The report by Mary Ann Benitez (South China Morning Post, December 5) on Matilda Hospital's Electron Beam Tomography (EBT) heart scan has created negative views in the public eye.
As a doctor with no personal relationship with Matilda Hospital or with doctors practising there, I feel readers may have been misled about the value and use of the EBT scan.
Your report stated that one 50-year-old company executive underwent the scan and was diagnosed with 'left main artery' disease, but subsequently underwent an invasive angiogram which revealed everything was normal.
It is important to understand that the EBT quantifies the amount of calcium that is in the coronary artery and is not aimed at providing information about the degree of narrowing of the coronary arteries. The greater the calcium score, the greater the 'atheroma burden' for that vessel.
A coronary angiogram, on the other hand, provides precise information about patency (that is, unobstructed) of coronary arteries.
In patients with cardiac chest pain, a coronary angiogram is useful to determine how much narrowing there is and whether angioplasty or bypass surgery is indicated. On the other hand, an EBT scan is useful in individuals with high risk (such as diabetic patients) who have no symptoms, as it may serve as a guide to aggressiveness of therapy.