Cervical ultrasound for the evaluation of the vocal cords: A pilot study in an endocrine surgery unit Luis Eduardo Pérez-Sánchez; Eugenia Caballero-Rodríguez; Rafael Orti-Rodríguez; Ana Soto-Sánchez; Miguel Ángel García-Bello; Julio César Jordán-Balanza; Manuel Ángel Barrera-Gómez;