ABSTRACT
Objective: To evaluate the prevalence and imaging characteristics of persistent petrosquamosal sinus (PSS) in adults based on HRCT. Methods Data of 708 adult patients who underwent thin-slice HRCT without bilateral temporal bone abnormalities were retrospectively analyzed. Based on the standardized reconstructed axial and coronal images with 0.67 mm layer thickness, the presence of PSS and its HRCT signs, including the mean diameter, course, saccular dilation of PSS as well as wall dehiscence and postglenoid foramina were evaluated. The differences of PSS in different genders and age groups were analyzed. Results: HRCT showed that the prevalence of PSS in 708 adult patients (1 416 sides) was 10.59% (150/1 416), with the average diameter of (1.29±0.58)mm. The difference in prevalence of PSS was statistically significant between women (92/728, 12.64%) and men (58/688, 8.43%). No significant difference in the prevalence was shown between sides of each gender (Pmale=0.583, Pfemale=0.372). There was no significant difference in the prevalence of PSS between each two groups among the 18-29 years old group, the 30-39 years old group, the 40-49 years old group, the 50-59 years old group (all P>0.05), while there were significant differences in the prevalence of PSS between the ≥70 years old group and each other groups above, respectively (all P<0.05). In 150 sides PSS, 24.67% (37/150) coursed in the petrosquamosal fissure, 75.33% (113/150) in the outer sulcus of the fissure, while 47.33% (71/150) showed postglenoid foramina formed, including 36.67% (55/150) horizontal ones to the outer subcutaneous tissue and 10.67% (16/150) into the temporomandibular joint; 2.67% (4/150) had dehiscent wall; 4.67% (7/150) had saccular expansion. Conclusion: HRCT can show the characteristics of PSS, which should be carefully evaluated before skull base or ear surgeries to avoid iatrogenic injury.
ABSTRACT
The petrosquamosal sinus (PSS) is a rare emissary vein of the temporal bone. This vein connects dural sinuses with external jugular venous system. This pathway has been known to regress during fetal and early postnatal life however, several cadavaricstudies have revealed that the PSS is a relatively common feature in human. The imaging diagnosis of the PSS, such as digital subtraction angiography or high resolution CT scan, has been rarely reported in humans. We report a case of PSS in a patient with cholesteatoma with a review of literature.