日本肺癌学会肺がん検診委員会は，2022年に「肺がん検診ガイドライン」の改訂を行った．本稿では改訂に至った経過とその概要について解説する．「現行検診」に対する「推奨」は2010年ガイドラインから変化はなかった．全国的な精度管理の徹底や，国全体の死亡率減少効果への寄与度や感度・特異度の測定などに関する評価が必要である．「重喫煙者に対する低線量CT検診」は，欧米において肺癌死亡率減少効果のエビデンスが得られたが，過剰診断，偽陽性，放射線被ばくなどの不利益は無視できない．安易な導入を行って混乱する事態を避けるためには，まずは適切な「実装研究」を行うことにより，日本の社会にどのように導入することが望ましいのかを検討することが重要である．一方，「非/軽喫煙者に対する低線量CT検診」は，現在のところ有効性のエビデンスは十分でないため，それを集積することが第一に重要である．

━━ Based on a questionnaire survey, the Lung Cancer Screening Committee considers that the aging of doctors involved in lung cancer screening and the high coverage rate of non-specialist doctors are problems; thus, the acquisition of new reading doctors and maintaining and improving the reading ability for doctors who currently perform reading, are considered very important. In 2012, we published Chest X-ray Interpretation Text-book for Lung Cancer Screening with the aim of solving these problems; however, we needed a method to apply the knowledge learned there. In 2018, screening image data were collected from facilities related to the Lung Cancer Screening Committee members, and the image data were evaluated by central judgment. Based on the data and results, we have developed a system that enables interpretation exercises similar to the examination interpretation environment. In May 2019, it started operation as a system that members can practice anytime and any-where via the internet. It is now stably operated at more than one year after the start of operation. This paper ex-plains the progress of the development of this system and how it is used. It also reports the usage status. ( JJLC. 2021;61:69-76)

━━ The practical guidelines for lung cancer screening have been revised in 2020. In this article, we will explain the background and aims concerning the revision to the requirements for doctors engaging in the interpretation of chest roentgenograms in lung cancer screening and the implementation of case review meetings, two topics that seem very important. The requirements in the 2017 version have been assessed as difficult to understand by many local government officials, necessitating a revision of the requirements. In the 2020 version, all doctors are required to participate in a case review meeting once a year, and senior doctors are also required to have a prescribed experience in the interpretation of chest roentgenograms. The important points to bear in mind when holding a case review meeting are also described. We hope that this paper will help improve the quality assurance in lung cancer screening in the future. (JJLC. 2020;60:929-935)

目的. Multidetecter-row CT (以下MDCT) では従来の横断面と同じ解像力でmultiplanar reconstruction (以下MPR) で矢状断や冠状断など任意の断面の画像が得られる. MPR像により右上葉動脈, A2, A3の分岐様式を検討した. 方法. 胸部に病変が疑われた症例及び正常ボランティアでMDCTによる検査を施行し, 肺野条件によりA2ai, A2aii, A2bi, A2bii, A3ai, A3aii, A3bi, A3biiの走行について, 上幹動脈から分岐する回帰型か, 中間肺動脈幹から分岐する上行型かを検討した. 結果. 通常, 右上葉の肺動脈は上幹動脈から分岐し, 気管支の上方に接して走行する. しかしA2あるいはA3の区域枝や亜区域枝は中間肺動脈幹から分岐し上行して上葉に入り, 気管支の下方に接して走行する. このような気管支と動脈の関係が逆になって走行するものもいくつか認められた. 結論. 動脈の分岐の検討や気管支の分岐をMPR像で検討することにより, 病変に対して詳細な情報や術前の既存構造の情報を提供し, 読影医の読影技術の向上にも非常に有用である.