Characteristics and Limitations of FDG PET/CT for Imaging of Squamous Cell Carcinoma of the Head and Neck: A Comprehensive Review of Anatomy, Metastatic Pathways, and Image Findings.

Objective: This image-based article illustrates the anatomic regions of squamous cell carcinomas of the head and neck and describes the metastatic pathways in and TNM staging for each region. Both the role and limitations of FDG PET/CT in imaging such cancers are discussed, and cases exemplifying these issues are reported. Also included is a discussion of the use of FDG PET/CT to monitor the response of squamous cell carcinomas of the head and neck to therapy, in addition to a brief comparison of PET/CT with such traditional imaging modalities as CT, MRI, and ultrasound.

The effects of external torque on polyethylene tibial insert damage patterns.

The forces and torques that occur during walking gait, particularly during toe-off, promote articulation in the posteromedial quadrant of tibial inserts. Retrieved components of failed knee arthroplasties show ultrahigh molecular weight polyethylene damage patterns in this region. Component-designed constraint, compromised polymer, and surgical factors account for these observations.