直腸，肛門のCT・MRIの診断法

CT and MR Imaging of the Anorectal Diseases

要旨　最近，CT・MRI機器の進歩は著しく，より早く，より細かく病変を描出可能となってきている．CT・MRIが従来の直腸，肛門部の診断法にさらに詳しい情報を提供する手段として広く活用されている．特に癌では進展と周囲臓器浸潤を，粘膜下腫瘍ではその進展と質的診断，また瘻孔では合併する膿瘍や複雑なルートを把握でき術前に欠くことができない．CT・MRIの診断法について利点と限界を知り活用されるべきである．

　Recently, advance and progress in CT and MR technology has brought about improvement in the diagnostic accuracy of these means. Multidetector CT enables us to obtein high quality three dimensional images rapidly. The high quality multiplaner abilities of MRI also afford a distinct advantage, especially in detecting tumor spread, recurrence of tumor and the morphology of anal fistula. However, further studies for diffusion images are needed to demonstrate its efficacy. We describe the method and usefulness of CT and MRI for detecting tumors and other conditions of the anorectal region.