• Title/Summary/Keyword: Single-voxel MR spectroscopy

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The Development of Signal Processing Software for Single-and Multi-Voxel MR Spectroscopy (단위용적 및 다용적 기법 자기공명분광 신호처리 분석 소프트웨어의 개발)

  • Paik, Moon-Young;Lee, Hyun-Yong;Shin, Oun-Jae;Eun, Choong-Ki;Mu, Chi-Woong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.544-555
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    • 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.

Alteration Analysis of Normal Human Brain Metabolites with Variation of SENSE and NEX in 3T Multi Voxel Spectroscopy (3T Multi Voxel Spectroscopy에서 SENSE와 NEX 변화에 따른 정상인 뇌 대사물질 변화 분석)

  • Seong, Yeol-Hun;Rhim, Jae-Dong;Lee, Jae-Hyun;Cho, Sung-Bong;Woo, Dong-Chul;Choe, Bo-Young
    • Progress in Medical Physics
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    • v.19 no.4
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    • pp.256-262
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    • 2008
  • To evaluate the metabolic changes in normal adult brains due to alterations SENSE and NEX (number of excitation) by multi voxel MR Spectroscopy at 3.0 Tesla. The study group was composed of normal volunteers (5 men and 8 women) with a mean ($\pm$ standard deviation) age of 41 (${\pm}11.65$). Their ages ranged from 28 to 61 years. MR Spectroscopy was performed with a 3.0T Achieva Release Version 2.0 (Philips Medical System-Netherlands). The 8 channel head coil was employed for MRS acquisition. The 13 volunteers underwent multi voxel spectroscopy (MVS) and single voxel spectroscopy (SVS) on the thalamus area with normally gray matter. Spectral parameters were as follows: 15 mm of thickness; 230 mm of FOV (field of view); 2000 msecs of repetition time (TR); 288 msecs of echo time (TE); $110{\times}110$ mm of VOI (view of interest); $15{\times}15{\times}15$ mm of voxel size. Multi voxel spectral parameters were made using specially in alteration of SENSE factor (1~3) and 1~2 of NEX. All MRS data were processed by the jMRUI 3.0 Version. There was no significant difference in NAA/Cr and Cho/Cr ratio between MVS and SVS likewise the previous results by Ross and coworkers in 1994. In addition, despite the alterations of SENSE factor and NEX in MVS, the metabolite ratios were not changed (F-value : 1.37, D.F : 3, P-value : 0.262). However, line-width of NAA peak in MVS was 3 times bigger than that in SVS. In the present study, we demonstrated that the alterations of SENSE factor and NEX were not critically affective to the result of metabolic ratios in the normal brain tissue.

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Compensatory change of opposite hippocampus after temporal lobe surgery in patients with temporal lobe epilepsy Evidence from single-voxel proton MR spectroscopy

  • Lee, Sang-Hyun;Chang, Kee-Hyun;Chung, Chun-Kee;Song, In-Chan;Han, Moon-Hee
    • Proceedings of the KSMRM Conference
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    • 2001.11a
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    • pp.172-172
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    • 2001
  • Purpose: To evaluate compensatory change of opposite hippocampus after temporal lobe surgery in th patient with temporal lobe epilepsy by using single-voxel proton MR spectroscopy. Method: Eighteen patients with intractable temporal lobe epilepsy (TLE) whose MR diagnos was unilateral hippocampal sclerosis (n=11) or localized unilateral anterior temporal lobe lesio (n=7) and who underwent anterior temporal lobectomy were included in the study. Singl proton MRS of opposite hippocampus was carried out on the same day or within 1 week af MR imaging before temporal lobe surgery and after over 1-year post-surgical follow-u Single voxel proton MRS were acquired using GE signa 1.5T scanner and spectrosco system (TR, 1500-2, 000: TE, 136-144). Region of interest (ROI) was placed in a simitar position for all examination to cover the medial temporal lobes including most of the head an body of hippocampus and a part of amygdala, the parahippocampal gyrus. The MR spectr were evaluated with a focus on the metabolite ratio of N-acetylaspartate (NAA choline-containing phospholipids (Cho), creatine (Cr). The metabolite ratios of NAA/ Cr were calculated from the relative peak height measurement. We evaluated change of th intensity ratio NAA/Cr between before and after surgery, to simplify quantification acro patients, because observed decreases in the ratio of NAA/Cr can be interpreted in terms o neuronal or axonal damage.

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Investigation of Varied MR Spectra by TE and Metabolite Amount in the Localized Voxel using the MR Cone-shape Phantom (자기공명분광법에서 TE와 Voxel 내의 대사물질 양에 따른 스펙트럼 변화 평가에 관한 연구)

  • Woo, Dong-Cheol;Kim, Sang-Soo;Rhim, Hyang-Shuk;Jahng, Geon-Ho;Choe, Bo-Young
    • Progress in Medical Physics
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    • v.18 no.3
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    • pp.179-185
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    • 2007
  • The purpose of this study is to investigate the spectra of a magnetic resonance spectroscopy (MRS) in accordance with the variance of TE and the volumes of metabolites in a localized voxel for the quality assurance using a designed single voxel spectroscopy QA phantom. Because a cone-shade phantom is designed as the volume of metabolite in a localized voxel is changeable, we try to analyze the peaks of each metabolite (NAA, Cr, Cho, Lac, etc.) in accordance with metabolite volume in a localized voxel as well as echo time (TE). All data were obtained using a 3T MRI/MRS machine and analyzed using $jMRUI^{(R)}$. The results of this study show that TE is in inverse proportion to the noise of MRS and the longer TE and the less metabolite volume in the localized voxel, the peak intensities of each metabolite decrease. In case of the lactate, its peak was observed on the all TE only if the greatest metabolite is included in the localized voxel. Then, the intensity of a metabolite is more sensitive to the metabolite volume in the localized voxel than the TE. These obtained in vitro MRS data is provide the guideline that is important for in vivo metabolite quantification. But, in the edge of cone-shape vial air bubbles were observed and spectrum could not obtained. Therefore our cone-shape MRS phantom needs to be modified in order to solve these problems.

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Assessment of Malignancy in Brain Tumors by 3T MR Spectroscopy

  • 최보영;전신수;김범수;이재문;정성택;안창범;오창현;김선일;이형구
    • Proceedings of the KSMRM Conference
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    • 2003.10a
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    • pp.84-84
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    • 2003
  • Purpose: To assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating 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.

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MR Spectroscopy and Diffusion Weighted Imaging Findings of Primary Non-Hodgkin Lymphoma of the Breast: Two Case Reports (유방에 발생한 일차성 비호지킨림프종의 자기공명 분광법 및 확산강조 영상: 2예)

  • Nam, Sang Yu;Yoo, Eun Young;Choi, Hye-Young
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.2
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    • pp.176-181
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    • 2014
  • Primary non-Hodgkin lymphoma (NHL) of the breast is a very rare disease, and the mammographic and ultrasonographic findings of breast lymphoma are variable. There are several reports of magnetic resonance (MR) imaging findings in patients with breast lymphomas; however, few reports have described the findings observed on MR spectroscopy or the features of diffusion weighted (DW) imaging. The authors report the findings of classical MR imaging, MR spectroscopy and DW imaging of a 48-year-old woman and a 40-year-old woman with primary non-Hodgkin's lymphoma of breasts. Mammography and breast ultrasonography revealed a mass with circumscribed margin. The mass showed strong enhancement after contrast injection on MR imaging. DW imaging showed reduced diffusion and high-amplitude choline (Cho) peak at 3.22 ppm was detected by single voxel MR spectroscopy which was consistent with malignancy.

Assessment of Malignancy in Human Brain Tumors by in vivo 1H MR Spectroscopy at 3 Tesla

  • Choe, Bo-Young;Baik, Hyun-Man;Chu, Myung-Ja;Kwon, Kang-Sei;Chung, Sung-Taek;Oh, Chang-Hyun;Kim, Sun-I;Park, Chi-Bong;Lee, Hyoung-Koo
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.80-80
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    • 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.

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Assessment of Malignancy in Brain Tumors by 3T MR Spectroscopy

  • 최보영;전신수;이재문;정성택;안창범;오창현;김선일;이형구;서태석
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.76-76
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    • 2003
  • Purpose: To assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating tumor malignancy at 3T high field system. 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. Results: 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 1.16:1:0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (P=0.005). 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. Conclusions: 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. This results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy. Acknowledgement: This study was supported by a grant of the Mid and Long Term Nuclear R/D Plan Program, Ministry of Science and Technology, Republic of Korea.

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