Correlation of bioscintigraphy, contrast venography, and iodine-125 fibrinogen uptake test.

In 40 patients believed to have deep venous thrombosis, bioscintigrams performed with I-123 fibrinogen were available for comparison with either contrast venograms or I-125 fibrinogen uptake tests. If either contrast venography or the fibrinogen uptake test was accepted as a standard for comparison, the accuracy of bioscintigraphic imaging was 90%. Most discrepancies between the procedures could be interpreted as due to heparin treatment, although bioscintigrams often were positive in patients treated with heparin for a short interval of time.

Work in progress. Gastrointestinal ulcerations: detection using a technetium-99m-labeled ulcer-avid agent.

Technetium-99m-labeled sucralfate, an ulcer-avid material, was shown in preliminary animal and human studies to be stable in vivo with good sensitivity. Eight experimentally produced discrete gastric ulcers in three rabbits were visualized using this material. Of seven human studies, four studies were true-positive and three were true-negative.

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.