大野 良治

PURPOSE: To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). MATERIALS AND METHODS: This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 +/- 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distrib

術前評価のための三次元シミュレーション画像作成において、320列エリアエリアディテクターCT(ADCT)の有用性について検討するため、肺区域切除が予定された32例(男24例、女8例、平均67歳)にADCT検査を行い、従来の64列マルチディテクター(MDCT)と比較した。ADCTとMDCTで作成した三次元の肺血管構造画像に対し、2名の呼吸器外科専門医が切除区域に関する肺動脈と区域間肺静脈の可視化を5点満点で評価した。その結果、ADCTの評価点は平均4.4点、MDCTは3.9点と有意差を認めた。また肺動脈の存在についての診断能力のROC分析では、ADCTにおける曲線下面積(AZ=0.93)とMDCT(AZ=0.92)との間に有意差はなかった。各方法での確率スコアのための観察者間の一致に関しては、kappa値は0.70で、客観的な判定法として問題ないと考えられた。