Meeting Banner
Abstract #3220

T1ρ Response to the Activity-Dependent Localized Acidosis

Hye-Young Heo1, 2, Casey P. Johnson1, Daniel R. Thedens1, John A. Wemmie3, 4, Vincent A. Magnotta1, 3

1Department of Radiology, University of Iowa, Iowa City, IA, United States; 2Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States; 3Department of Psychiatry, University of Iowa, Iowa City, IA, United States; 4Department of Neurosurgery, University of Iowa, Iowa City, IA, United States

The purpose of this study is to measure the change of T1ρ response to the activity-dependent localized acidosis. We used a flashing checkerboard with different temporal frequencies of 1, 4, and 7Hz to evaluate if dynamicT1ρ imaging responds to the varied degree of neuronal activity. In addition, 31P spectroscopy was used to validate pH changes in visual cortex during visual fixation and visual stimulation with the different temporal frequencies. We found that the magnitude of the T1ρ response was proportional to the stimulus intensity induced by the change of the temporal frequencies. Furthermore, brain pH estimated by 31P spectroscopy in the visual cortex was found to decrease with the temporal frequency. Consequently, it suggests that T1ρ and pH changes depend on the degree of neuronal activity.

Abstract PDF Presentation Video

Keywords

acidosis acquisition activated activation activity alter analyzed assess biomedical block blocks bold brain causes checkerboard chemical city closely cluster collected consequently consisted contrast corrected correction correlate correlation cortex curve cycles decay decreased degree depend dependent depends design detect detecting determine discovery duration dynamic engineering evoked false females filtering findings fitting fixation flashing free frequencies frequency functional furthermore general generate generation gradient greater hypothesis hypothesized included individual induction inorganic intensity john knowledge larger likely linear localized lock magnitude males mapped maps matrix measure medical metabolic model motion neural neurosurgery peaks percent phosphate planar preprocessed preprocessing prior psychiatry pulses radiology random recently reduced repeated response responses rest runs scanner seven significance significantly since slice slightly smoothing software solutions space spatial spectra spectroscopic spectroscopy spin statistical statistically steps stimulation stimulus strong studies subjects support table task temporal threshold timing trend trends trio twice underwent varies vector viewing visual years young