31P RINEPT MRSI and VBM reveal alterations in brain aging associated with major depression.

PurposePhosphomono- and diesters, the major components of the choline peak in H-1 magnetic resonance spectroscopy, are associated with membrane anabolic and catabolic mechanisms. With the refocused insensitive nuclei-enhanced polarization transfer technique, these phospholipids are edited and enhanced in the P-31 MR spectrum. In depressed patients, alterations of the choline peak and cerebral volume have been found, indicating a possible relation. Thus, combining MR phosphorous spectroscopy and volumetry in depressed patients seems to be a promising approach to detect underlying pathomechanisms. MethodsDepressed in-patients were either treated with antidepressive medication or with electroconvulsive therapy and compared to matched healthy controls. P-31 magnetic resonance spectroscopy imaging was conducted before and after the treatment phases. A 3D MRI dataset for volumetry was acquired in a dedicated H-1 head coil. ResultsPhosphocholine and phosphoethanolamine were increased in depressed patients. Though patients responded to the treatments, phospholipids were not significantly altered. An increased age-related gray matter loss in fronto-limbic regions along with an altered relation of phosphomonoesters/phosphodiesters with age were found in depressed patients. DiscussionThe findings of increased phosphomonoesthers and an age*group interaction for gray matter volumes need further research to define the role of phospholipids in major depression and possible associations to gray matter loss. Magn Reson Med 73:1390-1400, 2015. (c) 2014 Wiley Periodicals, Inc.