Corrugation v. Plication?
Lee Herold, DVM, DACVECC
The gastrointestinal tract can be one of the most the challenging organs to image with ultrasound. Although small intestinal segments are typically easily visualized the challenge stems from the wide range of normal variation as well as the difficulty in interpreting many states of pathology. In addition, not all of the small intestines will be uniformly affected by an abnormality.
The following images are presented in the hopes of bringing some clarity into two commonly observed sonographic abnormalities of small intestines: corrugation and plication.
Figure A. Normal small intestines
Figure A represents the normal appearance of the small intestines on abdominal ultrasound. The wall layering is well defined and the lumen is easily visualized and followed. If this image were a dynamic ultrasound, the sonographer would be able to trace the intestines through smooth and gentle curves throughout the abdomen.
Figure B demonstrates intestinal corrugation. Although the lumen remains easily visualized and followed, you may be able to appreciate that the intestinal wall appears rippled. Bowel corrugation is a non-specific finding. In a retrospective analysis of diagnosis in dogs and cats with bowel corrugation, 12 of 24 had pancreatitis. Other diagnoses included peritonitis, enteritis, pancreatic neoplasia, diffuse abdominal neoplasia, lymphoplasmacytic enteritis, infarction, protein losing enteropathy and renal failure. My primary differentials when seeing patients with corrugation include enteritis, peritonitis of any cause (sterile peritonitis secondary to pancreatitis versus septic peritonitis), and bowel ischemia.
Figure B. Corrugation
Figure C. Plication
Figure C demonstrates bowel plication. The primary difference between bowel plication and corrugation is the inability to easily trace the small intestinal lumen. In Figure C you might be able to observe that the small intestine appears almost bunched into a “floret”. Although the lumen can be seen in a few loops you can appreciate that the intestinal loops turn sharply and the lumen is tortuous. If this were a dynamic study the sonographer might observe that these hairpin turns seem fixed and would not be able to trace the tortuous lumen path. Plication almost always presents a linear foreign body. Sometimes within the lumen, foreign material will be visualized as a hyperechoic line (in the case of thread type material) or echogenic focus with distal shadowing (if the linear foreign material is larger/thicker than thread). Less commonly, plication can be the result of mature intestinal adhesions which cause the small intestines to be fixed into tight turns.
Suggested Reading
- Moon ML, Biller DS, Armburst LJ. Ultrasonographic appearance and etiology of corrugated small intestine. Vet Radiol Ultrasound. 2003 Mar-April; 44(2):199-203.
- Hoffman KL. Sonographic signs of gastroduodenal linear foreign body in 3 dogs. Vet Radiol Ultrasound. 2003 Jul-Aug; 44(4):466-469