Supratubal recess and sinus tympani: CT analysis of middle ear hidden areas

Abstract

Background: High-resolution computed tomography (HRCT) magnifies the role of preoperative imaging for detailed middle ear anatomy particularly its hidden area. The purpose of the current study was to assess the sinus tympani (ST) and supratubal recess (STR) by HRCT, to create CT classification of the STR depth, and to study the relationship between ST types and the new STR grades. Results: In HRCT of non-pathological temporal bones of 100 subjects (200 ears), measurements of the STR and ST were calculated, registered, and analyzed. The depth of the STR was classified into grade 1 with depth less than 3 mm, grade 2 with depth ranged between 3 and 5 mm, and grade 3 with depth more than 5 mm. The mean STR length, width, and height were 4.17 ± 0.86, 3.55 ± 0.65, and 3.64 ± 0.7 mm, respectively, while the ST mean length and width of were 2.52 ± 0.5 and 1.82 ± 0.78 mm, respectively, without significant differences between either sexes or sided. The ST types were found to be type A in 56 ears (28%), type B in 142 ears (71%), and type C in 2 ears (1%). The STR grading was grade 1 in 12 ears (6%), grade 2 in 160 ears (80%), and grade 3 in 28 ears (14%) without significant relationship between ST types and STR grading (P = 0.3). Conclusion: The current study provided reliable and applicable methods of CT assessment of STR and ST that can help to predict the degree of surgical visibility of the ST and STR during ear surgery.

Comparison of preoperative high resolution computerized tomography of temporal bone with intra-operative findings in patients with cholesteatoma

“…So HRCT scan are very useful in assessing the hidden areas of the middle ear. 26 Our study showed that all the 72 patients with cholesteatoma were accurately diagnosed with HRCT scans that correlated with surgical findings. Mafee et al also reported in their series of 48 patients with cholesteatoma 46 of them (96%) had been diagnosed correctly with preoperative HRCT.…”

Distribution of different morphological types of anterior epitympanic plate “cog” and Köerner’s septum in CT images of cholesteatomatous and non-cholesteatomatous CSOM: is it really significant?

“…The complexity of the anatomical architecture of epi-tympanum necessitates accurate and deep knowledge of the surgeon about the spatial relationships present at this site, thus avoiding misguided procedure and inadvertent injury of vital structures [8,26,27]. HRCT has a crucial role in the preoperative detailed anatomical information [9,28].…”

“…To best of our knowledge, few studies mentioned two different types of cog without correlation to chronic infection predisposition [10,28]. Also, few studies investigated the radio-anatomical assessment of the KS and its predisposition to middle ear infection [13,14] A single more recent prior study in oto-laryngology literature proposed a classification of morphological types of "cog" on an oligo-slice CT, which was followed in our study on multi-slice CT (MSCT) [12].…”

“…Also, Li et al [10] pointed to the correlation between types of TTF and abnormal anterior epitympanic recess aeration; however, they found no statistical difference between types of cog and types of TTF [10]. On the other hand, El Anwar et al [28] and Hong et al [31] made their studies on "nonpathologic" temporal bones. They reported that the cog was a constant boundary of the STR and that the "complete cog" was the commonest among the studied group, which was associated with single-cell STR; seen in (79.5%) of temporal bones [28,31].…”

“…On the other hand, El Anwar et al [28] and Hong et al [31] made their studies on "nonpathologic" temporal bones. They reported that the cog was a constant boundary of the STR and that the "complete cog" was the commonest among the studied group, which was associated with single-cell STR; seen in (79.5%) of temporal bones [28,31]. Lee et al [12] assumed that the development of the chronic otitis media is relatively correlated to the type of the anterior attic bony plate.…”