ABSTRACT
To test the sensitivity and specificity of technetium-99m stannous pyrophosphate myocardial imaging in the diagnosis of acute myocardial infarction, myocardial scintigrams were performed in 115 patients. Positive scintigrams were found in all 48 patients with acute myocardial infarction; uptake was localized in 29 patients with transmural infarction and diffuse in 2 patients with transmural infarction and in the remaining 17 patients with subendocardial myocardial infarction. Positive scintigrams were also found in 31 of 67 patients without clinical evidence of acute myocardial infarction. Diffusely positive scintigrams were found in 3 of 3 patients with unstable angina pectoris, 7 of 30 patients with stable angina pectoris, 4 of 13 patients who had undergone aortocoronary bypass surgery, 4 of 4 patients with congestive cardiomyopathy and 1 patient studied 1 day after direct current cardioversion. Localized uptake of 99mTc-pyrophosphate was found in 9 of 10 patients with left ventricular aneurysm and in 3 of 13 patients after aortocoronary bypass surgery. All four patients with atypical chest pain and two patients with pericarditis had normal scintigrams. Our data confirm the previously reported sensitivity of 99mTc-pyrophosphate imaging in detection of acute myocardial infarction but indicate that positive scintigrams are not specific for this entity.
Subject(s)
Myocardial Infarction/diagnosis , Radionuclide Imaging , Adult , Aged , Angina Pectoris/diagnosis , Aspartate Aminotransferases/blood , Creatine Kinase/blood , False Positive Reactions , Heart Diseases/diagnosis , Humans , L-Lactate Dehydrogenase/blood , Middle Aged , Technetium , Tin PolyphosphatesABSTRACT
Thyroid scans were performed at 4 and 24 hr after administration of Na123I solution in 124 examinations. The 4-hr and 24-hr scans were found to be of equal diagnostic value. Thus, in individuals with structural thyroid abnormalities, one can effectively reduce the time required for scan evaluation from the standard 24 hr to 4 hr.
Subject(s)
Iodine Radioisotopes , Radionuclide Imaging/methods , Thyroid Diseases/diagnosis , Humans , Time FactorsABSTRACT
Sixty-four patients with well-differentiated carcinoma of the thyroid were treated with initial high (80 to 100 mCi) or low (less than 30 mCi) doses of I131 after bilateral subtotal thyroidectomy. A total of 36 patients in the various histologic categories were initially treated with the low dose of I131 (group 1), and a total of 28 patients were treated with the higher dose (group 2). Disease-free criteria were no visible tissue in the neck or body, a protein-bound radioactive iodine (PBI131) of less than 0.005 per cent per liter at seven days and/or whole body retention of less than 3 per cent at seven days. Of the patients receiving less than 30 mCi (group 1), 56 per cent with papillary carcinoma, 67 per cent with follicular carcinoma and 56 per cent with mixed carcinoma of the thyroid were rendered disease-free after this initial dose. Of the patients receiving the higher dose of I131 (group 2), 67 per cent with papillary carcinoma, 50 per cent with follicular carcinoma and 67 per cent with mixed carcinoma of the thyroid were rendered disease-free after this initial dose. Disease-free mean follow-up time was 5.17 years (group 1) and 5.82 years (group 2). There was no statistical difference in these mean follow-up times, nor was there a statistical difference in the net (total minus initial) dose of I131 needed to render the patient disease-free. These data demonstrate that low dose I131 therapy is as effective as the larger more routine doses of I131 given in this disease.
Subject(s)
Adenocarcinoma/radiotherapy , Carcinoma, Papillary/radiotherapy , Iodine Radioisotopes/therapeutic use , Thyroid Neoplasms/radiotherapy , Adenocarcinoma/surgery , Adolescent , Adult , Carcinoma, Papillary/surgery , Female , Follow-Up Studies , Humans , Iodine Radioisotopes/administration & dosage , Male , Middle Aged , Thyroid Neoplasms/surgery , ThyroidectomyABSTRACT
Nineteen patients, representing a spectrum of thyroid function, were studied. The mean 24-hr thyroid 131I uptakes determined by a standard counting procedure and by our scintillation camera counting method were 15.0% and 16.4%, respectively, for the entire patient population. The 24-hr 131I uptakes from these two methods correlated with a coefficient of 0.99. A high degree of correlation between the two methods was found in evaluating euthyroid and hypothyroid patients and a similar finding was noted in the one hyperthyroid patient studied.
Subject(s)
Iodine Radioisotopes , Radionuclide Imaging/instrumentation , Thyroid Function Tests/instrumentation , Adult , Female , Humans , Hyperthyroidism/diagnosis , Hypothyroidism/diagnosis , Male , Middle Aged , Scintillation Counting , Whole-Body CountingABSTRACT
To further explore the usefulness of technetium 99m pyrophosphate (99mTc-PYP) myocardial imaging and test its validity in the diagnosis of acute myocardial infarction, 99mTc-PYP myocardial scintigrams were performed in 50 patients. Out of 28 patients with acute myocardial infarction, myocardial scintigrams demonstrated localized activity in the 15 patients with transmural, and diffuse activity in the 13 patients with subendocardial myocardial infarction. Twenty-two patients with significant coronary artery disease documented by coronary angiography but without acute myocardial infarction were also studied. Nine of ten patients with clinical evidence of left ventricular aneurysm from previous myocardial infarction and definite left ventricular dyskinesis had positive scintigrams with activity localized to the site of the wall motion abnormality. Two of five patients without definite aneurysm but with left ventricular akinesis also had localized uptake in the involved area of the left ventricle. Seven patients with normal left ventricular wall motion had negative scintigrams. These findings suggest caution in interpreting positive 99mTc-PYP scintigrams as being indicative of acute myocardial infarction when evidence of a left ventricular aneurysm is also present.
