
Keywords: غضروف کریوئید; PDT; Percutaneous dilational tracheostomy; ICU; Intensive care unit; US; Ultrasound; CNS; Central nervous system; MV; Mechanical Ventilation; CC; Cricoid cartilage; A-M; air-mucosa; CTA; Comet tail artifact; SM; Strap muscle; TG; Thyroid gland; Tracheosto