/-8.9 and the median ASPECTS was 8 (interquartile range, 6-9). Correlation between ASPECTS and GRAVES was good (Spearman's rank correlation coefficient, 0.642; P<0.001). ROC comparison analysis showed that the predictive value of GRAVES for favorable outcome was not significantly different from that of ASPECTS (area under curve, 0.765 vs. 0.717; P=0.308). ICC comparison analysis revealed that inter-rater agreement of GRAVES was significantly better than that of ASPECTS (0.978 vs. 0.895; P<0.001).
CONCLUSIONS
GRAVES had a good correlation with ASPECTS. GRAVES was as good as ASPECTS in predicting a favorable clinical outcome, but was better than ASPECTS regarding inter-rater agreement. GRAVES may be used to predict the outcome of IAT.

Keyword

Acute ischemic stroke; Acute stroke imaging; Computed tomography; ASPECTS; Prediction of outcome

MeSH Terms

Alberta
Cohort Studies
Humans
Male
Retrospective Studies
ROC Curve
Stroke