An anatomical and radiological study of the high jugular bulb on high-resolution CT scans and alcohol-fixed skulls of adults

Although many reports mention a “high jugular bulb” (HJB), it is often not clearly defined. We examined the relationship between the jugular bulb (JB) and the internal auditory canal (IAC) in 200 temporal bones on high resolution CT scans and alcohol-fixed skull bases of adults. The average distance (±standard deviation) between the IAC and the JB was 7.5 ± 2.3 mm (range, 1–16 mm). The JB was higher on the right side than its companion in 53.3% of patients (left side only in 22%; no side dominance in 23.7% of bases). When the JB reached or exceeded the floor of the IAC (16.5%), it was defined as a HJB; 61% of HJB were found in females. Bilateral HJB was found in 0.5% of patients. The HJB was not associated with a contralateral flat JB. Preoperative multiplanar high resolution CT reconstructions make the most detailed assessment of structural topography.