FDG-CT/PET false positive case in hip prosthesis: a clue to avoid error.

Area of Science:

• Nuclear medicine
• Radiology
• Orthopedic surgery

Background:

• Persistent joint pain after total hip arthroplasty can indicate complications.
• ¹⁸F-FDG PET/CT is used to assess joint inflammation and infection around implants.

Observation:

• A patient presented with symptoms suggestive of prosthetic joint infection.
• Initial ¹⁸F-FDG PET/CT showed abnormal tracer uptake near the hip prosthesis.
• Reconstruction of PET images without attenuation correction led to the disappearance of this uptake.

Findings:

• Computed tomography (CT) artifacts near metal implants can propagate into positron emission tomography (PET) data.
• Attenuation correction is crucial for accurate PET imaging interpretation in the presence of metallic hardware.
• The disappearance of focal uptake after reconstruction suggests it was an artifact, not true pathology.

Implications:

• Careful consideration of CT artifacts is essential when interpreting ¹⁸F-FDG PET/CT scans in patients with metallic implants.
• Standardized imaging protocols, including appropriate attenuation correction, are vital for reliable diagnostic accuracy.
• Misinterpretation of artifactual uptake could lead to incorrect clinical management decisions.