Carotid body measurement by computed tomography angiography: a cross-sectional population-based study

Carotid bodies (CBs) are chemoreceptors located at the bifurcation of the common carotid arteries, playing an essential role in maintaining blood gas homeostasis and regulating cardiovascular function. CBs are increasingly affected in various systemic pathologies, particularly those involving sympathetic overactivation, including hypertension and heart failure. Despite CB hypertrophy in these conditions has been well-studied, normative data on dimensions remain scarce. This study aimed to establish reference ranges for CB size in a large Iranian population using computed tomography angiography (CTA).

A cross-sectional study of 650 patients who underwent neck CTA (April 2023-April 2025) was conducted. After excluding 36 patients with carotid body tumors and further removing cases with missing, unmeasurable, or outlier measurements, 521 patients were included for final analysis. CB dimensions were measured in both the transverse (R1) and anteroposterior (R2) planes. Reference ranges were calculated and stratified by age, sex, and comorbidity status. In addition, subgroup analysis was performed to examine the influence of chronic diseases including hypertension, diabetes mellitus, hyperlipidemia, cardiovascular disease, chronic obstructive pulmonary diseases, cerebrovascular accident/transient ischemic attack (CVA/TIA), and thyroid disease.

In this study, the mean R1 of the CB was 2.66 ± 0.5 mm, and the mean R2 was 3.25 ± 0.61 mm. Notable size variations were observed across age groups, with the 60-70 years group showing a marginally significant larger R1 of 2.96 ± 0.45 mm and R2 of 3.54 ± 0.51 mm (p-value = 0.070). No statistically significant differences were observed across sex categories. Also, participants with chronic diseases exhibited slightly larger CBs compared to those without (R1 = 2.71 ± 1.20 vs. 2.57 ± 0.52, p-value = 0.128 and R2 = 3.30 ± 1.34 vs. 3.17 ± 0.63, p-value = 0.204, respectively).

This study provides a comprehensive reference ranges for CB dimensions in a general population, with specific subranges based on age, sex, and comorbidities. These findings can enhance diagnostic accuracy and help distinguish between normal CB enlargement and pathological conditions.