Can the estimation of ejection fraction during gated single photon emission computed tomography at rest add information to the cardiac perfusion study?

Left ventricular function is an important prognostic indicator in patients with coronary artery disease. The electrocardiogram gated, myocardial, single photon emission tomography (SPECT) program is coming into wide use. This program permits measurement of end diastolic volume, end systolic volume, and ejection fraction. This study was designed to show whether the measurement of ejection fraction by using (99c)Tc tetrofosmin gated SPECT at rest could give additional information to the interpretation of perfusion. Exercise 99mTc tetrofosmin SPECT and gated (99c)Tc tetrofosmin SPECT at rest were performed in 33 patients with or suspected of having coronary artery disease. Left ventricular ejection fraction was calculated from reconstructed gated SPECT at rest with a software quantitative gated SPECT. The results showed a poor correlation between segmental ejection fraction and segmental perfusion in stress and rest. There was an increasing probability of reversibility as the ejection fraction increased, while there was a greater chance of a fixed defect as the ejection fraction decreased. It is concluded that gated SPECT using (99c)Tc tetrofosmin provides clinically satisfactory functional data that, in combination with the perfusion information, will improve diagnostic and prognostic accuracy without an increase in cost or radiation dose to patients.

Radionuclide assessment of patients with urinary tract infection and vesico-ureteric reflux using tc-99m-dimercaptosuccinic Acid.

The purpose of this study was to evaluate pediatric patients with urinary tract infection and to identify the risk of developing renal scarring and its relationship to the presence of vesico-ureteric reflux. The subjects in this study were 29 pediatric patients between two months and 11 years of age with a history of urinary tract infection among which 69% were females. All the patients underwent radio-isotope scanning using Technetium-99-m-dimercaptosuccinic acid, 4-6 weeks after the eradication of the acute infection. Micturating cysto-urethrography and renal ultrasound examinations were performed before the radio-isotope scanning. Isotope scanning showed evidence of scarring in 34% of the kidneys, while ultrasound scanning was positive in only 29% of the kidneys. The agreement between the results of the two examinations was in 88% of the kidneys. Reflux was noted in 53% of the kidneys of which 62% showed scarring by isotope scanning. Only 11% of the kidneys with no reflux showed evidence of scarring, while 92% of kidneys with severe reflux had renal scarring. In patients with reflux, 57% of the kidneys in female patients and 50% of the kidneys in male patients developed renal scarring evident on DMSA scanning. Absence of reflux had a high predictive value for absence of renal scarring, while the presence of reflux did not necessarily imply the presence of renal scarring but the possibility increased with the severity of reflux.