Artin Arzoumanian

Kupffer cell depletion associated with capillarization of liver sinusoids in carbon tetrachloride-induced rat liver cirrhosis*

Rats were made cirrhotic by carbon tetrachloride inhalation associated with phenobarbital in the drinking water over 10 weeks. After a 1-week recovery period a 99mTc sulphur colloid radioisotope scan of the liver was carried out on each animal following bolus injection into the iliac vein. Kupffer cells were then histologically identified by one of three methods: colloidal carbon uptake, iron staining after ferritin-dextran, or endogenous peroxidase staining. The degree of liver injury was classified into four pathological groups and these were correlated with the phagocytic capacity of each liver as recorded on the isotope scan. All three histological markers demonstrated that in normal liver, Kupffer cells are more plentiful in periportal areas. In cirrhotic liver, there were very few Kupffer cells in nodular regenerative areas, where continuous capillaries are found, but Kupffer cells were present in the remaining more normal trabecular-sinusoidal areas. Morphometric counting of carbon- and ferritin-labelled Kupffer cells demonstrated a significant decrease in cirrhotic livers. A close correlation was also found between increasing degree of liver injury and diminished hepatic phagocytic capacity, as demonstrated by the radioisotope scan. The study demonstrates that where regenerative liver is capillarized, with replacement of fenestrated sinusoids, Kupffer cells are absent.

99mTc-IDA hepatobiliary imaging following upper abdominal surgery.

Bile flow patterns were studied with serial 99mTc-IDA images in 19 patients with cholecysto- and choledochointestinal anastomoses, gastroenteric bypasses, and combinations of the two. Complications such as anastomotic, afferent, and efferent loop obstruction and bile leakage were readily detected even in the presence of jaundice. This noninvasive technique warrants further investigation to determine its indications and weaknesses.

Assessment of the utility of gallbladder imaging with 99mTc-IDA.

Cholescintigraphy was performed in 113 patients of whom 38 had normal gallbladders, 37 had acute cholecystitis and 38 had chronic cholecystitis. The radiopharmaceuticals used in the study were either 99mTc-dimethyl acetanilide iminodiacetic acid or 99mTc-paraisopropyl acetanilide iminodiacetic acid, both of which performed equally well. All patients with nonvisualized gallbladders had cholecystitis, but visualization did not exclude disease. The rapidity of obtaining the results (within one hour), the complete absence of untoward reactions to the radiopharmaceuticals, the much lower frequency of subtle or indeterminate results, the ability to render useful information in the presence of moderate jaundice and the lack of interference from overlying intestinal contents establishes these radionuclide agents as superior to both radiographic oral and intravenous cholangiography in the investigation of the acute abdomen.

Differential diagnosis of jaundice by 99mTc-IDA hepatobiliary imaging.

The utility of 99m Tc-IDA imaging in the differential diagnosis of jaundice was assessed. Although overall accuracy was 84%, this method is still inferior to the reported efficiency of ultrasonography and CT in making the correct diagnosis. Radionuclide imaging is a good alternative when these other modalities are not available and it functions well in an adjuvant capacity. The diagnostic limitations of 99m Tc-dimethyl IDA imaging in cases of moderate to severe jaundice are largely overcome by the use of 99m Tc-p-butyl IDA.

A clinical comparison of MDP and DMAD.

Tc-99m labeled dimethyl-amino-diphosphonate (DMAD) was compared with methylene diphosphonate (MDP) in five healthy volunteers and 28 patients with a variety of bony afflictions. Although the normal bone uptake of DMAD is less than MDP, the lesion-to-normal bone ratio is significantly higher with DMAD. All 71 lesions detected with MDP were also seen with DMAD. However, 10 lesions were disclosed with DMAD that were not seen with MDP. These lesions tended to have low grade concentrations of the radiopharmaceutical and were detected with DMAD by virtue of the lower normal bone uptake rather than higher lesion uptake.

A Longitudinal Comparison of the Kinetics of 99mTc-MDP and 99mTc-EHDP in Humans

99mTc-MDP and 99mTc-EHDP were compared in 11 volunteers and 20 patients for blood retention, urinary excretion, bone to soft tissue background and overall quality of the radionuclide images. 99mTc-MDP showed significant superiority in most of the parameters tested making it the preferred radiopharmaceutical. However, in those patients exhibiting skeletal disease both 99mTc-MDP and 99mTc-EHDP disclosed the same lesions with approximately equal relief.