FIGURE 6.

Mesenteric panniculitis. Transverse grey scale ultrasound image (a) of the abdomen in a 63-year-old male reveals diffusely echogenic mesentery with no well-defined solid mass. Axial contrast enhanced CT images of the abdomen (b, c) reveals an ill-defined inhomogenous mass of mean attenuation ~ 5.8 HU (greater than that of retroperitoneal fat). Multiple hyperdense nodules are seen within the mass and surrounding mesentery. Thin discontinuous slightly hyperattenuating soft tissue rim is seen on the anterior and posterior aspect of the mass limiting the mass from the surrounding mesentery (thick white arrow in b) – tumoural pseudocapsule sign. The mass is seen to encase superior mesenteric artery (SMA), superior mesenteric vein (SMV) and their branches with preservation of a ring of fat around mesenteric vessels and nodules (thin white arrows in c) – fat ring sign. Coronal reformatted CT image (d) reveals an ill-defined inhomogenous mass in the mesentery encasing the SMA, SMV and their branches with preservation of a rim of fat around SMA (thin white arrow – fat ring sign).