Differential diagnosis of jaundice by 99mTc-IDA hepatobiliary imaging

Acute cholecystitis, biliary obstruction, and biliary leakage

The use of cholescintigraphy to diagnose acute cholecystitis, biliary obstruction, and biliary leakage dates back to the late 1970s. Today, despite the many advances in imaging instrumentation, radiopharmaceuticals, and methodology over these years, cholescintigraphy still plays an important role in confirming or excluding these diagnoses in acutely ill patients. Acute calculous and acalculous cholecystitis, gallbladder perforation, biliary obstruction, and biliary leakage often present as acute abdominal pain, and must be differentiated from other surgical and nonsurgical etiologies with similar symptoms and presentation. Understanding the pathophysiology of acute hepatobiliary diseases is vital for deciding on the most advantageous imaging work-up and for interpretation of the studies. To optimize the value of cholescintigraphy, up-to-date methology, proper use of appropriate pharmacologic interventions, and recognition of characteristic image findings are critical.

Evidence of impaired gallbladder function in patients with non-insulin-dependent diabetes mellitus by quantitative cholescintigraphy

Non-insulin-dependent diabetes mellitus (NIDDM) is considered to predispose impaired gallbladder function and an increased prevalence of gallbladder disease. The aim of this study was to evaluate the gallbladder function of patients with NIDDM by quantitative technetium-99m-labeled imino-diacetic acid analogue (Tc-99m DISIDA) cholescintigraphy. One hundred and forty-five NIDDM patients (100 males, 45 females; age: 58.7+/-9.5 years) with the absence of autonomic or peripheral neuropathy and without gallbladder or liver disorders were enrolled in this study. The patients were categorized by blood sugar control (HbA(1c)> or =10% as a poor blood sugar control group and HbA(1c)<10% as a good blood sugar control group) and disease duration (diabetic duration > or =10 years as a longer-duration group and diabetic duration <10 years as a shorter-duration group). In addition, 60 normal controls (38 males, 22 females; age: 59.1+/-10.2 years) were also studied for comparison. All NIDDM patients and normal controls underwent Tc-99m DISIDA cholescintigraphy, and the filling fraction (FF) and ejection fraction (EF) of gallbladder were calculated. The results showed significant difference between (1) NIDDM patients versus normal controls in FF and EF, (2) poor versus good blood sugar control of NIDDM patients in FF and EF, and (3) longer versus shorter disease duration of NIDDM patients in FF and EF. Our study, including a large number of subjects, showed that gallbladder function of patients with NIDDM is more impaired than the normal controls; and impaired gallbladder function in NIDDM patients is related to disease duration and blood sugar control.

Assessment of the biliary tract after liver transplantation: T tube cholangiography or IODIDA scanning

Biliary tract obstruction or anastomotic leakage are common problems following liver transplantation. In a sequential study, 31 patients with a liver transplant were investigated by 99mTc-IODIDA (IODIDA) scanning and T tube cholangiography (TTC) and the results were compared with clinical outcome. Seven patients had an extrahepatic biliary obstruction and one patient had a biliary leak. In the detection of biliary complications TTC and IODIDA scanning were similar in terms of sensitivity (63 per cent for both) but TTC had a better specificity (79 per cent versus 60 per cent) and accuracy (74 per cent versus 60 per cent) than IODIDA scanning. When liver function was taken into account, the diagnostic efficacy of both tests in patients with bilirubin levels of less than 200 mumol/l was similar. With levels greater than 200 mumol/l there was a greater number of false positive results with IODIDA scanning (12 per cent versus 54 per cent). The only significant biliary leak was clearly detected by TTC but not IODIDA scanning. TTC remains the more effective way of evaluating the biliary tract after transplantation. IODIDA scanning has limited value when bilirubin levels are elevated, but may provide additional information about blood supply, hepatocyte function and intrahepatic cholestasis.

99mTc-PIPIDA cholescintigraphy in the diagnosis of gallbladder disease

The efficacy of 99mTc cholescintigraphy in the diagnosis of gallbladder disease was studied in 116 patients. Sixty-one demonstrated gallbladder visualization (normal) and 55 had nonvisualization. In patients with acute abdominal pain, test sensitivity is 100%, specificity is 77%, and accuracy is 83% for the diagnosis of acute cholecystitis; no patient with gallbladder visualization had acute cholecystitis. Test sensitivity for any form of gallbladder disease is 66%, specificity is 82%, and accuracy is 71%; excluding patients with laboratory evidence of hepatobiliary disease, the predictability of acute or chronic cholecystitis increases to 100%. Cholescintigraphy demonstrated common bile duct patency in all eight post-cholecystectomy patients referred for evaluation of possible choledocholithiasis. Thus, gallbladder visualization with 99mTc-PIPIDA virtually excludes the diagnosis of acute cholecystitis, an abnormal test is a good predictor of gallbladder disease because of high specificity, and cholescintigraphy is extremely safe and simple to perform and may be used to demonstrate common bile duct patency.

Radionuclide scanning for the rapid diagnosis of acute cholecystitis

Radionuclide scanning with Technetium 99-m HIDA was performed in eighty-nine patients with suspected acute cholecystitis. In twenty-three patients (25.8%), the study demonstrated evidence of cystic duct obstruction and non-visualisation of the gallbladder. Almost all of these patients subsequently were shown to have acute cholecystitis at surgery. The sensitivity and specificity of the procedure for the diagnosis of acute cholecystitis was 95.8% and 100% respectively. The use of radionuclide cholescintigraphy in the assessment of hepatobiliary disorders is reviewed, and it is suggested that it is the test of choice at present for diagnosis of acute cholecystitis.

Utility and accuracy of ultrasonically measured gallbladder wall as a diagnostic criteria in biliary tract disease

Biliary tract sonography has achieved wide acceptance as a screening test for chronic calculous disease. However, the clinical usefulness of biliary sonography is limited by the inability of this test to identify patients with acalculous cholecystitis or to separate patients with calculous cholecystitis from those with asymptomatic calculi. A prospective blinded study of 106 patients undergoing cholecystectomy was performed to determine if, cholecystosonography could visualize the gallbladder wall accurately and to evaluate gallbladder wall thickening as a predictor of disease. Of these patients, 88 had a sonographically visible gallbladder wall and in 95% of the patients the ultrasonic and direct surgical measurements of the gallbladder wall agreed within 1 mm. To determine the sonographic size range of gallbladder wall thickness in the normal population, the width of the gallbladder wall in the fasting state was measured in 100 patients without biliary tract disease. One percent of the normal population had thickened gallbladder walls, in contrast to 96% of the patients with acute calculous or acalculous cholecystitis. Gallbladder wall thickness appears to be an accurate noninvasive technique for diagnosing patients with acute calculous and acalculous cholecystitis in the absence of other entities which thicken the gallbladder wall such as ascites and hypoproteinemic states.

Current aspects of nuclear imaging in clinical oncology

This presentation will focus on the recent developments in nuclear medicine that relate to diagnosis and staging in the cancer patient. The commercial availability of new Agar cameras as well as longitudinal tomographic scanning devices has improved gallium imaging significantly. This has enhanced tumor detection and resulted in better use of gallium scanning in the cancer patient. Areas of controversy have also developed. In particular, the question of whether or not the gallium scan can be used to avoid mediastinoscopy in some case of bronchogenic carcinoma will be detailed. Techniques in nuclear medicine must be carefully integrated with other noninvasive investigation such as CT and ultrasound. At Yale, the authors have gathered considerable data indicating the best way to interact nuclear medicine radionuclide scintigraphy of the liver with the ultrasound examination. Our approach to this problem for the detection of focal disease in the liver will be discussed. 99mTc-HIDA has been proven useful in a wide variety of biliary disorders. Use of scintigraphy in the evaluation of cholangio-enteric bypass procedures in the cancer patient will be reviewed.