Jugular Bulb Position Variability on Temporal Bone HRCT

Objective: To determine the prevalence of jugular bulb (JB) variations in a Pakistani population, including high-riding jugular bulbs (HRJB) and JB dehiscence. Study Design: A cross-sectional study. Place and Duration of the Study: Department of Radiology, the Aga Khan University Hospital, Karachi, Pakistan, from May 2024 to April 2025. Methodology: This study analysed HRCT images of 199 patients to evaluate the height of JB within the temporal bone on both the left and right sides. Patients who underwent a temporal bone HRCT scan, regardless of age or gender, were included in the study. Experienced radiologists reviewed the images to identify and classify the JB levels in the tympanic cavity according to the Manjila classification. The patients were categorised into five age groups. Demographic data and clinical indications were summarised using descriptive statistics. The chi-square analysis was used to determine the association between categorical variables, including JB type, age category, and gender. Results: Type 2 was the most common on both sides combined, followed by Types 1, 4, and 3, respectively. A significant association was observed between JB type and age category (p = 0.002). However, JB type and gender were not significantly associated (p = 0.857). A significant association was also observed between the presence of an HRJB and age category (p = 0.005). Conclusion: The frequency of HRJB and the significance of individual variations in JB anatomy underscore the need for comprehensive preoperative evaluation and advanced imaging techniques.