A multispectral 3D-Endoscope for Cholesteatoma Removal

Eric L Wisotzky,Jean-Claude Rosenthal,Peter Eisert,Anna Hilsmann,Florian C Uecker

doi:10.1515/cdbme-2020-3065

Abstract

Abstract We present a stereo-multispectral endoscopic prototype using a filter-wheel to guide the removal of cholesteatoma tissue in the middle ear. An image-based method is used that combines multispectral tissue classification for the detection of tissue to be removed and 3Dreconstruction to determine its metric dimensions. The multispectral illumination used for tissue classification ranges from λ = 400 nm to λ = 500 nm with step-size of 20 nm, which results in six different narrow-band illumination modes. For classical RGB imaging and metric calculations, a broadband illumination mode is applied before and after the narrow-band illumination. The spectral information is augmented into the broadband mode using an overlay technique. The combination of multispectral imaging with stereoscopic 3D-reconstruction results in new valuable visualization of intraoperative data. This allows to generate a 3D-model of the patients anatomy highlighting the identified malicious tissue and compare the anatomical dimensions with pre-operative CT data.

Highlights

2 Materials and MethodsCholesteatoma is a disease in the middle ear and consists of sprawling squamous epithelium
Cholesteatoma requires a complete resection to avoid recurrence. The proliferation of this epithelium in the middle ear cavity and further growth into the mastoid and lateral skull base can lead to life-threatening complications [7]
The main difference between the optical properties of these tissues lies within lies within the spectral range of λ = 400 nm to λ = 575 nm, where cholesteatoma shows a much higher reflectance rate than bone

Summary

Materials and Methods

Cholesteatoma is a disease in the middle ear and consists of sprawling squamous epithelium. It can lead to life-threatening complications due to its destructive growth and needs to be treated by surgery as only possible treatment. Cholesteatoma requires a complete resection to avoid recurrence. The proliferation of this epithelium in the middle ear cavity and further growth into the mastoid and lateral skull base can lead to life-threatening complications [7]. The goal during surgery is a complete removal while recovering or preserv-

Imaging Setup

Cholesteatoma Visualization

Surgical Case

Results

Spectral Visualization Analysis

Discussion and Conclusion