Coronary Artery CT

At Berkshire Imaging we offer Coronary Artery CT, a non invasive CT scan which can safely and reliably identify coronary artery disease and in some patients avoid the need for an invasive angiogram or other tests.

Introduction

Angina, or pain from the heart, is caused by narrowing in the vessels (coronary arteries) that supply the heart muscle. During exercise when the heart is working hard and needs more oxygen, these narrowing limit the supply of blood causing angina.

In high risk patients with typical symptoms of angina, a conventional invasive angiogram - passing a thin catheter into the coronary arteries via the groin or wrist - is often recommended as it allows any diseased areas to be imaged and treated simultaneously.

However, low risk patients who have chest pain or breathlessness which are possibly not of caused by the heart, but equally without a good alternative explanation, are increasingly undergoing Coronary Artery CT.

Coronary Artery CT utilises the latest scanner technology to obtain detailed views of the coronary arteries and usually provides patients with a definitive answer as to whether their chest pains or symptoms are caused by the heart. It can therefore help prevent some patients undergoing more invasive testing and is now recommended by NICE as the test of choice for low risk patients.

How is a coronary CT performed

Coronary artery CT is very similar to a normal CT scan with just a few minutes in the scanner. To acquire the best images your heart rate should ideally be less than 60 beats per minute and to achieve this most patients are given a dose of short acting beta blocker either as a tablet several hours before or as an injection immediate prior to the scan. During the scan contrast dye is injected via a vein in the arm and you will be asked to hold your breath for approximately 15 seconds.

As part of the Coronary Artery CT scan also provides an assessment of the amount of calcification of the coronary arteries or calcium score. The presence of any calcium is abnormal, regardless of whether it is causing angina and is an independent marker for future cardiac events.

What are the risks of cardiac CT

Cardiac CT is very safe and avoids the rare, but potentially serious complications associated with a conventional invasive angiograms such as stroke or myocardial infarction. As with an invasive coronary angiogram, contrast dye is administered during the scan which can be problematic for patients with kidney impairment or rarely cause an allergic reaction. Also similar to invasive coronary angiograms is the use of radiation to generate the images. With advanced techniques this is kept to a minimum, and is equivalent to approximately 3 years of background radiation. Although this is not taken lightly, the radiation dose must be weighed against the possibility of not identifying a potentially treatable narrowing of the coronary artery.

Where is cardiac CT performed

Berkshire Imaging performs Coronary Artery CT on a state of the art Toshiba 128 slice scanner at Dunedin Hospital installed in March 2013 and offers excellent image quality. All scans are reported by a specially trained Consultant Radiologist Dr Archie Speirs who holds British Society of Cardiac Imaging level 2 accreditation. He works closely with Consultant Cardiologists Dr Andrew Elkington and Dr Bhavsh Sachdev.

Case report

A 46 year old male with known high cholesterol presented with chest pain only on severe exercise. He underwent an exercise treadmill test which was normal - he lasted 13 minutes and had no ECG changes or chest pain. A coronary artery CT was requested by his cardiologist for further reassurance. This demonstrated a severe narrowing of his left anterior descending artery (fig 1). This narrowing was then stented during a subsequent invasive coronary angiogram. (figs 2 and 3)

FIGURE 1:

FIGURE 2:

FIGURE 3:

Further information can be found at:

Patient information sheet
NICE guidelines
General information about coronary CT

If you would like to discuss the merit of a Coronary Artery CT with a cardiologist of have any other queries, please contact Berkshire Imaging.

Berkshire Imaging LLP . The Forbury Clinic . 23 Craven Road . Reading . Berkshire . RG1 5LE . Telephone: 0118 921 3177
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