Brain metabolic pattern analysis using a magnetic resonance spectra classification software in experimental stroke.
BACKGROUND
Magnetic resonance spectroscopy (MRS) provides non-invasive information about the metabolic pattern of the brain parenchyma in vivo. The SpectraClassifier software performs MRS pattern-recognition by determining the spectral features (metabolites) which can be used objectively to classify spectra. Our aim was to develop an Infarct Evolution Classifier and a Brain Regions Classifier in a rat model of focal ischemic stroke using SpectraClassifier.


RESULTS
A total of 164 single-voxel proton spectra obtained with a 7 Tesla magnet at an echo time of 12 ms from non-infarcted parenchyma, subventricular zones and infarcted parenchyma were analyzed with SpectraClassifier ( http://gabrmn.uab.es/?q=sc ). The spectra corresponded to Sprague-Dawley rats (healthy rats, n = 7) and stroke rats at day 1 post-stroke (acute phase, n = 6 rats) and at days 7 ± 1 post-stroke (subacute phase, n = 14). In the Infarct Evolution Classifier, spectral features contributed by lactate + mobile lipids (1.33 ppm), total creatine (3.05 ppm) and mobile lipids (0.85 ppm) distinguished among non-infarcted parenchyma (100% sensitivity and 100% specificity), acute phase of infarct (100% sensitivity and 95% specificity) and subacute phase of infarct (78% sensitivity and 100% specificity). In the Brain Regions Classifier, spectral features contributed by myoinositol (3.62 ppm) and total creatine (3.04/3.05 ppm) distinguished among infarcted parenchyma (100% sensitivity and 98% specificity), non-infarcted parenchyma (84% sensitivity and 84% specificity) and subventricular zones (76% sensitivity and 93% specificity).


CONCLUSION
SpectraClassifier identified candidate biomarkers for infarct evolution (mobile lipids accumulation) and different brain regions (myoinositol content).
['Jiménez-Xarrié|Elena|E|', 'Davila|Myriam|M|', 'Candiota|Ana Paula|AP|', 'Delgado-Mederos|Raquel|R|', 'Ortega-Martorell|Sandra|S|', 'Julià-Sapé|Margarida|M|', 'Arús|Carles|C|', 'Martí-Fàbregas|Joan|J|']
D000818:Animals D001921:Brain D002545:Brain Ischemia D003401:Creatine D007091:Image Processing, Computer-Assisted D007294:Inositol D019344:Lactic Acid D050356:Lipid Metabolism D009682:Magnetic Resonance Spectroscopy D008297:Male D055442:Metabolome D055432:Metabolomics D017207:Rats, Sprague-Dawley D012680:Sensitivity and Specificity D012984:Software D020521:Stroke
Stroke Magnetic resonance spectroscopy Animal model Metabolomics Pattern recognition