ultrasound perm its continuo us monitoring of the puncturing need le(or trochar-catheter dev ice) to insure its proper placement w ith in the fluid collection. The suppleme ntal use of fluoroscopy to follow guide wires and catheters during the introduction process serves to minim ize chances for kinking of wires or tubes. We have found the combined use of sonographic and fluoroscopic monitoring of fluid draina ge to provide the most cost effective, rapid, and readily available approach(8, 12-18 Chronic pancreatitis Recurrent bouts of acute pancreatitis will produce sonographically demonstrable signs of chronic inf lammation, inc luding irregular areas of increased echogen icity representing fibrosis and/or calcification The increase in echoge nic ity in chronic pancreatitis is patchy and heterogeneous in contrast to the norma homogene us increase in echotex ture of the pancreas which results from f atty replacement of glandular tissue. In chronic pancreatitis the gland is usually diminished in volume and often dif f icult to outline Pseudocyst formation has been reported in 25-60 of patients with chronic pancreatitis as wel (19)(Figure 11 Figure -11a Transverse scan of a patient w ith chron ic calcif ic pancreatitis. Multiple shadowing calculi (arrows) are seen distributed throughout the gland a aorta Figure- 11b Sagittal scan of the same pancreas seen in Figure 11a. In this view the conglomerate calcif ications produce a large area of shadowing arrowheads). The gland is outlined by short white arrows. a aorta Dilatation of the pancreatic duct may also be a result of chronic inf lammation; the dilatation is of ten described as irregular or string of beads as a consequence of alternating areas of dilatation and fibrotic stricture. This appearance is sometimes offered as a means by which to distinguish ductal dilatation secondary to inf lammation from the smooth, tubular ectas ia which results from neoplastic obstruction as with carcinoma of the ampulla of Vater. The two dangers in relying upon this distinction too heavily are first that the morpholog ic differentiation is not always suf f iciently clear to allow the diag nos is. Secondly patients with chronic pancreatitis may also develop neoplasms and the coexistence of chronic inf lammation and carcinoma is an ever-present possibility (Figure 12) With the production of fibrosis and calcif ication, chronic pancreatitis may produce a mass composed of inf lammatory tissue which may simulate a neoplasm and, in fact, if it arises in the head of the gland, result in obstruction of the biliary or pancreatic ducts(Figure 13)ultrasound permits continuous monitoring of the puncturing needle (or trochar -catheter device) to insure its proper placement within the fluid collection. The supplemental use of fluoroscopy to follow guide wires and catheters during the introduction process serves to minimize chances for kinking of wires or tubes. We have found the combined use of sonographic and fluoroscopic monitoring of fluid drainage to provide the most cost ef fective, rapid, and readily available approach (8, 12-18) Chronic pancreatitis Recurrent bouts of acute pancreatitis will produce sonographically demonstrable signs of chronic inflammation, including irregular areas of increased echogenicity representing fibrosis and/or calcification. The increase in echogenicity in chronic pancreatitis is patchy and heterogeneous in contrast to the normal homogeneous increase in echotex ture of the pancreas which results f rom fatty replacement of glandular tissue. In chronic pancreatitis the gland is usually diminished in volume and of ten dif ficult to outline. Pseudocyst formation has been reported in 25- 60 % of patients with chronic pancreatitis as well (19) (Figure 11) . Figure - 11a. Transverse scan of a patient with chronic calcific pancreatitis. Multiple shadowing calculi (arrows) are seen distributed throughout the gland. a = aorta Figure - 11b. Sagittal scan of the same pancreas seen in Figure 11a. In this view the conglomerate calcifications produce a large area of shadowing (arrowheads). The gland is outlined by short white arrows. a = aorta Dilatation of the pancreatic duct may also be a result of chronic inflammation; the dilatation is of ten described as irregular or "string of beads" as a consequence of alternating areas of dilatation and fibrotic stricture. This appearance is sometimes of fered as a means by which to distinguish ductal dilatation secondary to inflammation f rom the smooth, tubular ectasia which results f rom neoplastic obstruction as with carcinoma of the ampulla of Vater. The two dangers in relying upon this distinction too heavily are first that the morphologic differentiation is not always suf ficiently clear to allow the diagnosis. Secondly, patients with chronic pancreatitis may also develop neoplasms and the coexistence of chronic inflammation and carcinoma is an ever-present possibility (Figure 12) . With the production of fibrosis and calcification, chronic pancreatitis may produce a mass composed of inflammatory tissue which may simulate a neoplasm and, in fact, if it arises in the head of the gland, result in obstruction of the biliary or pancreatic ducts (Figure 13)