Irina Bodrova MD, PhD, Presenter: Nothing to Disclose

to study facilities of fMSCT in evaluation of mobile middle ear structures and to apply obtained results in further planning of an optimal surgical approach.

21 persons participated in the study. Average age was 39,4±0,73 years old. All patients have been examined by microotoscopy, audiologic tests, MSCT and fMSCT. First part of the study enrolled 10 healthy adult volunteers in whom normal parameters of the middle ear mobile structures were measured. In the second part, 11 patients (three of them had underwent stapedoplasty before) with suspected stapes footplate (or prosthesis) immobility were examined. The CT study was conducted in dynamical mode with simultaneous supply of audio signals by means of audiometer during 5 second. Radiation dose was 1.5-2 mSv. Then, 11 patients underwent middle ear surgery, which allowed for comparison of fMSCT data and intra-operative findings

Evaluation of normal functional anatomy of the middle ear structures was based on the results of the study in the healthy volunteer group. The main criteria for evaluation of the ossicles and ligaments mobility was displacement of the structures. Maximal displacement amplitude in healthy volunteers was 1 mm. In the patients’ group, fMSCT revealed induration of the stapes footplate and the oval window membrane (8 cases). It was accompanied by decreased range of the footplate motions (5 patients) or complete absence of its mobility (3 patients). In 4 cases the ligaments’ density was higher , which correlated with lower range of the ossicles motions (3 cases) or complete immobility of entire ossicles chain in 1 case.  In one case, fMSCT revealed unchained and displaced prosthesis loop with change of the footplate motility. In the one case, perforation in the stapes footplate was narrow, stapes prosthesis was locked in the oval window and its mobility was almost absent. In the one case, mobility of stapes prosthesis was not disturbed.  

fMSCT is a new noninvasive diagnostic method providing precise evaluation of the middle ear structures mobility. It helps to choose an optimal surgical approach and, in some cases, to avoid unnecessary revision.

The fMSCT findings allowed for precise noninvasive differentiation between different types of conductive hearing loss and optimal planning of a future middle ear surgery.

Bodrova, I, The Functional MSCT of the Middle Ear Mobile Structures Is New Noninvasive Objective Diagnostics Method.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12036455.html