title: Brain abnormalities in bipolar disorder detected by quantitative T1ρ mapping.
abstract: Abnormal metabolism has been reported in bipolar disorder, however, these studies have been limited to specific regions of the brain. To investigate whole-brain changes potentially associated with these processes, we applied a magnetic resonance imaging technique novel to psychiatric research, quantitative mapping of T1 relaxation in the rotating frame (T1ρ). This method is sensitive to proton chemical exchange, which is affected by pH, metabolite concentrations and cellular density with high spatial resolution relative to alternative techniques such as magnetic resonance spectroscopy and positron emission tomography. Study participants included 15 patients with bipolar I disorder in the euthymic state and 25 normal controls balanced for age and gender. T1ρ maps were generated and compared between the bipolar and control groups using voxel-wise and regional analyses. T1ρ values were found to be elevated in the cerebral white matter and cerebellum in the bipolar group. However, volumes of these areas were normal as measured by high-resolution T1- and T2-weighted magnetic resonance imaging. Interestingly, the cerebellar T1ρ abnormalities were normalized in participants receiving lithium treatment. These findings are consistent with metabolic or microstructural abnormalities in bipolar disorder and draw attention to roles of the cerebral white matter and cerebellum. This study highlights the potential utility of high-resolution T1ρ mapping in psychiatric research.
authors.affiliation: Department of Radiology, University of Iowa, Iowa City, IA, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Johnson
authors.affiliation: Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Follmer
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, USA.
authors.forename: I
authors.initials: I
authors.lastname: Oguz
authors.affiliation: Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Warren
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Christensen
authors.affiliation: 1] Department of Psychiatry, University of Iowa, Iowa City, IA, USA [2] Department of Epidemiology, University of Iowa, Iowa City, IA, USA [3] Department of Internal Medicine, University of Iowa, Iowa City, IA, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Fiedorowicz
authors.affiliation: 1] Department of Radiology, University of Iowa, Iowa City, IA, USA [2] Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
authors.forename: V A
authors.initials: VA
authors.lastname: Magnotta
authors.affiliation: 1] Department of Psychiatry, University of Iowa, Iowa City, IA, USA [2] Veterans Affairs Hospital Center, Iowa City, IA, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Wemmie
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D018709:Statistics, Nonparametric; D055815:Young Adult