Abstract:
5. Abstract
Objectives
i. Investigate whether morphologic measurements of Eustachian tubes on computed tomography scans are correlated with Eustachian tube dysfunc-tion scores.
ii. Investigate whether sinonasal or middle ear radiological findings on tem-poral bone computed tomography are associated with the side of Eusta-chian tube dysfunction.
iii. Determine the diagnostic validity of the computed tomography scan as a screening tool for Eustachian tube dysfunction.
Study design
Prospective, cross-sectional case series study in a tertiary referral centre (ViD-ia Christian Hospitals Karlsruhe).
Methods
The study included forty patients with clinically diagnosed unilateral Eusta-chian tube dysfunction, verified through Eustachian tube score – 7 and Eusta-chian tube dysfunction questionnaire – 7.
Each patient underwent pre-interventional radiological assessment by tem-poral bone computed tomography while performing a Valsalva-maneuver to enhance visualization of Eustachian tube lumen. The complete course of Eu-stachian tube, from the epipharynx to the middle ear cleft was included in the scanning field.
A curved planar reconstruction delineated the Eustachian tubes and 3D mod-els were constructed using volume rendering software. Seven morphological parameters were independently measured for each Eustachian tube by two board-certified neuroradiologists blinded to the side of pathology: the cross-sectional size of the tympanic and pharyngeal orifice, visualization length of cartilaginous, bony and overall Eustachian tube lumen as well as inclination angle to Frankfurt horizontal plane and curvature angle of the S-shaped Eu-stachian Tube. Furthermore, the Eustachian tubes were analyzed for inter-side morphological differences, presence of mucus in the lumen or middle ear cleft and secretion retention or mucosal swelling in the adjacent sinuses. Finally, a radiological statement about the side of pathology was delivered, always blinded to the clinical diagnosis.
Statistical correlation studies between morphological measurements and Eu-stachian tube scores analyzed the association between the presence of mu-cus or accompanying sinonasal disease. Additionally, the diagnostic validity of the computed tomography scan as a screening tool for Eustachian tube dys-function was calculated.
Results
There was no significant correlation between Eustachian tube scores and the cross-sectional size of pharyngeal orifice. On the other side, correlation be-tween Eustachian tube score - 7 and the cross-sectional size of tympanic ori-fice could be identified (r=0,361, p<0,05, Pearson). The mean value of visuali-zation length of complete Eustachian tube and in its’ bony segment was higher in healthy sides rather than in pathological sides [Z = -2,124, p = 0,034 < 0,05 / t(39) = 2,427, p = 0,020 < 0,05 and Z = -2,177, p = 0,029 < 0,05 and t(39) = 2,817, p = 0,008 < 0,05 respectively]. Moreover, correlation between Eusta-chian tube score - 7 and visualization length of complete Eustachian tube and in its’ bony segment could be identified (r=0,462, p<0,01, Pearson and r=0,598, p<0,01, Spearman respectively). No significant correlation could be found between different grade of inclination/curvature and Eustachian tube scores.
The radiologic detection of mucus in Eustachian tube or adjacent middle ear cleft structures was associated with the pathological side. On the contrary, there is no association between radiological findings of sinus disease and side of Eustachian tube dysfunction.
The diagnostic value of radiologic assessment in Eustachian tube dysfunction has a sensitivity of 52,5 and specificity of 97,5%.
Conclusion
Measuring the tympanic orifice could be a specific imaging feature indicating obstructive Eustachian tube dysfunction and thus could be integrated into a preoperative radiological evaluation protocol. The sensitivity of radiologic as-sessment is rather low. Hence, Valsalva-CT is inappropriate as a screening tool for Eustachian tube dysfunction in routine clinical practice. However, the presence of mucus in Eustachian tube or adjacent structures on temporal bone CT scan is the most specific morphologic correlate to Eustachian tube dysfunction.
Savvas Kourtidis, 01.04.2020
Prof. Dr. med. Serena Preyer, 01.04.2020
computertomography
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