Cerebral phosphorus metabolite as imaging biomarkers in Alzheimer’s disease: a 31P magnetic resonance spectroscopy study

This study employed phosphorus-31 magnetic resonance spectroscopic imaging (31P-MRSI) to characterize hippocampal and frontal metabolic alterations in Alzheimer's disease (AD) and to evaluate their associations with cognitive decline. We enrolled 30 patients with AD, 26 with amnestic mild cognitive impairment (aMCI), and 25 healthy controls (HC), all of whom underwent ³¹P-MRSI using a 3.0 T MRI scanner with a dual-tuned ¹H/³¹P head coil. Spectroscopic data were acquired from the hippocampus, prefrontal gray matter, and prefrontal white matter regions for subsequent analysis.The results of this study indicate that compared to the HC groups, patients with AD showed a significantly reduced phosphocreatine to inorganic phosphate ratio in the hippocampal region (p = 0.018). Meanwhile, the phosphomonoesters to phosphodiesters (PME/PDE) ratio in both the hippocampus and prefrontal gray matter exhibited a progressive increase along the HC-aMCI-AD disease continuum(all p < 0.001), although the difference between the aMCI and HC groups did not reach statistical significance in the frontal gray matter. Further analysis revealed a association between the elevated PME/PDE ratios in these brain regions and the decline in cognitive function. These findings support the potential of ³¹P-MRSI as a noninvasive imaging tool for detecting metabolic alterations associated with Alzheimer's disease, providing important insights for future clinical research and early diagnosis.