Gary Allan Ulaner MD,PHD, Presenter: Nothing to Disclose

L. Nayeli Aldrete, Abstract Co-Author: Nothing to Disclose

Barry Huang, Abstract Co-Author: Nothing to Disclose

Linh T. Ho MD, Abstract Co-Author: Nothing to Disclose

Peter Stephen Conti MD, PhD, Abstract Co-Author: Nothing to Disclose

John Louie Go MD, Abstract Co-Author: Nothing to Disclose

To assess FDG avidity in normal head and neck structures during aging.

A retrospective review was performed of 101 patients with no known head or neck disease who underwent FDG-PET/CT. 11 patients were under 20 years of age, 13 were 20-29, 40 were 30-49, and 37 were 50 or older. Standardized uptake values (SUV) were determined for the lymphoid and salivary tissues of the head and neck. Correlation between SUV and age was determined using the Pearson correlation coefficient (r).

SUV in normal head and neck structures ranged from 1.08 to 7.96. There was no more than 35% asymmetry in left-right paired structures. Individual examples of high FDG avidity in normal structures were seen at all ages, with a 38 year old patient having a sublingual gland SUV of 7.96, and even an 85 year old patient having a palatine tonsil SUV of 4.68, both of which were higher than their corresponding malignancies. In patients under 30 years of age, the palatine tonsils were most commonly the site of highest FDG avidity (SUV mean ± standard deviation of 4.34 ± 1.74). In patients between 30 and 49 years, the sublingual glands were most commonly the site of highest FDG avidity (SUV 4.13 ± 1.44). In patients older than 50, the palatine tonsils again had the highest FDG avidity (mean SUV 3.28 ± 1.03). There was a negative linear correlation between maximum SUV of normal head/neck structures and age (r = -0.375, 95% CI = -0.53 to -0.19, P = .0001).

The head/neck regions with the greatest FDG avidity change with age. There is a negative linear correlation between FDG avidity in the normal head/neck and age. Examples of high FDG avidity in the normal head/neck could be seen in patients from less than 10 to more than 80 years old. Normal FDG avidity in the head and neck shows symmetry in left-right paired structures.

Normal FDG avidity may be confused with disease. We provide ranges of FDG avidity in the normal head/neck from adolescence to older adults, guiding differentiation of normal and abnormal FDG avidity.

Ulaner, G, Aldrete, L, Huang, B, Ho, L, Conti, P, Go, J, FDG Avidity in the Head and Neck on PET/CT: Normal Ranges during Aging.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4428431.html