In Vivo Detection Of Human Brain GABA By Single-voxel~1H Magnetic Resonance Spectroscopy

MRS is a non-invasive technique to study the chemical properties of the metabolites in vivo,which can detect the biochemical information and give a quantitative analysis of the metabolites.With the rapid development of magnetic resonance technology, MRS has been widely used to diagnosis and identify the diseases and assess the efficacy in clinical contex.GABA is an important inhibitory neurotransmitter in the central nervous system of human brain and plays a leading role in the regulation of neural activity. The altered concentrations of GABA are associated with the acute deafferentation, visual light-dark adaptation, alcohol and substance abuse, epilepsy, depression, schizophrenia and other diseases. The detection of GABA in human brain allows to assess the effect of drug treatment, help to elucidate the pathology and the pathogenesis of the above mentioned diseases.The measurement of GABA in human brain confronted with two main challenges. The peaks of GABA spectrum overlaped with peaks of other metabolites under the action of the chemical shift and scalar coupling effect. And the inherent low concentration of GABA result in low signal-to-noise ratio.Therefore, it is difficult to directly detect GABA with PRESS or STEAM pulse sequence in clinical MRI system.This paper adopted the J-difference editing technique to solve the above mentioned problems,and incorporated this technique into the PRESS pulse sequence.In addition, the implementation of detection of GABA through a single-voxel spectroscopy J-difference editing sequence of MEGA-PRESS,which was developed on a clinical3T MR imaging system pulse sequence development platform. The results from phantoms and human brain indicated the feasibility of MEGA-PRESS sequence in3T clinical MRI system.This paper also studied the reproducibility of GABA in the occipital of human brain and the results suggested the good reproducibility of GABA measurement.