Resolution of Pulmonary FDG-embolus on Same-day Delayed Imaging

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Imaging

Background:

• 18F-FDG PET/CT scans are crucial for diagnosing various conditions, including lung nodules.
• Artifacts can mimic true pathology, leading to misdiagnosis and unnecessary procedures.
• Iatrogenic FDG-emboli, or "hot-clots," are a known artifactual finding in PET/CT imaging.

Purpose of the Study:

• To investigate the resolution time of iatrogenic 18F-FDG emboli on delayed PET/CT imaging.
• To determine if early resolution can obviate the need for repeat radiotracer injection and imaging.
• To highlight a method for reducing patient radiation exposure from artifactual findings.

Main Methods:

• A 32-year-old woman underwent an 18F-FDG PET/CT scan for a lung nodule.
• Incidental focal uptake was noted in the right lung without CT correlation.
• Repeat imaging was performed 55 minutes later to assess the uptake's persistence.

Main Results:

• The focal uptake resolved completely on delayed imaging.
• This resolution confirmed the finding as an iatrogenic FDG-embolus artifact.
• The artifact resolved within one hour, suggesting a short-lived phenomenon.

Conclusions:

• Iatrogenic FDG-emboli can resolve rapidly on delayed PET/CT imaging.
• Early resolution within an hour can negate the need for repeat radiotracer injection.
• This approach minimizes patient radiation exposure and healthcare costs.