Radionuclide fetal imaging: radio-activity in the fetal bladder confirmed by ultrasound after maternal hepato-biliary scanning.

Hepato-biliary scanning with 99mTc-P.G. demonstrated in a jaundiced patient at 31 weeks pregnancy the filling of the fetal bladder 6 h after injection. This finding was confirmed by ultrasound. Fetal urinary bladder activity was seen until 33 h after injection. Fetal hepatic radio-activity could not be displayed although the localisation of the fetal liver was marked by ultrasound.

Hepatobiliary scanning with 99mTc-pyridoxylidene glutamate. A retrospective study investigating the criteria for differentiation between intrahepatic and extrahepatic obstruction.

In 70 99mTc-pyridoxylidene glutamate (PG) studies with verified diagnoses, the following scan patterns were found. (1) Normal: within 30 min of PG injection the scan reveals the liver, hepatic ducts, common bile duct, gallbladder and flow to the intestine; after 2 h the liver had a higher concentration of activity than the hepatic ducts or the common bile duct. (2) Complete extrahepatic obstruction: no hepatic excretion to the intestine is observed 18-24 h after PG injection, nor is activity observed in the hepatic ducts, common bile duct and gallbladder. (3) Incomplete extrahepatic obstruction: intestinal activity is observed within 18-24 h of PG injection; after 2 h the concentration of activity in the hepatic ducts or the common bile duct exceeds that in the liver (regardless whether activity is or is not demonstrated in the gallbladder). (4) No extrahepatic obstruction: serum bilirubin normal or increased; intestinal activity is observed within 18-24 h after PG injection, and activity is demonstrable during this period somewhere in the hepatic ducts, the common bile duct or the gallbladder; after 2 h the concentration of biliary activity should not exceed that in the liver. (5) If excretion to the intestine is observed within 18-24 h of PG injection without demonstrable activity in the hepatic ducts, common bile duct or gallbladder, then it is impossible to differentiate between (3) and (4).

Sensitivity of ultrasound in the detection of biliary tract obstruction.

In 28 patient with varying degrees of biliary obstruction, the ultrasonic findings were correlated with the serum bilirubin levels and with the size of the bile ducts as measured by percutaneous transhepatic cholangiography (PTC). With ultrasound, study of the intrahepatic ducts achieved the greatest accuracy (71%); examination of common bile ducts and the gallbladder were found to be less sensitive (54 and 53%). Ultrasound proved to be very accurate in biliary obstruction, when the serum bilirubin was above 4.8 mg/100 ml (80 mumol/1).