Skip to main content
. 2024 Oct 25;6(6):e240073. doi: 10.1148/rycan.240073

Figure 2:

Demarcation of a standard total mesorectal excision specimen on (A, B) surgical and whole-mount histology (WMH) slices and (C) radiology-pathology workflow of segmentation and landmark definition. (A) Circumferential margins of the rectal cancer resection specimen were marked with different ink colors to distinguish anterior and posterior and right and left regions of the specimen and enable proper orientation. (B) WMH slice of the total mesorectal excision specimen demonstrates the color code that was used to guide the spatial localization of the rectum portions, as follows: black = anterior, red = posterior, blue = left, and green = right. (C) A gastrointestinal pathologist and a radiologist conducted a collaborative review of WMH and MR images to ensure precise correspondence between pathology and high-resolution T2-weighted imaging. Three corresponding levels were established for each patient at WMH and MRI: the midpoint of the tumor bed, one slice or section above, and one slice or section below. Subsequently, both experts manually delineated the external rectal contour (the outer edge of the muscularis propria), internal rectal contour (inner aspect of the mucosa), and tumor bed at each designated level (illustrated at the midpoint level). Additionally, the radiologist and pathologist annotated eight corresponding point-based landmarks in each modality along the internal and external borders of the rectal wall, encompassing the anterior, posterior, leftward, and rightward directions.

Demarcation of a standard total mesorectal excision specimen on (A, B) surgical and whole-mount histology (WMH) slices and (C) radiology-pathology workflow of segmentation and landmark definition. (A) Circumferential margins of the rectal cancer resection specimen were marked with different ink colors to distinguish anterior and posterior and right and left regions of the specimen and enable proper orientation. (B) WMH slice of the total mesorectal excision specimen demonstrates the color code that was used to guide the spatial localization of the rectum portions, as follows: black = anterior, red = posterior, blue = left, and green = right. (C) A gastrointestinal pathologist and a radiologist conducted a collaborative review of WMH and MR images to ensure precise correspondence between pathology and high-resolution T2-weighted imaging. Three corresponding levels were established for each patient at WMH and MRI: the midpoint of the tumor bed, one slice or section above, and one slice or section below. Subsequently, both experts manually delineated the external rectal contour (the outer edge of the muscularis propria), internal rectal contour (inner aspect of the mucosa), and tumor bed at each designated level (illustrated at the midpoint level). Additionally, the radiologist and pathologist annotated eight corresponding point-based landmarks in each modality along the internal and external borders of the rectal wall, encompassing the anterior, posterior, leftward, and rightward directions.