Acute pancreatitis in infancy and childhood is usually associated with nonspecific symptomatology such as abdominal pain, nausea, and vomiting. Amylase, lipase, and amylase creatinine clearance ratios may be normal in patients with pancreatitis, and therefore, sonographic evaluation of the pancreas can provide valuable clues to the diagnosis. In most children, the gland is easily imaged sonographically because of the relatively thinner body habitus, less well developed musculature, and fewer problems with excess gas within the gastrointestinal tract. The normal pancreatic parenchymal texture is "cobblestoned," with an even distribution of high- and medium-level echoes. The overall echogenicity of the pancreas is either isoechoic with adjacent normal liver or relatively slightly hyperechoic. In the presence of pancreatitis in children, the pancreatic echogenicity may vary considerably. It may be normal, homogeneously or heterogeneously increased or decreased.

Superimposed bright hyperechoic foci may be seen in the pancreas in patients with hemorrhagic pancreatitis. Hyperechoic (complicated) ascites is usually associated with hemorrhagic pancreatitis but can also be seen with superimposed infection. The most important parameter for the sonographic diagnosis of acute pancreatitis in children is the size of the gland, since it enlarges due to edema. In children, the normal AP dimensions of the pancreas are as follows: head 1.0-2.2 cm, body 0.4-1.0 cm, tail 0.8-1.8 cm. With pancreatitis, the respective measurements may be 2.2-4.0 cm for the head, 0.8-2.0 cm for the body and 1.4-3.5 cm for the tail. The enlargement and abnormal echogenicity may be focal or generalized. One can use ultrasound to look for the complications of pancreatitis such as lesser sac collections, pancreatic pseudocysts, biliary obstruction, hemorrhage, and ascites.

There are several etiologies that one must consider when children develop pancreatitis. These include trauma (bicycle and motorcycle accidents, child abuse), drugs (e.g., steroids, L-asparaginase, valproic acid, hydrochlorothiazide, azothioprine, salicylazosulfapyridine), infections (frequently viral; less often measles, mumps, rubella), congenital anomalies, and familial or idiopathic disease.