Doppler Optical Coherence Tomography (OCT) as a New Diagnostic Tool in Otology

The OCT provides a high-resolution and three-dimensional visualization of the tympanic membrane and the adjacent tympanic cavity. The high spatial resolution allows the thickness and morphology of the tympanic membrane to be assessed quantitatively. In addition, an innovative measurement protocol has been developed for functional diagnostic examinations on the eardrum, which allows the measurement of the eardrum vibration with high local and frequency resolution using Doppler OCT. This functional OCT covers the relevant frequency range from 200 Hz to 6000 Hz (speech perception).

The detection of the tympanic effusion, which occurs in conjunction with a middle ear inflammation, is particularly relevant, since its differentiation is decisive for the therapy. Direct visualization of mucous / scattering fluids could be performed. Serous / transparent fluids, which normally can not be differentiated by common diagnostics, can be indirectly detected by means of functional OCT. Specialized semiautomatic image processing methods have been developed for this purpose. In addition, the OCT was also used ex vivo for the detection of characteristic changes in the vibration behavior during tubal ventilatory disturbance and was tested with tympanoplasty.