Fusing MRI and CBCT: Muscle atrophy as key to explaining eustachian tube dysfunction?

Area of Science:

• Otolaryngology
• Medical Imaging
• Anatomy

Background:

• Eustachian tube dysfunction (ETD) significantly impacts quality of life.
• Understanding the anatomical variations associated with ETD is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the correlation between Eustachian tube (ET) dimensions and Eustachian tube dysfunction (ETD).
• To evaluate the feasibility of fusing MRI and CBCT for ET assessment.

Main Methods:

• 28 patients with ETD and 10 controls underwent 3 Tesla MRI and CBCT scans.
• Image fusion using anatomical landmarks allowed for precise measurement of ET dimensions and angles.
• Comparison of ET length and angles between ETD ears, asymptomatic ears, and controls.

Main Results:

• Eustachian tube (ET) length was significantly longer in ETD ears compared to controls.
• The osseous portion of the ET (OET) was longer in symptomatic ETD ears, while the cartilaginous portion (CET) was shorter in controls.
• A positive correlation was observed between ET length and patient height.

Conclusions:

• Fusion of MRI and CBCT is a viable method for evaluating ET anatomy.
• ETD is associated with a longer overall ET, specifically the OET.
• Smaller Ostmann's Fat Pad and levator veli palatini muscle in ETD ears suggest potential atrophy contributing to dysfunction.