When a doctor suspects that a patient has coronary artery disease, a heart scan may be ordered to visualize the blood flow into the heart. A heart scan, اسکن هسته ای قلب commonly referred to as an imaging test, uses various technologies like positron emission tomography (PET) scans, single photon emission computed tomography (SPECT) scans, and computed tomography (CT) scans to create detailed images of the heart and its blood vessels. These imaging tests are useful in helping doctors diagnose artery problems that may lead to heart attacks.
Understanding the results of a heart scan requires basic knowledge with some key concepts. Cardiac function and anatomy will be directly studied using cardiac imaging techniques. Imaging tests that reveal myocardial perfusion defects may suggest a lack of blood flow to the coronary arteries.
A typical heart scan typically involves injecting a small dose of radioactive material into the blood in order to evaluate cardiac blood flow. The injected radioactive material accumulates in areas of high blood flow, showing as brighter areas in images. This contrasts with damaged heart tissue which is seen as darker regions where there was once blood flow.
The results of a heart scan can be interpreted in two main categories: presence of blood vessel narrowing and structural heart changes.
Presence of blood vessel narrowing indicates a obstruction on blood flow. Typically reported as 'ischemia', narrowed or blocked coronary arteries reduce the normal heart's ability to pump in an efficient manner. Decreased perfusion as a whole can be classified according to a five-point scoring system.
Normal means there will be very little damage present, and no 'scarring' found through PET scans. Mild perfusion in the event of a PET scan refers to microvascular impairment - wherein blood flow is being reduced due to poor angiogenesis. Moderate describes regions of heart muscle which have a decreased rate of blood flow as well as the potential of further clinical progression if not assessed earlier. If further narrowing of arteries occurs in the region of decreased heart function, then it signifies severe damage in the final sector identified through standard 12-lead ECG evaluation that shows considerable perfusion blockade.
Additionally, the scans can help in monitoring the heart's function over time, typically through identifying 'remodeling' in cardiac muscles, meaning the overall shape change that happens progressively as heart function gradually changes over time.
It's also very trustworthy and best to refer your health professional in case a diagnosis seems close, whether your medical staff have a further procedure for an imaging test to ensure both you and your care team better understand the problem both clinically and how to resolve it.