a-scan ultrasound biometry acoustic impedance angular resolution aorta appendicitis autocorrelation technique b-scan ultrasonography backscatter bile duct biopsy blood-brain barrier bone brain breast cardiology carl hellmuth hertz cataract ceramic computed tomography confocal laser scanning microscopy contrast-enhanced ultrasound cross-correlation dental hygienist diagnosis digital object identifier doppler effect dual energy x-ray absorptiometry duplex ultrasonography echo sounding echocardiography emergency ultrasound endocrinology experimental cancer treatment fetus frequency gastroenterology george ludwig glasgow glasgow royal maternity hospital gustav ludwig hertz gynaecology gynecologic ultrasonography hemolytic disease of the newborn hertz hue ian donald impedance impedance matching inferior vena cava intravascular ultrasound kidney kidney stone kockums lesion liver lund university magnetic resonance imaging medical imaging medicine muscle needle aspiration biopsy night writing nondestructive testing nuclear physics obstetric ultrasonography obstetrics occupational therapy ophthalmology ovary pancreas phacoemulsification phased array physical therapy placenta praevia portal hypertension pregnancy probe professional prostate radar redshift scotland soft tissue sonographer spleen tendon the lancet transcranial doppler transducer transfusion ultrasound university of colorado denver urinary bladder urology uterus vagina vermiform appendix yorkhill