ultrasound-assisted extraction
ultrasound-guided fine-needle aspiration
ultrastructural
ultrastructural alterations

ultrastructural analysis
ultrastructural aspects
ultrastructural changes
ultrastructural characteristics
ultrastructural characterization

ultrastructural damage
ultrastructural data
ultrastructural description
ultrastructural differences
ultrastructural evaluation

ultrastructural evidence
ultrastructural examination
ultrastructural features
ultrastructural findings
ultrastructural investigations