Imaging modalities in the diagnosis and monitoring of IgG4-Related disease: Utilization patterns and clinical implications

Objective: Immunoglobulin G4-related disease (IgG4-RD) is a chronic fibroinflammatory disorder affecting multiple organ systems, often requiring imaging for diagnosis and monitoring. Despite its critical role, an optimal imaging strategy, including modality preference and follow-up intervals, remains undefined. This study evaluates the utilization patterns of different imaging modalities in IgG4-RD.Materials and methods: This retrospective, single-center study included 18 patients diagnosed with IgG4-RD according to ACR/EULAR criteria between May 2020 and December 2024. Clinical, laboratory, histopathological, and imaging data were collected. Computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET-CT) were analyzed for diagnostic and follow-up trends. Patients were stratified based on the presence of acute kidney injury (AKI) at diagnosis.Results: At diagnosis, CT (83.3%) was the most frequently used modality, followed by PET-CT (61.1%) and MRI (27.8%). Combined imaging was performed in 66.6% of cases initially but declined during follow-up. The choice of the first follow-up imaging differed between patients with and without AKI (p=0.072). Notably, follow-up imaging intervals were significantly shorter in AKI patients (30.5 vs. 49 months, p=0.049). Over time, PET-CT use decreased, while MRI became the preferred modality. Despite these variations, no standardized follow-up approach was observed.Conclusion: Our findings indicate a shift from multimodal to single-modality imaging during follow-up, with variations based on AKI status. The lack of a standardized imaging protocol indicates the need for consensus guidelines to enhance disease monitoring and optimize patient outcomes.