• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.345-351
• /
• 2002

The purpose of this study was to assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high field system. Using 3T MRI/MRS system, localized water-suppressed single-voxe1 technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67${\pm}$018 and 1.16${\pm}$0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (p=0.005), but Cho/Cr ratio of all tumor tissue was significantly higher (p=0.001). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas (P=0.001). Except 4 menigiomas, lactate signal was observed in all tumor cases. The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. Our results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy.

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.80-80
• /
• 2002

Purpose： Three tesla high field MR has been important to those disciplines that are SNR limited, such as MR spectroscopy. Additionally, increased spectral dispersion is critical for minimizing spectral overlap and simplifying resonance structures. The purpose of this study was to assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high field system Materials and Methods： Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio.

• Progress in Medical Physics
• /
• v.12 no.1
• /
• pp.31-39
• /
• 2001

NMR spectroscopy enables us to measure the molar concentration of the metabolites in the organisms, and this technique is the only method to measure the concentration non-invasively. The proton NMR spectroscopy has been used to study the biochemical changes in human as well as in animal brain. MRI uses the proton densities and its relaxation times for reconstructing images, but MRS gives the biochemical changes inside the body. NMR spectroscopy could provide the information which MRI and CT could not, and this makes NMR spectroscopy more useful in diagnosing diseases. This study was tried to develop the quantitation of the molar concentration of the metabolites in the brain using the proton MR spectroscopy. The spectra of each metabolites was obtained, and the proton MR spectra was obtained from the insula gray matter areas of the 16 volunteers. And this spectra was analyzed to estimated the molar concentrations of the metabolites in the region. The results showed the very similar to those of the others.

• Investigative Magnetic Resonance Imaging
• /
• v.12 no.1
• /
• pp.8-19
• /
• 2008

Purpose : To investigate the 3-bond and spatial connectivity of human brain metabolites by scalar coupling and dipolar nuclear Overhauser effect/enhancement (NOE) interaction through 2D- correlation spectroscopy (COSY) and 2D- NOE spectroscopy (NOESY) techniques. Materials and Methods : All 2D experiments were performed on Bruker Avance 500 (11.8 T) with the zshield gradient triple resonance cryoprobe at 298 K. Human brain metabolites were prepared with 10% $D_2O$. Two-dimensional spectra with 2048 data points contains 320 free induction decay (FID) averaging. Repetition delay was 2 sec. The Top Spin 2.0 software was used for post-processing. Total 7 metabolites such as N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), lutamine (Gln), glutamate (Glu), myo-inositol (Ins), and lactate (Lac) were included for major target metabolites. Results : Symmetrical 2D-COSY and 2D-NOESY pectra were successfully acquired: COSY cross peaks were observed in the only 1.0-4.5 ppm, however, NOESY cross peaks were observed in the 1.0-4.5 ppm and 7.9 ppm. From the result of the 2-D COSY data, cross peaks between the methyl protons ($CH_3$(3)) at 1.33 ppm and methine proton (CH(2)) at 4.11 ppm were observed in Lac. Cross peaks between the methylene protons (CH2(3,$H{\alpha}$)) at 2.50ppm and methylene protons ($CH_2$,(3,$H_B$)) at 2.70 ppm were observed in NAA. Cross peaks between the methine proton (CH(5)) at 3.27 ppm and the methine proton (CH(4,6)) at 3.59 ppm, between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(4,6)) at 3.59 ppm, and between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(2)) at 4.05 ppm were observed in Ins. From the result of 2-D NOESY data, cross peaks between the NH proton at 8.00 ppm and methyl protons ($CH_3$) were observed in NAA. Cross peaks between the methyl protons ($CH_3$(3)) at 1.33 ppm and methine proton (CH(2)) at 4.11 ppm were observed in Lac. Cross peaks between the methyl protons (CH3) at 3.03 ppm and methylene protons (CH2) at 3.93 ppm were observed in Cr. Cross peaks between the methylene protons ($CH_2$(3)) at 2.11 ppm and methylene protons ($CH_2$(4)) at 2.35 ppm, and between the methylene protons($CH_2$ (3)) at 2.11 ppm and methine proton (CH(2)) at 3.76 ppm were observed in Glu. Cross peaks between the methylene protons (CH2 (3)) at 2.14 ppm and methine proton (CH(2)) at 3.79 ppm were observed in Gln. Cross peaks between the methine proton (CH(5)) at 3.27 ppm and the methine proton (CH(4,6)) at 3.59 ppm, and between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(2)) at 4.05 ppm were observed in Ins. Conclusion : The present study demonstrated that in vitro 2D-COSY and NOESY represented the 3-bond and spatial connectivity of human brain metabolites by scalar coupling and dipolar NOE interaction. This study could aid in better understanding the interactions between human brain metabolites in vivo 2DCOSY study.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2003.09a
• /
• pp.74-74
• /
• 2003

Purpose: To investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease after thalamotomy using proton magnetic resonance spectroscopy (lH MRS). Methods: Fifteen patients with Parkinson's disease of mean age 56.5 years (7 males and 8 females; mean age, 56.5 years) that have treated with levodopa were included. All patients with tremor experienced amelioration of their symptoms on the side contralateral to the thalamotomy. As a single-voxel technique, 1H MR spectra were obtained from the volume of interested regions in thalamus and primary motor cortex. Spectral parameters were: 20 ms TE, 2000 ms TR, 128 averages, 2500 Hz spectral width, and 2048 data points. Results: We found that NAA/Cho ratios showed generally low levels in thalamus in Parkinson's disease patients with clinical improvement following thalamotomy. Conclusions: 1H MRS may be a useful utility for the aid in better understanding the pathophy-siologic process in Parkinson's disease patients on the basis of the variation of NAA/Cho ratio. Acknowledgement: This study was supported by a grant of the Center for Functional and Metabolic Imaging Technology, Ministry of Health & Welfare, Republic of Korea (02-PJ3-PG6-EV07-0002).

• Progress in Medical Physics
• /
• v.7 no.1
• /
• pp.37-52
• /
• 1996

Image-guided localized, water-suppressed in vivo $^1$H MR spectroscopic studies were performed on the patients with brain tumors, acute cerebral infarction and schizophrenia, and dogs. GE Signa 1.5 T whole-body MRI/MRS system using STEAM pulse sequence was used. Proton metabolite ratios relative to creatine (Cr) were obtained using a Marquart algorithm. In vivo $^1$H MR spectra in brain neoplastic tissues revealed the changes of signal intensities of N-acetylaspartate (NAA), choline (Cho) and lactate (Lac) resonances. The present results suggest that the observed metabolite alterations from localized, water-suppressed in vivo $^1$H MR spectroscopy can be useful as an index of brain tumors, cerebral infarction and schizophrenia, and provide good quality metabolic information of cerebral tissue in the field of thanato-chronology.

• Journal of the Korean Magnetic Resonance Society
• /
• v.10 no.2
• /
• pp.126-140
• /
• 2006

Purpose: Contrary to the human study, it has rarely investigated metabolic alterations in the dorsolateral prefrontal cortex (DLPFC) of depressed rats versus age and sex-matched controls using proton magnetic resonance spectroscopy (MRS). Thus, the purpose of this research was to verify the feasibility of metabolic differences between the normal rat and the depression model rat. Materials and Methods: A homogeneous group of 20 SD male rats was used for MRI and in vivo 1H MRS. To induce a depressed status in SD rats, we performed the forced swimming test (FST). Using image-guide, water suppressed in vivo 1H MRS with 4.7 T MRI/MRS system, NAA/Cr and Cho/Cr ratios were mainly measured between depressed rats and normal subjects. Results: In depressed rats, increased Cho/Cr ratio was measured versus control subjects. However, no significant group effect for NAA/Cr was observed between case-control pairs. Discussion and Conclusions: The present 1H MRS study shows significant brain metabolic alterations of dorsolateral prefrontal cortex with experimental depressed status of SD rat induced by FST compared to normal subjects. This result provides new evidence that in vivo 1 H MRS may be a useful modality for detecting localized functional neurochemical markers alterations in left DLPFC in SD rats.

• Proceedings of the KSMRM Conference
• /
• 2003.10a
• /
• pp.88-88
• /
• 2003

Purpose： To investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease after thalamotomy using proton magnetic resonance spectroscopy (1H MRS). Materials and methods： Fifteen patients with Parkinson's disease of mean age 56.5 years (7 males and 8 females； mean age, 56.5 years) that have treated with levodopa were included. All patients with tremor experienced amelioration of their symptoms on the side contralateral to the thalamotomy. As a single-voxel technique, 1H MR spectra were obtained from the volume of interested regions in thalamus and primary motor cortex. Spectral parameters were： 20 ms TE, 2000 ms TR, 128 averages, 2500 Hz spectral width, and 2048 data points.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.5
• /
• pp.544-555
• /
• 2002

The aim of this study is to develop the $^1H$-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

• Korean Journal of Radiology
• /
• v.1 no.1
• /
• pp.25-32
• /
• 2000

Objective: The purpose of our study was to determine the ability of H-1 MR spectroscopy (MRS) to lateralize the lesion in patients with hippocampal sclerosis. Materials and Methods: Twenty healthy volunteers and 25 patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis were included. This diagnosis was based on the presence of unilateral atrophy and/or high T2 signal intensity of the hippocampus. Single-voxel H-1 MRS was carried out on a 1.5-T unit using PRESS sequence (TE, 136 msec). Spectra were obtained from hippocampal areas bilaterally with volumes of interest (VOIs) of 6.0 cm³ and 2.25 cm³ in healthy volunteers, and of either 6.0 cm³ (n = 14) or 2.25 cm³ (n = 11) in patients. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from relative peak height measurements. The capability of MRS to lateralize the lesion and to detect bilateral abnormalities was compared with MR imaging diagnosis as a standard of reference. Results: In healthy volunteers, NAA/Cho and NAA/Cr ratios were greater than 0.8 and 1.0, respectively. In patients, the mean values of these ratios were significantly lower on the lesion side than on the contralateral side, and lower than those of healthy volunteers (p < .05). The overall correct lateralization rate of MRS was 72% (18/25); this rate was lower with a VOI of 6.0 cm³ than of 2.25 cm³ (64% versus 82%, p < .05). Bilateral abnormalities on MRS were found in 24% (6/25) of cases. Conclusion: Although its rate of correct lateralization is low, single-voxel H-1 MRS is a useful and promising diagnostic tool in the evaluation of hippocampal sclerosis, particularly for the detection of bilateral abnormalities. To improve the diagnostic accuracy of H-1 MRS, further investigation, including the use of a smaller VOI and measurement of the absolute amount of metabolites, are needed.