Does [18F]F-FDG-PET/MRI add metabolic information to magnetic resonance image in childhood-onset Takayasu’s arteritis patients? A multicenter case series

Abstract

Background The observation that 2-deoxy-2[18F]fluoro-D-glucose-positron emission tomography/magnetic resonance imaging ([18F]F-FDG-PET/MRI) revealed high-grade arterial wall FDG uptake, without arterial wall thickening with contrast-enhancement, in a considerable number of c-TA patients in our previous study, encouraged us to compare patients with both PET and MR angiography (MRA) positives, with those with PET positive but MRA negative. Our aim was to evaluate the relevance of these two imaging modalities together. Methods A three-center cross-sectional study with 17 patients who fulfilled the EULAR/PRINTO/PReS criteria for c-TA and who underwent [18F]F-FDG-PET/MRI was previously performed. Herein we compared patients/vessels with positive PET (arterial wall 18F-FDG uptake higher than liver) and positive MRA (arterial wall thickening with contrast-enhancement)—group 1, with those with positive PET but negative MRA—group 2. Results Median disease duration of 17 c-TA patients was 10.4 years. Nine patients were classified as group 1 and six as group 2. Median of metabolic inflammatory volume (MIV) of all arterial segments was significantly higher in group 1 (2346 vs. 1177 cm3; p = 0.036). Fifty-four (19%) from 284 available arterial segments presented positive findings in vessel wall in one or both images. Positive findings were concordant between PET and MRA in only 13% arterial segments (group 1); most changes (28–59.6%) that were discordant between both images, were positive in PET and negative in MRA (group 2). Conclusion Our study demonstrated that [18F]F-FDG-PET/MRI added information about inflammation in vessel wall of c-TA patients. Prospective multicenter studies are needed in order to get solid data to guide immunosuppressive tapering and withdrawal.

Role of18F-FDG PET/CT in Large Vessel Vasculitis and Polymyalgia Rheumatica

“…These systems, including the new-generation PET/MRI scanners, may also visualize pathologic uptake in the smaller cranial vessels (e.g., temporal and vertebral arteries) (20,52). PET/MRI will further reduce the radiation dose, because CT lacks comparable accuracy in GCA diagnosis (53), and it has the advantage of tissue characterization of GCA and PMR, which is of particular value in younger individuals and in (repetitive) monitoring of disease activity (54,55). Combining total-body systems with more specific immuno-PET tracers for vasculitis would allow more thorough insight into how specific cell subpopulations are involved and behave in the pathogenesis of specific types of vasculitis.…”

Systemic vasculitis: one year in review 2023

“…Many molecules have been proposed to replace 18 F-FDG ( 27), but still none of them found use in clinical practice. Another imaging technique that may find application in the future is [ 18 F]F-FDG-PET/MRI (28,29), even though at present there is still need to improve its interpretation parameters. Magnetic resonance angiography is an alternative technique already largely employed in clinical practice to assess vascular wall inflammation.…”

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

“…The combination of PET with MR imaging for anatomical localization (PET-MRI) was explored in a few reports in TAK and GCA [ 81 , 82 , 83 ]. One reported greater uptake in PET-MRI with active LVV than inactive LVV [ 81 ].…”

“…One reported greater uptake in PET-MRI with active LVV than inactive LVV [ 81 ]. Another study reported discordance between arterial wall uptake on PET-CT and vessel wall uptake on MRA [ 83 ]. The role of PET-MRI for the assessment of disease in TAK will require further evaluation.…”