401072 Lecture Notes - Lecture 7: Vaginal Ultrasonography, Gestational Sac, Echogenicity
Document Summary
Echogenic giving rise to re ections (echoes) of ultrasound waves: hyperechoic more echogenic (brighter) than normal, hypoechoic less echogenic (darker) than normal. Transvaginal ultrasonography - ultrasound is performed through the vagina. Trasnabdominal ultrasonography - ultrasound is performed across the abdominal wall or through the abdominal cavity. In normal state, each body tissue type, such as liver, spleen or kidney, has a unique echogenicity. Fortunately, gestational sac, yolk sac and embryo are surrounded by hyperechoic (brighter) body tissues. Traditional obstetric sonograms are done by placing a transducer on the abdomen of the pregnant woman. One variant, a transvaginal sonography, is done with a probe placed in the woman"s vagina. Transvaginal scans usually provide clearer pictures during early pregnancy and in obese women. Also used is doppler sonography which detects the heartbeat of the fetus. Doppler sonography can be used to evaluate the pulsations in the fetal heart and bloods vessels for signs of abnormalities.
