Victor W. Lee

Sensitivity of technetium-99m-pyrophosphate scintigraphy in diagnosing cardiac amyloidosis

To determine the value of technetium-99m-pyrophosphate myocardial scintigraphy in the diagnosis of amyloid heart disease this procedure was prospectively performed in 20 consecutive patients with biopsy-proven primary amyloidosis. Eleven patients had echocardiographic abnormalities compatible with amyloid cardiomyopathy, 9 of whom had congestive heart failure. Diffuse myocardial pyrophosphate uptake was of equal or greater intensity than that of the ribs in 9 of the 11 patients with echocardiograms suggestive of amyloidosis, but in only 2 of the 9 with normal echocardiograms, despite abnormal electrocardiograms (p less than 0.01). Increased wall thickness measured by M-mode echocardiography correlated with myocardial pyrophosphate uptake (r = 0.68, p less than 0.01). None of 10 control patients with nonamyloid, nonischemic heart disease had a strongly positive myocardial pyrophosphate uptake. Thus, myocardial technetium-99m-pyrophosphate scanning is a sensitive and specific test for the diagnosis of cardiac amyloidosis in patients with congestive heart failure of obscure origin. It does not appear to be of value for the early detection of cardiac involvement in patients with known primary amyloidosis without echocardiographic abnormalities.

Cardiac technetium-99m pyrophosphate scintigraphy in familial amyloidosis.

Recent studies have shown that in patients with biopsy-proved primary amyloidosis and echocardiographic features compatible with amyloid infiltration, technetium pyrophosphate scintigraphy of the heart is frequently positive. 1 However, in a small series of patients with secondary amyloid and evidence of heart disease, cardiac pyrophosphate uptake was absent. 2 Familial amyloidosis is a rare autosomal-dominant condition that may also affect the heart, although cardiac symptoms are uncommon) It is not known whether patients with familial amyloid and evidence of cardiac involvement have positive scans. We therefore report our experience with pyrophosphate scintigraphy in this disease.

Specific diagnosis of hepatoma using 99mTc-HIDA and other radionuclides

The difficulty of clinical and radiographical diagnosis of hepatoma is discussed. A case of hepatoma is reported. Both the primary tumor and distant metastases showed strong avidity for 99mTc-HIDA, which normally is concentrated by parenchymal cells of the liver. The potential of using 99mTc-HIDA for the noninvasive investigation of patients suspected of having hepatoma is discussed. The association between tumor avidity for 99mTc-HIDA and the bile-forming ability of tumor cells is of interest.

Occult gastric bleeding demonstrated by bone scan and Tc-99m-DTPA renal scan.

A patient is described who had coagulopathy and clinically intermittent gastrointestinal bleeding. The bleeding site was clearly shown on renal and bone imaging performed at a time when the patient was considered clinically to have stopped bleeding. A bleeding gastric ulcer was subsequently demonstrated by radionuclide and contrast angiography, and at surgery.

The specific diagnosis of hepatocellular carcinoma by scintigraphy: multiple radiotracer approach

The accuracy of scintigraphy in diagnosing hepatocellular carcinoma (HCC) at Boston City Hospital between January 1, 1978 and September 30, 1983 is retrospectively reviewed. A combined protocol using technetium‐99m sulfur colloid (TsSC), gallium (Ga), and scintiangiography (STA) was employed in order to enhance diagnostic specificity. There were 14 cases of HCC, of which 10 were proven histologically. The others were diagnosed clinically and angiographically. With one exception, all patients who had triple tracer scintigraphy showed a specific pattern of findings: (1) cold defects with TcSC; (2) Ga‐avid foci, and (3) increased vascular supply from hepatic arteries. One false‐positive study and one false‐negative study were originally reported, although in both cases, strict adherence to the three criteria above would have avoided diagnostic error. These results indicate that triple tracer scintigraphy may be an effective diagnostic test for HCC. The relative efficacy of scintigraphy, ultrasonography, and computerized tomography in diagnosing HCC is also discussed.

Gallium uptake in myositis ossificans. Potential pitfalls in diagnosis

Seven cases of gallium uptake in myositis ossificans are described. Gallium scans are done frequently in paraplegics, quadriplegics, and comatose patients to look for occult infection. It is important to be aware of possible gallium uptake in myositis ossificans, particularly in the extremities, which is frequent in these patients. Gallium uptake may be present prior to any abnormalities seen on plain films or CT scans. It is important to correlate roentgenograms with abnormal gallium scans, particularly in the extremities, to avoid potential pitfalls in diagnosis and prevent unnecessary antibiotic treatment. A bone scan should be obtained whenever possible, particularly when roentgenograms are negative, to confirm the diagnosis.

Renal amyloidosis. Evaluation by gallium imaging.

A study has been performed to evaluate the efficacy of gallium imaging in the detection of renal amyloidosis. Ten of the 11 patients who had biopsy-proven renal amyloidosis demonstrated marked uptake in both kidneys. One patient revealed moderate gallium uptake in his kidneys. None of the patients had underlying renal or extrarenal pathology other than amyloidosis, which could account for renal gallium uptake (renal infection, neoplasm, hepatic failure or frequent blood transfusions). Four patients also had extrarenal foci of abnormal gallium uptake, suggesting other sites of amyloid deposits. Our data strongly suggest that gallium imaging has a high sensitivity for detection of renal amyloidosis. Its specificity is enhanced significantly by careful review of the clinical history to exclude other known causes of renal gallium uptake. Potentially, gallium imaging may be used to monitor the progress of patients under experimental therapy.

The diagnosis of pneumothorax by radionuclide lung scan.

A case of pneumothorax diagnosed by ventilation-perfusion lung scintigraphy is reported. The diagnosis was not suspected clinically initially and a chest x-ray taken before the lung scan was also interpreted as normal.

Lesser sac cerebrospinal fluid collection. An unusual complication of a ventriculoperitoneal shunt.

Ventriculoperitoneal shunts provide an effective means of decreasing intracranial pressure and diverting cerebrospinal fluid (CSF). A variety of complications may be seen, however, with the peritoneal limb. This study describes the scintigraphic evaluation of a large intra-abdominal CSF pseudocyst and the migration of the shunt tip into the lesser peritoneal sac.

Primary tuberculosis diagnosed by gallium scan.

We report a case of tuberculosis which, although clinically unsuspected, was diagnosed on a 67Ga scan. It is well known that 67Ga scintigraphy may be used as an adjunct to radiography for assessing extent and localization of inflammatory activity and for follow-up and progression evaluation of diffuse granulomatous diseases such as sarcoid and tuberculosis.