Figure 10b. Acute pancreatitis. (a) Drawing of the pathway for pancreatic fluid shows the fluid extending through the root of the SBM anteriorly into the transverse mesocolon (TM) and in a left lateral direction into the anterior pararenal space behind the descending mesocolon (DM). Note the relationship between the inferior mesenteric vein (IMV) and the pathway for pancreatic fluid from the root of the SBM to the left anterior pararenal space behind the descending mesocolon. DC = descending colon, P = pancreatic head. (b, c) Postcontrast CT scans (b obtained superior to c) show pancreatic fluid extending to the SBM and transverse mesocolon (arrowheads). The fluid also extends laterally to the left anterior pararenal space behind the descending mesocolon (*) and to the right anterior pararenal space behind the ascending mesocolon (**). The inferior mesenteric vein, which is the landmark for the descending mesocolon, is clearly visualized (arrow).