as compared with the normal liver. This is attributed to the preponderance of glandular tissue and relative paucity of both fat and fibrous elements( Figure 4) Figure -4. Transverse scan in a young child. Note that the normal size pancreas (p) appears less echogenic than the liver(L. Predominance of glandular tissue and paucity of fat and fibrous stroma at this age make this a normal finding. S= splenic vein; v= inferior vena cava arrow superior mesenteric artery In the adult, the echogenicity of the pancreas is taken to be normal if it is equal to or greater than that of the liver assuming of course that organ to be normal. Clear def inition of the collagen and fat in the portal triads coup led w ith he patic parenchyma which is slig htly more echogenic than the adjacent renal cortex is reasonable assurance that the liver can be used as a normal internal standard(Figure 5) Figure-5. The pancreas(p) appears somewhat hy poechoic as compared with the liver(). This is due to increased echogenicity of the liver(fatty inf iltration rather than edema of the pancreas which is normal in this patient. Arrow= normal pancreatic duct; a aorta; v= inferior vena cava At and beyond the f if th decade, replacement of glandular tissue w ith fat and fibrosis produces a diff use, homogeneo us increase in the echogenic ity of the pancreas; it is not uncommon for the pancreas to reach a level of echogenicity at which it is indistinguisha ble from the contiguous retroperitoneal fat. These changes are considered a product of normal aging and are not associated with pancreatic insufficiency (3)(Figure 6) Figure-6 The pancreas(p) in this elderly patient is markedly echogenic becoming essentially isoechoic with the fat at the root of the mesentery which surrounds the superior mesenteric artery(arrow) This is a consequence of replacement of glandular tissue with fat and represents a normal aging change. s= splenic vein; a =aorta;V inferior vena cava:L= liver PATHOLOGIC CONDITIONS Acute pancreatitis Acute inf lammation of the pancreas may result from alcohol abuse biliary tract disease, trauma, or familial predisposition. Generally the history will provide strong indications of the etiology but sonographic evaluation of the biliary tree is frequently requested to establish primary or secondary involvement (e.g. biliary tract obstruction by pseudocyst or inf lammatory mass)as compared with the normal liver. This is attributed to the preponderance of glandular tissue and relative paucity of both fat and fibrous elements (Figure 4). Figure - 4. Transverse scan in a young child. Note that the normal size pancreas (p) appears less echogenic than the liver (L). Predominance of glandular tissue and paucity of fat and fibrous stroma at this age make this a normal finding. S = splenic vein; v = inferior vena cava; arrow = superior mesenteric artery. In the adult, the echogenicity of the pancreas is taken to be normal if it is equal to or greater than that of the liver assuming, of course, that organ to be normal. Clear definition of the collagen and fat in the portal triads coupled with hepatic parenchyma which is slightly more echogenic than the adjacent renal cortex is reasonable assurance that the liver can be used as a normal internal standard (Figure 5) . Figure - 5. The pancreas (p) appears somewhat hypoechoic as compared with the liver (L). This is due to increased echogenicity of the liver (fatty infiltration) rather than edema of the pancreas which is normal in this patient. Arrow = normal pancreatic duct; a = aorta; v = inferior vena cava. At and beyond the fif th decade, replacement of glandular tissue with fat and fibrosis produces a diffuse, homogeneous increase in the echogenicity of the pancreas; it is not uncommon for the pancreas to reach a level of echogenicity at which it is indistinguishable f rom the contiguous retroperitoneal fat. These changes are considered a product of normal aging and are not associated with pancreatic insuf ficiency (3) (Figure 6) . Figure - 6. The pancreas (p) in this elderly patient is markedly echogenic, becoming essentially isoechoic with the fat at the root of the mesentery which surrounds the superior mesenteric artery (arrow). This is a consequence of replacement of glandular tissue with fat and represents a normal aging change. S = splenic vein; a = aorta; v = inferior vena cava; L = liver. PATHOLOGIC CONDITIONS Acute pancreatitis Acute inflammation of the pancreas may result f rom alcohol abuse, biliary tract disease, trauma, or familial predisposition. Generally, the history will provide strong indications of the etiology but sonographic evaluation of the biliary tree is f requently requested to establish primary or secondary involvement (e.g. biliary tract obstruction by pseudocyst or inflammatory mass)