Narrow-band Imaging Hysteroscopy Research Articles

Identification of vessel degeneration and endometrosis in the equine endometrium, using narrow-band imaging hysteroscopy

In this study, endometrosis and angiosclerosis in mares were studied. Endometrosis is a severe, progressive, and irreversible fibrotic condition that affects the endometrium, whereas angiosclerosis refers to thickening of vessel walls due to degenerative changes leading to reduced elasticity of the walls and lower perfusion. Histologic evaluations were performed on biopsies and compared with vascular features of the endometrial surface obtained via narrow-band imaging (NBI) hysteroscopy. First, it was determined if hysteroscopic evaluation of the endometrium using NBI resulted in a better visualization of the vascular pattern (i.e., vessel-versus-background contrast was increased) compared with using white light. This was found to be the case for examinations in vivo (n = 10), but not when using abattoir uteri (n = 3). In the second part of this study, it was determined if vascular densities and sizes as derived from NBI images could be used as indicators for the degree of degenerative changes of the equine endometrium and its vessels. Narrow-band imaging hysteroscopic evaluations were performed (n = 10), and endometrial biopsies (n = 32) were collected. Histologic specimens were evaluated for degree of endometrosis and angiosclerosis, and they were classified in Kenney categories. Narrow-band imaging images were analyzed for vascular pattern. Samples classified to Kenney category I, or without signs of vessel degeneration, had significantly higher vascular densities than samples from Kenney category IIa or with angiosclerosis. In conclusion, narrow-band imaging facilitates enhanced visualization of the vasculature of the equine endometrium during hysteroscopies, which has applications in detection of endometrosis and angiosclerosis.

Equine endometrial vascular pattern changes during the estrous cycle examined by Narrow Band Imaging hysteroscopy

The aim of this study was to evaluate the uterine blood supply and endometrial vessel architecture, during the equine estrous cycle. Narrow Band Imaging (NBI) hysteroscopy was used for evaluating changes in the endometrial vasculature during the estrous cycle [six mares, d 0 (representing the day of ovulation), d 6 and 11 in four locations]. In addition, endometrial biopsy samples were used for immunodetection of markers for angiogenesis (Vascular Endothelial Growth Factor A, its receptor 2, as well as angiopoietin-2 and its receptor-tyrosine-kinase Tie2) during the estrous cycle (three mares, d 0, 5 and 10; one biopsy per mare). Detailed analysis of hysteroscopic images revealed an increase in the vascular density from estrus towards diestrus. In contrast, microscopic specimens prepared from biopsies revealed no evidence for changes in the endometrial vessel number during the estrous cycle. Studies on expression of angiogenesis markers indicated that cyclic changes in the endometrial vascular density observed by NBI-hysteroscopy were not due to formation of new vessels. It is concluded that vessels are involved in blood supply of a smaller area during diestrus, facilitating better distribution of nutrients during this phase.

Application of Narrow-Band Imaging Hysteroscopy in the Diagnosis of Endometrial Lesions.

Application of Narrow-Band Imaging Hysteroscopy in the Diagnosis of Endometrial Lesions.

Accuracy and efficacy of narrow-band imaging versus white light hysteroscopy for the diagnosis of endometrial cancer and hyperplasia

The aim of this study was to evaluate, in a multicenter study, whether the narrow-band imaging (NBI) technology may improve the diagnostic reliability of hysteroscopy in the diagnosis of endometrial cancer and hyperplasia. A total of 801 outpatient women undergoing diagnostic hysteroscopy were enrolled. All women underwent fluid minihysteroscopy with white light (WL) and NBI exploration with endometrial eye-directed biopsy. NBI hysteroscopy significantly improved the sensitivity for diagnosing endometrial cancer compared with WL (93% and 81%, P < 0.05). In detecting low-risk hyperplasia, the use of NBI significantly improved the sensitivity (82% vs 56%, P < 0.005) and positive predictive value (79% and 71%, P < 0.05) compared with WL hysteroscopy. In the diagnosis of high-risk hyperplasia, NBI significantly improved the sensitivity (60% vs 20%, P < 0.005) and positive predictive value (67% and 25%, P < 0.0001), whereas no difference was seen for specificity (99% and 99%, P > 0.005), negative predictive value (99% and 99%, P > 0.05), and accuracy (99% and 98%, P > 0.05). NBI showed significantly higher values in sensitivity for the detection of low-risk and high-risk hyperplasia, and this could be useful for reducing the risk of missing severe pathologies at hysteroscopy, and improving the diagnosis of preneoplastic and neoplastic pathologies. NBI hysteroscopy showed a very high diagnostic accuracy for the exploration of the uterine cavity, reducing the number of biopsies performed in wrong areas, although multicenter randomized trials are required to establish the true value of this interesting technological advancement.

Magnifying hysteroscopy with narrow-band imaging for visualization of endometrial lesions

⁎ Corresponding author at: 35 Shinanomachi, Shinjuku-ku, Tokyo 160–8582, Japan. Tel.: +81 333531211; fax: +81 333530249. E-mail address: kbanno@sc.itc.keio.ac.jp (K. Banno). Narrow-band imaging (NBI) is a novel endoscopic technique in which images of microvessels in the mucosal superficial layer and mucosal surface are enhanced by narrowing the spectral bands of the observation light. In NBI, the light spectrum is shifted to wavelengths of 415±30 nm and 540±30 nm to facilitate wavelength-induced changes in visibility. In digestive endoscopy, NBI has improved qualitative diagnosis and enabled more accurate detection of lesions [1]. In gynecology, the use of NBI has recently been reported for laparoscopic identification of peritoneal endometriosis, evaluation of vascular density in endometriosis, and diagnosis of endometrial lesions [2,3]. Via these applications, NBI has attracted attention owing to the clear visualization that can be achieved. The use of NBI for image enhancement has recently been applied to magnifying endoscopy for the evaluation of blood microvessels and surface microstructure in the digestive tract, with the goals of qualitative diagnosis and evaluation of invasion depth [4]. In gastrointestinal endoscopy, magnifying endoscopy using NBI is referred to as because a macroscopic observation is conducted. The latest techniques, which include endocytoscopy and endomicroscopy, enable direct observation of cells and cell nuclei, and are potential alternatives to histology via biopsy. The feasibility of applying NBI in magnifying hysteroscopy for the evaluation of surface microstructure and bloodmicrovessels in endometrial lesions was investigated at the Department of Obstetrics and Gynecology, Keio University Hospital, Tokyo, Japan, in August 2009. Magnifyinghysteroscopic images of endometrioid adenocarcinomawere taken via conventional hysteroscopy and NBI (Fig. 1). The images were taken using a charge-coupled device digital camera (OTV-S7ProH-HD12E; Olympus Medical Systems, Tokyo, Japan), a light source (VISERA Pro Xenon Light Source [CLV-S40Pro]; OlympusMedical Systems, Tokyo, Japan), and a video system/processor (VISERA Pro Video System Center [OTV-S7Pro]; OlympusMedical Systems, Tokyo, Japan) via a 2.9-mm/30 ° telescope at magnification×60 (HOPKINS II; Karl Storz, Tuttlingen, Germany). There were no special requirements or patient preparation for NBI, and observation with conventional white light and NBI was interchangeable at the touch of a button by the surgeon. Magnifying NBI hysteroscopy enables visualization of the microstructure and blood microvessels in an endometrial lesion as dark green with a clear contrast (Fig. 1). This visualization results in easier detection—compared with conventional white-light hysteroscopy—of an abnormal protruding lesion and atypical vessels. Preliminary experience indicates that this method may be a useful new imaging tool for supplementing endoscopic diagnosis of endometrial lesions and that it is likely to have a role in optical biopsy in the future.

Narrow band imaging hysteroscopy: A comparative study using randomized video images

Narrow band imaging (NBI) has been used in the gastrointestinal endoscopy field as a novel endoscopic imaging technique and has contributed to improved qualitative diagnosis and detection of lesions. However, there are only a few studies of use of NBI in the gynecology field. We applied NBI in flexible hysteroscopy at our outpatient clinic and evaluated the utility of NBI hysteroscopy for diagnosis of malignant endometrial lesions by comparison of the sensitivity and specificity between white light alone and white light+NBI using hysteroscopic video images. The subjects were 65 patients with a suspected endometrial lesion in the uterine cavity. These patients underwent flexible hysteroscopy using NBI in addition to conventional white light. Video images from 65 patients were edited into two groups, white light alone (WL group) and white light+NBI (NBI group) (130 images in total). Computerized block randomization of the order was then performed. Four raters independently diagnosed the images without use of other clinical information. Using the pathological diagnosis as the gold standard, we evaluated the sensitivity and specificity of diagnosis of atypical endometrial hyperplasia (AEH) or endometrial carcinoma compared between the WL and NBI groups. The sensitivity of diagnosis of AEH or endometrial carcinoma was numerically higher in the NBI group for all raters, and the average sensitivity was significantly higher in the NBI group compared to the WL group (78.6% vs. 63.7%, P<0.001). The specificity for each rater and the average specificity were comparable between the two groups. Compared to white light hysteroscopy, NBI hysteroscopy had a higher sensitivity for diagnosis of AEH or endometrial carcinoma without loss of specificity. This suggests that NBI hysteroscopy may be more useful than white light hysteroscopy for endoscopic diagnosis of malignant endometrial lesions.

Flexible hysteroscopy with narrow band imaging (NBI) for endoscopic diagnosis of malignant endometrial lesions

Narrow band imaging (NBI) for detection of blood vessels and microstructures on the mucosal surface is used in gastrointestinal endoscopy since it can improve qualitative diagnosis and detection of lesion. However, there are no studies on flexible hysteroscopy using NBI. We performed flexible hysteroscopy with NBI for outpatients to investigate the sensitivity and specificity of endoscopic diagnosis of malignant endometrial lesions. Of patients who attended our hospital for suspected lesions in the uterine cavity between April 2009 and May 2010, 104 subjects underwent hysteroscopy with NBI, in addition to white light. Using the pathological diagnosis as the gold-standard, we evaluated the sensitivity and specificity of NBI hysteroscopy for detecting atypical endometrial hyperplasia (AEH) or carcinoma. The results were also compared with historical data (n=209) for conventional hysteroscopy using white light only in 2008. The sensitivities were 97.2% [95% confidence interval (95% CI): 90.3-99.7%] and 82.6% (95% CI: 74.4-89.0%) for NBI hysteroscopy and conventional hysteroscopy, respectively. The 95% CIs for the two methods did not overlap and the sensitivity of lesion detection was higher with NBI hysteroscopy. Specificities were comparable, 90.6% (95% CI: 75.0-98.0%) and 85.1% (95% CI: 76.3-91.6%) between the methods. NBI hysteroscopy has increased sensitivity for detection of atypical endometrial hyperplasia (AEH) or carcinoma. A comparison with historical data suggested that NBI may be useful for diagnosis of malignant endometrial lesions. As far as we are aware, this is the first evaluation of flexible hysteroscopy with NBI for diagnosis of malignant endometrial lesions.

Narrow band imaging hysteroscopy: a new diagnostic technique in recurrent IVF failure?

Narrow band imaging (NBI) is an optical filter technology that improves the visibility of capillaries, veins and other subtle tissue structures, by narrowing the bandwidth of spectral transmittance using optical filters. In this short communication, we want to share our preliminary experience in assisted reproductive technology patients where we had used NBI hysteroscopy for the evaluation of uterine cavity abnormalities who had previous IVF failure.

Narrow-Band Imaging in Diagnosis of Endometrial Cancer and Hyperplasia: A New Option?

Study Objective To estimate whether the use of narrow-band imaging (NBI) hysteroscopy increases concordance between visual identification and a histologic diagnosis of endometrial cancer and hyperplasia. Design Prospective study (Canadian Task Force classification: II-2). Setting Department of obstetrics and gynecology, University of Eastern Piedmont, Novara, Italy. Patients 209 consecutive patients with abnormal uterine bleeding. Interventions White-light hysteroscopy and NBI hysteroscopy followed by direct biopsy. Measurements and Main Results The sensitivity and specificity of conventional hysteroscopy in predicting a diagnosis of cancer and hyperplasia were, respectively, 84.21% (95% confidence interval [CI], 79.27–89.15) and 99.47% (95% CI, 98.49–100.0), and 64.86% (95% CI, 58.39–71.34) and 98.77% (95% CI, 97.27–100.0), and of NBI hysteroscopy were 94.74% (95% CI, 91.71–97.76) and 97.89% (95% CI, 95.95–99.84), and 78.38% (95% CI, 72.8–83.96) and 97.67% (95% CI, 96.63–99.72). The concordance of conventional and NBI hysteroscopy with the histopathologic findings (measured using the Cohen κ) was, respectively, 88.80% (95% CI, 86.2%–96.3%) and 91.78% (95% CI, 89.6%–98.2%), a difference of 2.98% (95% CI, 0–9) in favor of NBI. Conclusion Narrow-band imaging hysteroscopy can accurately predict a histologic diagnosis of endometrial cancer or hyperplasia.

Reliability of narrow-band imaging (NBI) hysteroscopy: A comparative study

To evaluate the usefulness of narrow-band imaging (NBI) technology for improving the diagnostic reliability of hysteroscopy. Prospective controlled clinical study (Canadian Task Force classification II-2). University hospital. Three hundred ninety-five outpatient women undergoing diagnostic hysteroscopy were enrolled. All patients underwent fluid minihysteroscopy with white light (WL) and NBI exploration with endometrial eye-directed biopsy. Hysteroscopic findings with WL and NBI were compared with histology, which was considered the gold standard. Overall, the number of correct diagnoses with NBI was significantly higher than with WL. For differentiating normal from abnormal endometrial histopathology, the use of NBI showed a significantly higher specificity (0.93 vs. 0.78) and negative predictive value (0.92 vs. 0.81); NBI hysteroscopy significantly improved the sensitivity for the diagnosis of proliferative endometrium (0.93 vs. 0.78), chronic endometritis (0.88 vs. 0.70), low-risk hyperplasia (0.88 vs. 0.70), and high-risk hyperplasia (0.60 vs. 0.40). The use of NBI improved the reliability of diagnostic hysteroscopy. The high specificity and the low number of false negatives may reduce the number of unnecessary biopsies or of those performed in wrong areas. Moreover, compared with WL observation, NBI hysteroscopy showed significantly higher sensitivity for the detection of chronic endometritis and low-risk and high-risk hyperplasia.

Narrow Band Imaging Hysteroscopy: A Pilot Feasibility Study for the Detection of Endometrial Cancer and Hyperplasia

Narrow Band Imaging Hysteroscopy: A Pilot Feasibility Study for the Detection of Endometrial Cancer and Hyperplasia