Serum transaminase levels and cholescintigraphic abnormalities in acute biliary tract obstruction.

Twenty-five patients presenting to the hospital with symptoms suggestive of acute biliary tract disease were noted to have a characteristic pattern of transaminase and cholescintigraphic abnormalities. There was marked variability in the initial serum transaminase levels; however, 16 patients had aspartate aminotransferase levels greater than 300 IU, and 19 patients had alanine aminotransferase values greater than 300 IU. Regardless of the initial values, there was a 76% (aspartate aminotransferase) and 58% (alanine aminotransferase) reduction in transaminase levels within 72 hours, prior to therapeutic relief of bile duct obstruction. In ten patients with common bile duct obstruction, cholescintigraphy revealed no excretion of technetium Tc-99m-labeled iminodiacetic acid, for up to two hours after injection, into the extrahepatic biliary tract or small bowel. Common bile duct stones were present in 16 patients, five patients had acute pancreatitis, and four patients were thought to have spontaneously passed common duct stones. We believe that high transaminase levels may be found in patients with obstructive biliary tract disease, sequential measurements of transaminase levels may provide an important diagnostic clue for biliary tract disease, and nonexcretion of radionuclide on cholescintigraphy may be a feature of acute bile duct obstruction.

Initial clinical experiences with a Fresnel zone-plate imager.

First clinical studies with a Fresnel zone-plate radioisotope imager demonstrate high resolution, sharp tomography, and freedom from scatter. Improved radionuclide imaging is demonstrated, at least for small organs like the thyroid. Certain limitations are present that indicate a need for additional development before application to routine clinical practice.

A urinary double-radioisotope technique for the detection of fat malabsorption.

The possibility that the unreliability of urinary excretion of radioactivity after the administration of oral 131I-triolein, as a measure of fat absorption, is due to variable renal clearance of iodide prompted investigation of a double-radioisotopic method. Intravenously administered radioiodide should be cleared identically with radioiodide split from absorbed fat and serve as an internal standard. Oral 131I-triolein was given in an 80 gm fat liquid meal; 125I-iodide was given intravenously; urine was collected fractionally for 72 hr. Accepted stool fat excretion data and stool radioactivity excretion data developed in this study were used to define groups of normals (less than 5.4 gm of fat or less than 7.8% 131I) and malabsorbers (greater than 5.4 gm of fat or greater than 7.8% 131I). In 26 normals urinary 131I ranged from 24.6% to 77.1% in 48 hr and 27.7% to 86.8% in 72 hr; in the malabsorbers these values lay between 0.6% and 62.8% in 48 hr and 1.0% and 66.8% in 72 hr, showing much overlap with normal. An index of the cumulative percentage of urinary 131I/125I X 100 at either 48 or 72 hr completely separated the groups, the index in normals ranging from 68.7 to 100 in 48 hr and 72.5 to 100 in 72 hr, whereas the malabsorbers varied between 2.0 and 64 in 48 hr and 2.2 and 67.5 in 72 hr.

Sensitivity and specificity of radioisotope renography in renovascular hypertension.

Effective drug therapy for hypertension modifies the urgency of establishing a diagnosis of renal arterial stenosis. The cost of establishing a diagnosis must be considered with other factors in determining the usefulness of renography in renovascular hypertension. Recently published studies estimate the cost effectiveness of this procedure based on some data from a cooperative study of renal vascular hypertension. The small but costly incidence of false positives contributes significantly to the total cost of patient screening. Careful attention to technical details that are presented here could reduce false positives without sacrificing the true positives. However, even with increased specificity economic considerations would indicate limiting a screening program to younger patients or those in whom a drug regimen is unsuccessful.