Centers of Excellence
Magnification endoscopy, Narrow Bank Imaging, Blue Light Imaging, LCI
Endoscopy is one of the innovations that have had a huge impact on and drastically changed the diagnosis of gastrointestinal disorders. Nonetheless, endoscopy is based on the detection of lesions that are visible to the naked eye or on the collection of blind biopsies.
As a result, cancer is diagnosed at an end and usually non-treatable stage. Recently, new techniques and new endoscopes have been made available, with the aim of achieving diagnosis of non-visible lesions and, therefore, prevention and early diagnosis of cancer.
High-resolution magnification endoscopy
Before discussing this technique it is important to clarify that magnification and resolution are two different concepts. The resolution of an endoscopic image is the capability to distinguish between two points that are very close together.
New high-resolution endoscopes incorporating high-pixel density charged-coupled devices (CCD) make possible the inspection of objects 7.9-71μm in diameter, providing the ability to detect red blood cells.
Prior to the exam, patients must drink 60ml of water with simethicone and acetylcysteine, to dissolve the mucus and bubbles, which obstruct the view and impede the detection of early lesions. A plastic hood is placed on the tip of the endoscope, so that the distance between the endoscope and the mucosa is 3mm, to achieve maximum magnification at maximum focal distance.
Usually, magnification endoscopy is combined with chromoendoscopy, i.e. spraying the mucosa with different stains, to make otherwise invisible lesions visible.
Narrow Band Imaging – BLI / LCI
Modern video endoscopes are equipped with a rotation disc with RGB (red, green, blue) optical filters in front of a light source, typically a xenon lamp.
Narrow band imaging (NBI) is a new technique, using narrow band optical filters instead of the full spectrum of white light. The penetration depth of light depends on its wavelength; the longer the wavelength the deeper the penetration. Consequently, blue light, which has a short wavelength, penetrates tissue only superficially.
The use of blue light with the help of special narrow band filters (415nm, 445nm, 500nm) enables visualization of superficial tissue structures.
Therefore, NBI has been designed and developed to improve the quality of endoscopic images, so that the microvascular and microstructural architecture is visualized.
BLI and LCI are similar techniques, more advanced than NBI, aiming to visualize microvessels and microstructures on the mucosal surface through electronic data conversion, with the end goal being to early cancer and gastric dysplasia diagnosis.