In 1914, Dr. Hunter was the first to describe a rare type of bladder ulcer, which subsequently was named after him. In 2011, the American Neurological Association issued guidelines for the diagnosis and treatment of interstitial cystitis, bladder pain syndrome. It reiterated the value of cystoscopy in excluding other mimicking conditions and in the identification of Hunter's lesions. Narrowband imaging is an optical image enhancement technology that enhances vessels in the surface of the mucosa by employing the light absorption characteristics of hemoglobin at a specific wavelength. Conventional light is composed of an equal mixture of red, blue, and green wavelengths. Short wavelengths have shallow penetration characteristics, whereas long wavelengths penetrate deeper into the mucosa. On the other hand, the narrowband light is composed of two specific bands that are strongly absorbed by hemoglobin. The 415 nm short wavelengths, in blue, penetrate only the superficial layer of the mucosa and enhance the visualization of the superficial capillaries. The 540 nm longer wavelengths, in green, penetrate deeper into the mucosa and enhance the vessels right beneath the mucosal surface. The NBI system filters the white light only to allow the two specific bands of light to emerge through the tip of the cystoscope. A camera captures the reflected light from the mucosal surface and channels it through a specific processor. The system applies the information obtained with the 415 nm band to the monitor's B and G inputs and displays it in a brownish color. The information obtained with the 540 nm band goes to the R input and is displayed in cyan. Therefore, the capillaries closer to the surface look brownish and the deeper vessels appear in cyan. In urology, the value of NBI has been demonstrated in the identification of various bladder pathology such as carcinoma in situ and bladder tumors. This video will demonstrate the use of narrowband imaging in the evaluation of patients with interstitial cystitis, bladder pain syndrome. A thorough bladder survey is performed first under white light and then under narrowband imaging light to look for any bladder structural pathology and to identify normal anatomy. Narrowband imaging enhances superficial capillaries and makes identification of vascular lesions easier. The finding of cracks or fissures in the mucosal surface is common in our interstitial cystitis, bladder pain syndrome patient population. Although the clinical significance is unclear, we have noticed a possible correlation with the severity of patient's symptoms. Narrowband imaging enhances the contrast between the crack and the normal mucosa and makes the identification easier. The cracks can be seen before, during or after hydrodistension. The cracks can be seen before, during or after hydrodistension. Following distension and while draining the bladder, bleeding from the mucosa can be seen in a rainfall pattern. Or a waterfall pattern from hunter's lesions. The bladder is reexamined after hydrodistension and the density and distribution of glomerulations are noted. Typical hunter's lesions are easily seen on narrowband imaging. They are described as circumscript, reddened mucosal area with small vessels radiating toward the central scar, with a fibrin deposit or coagulum attached to this area. The lesion ruptures with increasing bladder distension and bleeding can occur. Fulguration is recommended for therapeutic purposes. Brown areas seen on narrowband imaging before hydrodistension are hypervascular superficial lesions that have been shown in a recent paper to correspond to the site of hunter's lesions seen after hydrodistension. The brown areas are now typical hunter's lesions after hydrodistension. Submucosal steroid injections into the lesions have been shown to improve patient's symptoms and are therefore recommended. Bladder biopsy and fulguration are performed at the end as indicated. The easily identifiable bleeders on narrowband imaging make fulguration more precise and avoid unnecessary thermal damage.

Narrowband Imaging

Interstitial Cystitis

Bladder Pain Syndrome

Optical Image Enhancement

Bladder Pathology