Thyroarytenoid muscle uptake and attenuation in PET/CT in elderly.

The objective of this study is to compare uptake and attenuation on positron emission tomography/computed tomography (PET/CT) imaging modality at the thyroarytenoid muscle between subjects aged less and older than 65 years old. The study design is retrospective chart review. The setting is academic medical center. PET/CT images of 60 patients aged less than 65 years old and 60 patients aged more than 65 years old were selected. Demographic data were collected. Both the groups were compared with respect to the maximum standardized uptake value (SUV max) and CT attenuation of bilateral thyroarytenoid muscles. The mean SUV max of the right thyroarytenoid muscle was 2.09 ± 0.8 in the group of patients aged less than 65 years old compared to 1.9 ± 0.6 in the group of patients aged more than 65 years old. For the left thyroarytenoid muscle, the mean SUV max in the first and second groups was, respectively, 2 ± 0.6 and 1.9 ± 0.6. The differences were not statistically significant. As for the CT attenuation, the mean value at the right thyroarytenoid muscle in the first and second groups was, respectively, 31.2 ± 0.8 HU and 20.8 ± 14.4 HU (p < 0.05). At the left thyroarytenoid muscle, the mean value was, respectively, 29.6 ± 9.9 and 22.8 ± 15 (p < 0.05). This study suggests that CT attenuation measurements can be used for objectively assessing the change in the density of aging thyroarytenoid muscle.