Anatomy of the Surrounding Tissue of the Eustachian Tube in Patulous Eustachian Tube: 3 Tesla Magnetic Resonance Imaging Approach.

To clarify the possible pathological conditions of cartilaginous portion of the Eustachian tube (ET) and its surrounding tissues. Retrospective review. Twenty-five normal subjects (control group) and 25 patients with patulous ET (patulous group). We reconstructed cross-sectional 3 Tesla magnetic resonance (MR) images using the multiplanar reconstruction (MPR) technique. Cross-section area widths that were measured included the following: 1) inferior head of lateral pterygoid muscle (PM); 2) pterygoid venous plexus (PVP); 3) medial soft tissues of ET, including ET cartilage; and 4) maximum cross-sectional area of high intensity surrounding the medial ET lumen. A statistically significant difference was found in the thickness of the inferior head of the lateral PM between male and female; it was thicker in the male participants. Ostmann's fatty tissue (OF) was significantly smaller in the patulous ET group. Smaller size of the surrounding tissues of the ET, viz., the OF, may contribute to the pathogenesis of patulous ET.