Normative values of thymus in healthy children; stiffness by shear wave elastography

• Published in: Diagnostic and interventional radiology (Ankara, Turkey) Turkey), 2020-03, Vol.26 (2), p.147-152
• Main Authors: Bayramoglu, Zuhal, Ozturk, Mehmet, Caliskan, Emine, Ayyildiz, Hakan, Adaletli, Ibrahim
• Format: Article
• Language: English
• Subjects: Age; Age Factors; Age groups; Body size; Child; Child, Preschool; Children; Elasticity; Elasticity Imaging Techniques - methods; Female; Gender; Humans; Infant; Infant, Newborn; Involutes; Male; Pediatric Radiology; Prospective Studies; Reference Values; Shear; Stiffness; Thymus gland; Thyroid Gland - anatomy & histology; Ultrasonic imaging; Wave propagation; Wave velocity; Weight
• ISSN: 1305-3612; 1305-3825; 1305-3612
• DOI: 10.5152/dir.2019.19344

Thymus grows after birth, reaches maximal size after the first few years and involutes by puberty. Because of the postnatal developmental and involutional duration, we aimed toinvestigate normal stiffness values of mediastinal thymus by shear wave elastography (SWE) in different age groups of children and discuss imaging findings of thymus. We prospectively examined 146 children (90 girls, 56 boys) who underwent a thyroid or neck ultrasound examination. All subjects underwent ultrasound and SWE evaluation of mediastinal thymus by parasternal and suprasternal approach. We subdivided the subjects based on the ages as 0 to 2 months (group 1), >2 to 6 months (group 2); >6 months to 2 years (group 3), >2 to 5 years (group 4), >5 to 8 years (group 5), and greater than 8 years old (group 6).We investigated differences of mean shear wave elasticity (kPa) and shear wave velocity (m/sec) values among age groups and the association of SWE values with age, body mass index (BMI), height, and weight of the patients. Medians and ranges of age, height, weight, and BMI were 24 (2-84) months, 85 (55-120) cm, 12(4.55-22) kg, 15.37 (13.92-17.51) kg/m2, 11 (2.64-23.15) cc, respectively. Mean shear wave elasticity of thymus when all participants were included was 6.76±1.04 kPa. Differences of mean elasticity values among age groups and also gender groups were not statistically significant. There were highly significant negative correlations among age (r:0.3), height (r:0.26), weight (r:0.3) with elasticity and also velocity values (p