OCT or Optical Coherence Tomography is an imaging technique, that is being more and more used in various medical fields. Unlike other imaging techniques, the images obtained through the use of OCT are comparable to those obtain under a low-powered microscope. These images are also useful in determining the composition of the tissue and can be very helpful in a number of intervention procedures.
One of the foremost fields of medicine, that is using OCT as a diagnostic tool, is the field of cardiology. Due to the high resolution of the images obtained through this imaging technique and the ability to better understand the composition of the tissue being surveyed, OCT allows greater success and accuracy in cardiac intervention procedures like the placements of stents into coronary arteries.
While using Optical Coherence Tomography in the field of cardiology, the OCT catheter emits infrared light which allows for greater resolution with less tissue penetration. OCTs measure the echo time delay and the signal intensity after its reflection from the coronary wall structures. It simultaneously operates a pull-back along the coronary artery, thus performing a scan of the segment of interest.
Optical Coherence Tomography can be used in a minimally invasive manner to construct a three dimensional image of coronary arteries. It also deciphers the characteristics of the plaque, i.e. lipid rich, fibrous, calcified or mixed. This helps to avoid the rupture of atherosclerotic plaque and the subsequent thrombosis which is the most frequent cause of acute coronary syndromes.
Whilst placing a stent, a cardiologist needs to know not only the composition of the plaque, but also the size of the vessel, the length of lesions apposition to the stent and expansion of the stent. Opitcal Coherence Tomography produces images that allow for all of these calculations to be made, thus enabling the Cardiologist to position the stent so that both edges are in a normal position in the artery, thus avoiding edge dissection.
Although this technology is at the forefront of developments in diagnostics and imaging, few hospitals in India have invested in it, as of now. Holy Family Hospital is one of the forward-thinking institutions that has not only invested in OCT, but also in angiographic co-registration. This combination allows the Cardiologist to superimpose images obtained through the OCT, on an angiography. The precision of stent placement in such a technique limits the chance of error and the possibility of recurrence.