量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum and Radiological Science and Technology.
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In vivo sodium-23 magnetic resonance (MR) imaging in the head was performed in ten normal volunteers and six patients with brain tumors on a commercially available 1.5 Tesla whole-body MR system. Although sodium MR signal from the brain parenchyma could hardly be detected on routine spin echo (SE) pulse sequence, free induction decay (FID) image with echo time of 1.9 msec demonstrated MR signal in the normal brain tissue. On the other hand, extracellular sodium of cerebrospinal fluid, large venous sinus, and vitreous humor offered high sodium MR signal intensity due to the quantity of sodium and the relatively longer transverse relaxation time (50-60 msec) compared to that of intracellular sodium (less than a few msec). Strong signal was obtained in gliomas with superior contrast, though the delineation of the tumor tissue from edema was as difficult as when seen on proton T2 weighted SE image. Meningioma itself gave much less of a sodium MR signal compared to glioma. Peritumoral edema associated with meningioma showed a markedly high sodium MR signal which was more prominent adjacent to the tumor, although proton SE image revealed the peritumoral edema as homogeneous. Pathological tissues such as brain tumors and edema could be readily depicted as significantly high sodium-23 MR signal, apparently different from normal brain tissues. The current status of in vivo sodium MR imaging is discussed. The authors concluded that early clinical experience of in vivo sodium-23 MR imaging brought promising results in the evaluation of brain tumors and edema; otherwise, discrimination and quantification of multiple T2 components and the improvement of spatial resolution are desperately needed.(ABSTRACT TRUNCATED AT 250 WORDS)
In vivo sodium-23 MRI in brain tumors: evaluation of preliminary clinical experience.
