αc refers to the abdominal circumference of the fetus when B-ultrasound is performed, and ac277mm refers to the abdominal circumference of the fetus of 277mm.
B-ultrasound is the main examination method of ultrasound, and ultrasound has developed rapidly, such as endoscopic ultrasound, contrast-enhanced ultrasound, three-dimensional imaging, elastic imaging, etc., all of which are developed on the basis of B-ultrasound. Therefore, all doctors and patients undergoing ultrasound examination should understand the characteristics, preparation before examination, examination scope and matters needing attention of B-ultrasound, so as to make better use of it to serve the patients under examination.