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In this multicenter study, 2D spatial mapping of J-coupled resonances at 3T and 4T was performed using short-TE (15 ms) proton echo-planar spectroscopic imaging (PEPSI). Water-suppressed (WS) data were acquired in 8.5 min with 1-cm(3) spatial resolution from a supraventricular axial slice. Optimized outer volume suppression (OVS) enabled mapping in close(More)
Microscopic susceptibility variations invariably increase apparent transverse relaxation rates. In this paper, we present comparisons between Monte Carlo simulations and experiments with polystyrene microspheres to demonstrate that this enhanced relaxation can be explained quantitatively for both spin echo and gradient echo imaging experiments. The spheres(More)
OBJECTIVE The authors hypothesized that changes in brain membrane composition resulting from omega-3 fatty acid administration in patients with bipolar disorder would result in greater membrane fluidity, as detected by reductions in T(2) values. METHOD Women with bipolar disorder (N=12) received omega-3 fatty acids for 4 weeks. A cohort of bipolar(More)
Characterization of the default mode network (DMN) as a complex network of functionally interacting dynamic systems has received great interest for the study of DMN neural mechanisms. In particular, understanding the relationship of intrinsic resting-state DMN brain network with cognitive behaviors is an important issue in healthy cognition and mental(More)
INTRODUCTION Despite the prevalence, associated comorbidities, and functional consequences of bipolar depression (BPD), underlying disease mechanisms remain unclear. Published studies of individuals with bipolar disorder implicate abnormalities in cellular energy metabolism. This study tests the hypotheses that the forward rate constant (k(for)) of creatine(More)
The chemical shifts of 31P and 1H in thulium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonate) (TmDOTP5-) are approximately two orders of magnitude more sensitive to temperature than are water proton and 19F shifts. In the physiologically relevant pH range, the 31P and 1H chemical shifts of TmDOTP5- are linear functions of temperature(More)
RATIONALE Chronic cocaine exposure has been associated with progressive brain structural and functional changes. Clarifying mechanisms underlying cocaine's progressive brain effects may help in the development of effective cocaine abuse treatments. OBJECTIVES We used a controlled squirrel monkey model of chronic cocaine exposure (45 mg/kg/week for 9(More)
OBJECTIVES The aim of the present study was to measure brain phosphorus-31 magnetic resonance spectroscopy ((31) P MRS) metabolite levels and the creatine kinase reaction forward rate constant (kf ) in subjects with bipolar disorder (BD). METHODS Subjects with bipolar euthymia (n = 14) or depression (n = 11) were recruited. Healthy comparison subjects(More)
Normal brain activity is associated with task-related pH changes. Although central nervous system syndromes associated with significant acidosis and alkalosis are well understood, the effects of less dramatic and chronic changes in brain pH are uncertain. One environmental factor known to alter brain pH is the extreme, acute change in altitude encountered(More)