Fat stranding is a common sign on CT seen anywhere fat can be found but is most commonly seen in the abdomen/pelvis, but also in the retroperitoneum, thorax and subcutaneous tissues. It can be helpful in localising both acute and chronic pathology.
Fat stranding can appear as ill-defined increased attenuation and/or reticular/linear hyperdensity, or in the case of malignancy reticulonodular hyperdensity 1. It is a non-specific sign in itself and can be seen in infectious, inflammatory, malignant, or traumatic conditions.
There are several patterns of fat stranding in the abdomen which can occur within the mesentery or surrounding solid organs 1,2:
mesenteric fat stranding (misty mesentery)
- bowel and mesenteric trauma
- pericolonic fat stranding with bowel wall thickening
- pericolonic fat stranding disproportionate to bowel wall thickening
- sclerosing mesenteritis
- tuberculous peritonitis
- peritoneal malignancy / peritoneal carcinomatosis
- perinephric fat stranding
- peripancreatic fat stranding: acute pancreatitis
- pericholecystic fat stranding: acute cholecystitis
Fat stranding can also be seen in the thorax, and is mainly indicative of mediastinal pathology:
- 1. Thornton E, Mendiratta-Lala M, Siewert B et-al. Patterns of fat stranding. AJR Am J Roentgenol. 2011;197 (1): W1-14. doi:10.2214/AJR.10.4375 - Pubmed citation
- 2. Pereira JM, Sirlin CB, Pinto PS et-al. Disproportionate fat stranding: a helpful CT sign in patients with acute abdominal pain. Radiographics. 2004;24 (3): 703-15. Radiographics (full text) - doi:10.1148/rg.243035084 - Pubmed citation