Fig 1.

Comparison of spectral Hounsfield unit characteristics of normal nonossified thyroid cartilage in healthy subjects and patients with tumors. A, Baseline characteristics of NOTC evaluated in 10 healthy subjects is shown. For each patient, NOTC was evaluated with 9 ROIs on each side, corresponding to 18 ROIs total per patient, and 180 ROIs (90 ROIs for each side of the NOTC/curve). There was no significant difference in NOTC attenuation between the right and left sides across the virtual monochromatic range of 40–140 keV. B, Comparison of normal NOTC in healthy patients (right and left combined; n = 10, by using 180 ROIs) and normal or unaffected NOTC in the tumor group (n = 27, by using 243 ROIs). C, Pooled spectral Hounsfield unit curve demonstrating characteristics of normal NOTC in the entire patient population (n = 37). Values shown are mean ± SD.