Prevalence and imaging characteristics of nasopharyngeal and eustachian tube tonsilloliths in 2244 patients determined using computed tomography - Takahashi, Akira; Sugawara, Chieko; Akita, Kazuya; Kamada, Kumiko; Kudoh, Keiko; Tamatani, Tetsuya; Miyamoto, Youji (Dento-maxillo-facial radiology, 2018)