[1] Johns Hopkins Univ, Dept OtolaryngologyHead & Neck Surg, Sch Med, 610 N Caroline St,6th Floor, Baltimore, MD 21287 USA
[2] Hosp Univ Penn, Dept OtorhinolaryngologyHead & Neck Surg, 3400 Spruce St, Philadelphia, PA 19104 USA
[3] Childrens Hosp Philadelphia, Dept Radiol, Philadelphia, PA 19104 USA
[4] Childrens Hosp Philadelphia, Div Otolaryngol, Philadelphia, PA 19104 USA