Changes in the thymus gland with age: A sonographic evaluation.

Area of Science:

• Pediatric Radiology
• Medical Imaging
• Anatomy

Background:

• Ultrasound evaluation of the thymus in children presents challenges, particularly in differentiating normal variations from abnormalities.
• Few studies have comprehensively investigated age-related sonographic changes in the pediatric thymus.

Purpose of the Study:

• To investigate age-specific sonographic changes in the normal thymus of healthy children.
• To establish reference sonographic features of the pediatric thymus across different age groups.

Main Methods:

• A cross-sectional study involving 118 healthy children, categorized into six age groups.
• Sonographic assessment of thymic features including volume, position, symmetry, and echo-texture using ultrasound.
• Data collection from the suprasternal view, recording thymic visibility and characteristics.

Main Results:

• The thymus was consistently visualized via ultrasound in all age groups from the suprasternal view.
• Thymic echo-texture demonstrated distinct age-related patterns: hypoechoic (below 2-3 years), echogenic foci/starry sky (2-14 years), and uniform/geographic hyperechoic (above 14 years).
• No significant correlation was found between age and sex with total thymic volume; mean volume was 21.3 ± 10.5 mm.

Conclusions:

• Ultrasound is a reliable modality for visualizing the pediatric thymus across all ages.
• The echo-texture of the normal thymus exhibits significant age-dependent variations, aiding in its sonographic characterization.
• Thymic volume shows no significant correlation with age or sex, reinforcing ultrasound's role in pediatric thymic evaluation.