Neurological Surgery 脳神経外科38巻2号

2010年02月発行

総説

脳神経学におけるヒト用超高磁場（7T）装置の現状と展望

著者： 藤井幸彦¹² 宇塚岳夫¹ 松澤等² 五十嵐博中² 中田力²

所属機関： ¹新潟大学脳研究所脳神経外科学分野 ²新潟大学脳研究所統合脳機能研究センター

ページ範囲：P.107 - P.116

Ⅰ．緒言

　「Ultra high field MR: useful instruments or toys for the boys?」と題する論説¹²⁾の中に以下のようなことが述べられている．「超伝導物質線材や鉄のシールドのコストは容易には下がらないだろうし，超高磁場装置が将来的に研究や臨床に役立つ道具になるか否かは定かでない．超高磁場装置は完成された装置ではなく，この装置で何ができるかでもなく，科学や臨床に役に立つように装置自体を開発していくことが求められる．したがって，現時点において，超高磁場装置は極めて高価であるにもかかわらず，将来具体的に人類にとって有用な装置になるかは未知数である．しかし，3T-MRIなどの高磁場装置の開発研究がそうであったと同様に，超高磁場装置の研究は，直接的，間接的に，MRIの進歩・向上に貢献すると考えられてる．いずれにしても，超高磁場装置は，高磁場装置に取って代わり，MRIにおける“F1 machine”として生き残っていくだろう．」これは，21世紀に入る以前から，ヒト用7T装置の開発に取り組んできたわれわれのチームが常に公言していたことであり，現時点における超高磁場装置の置かれている立場をよく表している．

　術中MR装置などの特殊装置は例外として，現在利用可能なMRIシステムは磁場強度（テスラ：T）によって3つのグループにわけることができる．すなわち，通常装置（1.0～1.5T），高磁場装置（3.0～4.0T），超高磁場装置（7.0～9.0T）である．通常装置は，豊富な臨床経験を結集し，確立されたMRIシステムである．高磁場装置は，形態画像にも，機能画像にも対応した多目的の臨床装置として進化している．本稿では，超高磁場（7T）装置を用いた脳神経学研究の現状と今後の展望について概説する．

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