食道表在癌のX線診断における最近の進歩と問題点

Progress and Current Problems in Radiological Examination for Superficial Esophageal Carcinoma

要旨　新しく開発されたデジタルX線装置である平面検出器（FPD）は通常のフィルム－増感紙による撮影系（CSFF）に匹敵する良好な画像が得られ，従来のDRの欠点であったノイズの目立つ画質が改善した．また，FPDはDRと同様に連続撮影の利点を有しタイミングよく撮影ができ，様々な伸展性や造影剤の付着による写真が得られ，より容易に微細病変の診断が可能となった．粘膜癌の拾い上げや微小浸潤sm癌の診断にはまだ課題が残るが，FPDで得られる良好で繊細な画像は食道表在癌の深達度を含めた性状診断に極めて有用と考えられた．

　The flat panel detector（FPD）which is a newly developed digital radiography（DR）system enables us easily to detect the superficial esophageal carcinomas, because the resolving power of FPD has been remarkably improved compared with that of conventional DR usings the image intensifier（II）/TV system. In addition, FPD has more advantages than the conventional film screen system（CFSS）has. They are as follows : sequential exposure, real-time image acquisition and image processing. For example, real-time images enable us to observe a lesion during real-time examination, and to improve detectability and to decrease the failure rate. Sequential exposure helps to take pictures with best timed photography and with various degrees of wall expansions. Because of this, the amount of radiation to patients may be reduced and examination time is shortened. However, there still remain some limitations in the use of FPD in routine screening examination for the detecting of detect mucosal carcinoma and for the accurate diagnosis of micro-submucosal invasion.