The role of technetium-99m iminodiacetic acid (IDA) cholescintigraphy in acute acalculous cholecystitis.

Technetium-99m iminodiacetic acid (IDA) cholescintigraphy was performed in 15 patients with acute acalculous cholecystitis. Fourteen of the 15 patients with acute disease had positive findings, indicating the presence of cystic duct or common duct obstruction. One case in which the gallbladder was visualized failed to respond to sincalide stimulation; this was classified as a suggestive finding of disease. The diagnostic accuracy of 99mTc-IDA cholescintigraphy was far superior to the other imaging studies used (8 sonograms, 1 intravenous cholangiogram, 3 oral cholecystograms, 1 percutaneous transhepatic cholangiogram). The 99mTc-IDA study is recommended as the imaging procedure of choice for examining patients with suspected acute acalculous cholecystitis.

Evaluation of the postoperative patient with 99mTc-IDA cholescintigraphy.

In order to assess the role of 99mTc-iminodiacetic acid (IDA) cholescintigraphy in evaluating postoperative patients, a total of 213 studies were performed in 189 patients over a 3-year time period. Of these, 130 studies were obtained in 125 cases with signs and/or symptoms suggesting postcholecystectomy syndrome. A normal sized duct that emptied within an hour ruled out significant pathology with a high degree of accuracy (97%). A less reliable finding of normalcy was the combination of ductal dilatation with functional patency in that three of 20 patients (15%) who exhibited this pattern were proven to have nonobstructing calculi in their common bile duct. AZ spectrum of abnormal findings was encountered. Ductal dilatation was a most significant indicator of partial or intermittent ductal obstruction when it was associated with altered time-activity dynamics in the ducts and secondarily, delayed biliary-to-bowel transit time of the radiotracer. Patterns indicating complete common duct obstruction, cystic duct remnants, and bile leaks also proved to be very sensitive. Seventy-three studies in 56 patients very accurately evaluated the integrity of biliary-enteric bypass anastomosis. Complete and partial obstructive patterns were similar in appearance to those encountered in postcholecystectomy syndrome. Several leaks were also detected in this patient population. Ten studies were performed in eight patients who underwent Billroth II gastroenterostomies primarily to see if afferent loop obstruction was present. Three of these patients did demonstrate dilated A-loops with stasis, thereby making a positive diagnosis possible.

Choledochal cyst complicated by acute cholecystitis and bypass obstruction: diagnostic role of Tc-99m-HIDA cholescintigraphy.

An unusual case of malignant degeneration of a choledochal cyst is presented. The presence of acute cholecystitis with the cystic duct originating from the cyst as well as the subsequent obstruction of the cyst-jejunal surgical anastomosis was readily detected with Tc-99m-dimethyl-iminodiacetic (Tc-99m-HIDA) cholescintigraphy.

Role of cholecystokinetic agents in 99mTc-IDA cholescintigraphy.

Cholecystokinin (CCK) and its C-terminal octapeptide analog, Sincalide, have been utilized in two separate roles for the evaluation of gallbladder disease. These are: (1) prior to cholescintigraphy to evacuate the gallbladder and optimized subsequent filling with radiotracers, and (2) to study contractile function of visualizing gallbladders on cholecystography and cholescintigraphy. As a preparation for 99mTc-IDA studies, it clearly facilitates earlier gallbladder filling in patients with chronic cholecystitis, thereby ruling out complete cystic duct obstruction. The problem lies in the fact that the use of CCK as a premedication markedly decreases the sensitivity of the study to detect chronic cholecystitis, since the findings become indistinguishable from patients with normal gallbladders. For this reason, the authors prefer to obtain delayed images, since chronic cholecystitis is frequently associated with gallbladder filling beyond the first hour. The role of CCK in detecting abnormal gallbladder function in the normally visualizing gallbladder also is controversial. Other studies as well as the author's experience suggests that as much as one-forth of positive cases may be associated with normal gallbladders at surgery and often even on microscopic examination. However, most importantly, the great majority of these patients are relieved of their symptoms following surgery. It appears reasonable that CCK or Sincalide cholecystography or cholescintigraphy may be detecting functional abnormalities before anatomic changes occur and can, therefore, serve as a useful examination in selecting symptomatic patients who may benefit from cholecystectomy.

Scintigraphic features of cavernous transformation of the portal vein.

A case of portal vein obstruction with cavernous transformation is presented, in which findings on both Tc-99m-sulfur colloid and HIDA liver scintigrams suggested the diagnosis. These findings included a focal hyperconcentration of colloid on the former and notching of the common bile duct as well as "draping" of the right hepatic duct on the latter. All of these findings were shown at angiography and surgery to be secondary to extensive venous collateral vessels related to portal vein obstruction.

Spectrum of 99m-Tc-IDA cholescintigraphic patterns in acute cholecystitis.

Cholescintigraphy with 99m-Tc labeled iminodiacetic acid (IDA) derivatives has proved to be extremely reliable in the evaluation of suspected acute cholecystitis. The major diagnostic feature of the study is the presence (cystic duct patency) or absence (cystic duct obstruction) of gallbladder visualization. Secondary findings include degree and rate of liver uptake, visualization and caliber of the intrahepatic and common bile ducts, and the presence of intestinal activity as well as rapidity of biliary tract-to-bowel transit of the radiotracer. Various combinations of these secondary parameters result in a spectrum of cholescintigraphic patterns which can assist in determining the cause of the patient's acute clinical problem.

Radionuclide imaging and computed tomography in renal oncocytoma.

Renal oncocytoma is an apparently benign neoplasm that is being reported with increasing frequency. It is important to differentiate it from renal-cell carcinoma prior to surgery. Angiographic, CT, and ultrasound studies may suggest the diagnosis but are not pathognomonic. In 4 cases, 99mTc-glucoheptonate imaging of the renal tubules was performed; one patient was also scanned in 131I-orthoidohippurate. There was no evidence of radionuclide uptake by the tumor. Reasons for the lack of success in differentiating renal oncocytoma from renal-cell carcinoma are discussed.

Role of 99mTc-IDA cholescintigraphy in evaluating biliary tract disorders.

Technetium-99m IDA cholescintigraphy has provided a new, noninvasive means of visualizing biliary tract function. It has become the procedure of choice in patients with suspected acute cholecystitis because of its ability to most accurately detect functional obstruction or patency of the cystic duct as opposed to ultrasound's ability to detect only anatomic changes such as the presence of calculi or a thickened gallbladder wall. These latter findings are more important in establishing the diagnosis of chronic cholecystitis where ultrasound shares a position of prime importance with the oral cholecystogram. Tc-99m IDA cholescintigraphy has also been particularly useful in evaluating bile leaks, biliary-enteric anastomosis patency and the post-cholecystectomy patient with recurrent pain. In the patient with cholestasis, ultrasound is usually the procedure of choice since it establishes whether or not ductal dilatation is present and frequently can determine the cause of obstruction. Cholescintigraphy has played an ancillary role in many cases by demonstrating the level of partial obstruction, but it does not have the anatomic resolution to visualize the cause of obstruction. Occasionally, in the evaluation of cholestasis, cholescintigraphy has proven to be the only modality which has identified the presence of acute common duct obstruction or localized intrahepatic ductal obstruction. All in all, Tc-99m IDA cholescintigraphy has had a dramatic impact upon hepatobiliary diagnosis.

Myocardial visualization on a perfusion lung scan.

Myocardial activity was noted on a lung scan performed following the i.v. administration of Tc-99m macroaggregated albumin. The patient had primary pulmonary hypertension with a right-to-left shunt through a functionally patent foramen ovale.

Serendipity in technetium-99m dimethyl iminodiacetic acid cholescintigraphy: diagnosis of nonbiliary disorders in suspected acute cholecystitis.

Technetium-99m dimethyl iminodiacetic acid cholescintigraphy has contributed significantly to the diagnosis of acute and chronic biliary tract disorders. Yet attention should also be focused on the other structures visualized during the blood pool, hepatocyte, renal excretory, and intestinal phases of the study. Nonbiliary pathology was detected in 42 of 294 patients (14.3%) studied for suspected acute cholecystitis. The serendipitous detection of previously unsuspected abnormalities assisted in directing further work-up from suspected biliary disease and towards the real source of the patient's acute problem in 28 cases (9.5%).