Detection of Gray Matter Damage Using Brain MRI and SPECT in Carbon Monoxide Intoxication A Comparison Study With Neuropsychological Correlation

Purpose: While lesion patterns in white matter have been extensively reported in the literature on carbon monoxide (CO) intoxication, reports on the effects on gray matter damage are less common. The aim of this study was to investigate regional damage patterns focusing on gray matter using Tc-99m ethyl cysteinate dimer (ECD) brain single photon emission computed tomography (SPECT) and brain magnetic resonance imaging (MRI) with clinical correlation. Patients and Methods: Thirty CO intoxication patients and 15 age-matched controls were enrolled for standard neuropsychological tests. Six regions of interest (ROI) were analyzed qualitatively and quantitatively in both SPECT and MRI. The patients were further grouped according to clinical dementia rating score. The sensitivity, specificity, and positive and negative predictive ratios related to dementia from both imaging modalities were further examined. Results: In SPECT qualitative analysis, basal ganglia (n = 16) were the most common regions showing lower perfusion patterns. The basal ganglion and temporal, frontal, and parietal regions of the patients with dementia showed significantly lower perfusion patterns. MRI had a higher sensitivity while SPECT had a higher specificity and positive and negative predictive ratios in correlation with dementia among the ROI. The perfusion indices of the frontal, temporal, basal ganglion, and thalamus were inversely correlated with clinical severity (all P < 0.05). Conclusions: Our findings suggest that a multiparametric neuroimaging approach may provide more information in revealing the anatomical and neurobehavioral results in patients after CO intoxication. The atrophy pattern seen in MRI may explain in part the possible mechanism of the hypoperfusion state seen in SPECT.