Author + information
- Received November 30, 1982
- Revision received January 24, 1983
- Accepted March 2, 1983
- Published online July 1, 1983.
- Duncan S. Dymond, MD, MRCP*,1,
- Alex T. Elliott, PhD, MInst P*,
- William Flatman, BA, MSc*,
- David Stone, MB, MRCP*,
- Rodney Bett, BSc, PhD†,
- Gary Cuninghame, BSc, ARCS, FRSC† and
- Howard Sims, BSc, PhD†
- ↵1Address for reprints: Duncan S. Dymond, MD, Department of Cardiology, St. Bartholomew's Hospital, London EC1A 7BE, England.
With technetium-99m radiopharmaceuticals, first pass radionuclide angiocardiography is of limited use for multiple intervention studies because of the large radiation burden imposed on the patients. A portable mercury-195m/gold-195m generator has been developed capable of producing 17 to 20 mCi aliquots of the short half-life (30.5 seconds) gold-195m in less than 0.5 ml of generator eluate. Safety of the eluate has been established both in the experimental animal and in human beings.
Fifteen patients underwent two first pass radionuclide angiograms with gold-195m, followed by a standard technetium-99m study. There was a close correlation between the left ventricular ejection fraction measured from gold and technetium studies (correlation coefficient [r] = 0.99, standard error of the estimate [SEE] 3.1%). Interobserver and sequential reproducibility of gold studies were excellent (mean variability ± standard deviation [SD]2.0 ± 2.9 and 0.6 ± 2.7%, respectively). Statistical reliability of the gold studies, as assessed from the observed left ventricular end-diastolic counts, matched that of technetium studies, and similarly, the images obtained from the two radiopharmaceuticals were identical. Residual count rates 5 minutes after first pass acquisition with gold were 480 ± 140 counts/s in the whole field of view, and 50 ± 30 counts/s over the left ventricle, these values being less than 1% of the residual counts after technetium.
Accurate, reproducible, high count-rate first pass studies are obtainable with gold-195m, with a markedly reduced radiation exposure to the patients. It is now possible to perform rapid sequential first pass cardiac imaging studies without the constraints of an unacceptable high radiation burden.
- Received November 30, 1982.
- Revision received January 24, 1983.
- Accepted March 2, 1983.
- American College of Cardiology Foundation