[Prevalence of tonsilloliths and CT diagnosis]

Objective: To investigate the prevalence, gender and age distribution characteristics of tonsilloliths and its CT diagnosis, in order to improve the knowledge of clinicians. Methods: The images of 2 710 patients who underwent head and neck CT scans from November 2015 to November 2016 were retrospectively reviewed, the prevalence, gender and age distribution of tonsilloliths and CT manifestation were analyzed. SPSS 18.0 was used for statistical analysis. Results: Tonsilloliths were found in 383 (14.1%) of the 2 710 patients, including 217 men and 166 women. The prevalence was 15.1% in men and 13.1% in women, and no gender difference was seen. The age of patients with tonsilloliths ranged from 6-88 years, and the mean age was (51.1±16.8) years. The prevalence of tonsilloliths in patients 40 years and younger was significantly lower than in those who were over 40 years (χ(2)=15.201, P<0.001), and the prevalence of tonsilloliths was positively correlated with age(r=0.812, P=0.008). One hundred and twenty eight cases of tonsilloliths were located on the right side, and 157 were located on tleft side. Tonsilloliths were detected bilaterally in 98 patients. There was no significant difference between left and right sides(χ(2)=1.919, P=0.166). Most of tonsilloliths showed a single small tonsillolith, 60.6% of tonsilloliths showed only one tonsillolith, whereas 39.4% showed two or more. The size of tonsilloliths ranged from 1.0 to 10.0 mm, the mean maximum diameter was (2.3±1.2) mm, and 86.7% of tonsilloliths with a maximum diameter of no more than 3.0 mm. Tonsilloliths showed dot, round or oval hyperdense in tonsillar crypt or parenchyma. CT attenuation of majority tonsilloliths was over 120 Hu. Conclusion: Tonsilloliths are more common than previously suggested, its CT diagnosis is not difficult, and the knowledge of clinician and radiologist needs to be improved.