TITLE:
Pediatric Takayasu Arteritis Unmasked by Serial FDG-PET/CT: A Case-Based Comprehensive Review and Practical Diagnostic Algorithm
AUTHORS:
Ricardo Donado-Botero, Clara-Castiblanco Arroyave, Jorge Lujan-Pinzón, Ana Hernandez-Villadiego, Juliana Cardoso-Prada, Camila Duran-Naizir, María Camila Rodriguez-Acosta, Andrés Ahumada-Uribe, Carolina Polo-Batista, Emil Fonseca-Padilla, Alexa Pinto-Mejia, Daniela Zuluaga-Ramos
KEYWORDS:
Takayasu Arteritis, Pediatric Vasculitis, Large-Vessel Vasculitis, Positron Emission Tomography Computed Tomography, Magnetic Resonance Angiography, Vascular Inflammation, Early Diagnosis, Immunosuppressive Agents
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.14 No.4,
April
30,
2026
ABSTRACT: Background: Pediatric Takayasu arteritis (TA) often begins with nonspecific systemic inflammation, while classic vascular manifestations may be absent during the early inflammatory phase. This frequently results in diagnostic delay and exposes patients to progressive vascular injury. Structural imaging modalities such as magnetic resonance angiography (MRA) may be unrevealing before luminal compromise develops. In contrast, metabolic imaging with fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can detect early vessel-wall inflammation. Case Presentation: We reported a 12-year-old male presenting with persistent systemic inflammatory symptoms and elevated acute-phase reactants. Initial diagnostic evaluation, including contrast-enhanced MRA of the aorta and its major branches, did not demonstrate definitive structural abnormalities. Despite negative structural imaging, clinical suspicion for large-vessel vasculitis remained high due to sustained inflammatory markers and evolving clinical features. An initial FDG-PET/CT was nondiagnostic; however, a repeat FDG-PET/CT performed in the context of ongoing inflammation demonstrated increased metabolic uptake along the aorta and primary branch vessels, consistent with active Takayasu arteritis. High-dose glucocorticoids were initiated followed by steroid-sparing immunosuppression with methotrexate, resulting in clinical and laboratory improvement. Review Aim and Methods: Using this case as a framework, we conducted a comprehensive narrative review focusing on early pediatric TA presentation, diagnostic pitfalls, comparative imaging strategies (Doppler ultrasound, CTA, MRA, and FDG-PET/CT), and the role of serial metabolic imaging in cases with persistent inflammatory activity and inconclusive structural studies. Key Insights: Evidence suggests that FDG-PET/CT may detect inflammatory vascular activity preceding structural luminal changes. Serial metabolic imaging may therefore be particularly valuable in pediatric patients with sustained systemic inflammation and nondiagnostic initial MRA, helping reduce diagnostic delay and prevent irreversible arterial damage. Conclusion: In children with persistent inflammatory markers and high clinical suspicion for large-vessel vasculitis, a negative initial MRA should not exclude Takayasu arteritis. Serial FDG-PET/CT can unmask early inflammatory-phase disease and should be considered within a pragmatic diagnostic algorithm to facilitate timely diagnosis and treatment.