Comparative cardiac effects of three hepatobiliary radiopharmacologicals in the dog: concise communication.
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Three hepatobiliary agents with an acetanilide-imidoacetic-acid moiety resembling that in lidocaine were investigated for their possible effects on contractility and conductivity in the heart and on arterial pressure and aortic blood flow. This was done in the light of lidocaine's numerous cardiac side effects. HIDA, BIDA, and DIPA, each with traces of decayed Tc-99m, were injected i.v. into anesthetized dogs with an A-V block, and their effects on the above parameters were followed until control levels were reestablished. Whereas lidocaine raises the diastolic threshold and prolongs the refractory period, the three agents tested do not prolong myocardial conductivity. Both HIDA and BIDA have an effect similar to that of lidocaine, but DIPA has no effect on the latter two parameters. Moreover, whereas lidocaine depressed myocardial contractility, blood pressure, and blood flow, HIDA has a less prominent effect on these parameters, and neither BIDA nor DIPA has any such effect. It is concluded that even though the effect of HIDA on the heart is milder than that of lidocaine, the effects of both BIDA and DIPA are even less pronounced, and they are less likely to cause cardiac side effects when similar doses are administered during nuclear medicine procedures. (+info)
Radiation-dose calculation for five Tc-99m IDA hepatobiliary agents.
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The radiation absorbed doses from five commercially available hepatobiliary agents--Tc-99m-tagged analogs of IDA (EIDA, PIPIDA, HIDA, PBIDA, DISIDA) have been calculated from biokinetic data in 41 normal subjects. Serial gamma images, with blood and urine samples, were obtained to calculate cumulated radioactivity in the source organs: blood, kidney, bladder, liver, gallbladder, and intestines. The critical organ was the gallbladder, with an absorbed-dose range of 690 to 780 mrad/mCl. Absorbed doses for other target organs were: upper large intestine 320 to 370 mrad/mCi, lower large intestine 210 to 240, small intestine 170 to 200, liver 65 (DISIDA) to 130 (PBIDA), ovaries 63 to 72, and urinary bladder wall 23 (PBIDA) to 36 (EIDA). The radiation absorbed dose was largely independent of changes in chemical structure except in (a) the liver, where absorbed dose varied by a factor of two in proportion to the rate of excretion of the IDA agent from the liver, and (b) the urinary bladder, where absorbed dose varied by a factor of 1.6 because of differences in rate of excretion. When the stimulus for gallbladder emptying is changed from whole-meal ingestion to cholecystokinin injection, the absorbed dose to the gallbladder increases to approximately 1 rad/mCi; if no gallbladder emptying is assumed, its absorbed dose increases to approximately 1.9 rad/mCi. In the absence of contraindication, the gallbladder absorbed dose may thus be decreased by inducing gallbladder emptying at the end of the imaging study. (+info)
Evaluation of a liver transplant by Tc-99m dimethyl-IDA scintigraphy.
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In liver-transplant patients, it is always difficult to differentiate between rejection crises and extrahepatic biliary obstruction on the basis of standard biochemical tests alone. A case is reported of a patient who received a transplant following total hepatectomy performed because of a hepatoma. Scintigraphy with Tc-99m N-(dimethylphenylcarbamoylmethyl)iminodiacetic acid pointed conclusively to an obstructive process, which was confirmed at re-operation. (+info)
Intravenous cholescintigraphy using Tc-99m-labeled agents in the diagnosis of choledochal cyst.
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Twelve patients with choledochal cyst have undergone intravenous radionuclide cholescintigraphy (IVRC) with Tc-99m-labeled HIDA or PG before surgery. The most characteristic findings are: (1) A round or ovoid photon-deficient area in the region of the gallbladder in the early images; (2) progressive accumulation of radioactivity in the same region in later images, especially at 2 hr after injection; (3) the long axis of this particular area directed downward and to the patient's left from the right midclavicular line, suggesting the direction of the common bile duct; and (4) persistent pooling of the tracer up to 24 hr, even after a fatty meal. By these criteria, correct diagnoses have been made preoperatively in ten of 12 cases (83.3%). We conclude that IVRC using Tc-99m HIDA or Tc-99m PG is an excellent first-line diagnostic tool for choledochal cyst. (+info)
Transient nonvisualization of the gallbladder by Tc-99m HIDA cholescintigraphy in acute pancreatitis: concise communication.
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In five of seven patients with acute pancreatitis, Tc-99m HIDA scintigraphy failed to visualize the gallbladder. In all five patients the gallbladder was later found to be normal and in three of them normal filling was obtained at a repeat examination performed after the attack had subsided. Transient nonvisualization of the gallbladder in acute pancreatitis is probably due to disturbed motility of the biliary tree. (+info)
Scintigraphic detection of segmental bile-duct obstruction.
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In a patient with acute obstructive jaundice, cholescintigraphy with technetium-99m-labeled iminodiacetic acid (HIDA) showed uniformly reduced uptake in the left lobe of the liver. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated cholelithiasis and obstruction of the distal hepatic duct. Surgery, and later a T-tube cholangiogram, confirmed the presence of numerous stones in the left intrahepatic and common hepatic ducts. The liver was free of tumor. Intrahepatic segmental ductal obstruction may produce a spectrum of patterns on hepatobiliary imaging ranging from reduced uptake to intrahepatic pooling. (+info)
Tc-99m HIDA scintigraphy in segmental biliary obstruction.
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Segmental biliary obstruction as a result of primary or secondary hepatic malignancy has been reported with increasing frequency. For two representative patients, the clinical and Tc-99m HIDA scintigraphic findings in segmental biliary obstruction are described. The presence of photon-deficient dilated bile ducts in one segment of the biliary tree is highly suggestive of localized biliary obstruction and should be considered in the patient with suspected or proven hepatic malignancy despite the absence of jaundice. (+info)
The role of H.I.D.A./P.I.P.I.D.A. scanning in diagnosing cystic duct obstruction.
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A newer approach to the early diagnosis of acute biliary tract disease is review. Ninety-two patients were evaluated with a new hepatobiliary agent (H.I.D.A/P.I.P.D.A.) for the presence of cystic duct obstruction. Seven patients with suspected acute gall bladder disease were dropped from the study for the lack of pathologic confirmation of the diagnosis. Forty-four of the remaining 85 patients were subsequently operated on and found to have acute cholecystitis. Forty-three of the 44 had cystic duct obstruction demonstrated on H.I.D.A. Scan (one false negative). An additional 23 patients underwent cholecystectomy for chronic disease. In this group, the gallbladder scan was only 43% (10/23) accurate in correctly identifying disease. Eighteen patients with nonbiliary disease had normal scans. The accuracy of ultrasonography and the scan are also compared in a smaller subgroup of 53 patients who had both studies. (+info)