Calcium Score is a simple 10-minute examination in which the heart is thoroughly examined to detect the presence of calcium in the coronary vessels. Calcium is a reliable factor for identifying the existence of atherosclerotic disease. The atheromatous disease may well be developed without the deposition of calcium on the walls of the coronary vessels, but its discovery can be a warning sign for the existence of the underlying disease. Furthermore, it should lead to a change of dietary habits, the avoidance of aggravating factors, while administration of medication and the performance of more specialised diagnostic tests cannot be excluded.

This measurement precedes the coronary angiogram. If a patient so wishes, he/she may request a calcium score test and if calcium is detected, proceed to the rest of the procedure. In people living under the influence of aggravating factors such as smoking, cholesterol, blood sugar and stress, this measurement is a good indicator of just how much their blood vessels have been affected.

 Three-dimensional imaging of abdominal arteries where an aneurysm in the abdominal aorta has been detected

Up until recently, we could not even imagine that the 64-slice CT Scanner could offer such good imaging of the lumen of blood vessels. The major advantage here is that the examination is painless compared to standard angiography, avoiding the relatively painful procedure and the complications of standard angiography or coronary angiogram by catheterisation of the aorta.

Now the vessels of the body and the head can be examined either by standard angiography or magnetic resonance angiography or by using colour Triplex ultrasonography. Because of the use of intravascular catheters, standard angiography is a method that can have complications, the patient requires hospitalisation, and it should be performed when no other diagnostic option is available, especially when we want to intervene and correct faults using the so called 'balloon'. MRI angiography is highly accurate, but costs more, and does involve some limitations such as claustrophobia, the presence of a pacemaker or metallic foreign bodies within the body, while it does not allow the examination of the vessel walls and surrounding structures in the way that the CT scanner examines them. Colour ultrasonography is a very easy method that poses some limitations to the examination of deep vessels and as a result cannot be used in all cases.

The advantage of CT angiography is that it is absolutely bloodless and particularly suitable for the examination of all body, cervical and brain blood vessels. It only requires the intravenous infusion of iodinated contrast medium, the same one used for a CT coronary angiogram.

In identifying stenoses or occlusions or other vascular diseases such as aortic or cerebral aneurysm, the accuracy of diagnosis reaches 98%. At the same time it can examine the blood vessel walls, which is not possible in a standard digital angiography using catheters. The quantity of contrast medium required is usually smaller than that of standard angiography and is administered intravenously, while the radiation dose is slightly higher. A major advantage of this method, like in CT coronary angiogram, is that no hospitalisation is necessary, while the examination is normally completed within 30 minutes.

  Three-dimensional imaging of the root of the aorta and the coronary vessels

Virtual (CT) Colonoscopy is a new imaging examination of the large intestine to study its lumen without the use of an endoscope. The term "virtual colonoscopy" refers to "virtual reality" because in essence we create a three-dimensional image and navigate it in any direction we want.

Internationally, standard colonoscopy is recommended as a routine procedure for specific age groups, such as men over 50 years for the prevention of colorectal cancer. However, due to the fact that the test is not very pleasant, in some countries abroad discussion is underway on recommending virtual colonoscopy as a routine test and patients should then undergo endoscopy in the event of pathological findings. In this way, colorectal cancer, a very common type of cancer, could be effectively prevented and timely treated.

Virtual colonoscopy within the helix of the large intestine with identified polyp (marked in red)

Virtual colonoscopy is performed after 24-hour preparation of the patient using a special laxative substance, as in the conventional method. Air is introduced through a small nozzle which is placed under local anaesthesia in the rectum, followed by a scan of the abdomen with the patient in supine and prone position. The procedure has the advantage that it avoids the quite uncomfortable penetration of the endoscope deep into the large intestine, as well as the fact that it can examine areas which the endoscope cannot reach due to anatomical problems, poor cooperation of the patient or obstacles in the lumen of the intestine. The disadvantage is that biopsy samples cannot be obtained in case of pathological findings; however virtual colonoscopy can be performed parallel to a standard CT scan that shows in detail the intestinal wall and other abdominal organs, especially if intravenous contrast material is used at the same time. This procedure very often reveals other extra-intestinal findings related or not to the large intestine.

CT coronary angiogram is an innovative and bloodless diagnostic method which can quickly, easily and accurately produce an image of the heart and coronary vessels. The intravenous infusion of contrast material allows for the visualisation of the coronary vessels, in order to identify any stenoses or blockages.

HOW IS HEART CT SCAN PERFORMED

Before the examination, patients have to answer certain questions related to their medical history. Then, a venous catheter is placed in the patient's arm for the subsequent infusion of the contrast material and -if deemed appropriate- of any other drug that can help control his cardiac rhythm during the test. Then the patient lies on his/her back on the table of the CT scanner. The test takes only a few minutes, during which the patient is required to stay still and hold his/her breath for about 8-10 seconds.

FOR WHICH PATIENTS IS HEART CT SCAN INDICATED?

Although this new method cannot fully replace the standard coronary angiogram, it effectively helps certain patients who would otherwise undergo that test, and can be performed:

• proactively, on asymptomatic high-risk patients, due to the existence of aggravating factors, such as:
  • family history of heart disease (coronary disease),
  • smoking,
  • obesity,
  • hypertension,
  • diabetes mellitus,
  • high cholesterol,
• on patients with atypical chest pain
• on patients with positive or unclear fatigue test or thallium scintigraphy results,
• on patients who require follow-up after coronary by-pass surgery
• on patients with other known vascular diseases (peripheral arterial disease, renal hypertension, carotid artery disease, arteritis, etc.)
• on patients who for various reasons cannot undergo a standard coronary angiogram.

INFORMATION ACQUIRED FROM THE TEST

The information that may be acquired from this test includes the following:

• anatomy of the coronary vessels and their variations
• identification of parietal plaque and classification as soft, calcified or mixed
• examination of the blood vessel lumen and visualisation of stenoses, occlusions or collateral pathways
• coronary bypass patency examination
• examination of myocardium and adjacent soft tissue
• identification of congenital anomalies in the flagella of great vessels
• calculation of the risk of having coronary heart disease in the future expressed as an Agatston score (Calcium Score)

o exclusion of other findings, such as cardiac tumours, valvular disease, check of venous system, arteriovenous fistulas, or constrictive pericarditis

FREQUENTLY ASKED QUESTIONS

Can a heart CT scan replace the coronary angiogram?

A heart CT scan can actually eliminate the possibility of coronary disease. This means that patients with normal findings from a heart CT scan, will normally not need to also undergo the standard coronary angiogram.

However, the CT scan cannot replace the coronary angiogram in all cases. The main reason is that it cannot evaluate very small vessels. In these cases, a coronary angiogram is recommended for further investigation.

When the heart CT scan indicates stenoses in coronary vessels and where clinical symptoms and findings of other tests exist, which refer to coronary artery stenoses, the standard angiogram is inevitable.

What are the advantages of a heart CT scan compared to the coronary angiogram?

CT scan has the following advantages:

• It is bloodless, in other words no artery catheterisation is required, as in the standard coronary angiogram.
• It allows the examination of vascular walls and the identification of atherosclerotic lesions.
• It allows the simultaneous visualisation of other chest areas, e.g. lungs and pericardium.
• It is a fast procedure with minimal complication rates.
• It does not require hospitalisation.

How much radiation does a patient that undergoes a CT scan receive compared to the standard coronary angiogram?

Radiation in a heart CT scan is approximately equal to that of a standard coronary angiogram or thallium scintigraphy.

Can I take medication and eat before a CT scan?

There is no need to stop or change your medication. Also, you should avoid smoking, drinking any coffee and tea, consuming alcohol and food for 3-4 hours before the test.

What should I bring?

To undergo the test you need a referral note from a cardiologist and the results of recent tests for urea, serum creatinine, lipids and cholesterol. In case of thyroid diseases, the function of the gland should be checked before the test.

For proper assessment and evaluation of a CT scan, you should bring previous heart or angioplasty tests or the findings of a coronary surgical operation