Patterns of 18 F-fluorodeoxyglucose (FDG) uptake in the neck muscles on PET-CT imaging: Normal anatomy and interpretative pitfalls

Learning Objectives 1. Recognize normal anatomy and orientation of the major neck muscles. 2. Identify the common uptake patterns of 18F-Fluorodeoxyglucose (FDG) in the various neck muscle groups. 3. Understand the interpretative pitfalls from anatomic variants and unusual distribution of 18 F- FDG uptake in the neck musculature.

The neck region with its complex arrangement of muscles and vital structures connecting the head and thorax presents challenges for nuclear medicine physicians who are developing expertise in PET-CT. This educational exhibit illustrates various examples of the most common normal patterns of FDG neck muscle uptake on PET-CT imaging along with anatomic variants and unusual distribution patterns that may cause diagnostic dilemmas. Combined PET-CT has the dual advantage of using the anatomic depiction of neck muscles and the functional FDG muscle uptake to clearly delineate the location and orientation of these muscles. We demonstrate the major neck muscles using a variety of PET-CT images and diagrams. Unusual FDG uptake patterns due to muscle activity/contraction, muscle injury/imbalance and post surgical or radiation changes must be recognized during image interpretation to avoid misdiagnosis. This exhibit may improve the level of confidence of nuclear medicine physicians interpreting PET-CT