Clinical experience with 99mTc-disofenin as a cholescintigraphic agent.

99mTc-disofenin, a derivative of iminodiacetic acid, was used for cholescintigraphy in 6 volunteers (in addition to assessment of blood and urine clearance) and in 82 patients referred for evaluation of hepatobiliary tract disease. This radionuclide was cleared rapidly from the blood by the hepatocytes, which permitted satisfactory to excellent images of the hepatobiliary system; interference by renal activity was seen in only 9/82 patients (11%). Acute cholecystitis was correctly diagnosed in 20 patients, although 9 (45%) had jaundice; bilirubin levels ranged from 1.

Renal clearance and extraction parameters of ortho-iodohippurate (I-123) compared with OIH(I-131) and PAH.

o-[131I] iodohippurate [OIH(I-131)] has been used for many years in the estimation of effective renal plasma flow. This compound suffers from low photon yield and poor images when the quantity used is limited to stay within a reasonable radiation dose. To test the validity of substituting I-123 for I-131, a series of experiments was performed in a surgically prepared dog model.

Catabolism and protein binding of Tc-99m pyridoxylideneglutamate.

Various Tc-99m-labeled compounds have been suggested as replacements for [I-131] rose bengal for imaging of the hepatobiliary system. Among such compounds are Schiff's bases, which are tin-free Tc-chelates easily prepared by 30-min autoclaving of an equimolar mixture of pyridoxal and an amino acid at pH 8.5.

Assessment of conventional criteria for the early diagnosis of thrombophlebitis with the 125I-fibrinogen uptake test.

Analysis of 55 positive tests of a total of 300 tests by conventional criteria revealed that 125I-fibrinogen provides useful information early enough for clinical management. Of the tests which were ultimately interpreted as positive by conventional criteria, at least one was positive at 3-4 hours in 67% of the tests and 98% of the tests were positive at 24 hours after the administration of 125I-fibrinogen. A 20% difference between contralateral identical locations of the legs and a 20% difference between adjacent locations of the ipsilateral leg were found with almost equal frequency in the positive tests, whereas a 20% increase at the same location was less sensitive.

Technetium-99m pyridoxylideneglutamate (P.G.) cholescintigraphy.

Technetium-99m P.G. cholescintigraphy was performed in 27 human volunteers and 81 patients referred for hepatobiliary tract disease.

Production and characteristics of 125Xe: a new noble gas for in vivo studies.

Radionuclides of the noble gases are extensively used to assess ventilation and blood flow in clinical and investigative studies. Xenon-133 is most commonly used but is not optimal for these in vivo studies. Xenon-125 has better physical characteristics and can be produced with a cyclotron by a 127I(p,3n)125Xe reaction; this reaction results in a maximum of 25 mCi/gm/cm2/muA-hr for 31-MeV protons.