Normal norms of carotid vessel wall volume in Taiwanese adults as measured using three-dimensional ultrasound.

Purpose: The three-dimensional (3D) measurement of vessel wall volume (VWV) and plaque volume is sensitive for predicting cardiovascular risk. We established the normal norms of carotid VWV.

Methods: We retrospectively enrolled 352 patients with normal findings of the carotid ultrasound studies. Two-dimensional carotid intima-media thickness (IMT) was measured online. Grayscale 3D images of both sides of the carotid arteries were analyzed offline for measurement of IMT (QIMT) and VWV.

Results: The median age of the enrollees was 59 years. The median carotid IMT, QIMT, and VWV was 0.61 mm, 0.72 mm, and 90 mm3, respectively. No differences in IMT and VWV were observed between men and women or between the right and left side. We stratified participants into four groups, namely young adults (≤50 years), middle-aged adults (51-65 years), older adults (66-75 years), and senior adults (≥75 years). All the values of measured variables increased with advancing age. The median VWV of each group was 84, 90, 100, and 112 mm3, respectively. The increment percentage from young to senior adults was similar in terms of IMT and VWV. Nevertheless, the difference in the value of VWV (28 mm3) was much larger than that in IMT (0.18 mm). All three measured variables exhibited a positive linear correlation with age.

Conclusion: Both IMT and VWV have positive linear correlations with age. The application of QIMT measurements was limited by its inconsistent accuracy. VWV not only has a strong correlation with IMT but also enables observation of dynamic vessel wall changes, which is valuable for clinical observational studies.