Nuclear Cardiology testing investigates the blood flow to the heart and heart’s function and produces no difficulty to the patient. All tests in Nuclear Cardiology should be completed within few hours during the day and do not require hospitalization. A radioactive agent is injected to the body at a low dose and energy, which is specifically developed in the laboratory and has no side effects or hazards. Since the agent is radioactive, these tests cannot be performed for pregnant women and some measures should be taken for nursing mothers.
Diagnostic Nuclear Medicine Tests In Cardiology and Cardiovascular Surgery:
The patients are prepared by treadmill or pharmacologic stress. Technetium 99m MIBI or Tl201 are used as radiopharmaceuticals. The methods of SPECT & Gated (matched with ECG) are used to obtain data at stress and rest. Sections are taken in transaxial, coronal and sagittal planes to form polar graphics. These graphics are used to examine perfusion of left ventricular myocardium and moves of heart wall. The entire procedure lasts 2-3 hours together with waiting periods.
Myocardial perfusion scintigraphy provides information, with over 90% of accuracy, about blood flow to the left heart by distribution and retention of radioactive test material to the left heart muscle through coronary vessels. ECG matching (Gated Spect) during imaging shows contraction characteristic of heart muscle and moves of heart wall.
In myocardial perfusion scintigraphy, the left ventricular areas that did not retain the radioactive material on the images after stress but retained on images of resting are considered ischemia and the areas that did not retain the radioactive material on the images of stress and resting are considered scar. Lack of moves of heart wall and contraction in areas indicating decrease in or absence of perfusion increases diagnostic value. Areas of use for this procedure shortly called:
MUGA and Gated MUGA – Labeled red blood cells are first distributed in the cardiac cavity then matched with ECG (by Gated method) to measure heart ejection fraction, moves of heart wall and volume of quantitative ED and ES heartbeats.
- Investigation of intracardial shunt and anomalies with First Pass technique – Labeled red blood cells provide investigation of cardiac left-right shunt and quantitative evaluation.
VSD (ventricular septal defect), PDA (patent ductus arteriosus), Fallot tetralogy , Transposition of Major Arteries are easily performed in congenital heart diseases, e.g. hypoplastic left ventricle syndrome, particularly in children.
Nuclear Medicine Tests That Can Be Used To Help Diagnosis In Cardiology And Cardiovascular Surgery: