{"created":"2023-05-15T12:35:01.605324+00:00","id":3822,"links":{},"metadata":{"_buckets":{"deposit":"be39f384-2b01-414a-946f-7a70c0bb52f1"},"_deposit":{"created_by":91,"id":"3822","owners":[91],"pid":{"revision_id":0,"type":"depid","value":"3822"},"status":"published"},"_oai":{"id":"oai:nitech.repo.nii.ac.jp:00003822","sets":["31"]},"author_link":["4831","10733","4831","4832"],"item_10001_alternative_title_24":{"attribute_name":"その他（別言語等）のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"CTソウチ　ニオケル　ザツオン　ノ　コントラスト　ブンカイノウ　ニオヨボス　エイキョウ","subitem_alternative_title_language":"ja-Kana"},{"subitem_alternative_title":"Effect of noise on contrast resolution in CT system.","subitem_alternative_title_language":"en"}]},"item_10001_biblio_info_28":{"attribute_name":"bibliographic_information","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1985-06-20","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"6","bibliographicPageEnd":"489","bibliographicPageStart":"482","bibliographicVolumeNumber":"J68-C","bibliographic_titles":[{"bibliographic_title":"電子通信学会論文誌. C","bibliographic_titleLang":"ja"}]}]},"item_10001_description_36":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"X線CTの特長は目的とする断層面以外の情報を全く含まない完全な断層像を得，かつ被写体内部のわずかな吸収係数の差を提示できる高い吸収係数分解能を有する点にある．この吸収係数分解能は計測時に混入する雑音に大きく影響される．本論文ではこれら雑音の強度と周波数分布に着目し，CT装置使用の際に問題となる被写体全体の大きさ，関心病変部の大きさ，周辺組織とのX線吸収差などが分解能に及ぼす影響を定量的に解析し，又ファントムによりその関係を実験的に検証した．その結果，CT装置の吸収係数分解能は被写体が大きくなると著しく低下する．又関心病変部の大きさと検出可能最小吸収係数差との間には反比例の関係があり，この吸収係数差はX線量の平方根に反比例する．このX線量増加による分解能向上の効果は計測回路の雑音に大きく依存し，回路のSN比は100dB以上の極めて高精度な回路が要求される．さらに振動雑音のような周期性の高い雑音はCT像に粗い粒状性雑音をもたらし，分解能を著しく低下させるので，この雑音の低減は吸収係数の分解能向上に大きく寄与することなどが示された．","subitem_description_language":"ja","subitem_description_type":"Other"}]},"item_10001_full_name_27":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"4831","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Iwata, Akira"}]}]},"item_10001_publisher_29":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"Institute of Electronics, Information and Communication Engineers","subitem_publisher_language":"en"}]},"item_10001_source_id_30":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0373-6113","subitem_source_identifier_type":"ISSN"}]},"item_10001_source_id_32":{"attribute_name":"item_10001_source_id_32","attribute_value_mlt":[{"subitem_source_identifier":"AN00153304","subitem_source_identifier_type":"NCID"}]},"item_10001_version_type_33":{"attribute_name":"出版タイプ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"堀場, 勇夫"},{"creatorName":"&EMPTY&","creatorNameLang":"ja-Kana"}],"nameIdentifiers":[{"nameIdentifier":"10733","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"岩田, 彰"},{"creatorName":"イワタ, アキラ","creatorNameLang":"ja-Kana"}],"nameIdentifiers":[{"nameIdentifier":"4831","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"鈴村, 宣夫"}],"nameIdentifiers":[{"nameIdentifier":"4832","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-01-23"}],"displaytype":"detail","filename":"J68-C_482.pdf","filesize":[{"value":"1.1 MB"}],"format":"application/pdf","license_note":"Copyright(c)1985 IEICE　http://search.ieice.org/index.html","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"本文_fulltext","url":"https://nitech.repo.nii.ac.jp/record/3822/files/J68-C_482.pdf"},"version_id":"d498b368-04cb-4a09-9ee0-60d39e4a86bb"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"item_resource_type","attribute_value_mlt":[{"resourcetype":"journal article","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"CT装置における雑音のコントラスト分解能に及ぼす影響","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"CT装置における雑音のコントラスト分解能に及ぼす影響","subitem_title_language":"ja"}]},"item_type_id":"10001","owner":"91","path":["31"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2012-11-07"},"publish_date":"2012-11-07","publish_status":"0","recid":"3822","relation_version_is_last":true,"title":["CT装置における雑音のコントラスト分解能に及ぼす影響"],"weko_creator_id":"91","weko_shared_id":-1},"updated":"2025-03-12T04:16:25.714884+00:00"}