Significance of skeletal uptake detected on radionuclide renal perfusion studies.

Since the introduction of Tc-99m labeled radiopharmaceuticals, flow studies have become a useful and readily performed component of renal nuclear medicine examinations. In addition to detecting aberrations of renal perfusion, a number of extrarenal abnormalities may also be surreptitiously detected. Three cases of hyperperfused skeleton, an extremely unusual finding which complements two previous reports in the literature, have recently been observed. All three of the patients, as well as the two previously described, had underlying neoplastic abnormalities. The appearance of perfused skeleton should therefore be recognized as suggesting the presence of underlying neoplastic disease. Considerable interest as to the etiology and magnitude of the increased skeletal perfusion exists. Measurements of normal marrow and osseous perfusion have been reviewed in order to better appreciate the magnitude of increase required for skeletal visualization on renal flow studies. Some considerations as to the etiology of this increase are offered.

Detection of postcardiotomy bacterial pericarditis with gallium-67 citrate.

A 46-year-old man who had undergone apical cardiac aneurysmectomy with a ventriculotomy graft and implanted automatic cardioverter-defibrillator electrodes, presented with fever, left-sided pleuritic chest pain, and a draining sinus. A Ga-67 scan was performed to aid in determining whether the infection was limited to the chest wall or if it had penetrated deeper to the cardiac structures. Uptake of gallium within the cardiac region, in association with minimal rib uptake of Tc-99m MDP, strongly supported the existence of infection within the pericardium. CT scan demonstrated a pericardial collection which under CT-guided aspiration proved to be purulent. Definitive surgical drainage was performed, and the patient was discharged 4 weeks postoperatively. Ga-67 imaging can provide an accurate and relatively rapid means of localizing infection in the postcardiotomy patient. A thorough bibliography of pericardial gallium uptake is provided.

The early diagnosis of common bile duct obstruction using cholescintigraphy.

The technetium Tc 99m-labeled iminodiacetic acid cholescintigram is an extremely accurate examination for detecting early obstruction of the common bile duct in acutely ill patients suspected of having acute cholecystitis or possible obstruction days to years after cholecystectomy. The examination accurately detected common bile duct obstruction in 63 of 65 patients in these two diagnostic categories (positive predictive value, 96.9%). Sonographic evaluations in 43 of these patients failed to reveal ductal dilatation or other abnormality in 26 cases (false-negative rate, 63.4%), and was nondiagnostic because of overlying bowel gas in two cases. The success of the radionuclide examination is attributed to its ability to detect functional impedance to bile flow hours to days before anatomic ductal dilatation occurs, and occasionally even before the alkaline phosphatase level and other liver chemistry values suggest the presence of an obstruction.

The use of water ingestion to distinguish the gallbladder and duodenum on cholescintigrams.

Cholescintigraphic diagnosis of acute cholecystitis requires accurate assessment of gallbladder nonvisualization. Confusion may occur when the gallbladder overlies the duodenal sweep or when labeled bile pools in the duodenum. Gallbladder activity could not be differentiated from duodenal activity in 21 patients. The oral ingestion of 225 ml of water permitted successful differentiation of the gallbladder from the duodenum. In 25 control subjects, it was demonstrated that that volume of water did not have a cholecystokinetic effect.

Acute acalculous cholecystitis.

Sixty-eight patients with acute acalculous cholecystitis were reviewed. The results of history and physical examinations were usually nondiagnostic. IDA cholescintigraphy (93 per cent accuracy rate) was the only reliable diagnostic modality. The results of oral cholecystography, intravenous cholangiography and ultrasonography were considerably less reliable. One-half of the patients had gangrenous cholecystitis. Cholecystectomy was the preferred operation with an over-all mortality of 9 per cent. IDA cholescintigraphy is an important new modality for the diagnosis of acute acalculous cholecystitis which, in the past, has often been difficult to diagnose.

Gallstone ileus diagnosed by technetium-99m dimethyliminodiacetic acid cholescintigraphy. A case report.

Tc-99m IDA cholescintigraphy frequently provides information regarding nonbiliary pathology, such as small bowel obstruction. The cholescintigraphic finding of functional cystic duct obstruction concomitant with persistent small bowel dilatation and lack of progression of labeled bile suggests the diagnosis of gallstone ileus.

The radionuclide detection of lower gastrointestinal bleeding sites.

A retrospective review of two years' experience with radionuclide screening to detect lower gastrointestinal bleeding sites was conducted at New York's Montefiore Medical Center. Of 82 studies performed in 63 patients, 13 identified active bleeding sites. Only three of eight angiograms obtained in these 13 patients were positive. Thirteen contrast angiograms were performed in the group of 50 patients with negative radionuclide studies of which ten were negative and one was equivocal. The results of this study suggest that the Tc-99m sulfur colloid study for active lower gastrointestinal (GI) bleeding is an effective screening procedure. Positive studies help determine which vessel to catheterize selectively if an angiogram is to be performed. If vascular ectasis is still suspected following a negative radionuclide study, contrast angiography can be more efficaciously performed on a nonemergent basis.

Role of Tc-99m IDA scintigraphy in the evaluation of hepatobiliary trauma.

Each year approximately 52 million Americans are injured, of which 11 million require hospitalization and 110,000 die. This has an associated health care cost of 3 billion dollars. Hepatobiliary injuries have always constituted a significant area of involvement. They have become more easily detectable since the advent of technetium-99m analogs of iminodiacetic acid (IDA). Biliary leakage secondary to other causes, such as inflammation, neoplasm, and iatrogenic factors are also well demonstrated in a safe, simple, and rapid manner with radionuclide imaging. The relatively low patient radiation dose that is associated with these procedures permits follow-up studies when necessary.

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.

The radiological diagnosis of gallbladder disease. An imaging symposium.

Changes in the radiological diagnosis of gallbladder disease are occurring at a remarkable rate. In this symposium, several recognized authorities place the various diagnostic modalities and their interrelation in modern perspective. The present and future roles of oral cholecystography and intravenous cholangiography, the radiological diagnosis of chronic acalculous cholecystitis, and the use of ultrasonography and cholescintigraphy are analyzed.

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.