Comparison between Awake Endoscopy and Computed Tomography to Define Lingual Tonsil Hypertrophy

Objectives To analyze correlations between endoscopic lingual tonsil grade (LTG) by the Friedman Lingual Tonsil Hypertrophy grading system and computed tomography (CT) measurements of lingual tonsil thickness (LTT). Study Design Retrospective chart review. Setting Single-center database, September 2016 to April 2017. Subjects and Methods Patients who received CT covering base of tongue and endoscopic LTG were included. LTT was measured on axial and sagittal CT. LTT measurements were compared against endoscopic LTG. One-way analysis of variance with Tukey's post hoc adjustment for multiple comparisons was performed. Results Seventy-five charts were included for a total of 150 LTT measurements. Axial CT measurements of LTG 1 and LTG 2 were each significantly different from LTG 3 ( P < .001 for both), and LTG 1 and LTG 2 also differed significantly ( P = .010). Mean sagittal CT measurements were significantly different between LTG 1 and LTG 3 ( P < .001) and between LTG 2 and LTG 3 ( P = .002) but not between LTG 1 and LTG 2 ( P = .186). Those without lingual tonsil hypertrophy had a mean axial CT thickness of 6.45 ± 1.39 mm and mean sagittal CT thickness of 6.58 ± 1.53 mm, which was significantly different from both the mean axial CT thickness of 8.48 ± 1.52 mm and the mean sagittal CT thickness of 8.07 ± 1.16 mm in the LTG 3 group ( P < .001 for both). Threshold analysis showed a potential cutoff of approximately 7.5 mm on axial and sagittal CT for defining clinically significant lingual tonsil hypertrophy. Conclusion Awake endoscopy grading of lingual tonsil hypertrophy is a subjective measurement that seems to correlate with objective CT measurements. LTT measurements of LTG 1 and LTG 2 on awake endoscopy differed significantly from LTG 3.