Role of radionuclide perfusion study in cold solitary thyroid nodule for diagnosis of malignancy: a complimentary diagnostic modality to fine needle aspiration cytology.

One hundred and forty eight subjects with euthyroid solitary thyroid nodules (STN) were taken up for radionuclide perfusion study. They were found to have a cold STN on 99mTc thyroid static scan. All had fine needle aspiration cytology (FNAC), and except for subjects with chronic lymphocytic thyroiditis, were subjected to surgery for tissue diagnosis by histopathology. The diagnostic findings in these patients of solitary thyroid nodules were correlated with the histopathology. Radionuclide perfusion study is considered useful to differentiate benign from malignant cold thyroid solitary nodules with high degree of sensitivity (95%) and specificity (87.9%).

Evaluation of functional parameters and left ventricular size by radionuclide ventriculography (RNV) in myocardial infarction patients.

Functional parameters like left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and left ventricular size index were evaluated in 68 patients with myocardial infarction and in 50 normal subjects, by radionuclide ventriculography (RNV). Patients were divided into four groups (I to IV) according to increasing left ventricular size and the parameters were evaluated in each group. LVEF proved to be the most sensitive parameter of overall left ventricular performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that in extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a greater fall in left ventricular compliance. LV size and performance were least affected in inferior wall myocardial infarction. LVEF was however a better predictor of LV size than the site of the myocardial infarction.

Non-invasive evaluation of global ventricular functions in coronary artery disease by exercise radionuclide angiocardiography.

Rest and exercise radionuclide angiocardiographic measurement of left ventricular functions were obtained in 12 normal subjects (group I) and 42 patients with well documented coronary artery disease (group II). Additionally thirty-five patients had an exercise tread mill test. Resting left ventricular ejection fraction less than 50% provided the greatest diagnostic information. Exercise was induced by supine bicycle exercise ergometer. In group II 32 patients of coronary artery disease with normal global ventricular function at rest, new regions of dysfunction developed during exercise and global ejection fraction fell by 8 to 15 percent while in group I there was an increase in LVEF and no areas of any ventricular wall motion abnormalities were detected. Exercise radionuclide angiocardiography is a useful non invasive technique which permits accurate assessment of the presence and functional severity of coronary artery disease.