Comparison of 1.5 T and 3 T MRI hippocampus texture features in the assessment of Alzheimer's disease

Objective: Many studies evaluated how the Magnetic Resonance Imaging (MRI) field strength affects the effectiveness to detect neurodegenerative changes of Alzheimer's disease (AD), derived from atrophy or thickness. To the best of our knowledge, no study evaluated before how tissue texture changes are affected. In this research, hippocampus texture features extracted from 1.5 T and 3 T MRI are evaluated how are affected by the magnetic field strength. Methods: MR imaging data from 14 Normal Controls (NC), 14 with Mild Cognitive Impairment (MCI), 11 MCI converters (MCIc) and 10 CE subjects scanned at 1.5 T and 3 T were included. Haralick's texture features were extracted from the hippocampus, along with hippocampal and amygdala volumes and cortical thickness. One-way ANOVA, paired-samples and Wilcoxon signed t-tests were used to evaluate if there were significant differences between the features. Results: 3 T texture features were significantly different for NC vs AD, NC vs MCI and MCI vs AD, whereas, 1.5 T for MCI vs AD only. Amygdala and hippocampal volumes, showed significant differences for NC vs AD for both MRI strengths, whereas cortical thickness for MCI vs MCIc for the 3 T. Paired sample t-test and Wilcoxon signed-rank test revealed significant differences for Angular Second Moment (ASM), contrast, correlation, variance, sum variance and entropy, the amygdala volume and cortical thickness. Between NC vs MCI, 3 T texture revealed higher Area Under Curve (AUC). Conclusion: 3 T texture revealed significant differences for more features compared to 1.5 T, whereas, atrophy and thickness had similar results. Significance: 3 T texture changes provide earlier diagnosis compared to 1.5 T volume or texture changes.