直肠癌分界、分段与分期的磁共振成像解剖学思考OA

In recent years,magnetic resonance imaging(MRI)has achieved significant breakthroughs in both clinical ex-amination performance and image interpretation for locally advanced rectal cancer.However,several challenges remain re-garding the ambiguous definition of anatomical details.Unifying the standards for rectal boundary,rectal segmentation,and tumor staging is of clinical practice importance to promote standardized clinical research and optimize individualized treatment decisions in rectal cancer.Currently,the international imaging community has largely reached a consensus on defining the upper border of the rectum,unanimously adopting the"sigmoid take-off"as the anatomical landmark.Mean-while,in the field of surgery,the anorectal junction or the anal verge is clearly recognized as the reference standard for the lower border of the rectum.Regarding the segmentation of the rectum between the anorectal junction and the sig-moid take-off,different standards should be adopted based on specific clinical needs.From the perspective of preopera-tive neoadjuvant treatment strategy,the peritoneal reflection is recommended as the anatomical landmark to divide the rectum into the upper and lower segments.When focusing on the selection of surgical procedures,segmentation based on a distance of 5 cm from the lower tumor margin to the anorectal junction is suggested,as this criterion better aligns with the practical requirements of surgical decision-making.