Case w -  Cholecystitis

The gall bladder is distended.  There is gall bladder wall edema and pericholecystic fat stranding (1, 2).  There is also subtle hyperemia in the surrounding liver (1, 2, 3).  The findings indicate acute cholecystitis.

This case nicely demonstrates the appearance of gall bladder wall edema.  The mucosa enhances as a thin line.  Edema within the wall is seen at the band if low attenuation peripheral to the mucosa.  Wall edema can be circumferential or only be seen along parts of the gall bladder circumference.  In this case, the edema is almost completely circumferential.  Edema on ultrasound also looks like a band of low signal within the gall bladder wall.

Each of these findings are, individually, non-specific for cholecystitis.  Gall bladder distension can be seen with fasting or in patients on TPN.  Gall bladder edema can be seen with cirrhosis, congestive heart failure, hepatitis, and low protein states.  The pericholecystic stranding is more specific for cholecystitis but can be seen in pancreatitis, colitis (in the adjacent hepatic flexure), duodenitis, or trauma.  Adjacent liver hyperemia is fairly specific for cholecystitis.  The combination of findings, and the fact that the stranding is centered about the gall bladder, indicate cholecystitis.  This was confirmed at surgery.

There is also inflammation along the left anterior peri-renal fascia (Gerota's fascia).  Previously we discussed how this is seen in pancreatitis.  However, any inflammatory process in the peritoneum can track posteriorly.  In this case, the thickening is secondary to gall bladder inflammation.

Pelvis ascites outlines the uterus, probably secondary to the cholecystitis.  Notice the coarse aortic calcifications with mural thrombus, indicating severe atherosclerotic disease.  Look at the calcified splenic artery.  Also notice the severe coronary artery calcifications.  Luckily, this patient has already had cardiac bypass (there is a median sternotomy).  There are also small effusions with associated atelectasis.

Take home points:

• The combination of gall bladder distension, gall bladder wall edema, and pericholecystic fatty stranding, and surrounding hepatic hyperemia  indicates cholecystitis.
• Thickening of the Gerota's fascia indicates inflammation in the superior abdomen.  This is common in pancreatitis but can also be seen with cholecystis, duodenitis, pyelonephritis, and trauma.