Diffusion-weighted MRI and PET-CT in the follow up of chronic periaortitis

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Chronic periaortitis (CP) management requires effective monitoring.
• Assessing treatment response in CP often involves serial imaging and laboratory tests.
• Differentiating active inflammation from fibrotic changes in CP can be challenging.

Purpose of the Study:

• To compare magnetic resonance imaging (MRI) and positron emission tomography (PET) parameters for chronic periaortitis (CP) follow-up.
• To evaluate changes in apparent diffusion coefficient (ADC) on MRI and standardized uptake values (SUV) on PET-CT.
• To correlate imaging findings with laboratory markers of inflammation.

Main Methods:

• Retrospective analysis of 14 patients with CP undergoing parallel abdominal MRI and PET-CT examinations.
• Comparison of relative contrast uptake and diffusion-weighted MRI parameters with SUVmax and laboratory markers (ESR, CRP).
• Statistical analysis of imaging parameter changes between baseline and follow-up, and their correlations.

Main Results:

• Both MRI and PET-CT parameters showed significant changes between baseline and follow-up examinations.
• Median ADC values significantly increased (p < 0.001) during follow-up.
• SUVmax and other MRI parameters (contrast uptake, DWI-signal) significantly declined.
• Strong negative correlations were observed between ADC and SUVmax (rho: -0.61; p < 0.001), and ADC with ESR (rho: -0.64; p < 0.001) and CRP (rho: -0.54; p = 0.001).

Conclusions:

• MRI and PET-CT provide comparable insights for individual CP follow-up and correlate with laboratory inflammation markers.
• Increased ADC values and decreased SUVmax indicate reduced inflammation.
• MRI is supported as the preferred initial imaging modality for CP follow-up due to the absence of ionizing radiation.