How NBI Works

Olympus Narrow Band Imaging (NBI) is an optical technology available for a variety of medical disciplines which helps to visualize the minutest vascular and mucosal patterns. NBI uses only wavelengths absorbed by hemoglobin for maximum contrast. A number of studies highlight the clinical value of NBI, especially with regard to the detection of cancer and characterization of suspicious mucosal areas. Compared to white-light endoscopy, the images of capillaries are less blurred and the probability of missing a lesion is reduced.

Clinical and Practical Advantages of NBI

  • One platform throughout a hospital
  • Increased quality of outcomes due to early detection of cancer and mucosal changes
  • In situ characterization of tissue becomes a reality during colonoscopies
  • No preparation required – technology available at the touch of a button at no extra cost
  • Comprehensive training is available online and face-to-face with renowned experts

More Power for Accurate Diagnosis

The cutting-edge EVIS EXERA III video endoscopy system from Olympus features improved NBI technology. Each component has been enhanced to achieve the best possible images. Combining a brighter light source, a more sensitive CCD, and 3D noise reduction, the whole system provides up to twice the viewable distance as compared to EVIS EXERA II, giving you much more flexibility and helping to speed up your endoscopic examination.

The Result
Improved detection and new perspectives for diagnostic workflows.


This conclusion arises from an international, randomized, crossover trial comparing HD-WLE and NBI with 123 patients by Sharma et al. , published in Gut. 2013, 62 (1), pp. 15–21.

The aim of the study was to compare high-definition white-light endoscopy (HD-WLE) applying the Seattle protocol and NBI targeted biopsy for detection of IM and neoplastic tissue in Barrett’s Esophagus. The authors examined the differences of HD-WLE and NBI biopsies with respect to (1) the proportion of patients with intestinal metaplasia and neoplasia; (2) the proportion of neoplastic area; and (3) the number of overall biopsies performed.

The results: For detection of IM, HD-WLE and NBI each yielded detection rates of 92%. While HD-WLE required a mean of 7.6 biopsies per patient, NBI only required 3.6 biopsies. For detection of dysplasia, the diagnostic yield of HD-WLE and NBI were equivalent. However, NBI required fewer biopsies than HD-WLE in patients with short-segment BO (3.0 vs. 3.9) and patients with long-segment BO (4.1 vs. 10.9).

Thus, NBI may improve the efficiency of Barrett’s Esophagus endoscopic screening and surveillance and even reduce pathology costs, thanks to fewer biopsies being taken.

This result was found by Manabu Muto et a randomized controlled clinical study with 360 patients, comparing the real-time detection rate of superficial SCC and HNSCC with WLE and NBI in a back-to-back fashion. See details in the Journal of Clinical Oncology. 2010, 28 (9), pp. 1566–1572.

Esophageal cancer is the eighth most common cancer in the world with mostly a poor prognosis. This is mainly due to the fact that white-light endoscopy has a poor detection rate of early-stage cancers. Therefore, esophageal SCC and head & neck SCC (HNSCC) are often detected at a late stage. The aim of the study was to verify if NBI could improve the detection rates for squamous cell carcinoma of the head and neck region as well as the esophagus.

The results were promising. While primary NBI detected all (100%) of the superficial cancers in the H&N region, primary WLE detected only 8.0% (Table 1). In the esophagus, primary NBI detected 97% of the lesions while primary WLE reached only 55%. The detection rate of secondary NBI after primary WLE significantly increased in both the H&N region (8.0% vs. 77%) and esophagus (55% vs. 95%). In contrast, if NBI was followed by secondary WLE, the detection rate declined. Fifty-seven percent of superficial cancers in the H&N region and 23% in the esophagus even were detected only by NBI. There was only one lesion that was detected by WLE but was missed by secondary NBI.

In conclusion, NBI has a significantly higher detection rate for SCC than white-light endoscopy and may become the standard examination for the early detection of superficial cancer in the H&N region and the esophagus.


A meta-analysis byMcGill et al.published in Gut 2013; 62 : 1704–1713 analyzed 28 studies on the real-time diagnostic performance of NBI colonoscopy. They found that real-time endoscopic diagnosis of colorectal polyps with NBI is highly accurate, with the area under the summary receiver operator curve exceeding >0.90. High-confidence predictions provide >90% sensitivity and NPV for adenomateous histology. Furthermore, surveillance interval predictions based upon the optical diagnosis were in agreement with pathology in more than 90% of patients.

In conclusion, the adaption of NBI optical diagnosis of colorectal polyps, particularly in high-confidence predictions, is promising for making colonoscopy more cost effective and efficient by potentially avoiding the need for pathological examination.

Hewett et al.Hewett et al. developed a simple tool to assess the histology of colorectal polyps: the NBI International Colorectal Endoscopic (NICE) Classification. Their randomized controlled multi-center study, published in Gastroenterology. 2012, 143 (3), pp. 599–607, does not only provide a simple tool for NBI-supported real-time assessment of colorectal polyps. It also shows that applying this classification scheme is accurate enough to consider the resect-and-discard policy which is a promising practice to save pathology costs.

The criteria of the NICE classification were rated both with experts and fellows followed by an overall prediction of histology. Surface pattern reached the highest values in accuracy, sensitivity, specificity, and negative predictive value. When combining the criteria, the presence of adenomateous features achieved an overall accuracy, sensitivity, and specificity of 92%, 92% and 95% respectively. The negative predictive value for adenomateous histology was 92%. These values further increased when low-confidence predictions were excluded.

In conclusion, if used with high-definition endoscopy, the NICE classification is suitable to differentiate between hyperplastic and adenomatous polyps. Fulfilling the minimum performance benchmarks for assessing the histology of diminutive colorectal polyps, it may substantially contribute to reduce the cost of colonoscopy.

Begin with Good Preparation

Especially when it comes to colonoscopy, good preparation is obligatory. If the bowel is poorly prepared, optical diagnoses are very difficult to make. Ensure that the patient understands and adheres to the dietary restrictions. If you choose a polyethylene glycol (PEG) regime instead of sodium phosphate, consider splitting the dose (2.0 to 4.0 l) to increase acceptance (Kilgore et al.).

Flushing Pumps

Flushing pumps are very helpful to efficiently wash away any debris and remaining organic material to achieve a clear view of the mucosa. The use of flushing pumps also facilitates the identification of bleeding sources and can rapidly fill organs with fluid for “underwater” endoscopy or endoscopic ultrasound procedures.


The higher the image resolution, the greater the chance of detecting lesions at an early stage. EVIS EXERA III offers a resolution of 1920 × 1080 pixels, which helps you to see significantly more. However, you should consider that your images have to pass through several stations before being displayed. At Olympus, we refer to this as the HDTV chain.


The new EVIS EXERA III CV-190 automatically buffers a continuous, rapid series of procedural images. When capturing a still image, the pre-freeze function analyzes the previous images and displays and saves the sharpest image of the desired view. Thus, it helps you to obtain a clear visual record of the procedure in the shortest possible time and minimizes retakes.

Dual Focus

Using an innovative two-stage optical system, EVIS EXERA III allows you to switch between two focus settings: “normal mode” and “near mode.” Although they are comparable with older zoom endoscopes in terms of diagnostic power, the new Dual Focus endoscopes HQ190 exceed zoom scopes in terms of handling.

NBI Optical Diagnosis Training

Olympus is committed to providing the most advanced technologies for endoscopic diagnosis and treatment, helping you to advance patient care.

Try out our NBI training portal

Contact & Support

If you need help or would like to learn more about Olympus products or solutions, get in touch with us. We’re more than happy to accept your inquiry.