Small bowel volvulus resulting in acute obstruction.

Note: 

• this patient is 75 years old - this is not just a problem in pediatrics!
• however, in this case, there is a 5 x 3 cm exophytic oval mass arising from the mid ileum (likely a GIST) which likely contributed to this patient developing the volvulus by tethering that segment of bowel. 
• the location of volvulus is the distal ileum (remote from the mass)
• it is easiest to follow on the axial images
• the SMV wraps around the SMA counterclockwise, and thus has the opposite of normal relationship
• this results in vascular compression and mesenteric congestion
• the oral contrast gradually becomes more dilute in the distal small bowel