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

ABSTRACT

PURPOSE: Recently published data indicated (18)F-fluorocholine to be feasible for imaging vulnerable atherosclerotic plaques in an animal model. METHODS: Five patients undergoing whole-body (18)F-fluoromethylcholine-((18)F-FMCH-) PET/CT for imaging of prostate cancer disease were retrospectively evaluated. Whole-body PET scans were started immediately after i.v. injection of (18)F-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 (18)F-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 (18)F-FMCH uptake qualified as present and vice versa. RESULTS: A total of 31 WA were identified. Positive (18)F-FMCH uptake was found in 14 lesions (SWA n = 5; SWC n = 9). Sixteen of 17 (18)F-FMCH negative lesions were identified as CL without additional structural vessel wall alteration. One SWA did not show any (18)F-FMCH accumulation. None of the CLs as well as unaltered parts of the vessel wall showed (18)F-FMCH uptake. CONCLUSIONS: 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 (18)F-FMCH for in vivo imaging of structural WA in humans.