Figure 5: Transverse scans, (a) Over the hyoid bone, (b) At thyrohyoid membrane showing epiglottis with hyperechoic preepiglottic space and air–mucosal interface, (c) At the level of thyroid cartilage and false vocal cords, (d) At the level of cricoid cartilage seen as horseshoe-shaped hypoechoic structure (inverted-C) with a hyperechoic A-M interface beneath it, (e) At the suprasternal notch showing hypoechoic tracheal rings with a hyperechoic A-M interface and comet tail appearance beneath it. AM: air-mucosal interface, CC: cricoid cartilage, CTA: comet tail appearance, IsthT: thyroid isthmus, TC: thyroid cartilage, TG: thyroid gland, TrC: tracheal cartilage