The renal rind sign: a new ultrasound indication of inflammatory disease in the abdomen.

The width of the right anterior extrarenal tissue is increased on ultrasound examination in patients with abdominal inflammatory disease. Thickened perirenal fascia associated with acute pancreatitis has previously been reported on computed tomography. A case report has described increased echogenicity of the pararenal space on ultrasound in children with pancreatitis but increased width of the space between the liver and the renal capsule has not hitherto been described in association with inflammatory disease in the abdomen in adults. We have observed it in acute cholecystitis, acute pancreatitis, acute appendicitis, a perforated duodenal ulcer, a leaking anastomosis with a right subphrenic abscess following total gastrectomy and in a patient with septicaemia and liver abscesses. Normal values were obtained in 100 patients without detectable or known disease and were found to be between 1 and 6 mm (mean 2.5 mm) in men and 1 and 5 mm (mean 1.8 mm) in women. The patients with abdominal disease who demonstrated this sign had values ranging from 9-11 mm (mean 10 mm).