Assessment of age-related morphological and functional changes of selected structures of the head and neck by computed tomography, magnetic resonance imaging, and positron emission tomography.

The head and neck is a complex anatomical region that can be evaluated using many imaging modalities. It is important to discern normal structures from ones that are affected by disease and to study how these structures change in their morphological and functional properties with aging. Therefore, using magnetic resonance imaging (MRI), we retrospectively evaluated volumes of the parotid glands, submandibular glands, thyroid gland, tongue, soft palate, and lingual tonsils in 64 subjects ages 13 to 81 years. Volume, attenuation (HU), and metabolic activity (maximum SUV) of the parotid, submandibular, and thyroid glands were assessed retrospectively using positron emission tomography/computed tomography (PET/CT) imaging in 35 subjects ages 10 to 76 years. Metabolic activity (maximum SUV) of the parotid, submandibular, and sublingual glands; tongue; adenoids; and tonsils (lingual and palatine) were evaluated retrospectively using PET imaging in 15 subjects ages 6 to 20 years. Metabolic volumetric products of the parotid, submandibular, and thyroid gland were calculated and analyzed with increasing age in subjects who underwent PET/CT imaging. Structures that exhibited statistically significant changes (P < 0.05) with increasing age included the submandibular glands, thyroid gland, soft palate, and adenoids. The CT volume of the submandibular glands increased with age, and the attenuation decreased with age with statistical significance. The thyroid gland volume, as measured using MRI, showed a statistically significant decrease with aging. The volume of the soft palate and lingual tonsils, as measured by MRI, exhibited a statistically significant decrease in volume with aging. The maximum SUV of the adenoids demonstrated a statistically significant decrease with aging. In conclusion, CT, MRI, and PET may be used to quantitatively and qualitatively assess structures of the head and neck and are useful in the assessment of structural and functional changes of these structures with aging.