Okayama University Medical School Acta Medica Okayama 0386-300X 75 2 2021 Multiacquisition Variable-Resonance Image Combination Selective Can Improve Image Quality and Reproducibility for Metallic Implants in the Lumbar Spine 187 197 EN Yuta Fujiwara Division of Clinical Radiology Service, Okayama Central Hospital Tomoaki Sasaki Department of Radiological Technology, Graduate School of Health Sciences, Okayama University Yuki Muto Department of Radiological Technology, Graduate School of Health Sciences, Okayama University Masaki Hirano Department of Radiological Technology, Graduate School of Health Sciences, Okayama University Ryo Kamizaki Department of Radiological Technology, Faculty of Health Sciences, Okayama University Kaito Murakami Department of Radiological Technology, Faculty of Health Sciences, Okayama University Naoya Miura Department of Radiological Technology, Faculty of Health Sciences, Okayama University Yutaka Fujibuchi Department of Radiological Technology, Faculty of Health Sciences, Okayama University Nayu Ohmukai Department of Radiological Technology, Faculty of Health Sciences, Okayama University Nao Ueda Department of Radiological Technology, Faculty of Health Sciences, Okayama University Kouhei Sugimoto Department of Radiological Technology, Graduate School of Health Sciences, Okayama University Kazuhiro Ota Division of Clinical Radiology Service, Okayama Central Hospital Yoshiki Kamihoriuchi Division of Clinical Radiology Service, Okayama Central Hospital Tomoko Sasaki Division of Clinical Radiology Service, Okayama Central Hospital Souichirou Kaneshige Department of Radiology, Okayama Central Hospital Original Article 10.18926/AMO/61897 The aim of this study is to evaluate how metallic artifacts in the lumbar spine can affect images obtained from magnetic resonance (MR) sequences. We performed a phantom experiment by scanning an agar containing an orthopedic metallic implant using 64-channel multidetector row computed tomography (CT) and a 3-tesla MR unit. We compared the reproducibility in each measurement, enlargement or reduction ratio of the CT and MR measurements, and signal deviation in each voxel from the control. The reproducibility on CT and multiacquisition variable-resonance image combination selective (MAVRIC SL) was good, but that on the other MR sequences showed either fixed bias or proportional bias. The reduction ratios of the distance between the nails were significantly smaller in MAVRIC SL than in the other MR sequences after CT measurements (p<0.001, respectively). MAVRIC SL was able to reduce the metallic artifact, permitting observation of the tissue surrounding the metal with good reproducibility. No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 47 3 2016 地域サポート人材の定着とその支援のあり方について ―地域おこし協力隊制度と地域社会のサステイナビリティ― 1 27 EN Hiroyuki Nakao Masaki Hirano 10.18926/OER/54157 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 47 2 2016 バブル期以降の岡山県財政の変容 −長野・石井県政時代の財政状況を振り返ってみて− 53 80 EN Teiji Kameyama Masaki Hirano 10.18926/OER/54144 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 45 2 2013 地方交付税の合併算定替え終了が市町村に及ぼす影響 ―財源調整機能は維持されるか― 59 85 EN Yuji Ota Masaki Hirao 10.18926/OER/51693 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 43 4 2012 わが国の財政赤字　何が問題か 65 86 EN Masaki Hirano 10.18926/OER/48233 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 43 3 2011 わが国の財政支出の拡大について考える 29 48 EN Masaki Hirano 10.18926/OER/47298 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 42 3 2010 地方自治体における施策の優先順位に関する一考察−中四国地域の主要自治体からのアンケート調査結果による− 13 44 EN Masaki Hirano Keizo Taniguchi 10.18926/OER/41094 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 34 4 2003 A Study on the Burden of the Public Debt in Japan through System of National Accounts 7 23 EN Masaki Hirano 10.18926/OER/40606 This thesis will examine the economic and financial environment of the previous and current financial aggravation terms through macroeconomic data, namely, balance of saving and investment classified by institutional sectors in system of national accounts. It will also consider how far the concept of the burden of the public debt is applicable to Japanese actual economy. As long as measured by ex−post macroeconomic data, system of national accounts, though, there are a lot of possibilities of evaluating the burden and it cannot be exactly said which evaluation such as neutrality theorem is both realistic and appropriate. However, the current financial aggravation term, compared with the previous term, seems to cope insufficiently with household financial deficit as far as mutual action about saving between each institutional sector is concerned. Although there is no need to say that further empirical analyses are essential, this includes important suggestions for examining the problems involved in the burden of the public debt. Firstly, incorporated business benefit trend in this prolonged period of economic slump is a critical factor. Secondly, taxation system and political and economic structure have more and more impact on household saving. Thirdly, it has become essential to show specific ways to fiscal reconstruction with social security−related expenditure at its core, in order for household to adapt rationally to fiscal deficit. Therefore, it will be more crucial in further empirical analyses on the burden of the public debt to take into consideration these three points : benefit trend of incorporate business, political and economic structure, and policy operation such as public finance correction. No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 0386-3069 36 4 2005 消費税の論点整理と益税問題 167 179 EN Masaki Hirano 10.18926/OER/40543 No potential conflict of interest relevant to this article was reported.

岡山大学経済学会 Acta Medica Okayama 03863069 38 3 2006 ＜論説＞『家計調査』からみた税制改革の視点 1 22 EN Masaki Hirano 10.18926/OER/12398 財政制度の基本は租税制度であり，租税制度は歴史的かつ社会経済的な産物でもある。このため，各時代の社会経済情勢の変化に応じて，財政制度全般が変容を余儀なくされるとともに，租税制度もその変革が求められる。事実，戦後の租税制度は社会経済情勢の変化に対応して，累次にわたって改 革が実施されてきた。現在でも，財政健全化のための一応の目途を早期につけるために，財政制度全般を抜本的に見直し，歳出・歳入両面での一体改革を目指す議論が活発に行われている。具体的には，財政悪化に歯止めをかけるため，２０１０年代の初頭に財政健全化指標の一つであるプライマリー・ バランス（基礎的財政収支）を黒字化する必要があり，そのためには歳出削減だけでは限界であり，増税，例えば消費税率の引上げはやむを得ないとの見方が拡がっている。また，この消費税率の引上げによる財源は少子高齢化の進展に伴い急増すると見込まれる社会保障費に充当すべきであるとい う，消費税の「福祉目的税化」の議論もある。 ところで，わが国で財政事情が極端に悪化している主因はバブル崩壊以降の景気悪化に伴う税収の落込みや累次にわたる景気対策に加えて，少子高齢化の進展に伴う社会保障費の増加をはじめとした歳出規模の大きさに比較して租税負担の規模が相対的に小さいことが挙げられる。例えば，わが国の 租税負担率を他の主要先進国と比較してみると，わが国はアメリカと同様に低い水準にある。これは現在世代が政府から提供された便益の大きさに応じた租税負担を行わず，巨額な財政赤字という形で将来世代にその負担を先送りしているからである。今後，少子高齢化が一層進展すれば，社会保障費 が急増することは間違いなく，それに応じて租税負担の更なる上昇は不可避であると考えられる。とりわけ，主要先進国の中でも税率が低く，安定的な財源が見込まれる消費税は増税の対象になりやすい。しかし，所得税が税負担の累進性という租税の所得再分配機能を強く持っているのに対して， 消費税には税負担の逆進性という所得再分配機能を弱める働きがある。所得格差に関する議論が高まっている中で，家計への影響力が大きい所得税と消費税の所得再分配機能をどのように考えるべきであろうか。以下では，総務省（旧総務庁）の『家計調査』の中の「勤め先収入」（給与（勤労）所得，勤労者世帯）における所得格差と租税負担率に焦点を当てることで，戦後の所得税や消費税における所得再分配機能を検証したものである。この所得再分配機能の検証結果を踏まえたうえで，戦後の税制改革，とりわけ現行の所得税制を形成したと考えられる１９８０年代の抜本的な税制改革（租税政策）の背景を概観することによって，今後の税制改革の視点を提供したい。 No potential conflict of interest relevant to this article was reported.