医用画像情報学会雑誌
Online ISSN : 1880-4977
Print ISSN : 0910-1543
ISSN-L : 0910-1543
27 巻, 2 号
選択された号の論文の6件中1~6を表示しています
特別講演資料
論文
  • —胸部単純X線画像における初期検討—
    李 鎔範, 蔡 篤儀
    2010 年 27 巻 2 号 p. 29-32
    発行日: 2010年
    公開日: 2010/06/04
    ジャーナル フリー
    In this paper, a novel application of computer-aided diagnosis (CAD) system, namely portable CAD, was proposed. As a preliminary study, we investigated differences of feature values of nodules calculated by a CAD algorithm, between original chest radiograph and camera image taken by a digital camera. Sixty cases of chest radiographs were used in the study. These radiographs were initially displayed on the monitor, and then taken by the digital camera. Then, the CAD scheme was applied to the obtained camera images. In the CAD scheme, detection of nodule candidates was performed by using matched and ring filters. Two features, area and circularity, were calculated from nodule candidate regions in radiographs and camera images, and were compared respectively. In conclusion, a close correlation between the features calculated from radiographs and camera images was verified.
  • 田中 利恵, 市川 勝弘, 森 慎一郎, 土橋 卓, 熊谷 始紀, 川嶋 広貴, 箕原 伸一, 真田 茂
    2010 年 27 巻 2 号 p. 33-37
    発行日: 2010年
    公開日: 2010/06/04
    ジャーナル フリー
    The purpose of this study was to address image lag in target tracking and its influence on the accuracy of target tracking. Fluoroscopic images were obtained using a direct type of dynamic flat-panel detector (FPD) . Image lag properties, modulation transfer function (MTF) , and profile curves were measured. Digital phantoms of metal sphere with and without blurred edge due to image lag were simulated using the results, respectively, and then superimposed on breathing chest radiographs of a patient. The moving target with and without image lag was traced using a template-matching technique. In the results, the image lag for the first frame after X-ray cutoff was 2.0% and decreased to less than 0.1% in the fifth frame. In the measurement of profile curves on the edges of tungsten material plates, the effect of image lag was seen as blurred edges of the plate. The blurred edges of the plate were also indicated as reduction of MTF. However, the target could be traced without tracking error. The results indicated that there was no effect of image lag on target tracking in usual breathing speed in a radiotherapy situation.
  • 井原 佐知子, 小倉 敏裕, 塚田 文世, 藤井 雅典, 立川 智弘, 西村 宜子, 河野 敦, 下村 洋之助, 須田 悟志, 土井 邦雄
    2010 年 27 巻 2 号 p. 38-41
    発行日: 2010年
    公開日: 2010/06/04
    ジャーナル フリー
    In our previous study, fat tissues on abdominal CT tended to be concentrated around colon cancer sites, and the intra-abdominal fat area in patients with colon cancer presented a small secondary peak in the pelvis, which we called the sub-peak. We assessed the amount of the sub-peak to develop a novel method for early detection of colon cancer. The profile of intra-abdominal fat data was determined first by segmentation of fat components in CT images, and was approximated by removing the sub-peak part manually by use of six-degree polynominal approximation. The sub-peak value was obtained by subtracting the approximate data from the original data. The amount of the sub-peak was quantified by the sub-peak ratio which is defined by the ratio of the maximum value to the sub-peak value in the profile of intra-abdominal fat data. The subjects consisted of patients with rectal cancer (60 cases) , sigmoid colon cancer (72 cases) , and non-tumors in the pelvic cavity (59 cases) . Our result indicated that the accuracy in detecting colon cancer was 76.1% when the sub-peak ratio was equal to or greater than 10%. This amount of the sub-peak ratio may be useful in the development of a computer-aided diagnosis (CAD) scheme for early detection of colon cancer.
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