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RISS 인기검색어
- 검색키워드
- 저자 : Hyoung-KooLee (검색결과 2 건)
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Metabolic Alterations in Parkinson’s Disease after Thalamotomy, as Revealed by 1H MR Spectroscopy
백현만,Bo-YoungChoe,Hyoung-KooLee,Tae-SukSuh,Byung-ChulSon,Jae-MunLee 대한영상의학회 2002 Korean Journal of Radiology Vol.3 No.3
Objective: To determine, using proton magnetic resonance spectroscopy (1H MRS) whether thalamotomy in patients with Parkinson's disease gives rise to significant changes in regional brain metabolism. Materials and Methods: Fifteen patients each underwent stereotactic thalamotomy for the control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was performed on a 1.5T unit using a STEAM sequence (TR/TM/TE, 2000/14/20 msec), and spectra were obtained from substantia nigra, thalamus and putamen areas, with volumes of interest of 7-8ml, before and after thalamotomy. NAA/Cho, NAA/Cr and Cho/Cr metabolite ratios were calculated from relative peak area measurements, and any changes were recorded and assessed. Results: In the substantia nigra and thalamus, NAA/Cho ratios were generally low. In the substantia nigra of 80% of patients (12/15) who showed clinical improvement, decreased NAA/Cho ratios were observed in selected voxels after thalamic surgery (p < 0.05). In the thalamus of 67% of such patients (10/15), significant decreases were also noted (p < 0.05). Conclusion: Our results suggest that the NAA/Cho ratio may be a valuable criterion for the evaluation of Parkinson's disease patients who show clinical improvement following surgery. By highlighting variations in this ratio, 1H MRS may help lead to a better understanding of the pathophysiologic processes occurring in those with Parkinson's disease.
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Sei-KwonKang,Bo-YoungChoe,Tae-SukSuh,Hyoung-KooLee 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.40 No.3
In single-voxel magnetic resonance spectroscopy (MRS), the stimulated echo acquisition mode (STEAM) pulse sequence has been widely used, but if a short echo time is unnecessary, the pointresolved spectroscopy (PRESS) pulse sequence has its own advantage that, theoretically, the magnetization is twice that of STEAM, which provides a better signal-to-noise ratio (SNR). This might be helpful in the treatment of a weak signal, but, to our knowledge, there has been no theoretical description of the steady-state magnetization in PRESS. Thus, using the vector model, we derived the equation of magnetization as a function of the echo time (TE) and the repetition time (TR), and we compared the extracted T1 value of a water phantom with the simple exponentially fitted value.
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