CT Coronary Angiography
CT angiography is a bloodless examination of the coronary arteries with cross-sectional and three-dimensional images from a CT scanner. With CT coronary angiography, the visualization of the anatomy of the coronary vessels, the calculation of the degree of calcification of the walls of the arteries, the existence or not of atheromatous lesions as well as the degree of narrowing of the vessels is achieved . The average sensitivity of the test ( that is, to detect the truly sick ) reaches 97.2% and the specificity ( that is, the truly negative results ) reaches 84.7% to 87%. Based on these data, the test has a very good predictive value and accuracy .
- Indications for the examination are:
- Exclusion of significant lumenal stenoses in stable patients with suspected coronary stenoses but intermediate probability of disease before examination.
- Exclusion of coronary artery disease in acute chest pain .
- Coronary anomalies.
- Blocking stenosis before non- coronary surgery.
- Determining the patency of coronary artery bypass grafts.
- Use of computed tomography as an alternative method when cardiac catheterization is impossible or carries a high risk .
- Clarification of equivocal findings after interventional angiography.
- Providing perioperative information for percutaneous coronary intervention.
- Assessment of coronary artery stent patency .
- Determination of the presence and extent of coronary atherosclerotic plaque.
- Contraindications for the examination are divided into absolute and relative :
-Absolute contraindication is allergy-anaphylaxis to iodinated contrast agents and pregnancy .
-Related contraindications are:
- History of allergies to drugs or other substances.
- Renal dysfunction with creatinine >1.5 mg / dl .
- Congestive heart failure.
- History of thromboembolic events.
- Multiple myeloma .
- Unregulated hyperthyroidism .
- Phaeochromocytoma .
- Atrial fibrillation .
- Inability to hold breath for at least 15 seconds.
- Obesity – high body mass index.
- Ectosystolic ventricular arrhythmia .
- Anemia .
- Active infection .
- Tachycardia .
- History of receiving large amounts of radiation from previous examinations.
Possible side effects of the test may be:
- Nausea.
- Urticaria.
- Difficulty breathing.
- Redness.
- Itching.
- Burden of renal biochemistry.
- Radiation.
💡Necessary conditions for the examination are::
- Not consuming food and liquids a few hours before the examination. Especially energy drinks , coffee , tea and Coca-Cola should not be consumed for at least 12 hours before the examination.
- The removal of all metal objects .
- Placement of a venous line .
- The use of iodide contrast agent .
- The low heart rate and possibly the use of drugs for this purpose such as β-blockers.
- Possibly vasodilating substances such as nitrites .
- The examinee’s cooperation by holding his breath whenever asked, which can reach up to 20 seconds at a time.
It should be noted that the level of radiation depends to a great extent on the type , the generation of the CT scanner, on the technique and methodology of the examination.
CT coronary angiography is nowadays a powerful diagnostic tool but also a very good prognostic factor, slowly surpassing the other tests in the hierarchy, offering high diagnostic accuracy in a short examination time, with minimal risk, without particular discomfort for the examinee and with ever-improving cost-benefit for both the patient and the health system.
By Dimitrios Bethanis, Doctor – Cardiologist of Kosmoiatrik.
