Fig. 2

A, B The patient is a 22-year-old female diagnosed with acute myeloid leukemia, experiencing aGVHD with GI-GVHD. The enhanced CT venous images of the abdomen, as shown in both coronal (A) and axial (B) views, reveal several notable findings: (a) multifocal inflammation in the small bowel and colon is evident, with significant mucosal enhancement (indicated by the thick arrow on the left in both images). (b) The circular target sign is observable (indicated by the thick arrow in image (B)). (c) There is marked edema and comb sign changes in the mesentery (indicated by the arrow on the right in image (A)). (d) Small lymph node hyperplasia is visible around the mesentery (indicated by the arrow in the middle in image (A)). C, D The patient is an 11-year-old male with thalassemia and aGVHD affecting the gastrointestinal tract. The enhanced CT venous images of the abdomen, displayed in both axial (C) and coronal (D) views, with the following observations: (a) in image (C), there is the thickening of edema in the wall of the sigmoid colon with pronounced abnormal mucosal enhancement (indicated by the thick arrow). (b) Image D shows dilatation and pneumatization of the left colon. Additionally, there are multiple small submucosal air sac formations (also marked by the thick arrow). E The gastrointestinal micrograph displays significant congestion and edema in the mucosa of both of the large intestine and terminal ileum. Additionally, there is diffuse flushing and impaired peristalsis. F The pathology image at × 100 magnification reveals congestion and edema in the mucosa of the sigmoid colon. Notably, there is the formation of granulation tissue, along with hyperplasia of capillary and fibrous connective tissues, and the intestinal mucosa without epithelial covering