Frank Vieras

Extrapulmonary localization of gallium in sarcoidosis.

This paper describes the spectrum of extrapulmonary localization of gallium in patients with sarcoidosis. The usefulness of Ga-67 scintiscans in detecting clinically occult lesions, in directing clinicians to accessible sites for biopsy, and in following the course of extrapulmonary sites of involvement with therapy is emphasized.

Preoperative Scintigraphic Detection of Cervical Metastases from Thyroid Carcinoma with Technetium-99m Pertechnetate

A young man with papillary-follicular thyroid carcinoma demonstrated clear visualization of cervical metastases from thyroid cancer on Tc-99m pertechnetate scintigraphy while exhibiting a palpably and scintigraphically normal thyroid gland. This is a very rare occurrence which demonstrates that Tc-99m pertechnetate scintigraphy is capable of detecting cervical metastases from thyroid carcinoma before the appearance of palpable thyroid nodules or defects on scintigraphy.

Radiation Induced Skeletal and Soft Tissue Bone Scan Changes

Intense thoracic soft tissue uptake and decreased bone uptake of 99 mTc-Sn-polyphosphate were demonstrated in a patient who had undergone 60Co radiotherapy for carcinoma of the lung. The changes are attributed to radiation effects and the distinction is made between tumor uptake in the chest and radiation induced increased soft tissue accumulation of the tracer.

Evolution of Acute Epididymitis to Testicular Infarction: Scintigraphic Demonstration

A case of acute epididymitis evolved into testicular infarction. Scrotal scintigraphy identified the initial epididymitis and subsequent evolution into infarction.

Diffuse Pulmonary Uptake of Indium-111 Chloride in Idiopathic Myelofibrosis

Unusual indium-111 accumulation and extramedullary hematopoiesis in the lungs of a patient with idiopathic myelofibrosis are described. The bone marrow scan taken 24 hours after intravenous injection of 111InCl3 faithfully depicted the abnormal distribution of marrow elements as assessed histologically at autopsy, thereby supporting the usefulness of 111InCl3 for marrow imaging.

Clinically Silent Brain Metastases: Can Radionuclide Scintigraphy Detect Them?

The role of static and dynamic radionuclide brain imaging in the detection of occult brain metastases was evaluated by reviewing the brain images and case histories of 136 patients with neoplastic disease (mostly lung cancer) who, at the time of the scintigraphic study, lacked clinical evidence of brain metastases. Static studies were normal in 121, equivocal in 13, and abnormal in 2. One of the patients with an abnormal study had dural metastases; the other had skull metastases. None of the 13 equivocal scans was found to be indicative of metastasic disease. Cerebral flood flow studies were performed in 99 of the 136 patients and all were negative for evidence of metastatic disease. The results of this study do not support the use of brain scintigraphy for routine screening of asymptomatic cancer patients.

Quantitation of differential renal function with Tc-99m MDP.

This study was designed to evaluate the usefulness of the bone tracer Tc-99m MDP for quantitative assesment of relative renal function as compared with renal imaging radiotracers used for that purpose. Differential renal function, i.e., the percent contribution each kidney makes to global renal function, was determined prospectively in 15 consecutive patients using Tc-99m MDP and a renal radionuclide tracer, either Tc-99m DTPA or Tc-99m GHA. Differential function was computed in all cases from the early (1–3 minutes) renal uptake of the tracers by region-of-interest analysis of the computer-acquired data. There was a high correlation between values of differential function obtained with Tc-99m MDP and those obtained with Tc-99m DTPA or Tc-99m GHA (r = 0.98, P < 0.0001). Qualitative assessment of the images revealed equivalent scintigraphic patterns in all patients. It is concluded that the early characteristics of renal handling of Tc-MDP are sufficiently similar to those of Tc-DTPA and Tc-GHA so that accurate estimates of differential renal function are possible with this agent, and that Tc-MDP-determined renal differential most likely reflects differential glomerular filtration rate.

Preliminary observations on the potential of 99mTc-sulfur colloid as a radiopharmaceutical for detection of deep vein thrombosis.

The potential usefulness of 99mTc-sulfur colloid (Tc-SC) as a radiopharmaceutical for thrombus detection was evaluated in an animal model of deep vein thrombosis. One hour after injection of Tc-SC and 24 hours after induction of thrombus formation, a mean thrombus-to-blood uptake ratio of 11.38 was obtained in 12 beagles. This ratio is high enough to allow external detection.

Clinical Experience With the 20-Minute 99mTc-Neck/Thigh Ratio: A Quick, Simple, Reproducible Test of Thyroid Function

Technetium-99m neck/thigh ratios were obtained in 110 patients referred for evaluation of thyroid function by injecting 2 mCl of 99mTc-pertechnetate intravenously and 20 minutes after injection, taking 1-minute counts over the neck and thigh with a standard radionuclide uptake probe. The Tc-99m neck/thigh ratio was: 1) normal in all 46 patients judged to be free of thyroid disease; 2) normal in 28 and elevated in 6 of 34 patients with nontoxic goiters; 3) elevated in all 12 untreated hyperthyroid patients; 4) normal in all 5 patients with hypothyroidism; and 5) reliable in monitoring response to therapy for hyperthyroidism. Correlation was higher with the 2-hour 131I thyroid uptakes (r = 0.987) than with the 24-hour uptakes (r = 0.826). The 20-minute 99mTc-neck/ thigh ratio is a quick, safe, simple reproducible and reliable thyroid function test for the diagnosis of hyperthyroidism, followup of treated hyperthyroid patients, and for the evaluation of nontoxic goiters. The test is not useful in hypothyroidism. It is a measure of the trapping function of the thyroid gland; elevated values are indicative of a hyperactive thyroid trapping mechanism.