Transcutaneous very-high resolution ultrasound for the quantification of carotid arterial intima-media thickness in children – Feasibility and comparison with conventional high resolution vascular ultrasound imaging

Objective: To study the accuracy and feasibility of very-high resolution ultrasound (VHRU, 25e55 MHz) and conventional high resolution ultrasound (HRU, 12 MHz) in the assessment of common carotid intima-media thickness (IMT) in healthy children between 0 and 18 years of life. Methods: IMT was measured with VHRU and HRU in 135 children. Seventeen similar sized porcine arterial specimens were imaged with VHRU and HRU, and the IMT measurements compared to histology. Results: Adequate imaging was obtained and IMT quantified in all children with 25 and 35 MHz, but the far wall was rarely reached with 55 MHz, even in small children. HRU-IMT was significantly thicker compared with VHRU-IMT in young children (<12 years; HRU: 0.434 � 0.040 vs. VHRU: 0.341 � 0.054 mm, N ¼ 66; p < 0.001). No differences between HRU-IMT and VHRU-IMT were found among older children. No differences were found between far and near wall VHRU-IMT. An increase in porcine arterial IMT with decreasing transducer frequency was observed in comparison to histology. HRU-IMT was significantly overestimated compared with VHRU-IMT and histology-IMT in porcine vessels with an IMT within the pediatric range (0.20e0.50 mm). Conclusion: VHRU is feasible and more accurate than HRU in quantifying CIMT in young children (<12 years). We recommend using the highest ultrasound transducer frequency applicable to quantify CIMT in the pediatric population.