Feasibility of ¹⁸F-fluoromethylcholine PET/CT for imaging of vessel wall alterations in humans—first results

Recently published data indicated ¹⁸F-fluorocholine to be feasible for imaging vulnerable atherosclerotic plaques in an animal model.

Five patients undergoing whole-body ¹⁸F-fluoromethylcholine-(¹⁸F-FMCH-) PET/CT for imaging of prostate cancer disease were retrospectively evaluated. Whole-body PET scans were started immediately after i.v. injection of ¹⁸F-FMCH. About 5-15 min after tracer injection, acquisition of scans of the pelvis and abdomen was performed. PET, CT, and PET/CT slices were generated for review and visual analyses of the abdominal aorta and the common iliac arteries were performed. Vascular findings in examined arteries and surrounding structures due to artifacts were excluded from further analysis. The lower threshold of ¹⁸F-FMCH uptake was set above the background activity within the examined vessels. Morphological classification of vessel wall alterations (WA) included structural wall alterations without additional calcification (SWA), structural wall alterations associated with calcifications (SWC), and solely calcified lesions (CL). They were correlated with ¹⁸F-FMCH uptake qualified as present and vice versa.

A total of 31 WA were identified. Positive ¹⁸F-FMCH uptake was found in 14 lesions (SWA: n = 5; SWC: n = 9). Sixteen of 17 ¹⁸F-FMCH negative lesions were identified as CL without additional structural vessel wall alteration. One SWA did not show any ¹⁸F-FMCH accumulation. None of the CLs as well as unaltered parts of the vessel wall showed ¹⁸F-FMCH uptake.

Our initial data in five patients with a total of 31 vessel wall alterations show promising results indicating for the first time the feasibility of ¹⁸F-FMCH for in vivo imaging of structural WA in humans.