The Pitfalls and Important Distances in Temporal Bone HRCT of the Subjects with High Jugular Bulbs – Preliminary Report

Abstract

Background. High jugular bulb (HJB) may be detected unilaterally or bilaterally in temporal bone high resolution computerized tomography (HRCT). Objectives. In this retrospective study, we investigated the pitfalls and important surgical distances in patients with unilateral and bilateral HJB via temporal bone HRCT. Material and Methods. In this preliminary report, the study group consisted of 20 adult patients (12 male, 8 female), or 40 ears, all of which underwent temporal bone HRCT. We divided them into groups that consisted of bilateral HJB (14 ears), unilateral HJB (13 ears), and control (No HJB, 13 ears). The anotomical relationships of the sigmoid sinus, jugular bulb, and carotid artery with several landmarks in the temporal bone were studied via temporal bone axial and coronal HRCT. The shortest distances between certain points were measured. These measurements were analyzed in respect to pneumatization. Dehiscence on the jugular bulb (JB) and internal carotid artery (ICA) and the dominance of JB were also evaluated for all of the groups. Results. In the axial sections of the temporal bone HRCTs, the sigmois sinus (SS)-external auditory canal (EAC) distance of the bilateral HJB group (14.00 ± 1.17 mm) was significantly lower than that of the control group (16.46 ± 2.14 mm). The JB-posteromedial points of the umbo on the ear drum (ED) distance of the bilateral HJB (6.28 ± 1.72 mm) and the unilateral HJB groups (7.23 ± 2.00 mm) were significantly lower than that of the control group (11.15 ± 2.30 mm). In the coronal sections of the temporal bone HRCT, the JB-F distance of the bilateral HJB group (5.42 ± 2.10 mm) was significantly lower than that of the control group (8.30 ± 2.28 mm). As the mastoid pneumatisation and mastoid volume increased, the percentage of ICA-dehiscence and the percentage of JB-dehiscence increased. Conclusions. In subjects with well-pneumatised mastoids, the doctors should be aware of the increased risk of ICA-dehiscence and JB-dehiscence. These measurements should be done in greater series to yield more thorough knowledge (Adv Clin Exp Med 2015, 24, 2, 315-324).

Cranial venous sinus dominance: what to expect? Analysis of 100 cerebral angiographies

“…Because of its close relationship with the pneumatized petrous bone, this can be the cause for pulsatile tinnitus. 2 Identification of a high jugular bulb has great value when planning surgeries through the temporal bone and some authors have tried to correlate this with other anatomic findings 25 . The study by Friedmann et al 7 showed that jugular bulbs were not detected in patients younger than two years, became enlarged in adulthood, and remained stable in the elderly.…”

Jugular bulb and skull base pathologies: proposal for a novel classification system for jugular bulb positions and microsurgical implications

“…The upper limit of the jugular bulb is commonly found under the hypotympanum within the middle-ear cavity, 14,35 and an atypical presentation of the jugular bulb may be visualized as an upward extension of the bulb that invades into the hypotympanum. 35 Sasindran et al defines this extension of jugular bulb presenting in the middle-ear space with a thin or nonexistent bony septum as a high-riding jugular bulb (HRJB), which has been previously subclassified as "with dehiscence" or "without dehiscence."…”

Influence of pneumatization on morphology of temporal bone-related vasculatures and their morphometric relationship with ear regions: a computed tomography study

“…Anatomical variations of these vasculatures and their anomalies, such as protrusive SS, dehiscence SS, high or high riding JB, and JB dehiscence, are not rare in the TB 10 , 11 . For instance, high JB has been seen to occur in 6–20% of the population 11 .…”