Fig. 1
From: Changes in tonsillolith characteristics detected in a follow-up CT study
Methods for measurement of size, CT number, and depth of tonsilloliths on CT images. a The largest calculus (soft-tissue window setting, arrow) in the palatine tonsil was included in the analysis. b Size was defined as the long axis measurement (arrow) on soft-tissue window setting. c Position was defined as the shortest distance (arrow) from the surface of the respiratory tract on soft-tissue window setting. d Calcification level was defined as the maximum HU number on soft-tissue window setting, and the region of interest included the whole calculus (circle)