Infectious Aortitis on 18 F-FDG PET/CT

Area of Science:

• Cardiology
• Infectious Diseases
• Radiology

Background:

• Infectious aortitis presents diagnostic challenges due to overlapping imaging features with noninfectious aortitis.
• Early and accurate diagnosis is crucial for effective treatment and improved patient outcomes.

Observation:

• A 58-year-old woman with SARS-CoV-2 and Streptococcus pneumoniae bacteremia presented with symptoms suggestive of aortitis.
• 18F-FDG PET/CT imaging revealed extensive large vessel vasculitis affecting the thoracic aorta, abdominal aorta, and brachiocephalic branches.
• An incidental subcutaneous abscess was noted in the right arm.

Findings:

• The 18F-FDG PET/CT findings indicated infectious aortitis, specifically large vessel vasculitis.
• Treatment with standard of care resulted in significant clinical improvement.
• A notable reduction in aortic wall thickening was observed within one week of treatment initiation.

Implications:

• 18F-FDG PET/CT is a valuable tool for diagnosing infectious aortitis, even in complex cases involving concurrent infections.
• Rapid improvement in aortic wall thickening on PET/CT may serve as a surrogate marker for treatment response in infectious aortitis.
• This case underscores the importance of considering infectious etiologies in large vessel vasculitis, especially in the context of systemic infections.