Pancreas imaging by computed tomography after endoscopic retrograde pancreatography

ENDOSCOPIC RETROGRADE CHOLANGIO-PANCREATOGRAPHY IN DOGS WITH CHRONIC GASTROINTESTINAL PROBLEMS

Endoscopic retrograde cholangio-pancreatography is a combination of endoscopy and fluoroscopy used for radiographic imaging of the biliary and pancreatic ducts. In order to assess its feasibility and to describe abnormal findings in dogs, this technique was performed in 30 dogs with nonspecific chronic gastrointestinal disturbances. Using an 11-mm side-view endoscope, retrograde cholangiography was successful in 20/30 dogs (67%) and pancreatography in 21/30 (70%). Success was affected by intraduodenal food, mucus or blood, problems in papillary cannulation, stomach overdistention, body size, and changes in duodenal mucosa. It was impossible to perform the procedure in dogs weighing < 10 kg with the available material. Endoscopic retrograde cholangiography revealed findings that differed from previous reports in healthy beagles in 5/20 dogs. Findings included enlarged common bile duct (n = 2), intraductal filling defects (n = 2), and deviated course of common bile duct (n = 1), and major papilla stenosis (n = 1). In the dog with major papilla stenosis and intraductal filling defects, endoscopic guided sphincterotomy was performed. Endoscopic retrograde pancreatography revealed an abnormal course of the accessory pancreatic duct in 2/21 dogs. In both dogs with proven end-stage pancreatic acinar atrophy, the left duct branch did not run distal the stomach to the left but went parallel to the right duct branch and the duodenum. Repeated clinical and laboratory examinations revealed no signs of complications after endoscopic retrograde cholangio-pancreatography. It was concluded that this imaging technique is promising for the diagnosis of biliary and pancreatic diseases in dogs. It also offers the chance for new treatment options such as endoscopic guided sphincterotomy in dogs.

Differentiation of chronic focal pancreatitis from pancreatic carcinoma by in vivo proton magnetic resonance spectroscopy

OBJECTIVE

To determine the differences between the in vivo proton magnetic resonance spectroscopy (H-MRS) features of chronic focal pancreatitis and pancreatic carcinoma and to evaluate the possibility of discriminating chronic focal pancreatitis from pancreatic carcinoma by analysis of in vivo H-MR spectra.

METHODS

The H-MR spectra from 36 human pancreases were evaluated in vivo. This series included 15 cases of chronic focal pancreatitis and 21 cases of pancreatic carcinoma. All cases were confirmed histopathologically after surgical resection. The ratios of the peak area (P) of all peaks at 1.6-4.1 ppm to lipid (0.9-1.6 ppm) (P [1.6-4.1 ppm]/P [0.9-1.6 ppm]) in the chronic focal pancreatitis and pancreatic carcinoma groups were evaluated, and the results were compared. The sensitivity and specificity of the analysis were also evaluated by in vivo H-MR spectra for discriminating between chronic focal pancreatitis and pancreatic carcinoma.

RESULTS

In vivo H-MR spectra showed significantly less lipid in chronic focal pancreatitis than in pancreatic carcinoma. The ratio of P (1.6-4.1 ppm)/P (0.9-1.6 ppm) in chronic focal pancreatitis was significantly higher than that in pancreatic carcinoma (P < 0.05) because of a decreased peak area of lipids. The means +/- SDs of P (1.6-4.1 ppm)/P (0.9-1.6 ppm) in the chronic focal pancreatitis and pancreatic carcinoma groups were 2.78 +/- 1.67 and 0.51 +/- 0.49, respectively. Using a value of <2.5 as positive for pancreatic cancer, the sensitivity and the specificity for pancreatic cancer were 100% and 53.3%, respectively.

CONCLUSION

Chronic focal pancreatitis and pancreatic carcinoma can be distinguished from each other by analysis of in vivo H-MR spectra, and in vivo H-MRS can be a useful method for making a differential diagnosis between chronic focal pancreatitis and pancreatic carcinoma.

ENDOSCOPIC RETROGRADE CHOLANGIO-PANCREATOGRAPHY IN HEALTHY BEAGLES

Endoscopic retrograde cholangiography and pancreatography was performed in seven healthy Beagles to assess the common bile duct and the accessory pancreatic duct after retrograde filling with an iodine contrast medium. All dogs had a major and a minor duodenal papilla. One Beagle had additionally an accessory papilla. The diameter of the contrast filled ducts was measured at three defined measure points (MP1-3) in ventrodorsal radiographs and left lateral radiographs. In ventrodorsal radiographs of endoscopic retrograde cholangiography the common bile duct had a straight craniomedial course. The mean duct diameter was from proximal to distal 3.04 +/- 1.89mm at MP1, 2.38 +/- 1.23 mm at MP2, and 2.11 +/- 0.84 mm at MP3. In ventrodorsal radiographs of endoscopic retrograde pancreatography, the left and right branch of the accessory pancreatic duct united in the pancreatic body. The mean diameter of the right branch was 0.88 +/- 0.14 mm at MP1, 0.72 +/- 0.2 mm at MP2 and 0.61 +/- 0.11 mm at MP3. The left branch had a diameter of 0.93 +/- 0.28 mm at MP1, 0.86 +/- 0.21 at MP2, and 0.6 +/- 0.07 mm at MP3. The mean length was 81.6 +/- 14.3 mm for the right and 107.0 +/- 24.9mm for the left branch. In left lateral radiographs of endoscopic retrograde pancreatography, it was not possible to differentiate the left from the right branch. Both branches ran nearly parallel and showed similar diameters but slight differences in length. The study proves that endosopic retrograde cholangio-pancreatography is possible in dogs. Radiographs taken from dogs in dorsal recumbency allow an objective assessment of the common bile duct and the accessory pancreatic duct.

On-table pancreatography: importance in planning operative strategy

We describe our experience with 124 on-table pancreatograms performed during 117 operative procedures on 112 patients in a wide variety of clinical settings. Endoscopic retrograde cholangiopancreatography (ERCP) was performed on 84 occasions with a 73 per cent success rate for visualization of the main pancreatic duct. On-table pancreatography (OTP) was performed by one of five different techniques: retrograde, prograde or ambigrade ductography, cystography and ascending loopography after pancreaticojejunostomy. OTP provided important information about the main pancreatic duct when endoscopic visualization was unsuccessful (n = 23), incomplete (n = 17) or not performed (n = 33); there was a failure rate of 4 per cent. In 35 patients either the additional information or discrepancies between ERCP and OTP findings resulted in a change of operative plan (19 extra procedures, 16 altered procedures). Complete ductography was especially helpful in the 63 patients with chronic pancreatitis. OTP is technically simple, free from complications and invaluable for planning operative strategy.