18F-sodium fluoride positron emission tomography is a sensitive imaging technique to detect atherosclerosis in Amazon parrots (Amazona spp).

OBJECTIVE

To investigate and establish a protocol for 18F-sodium fluoride (18F-NaF) PET scan imaging in Amazon parrots for atherosclerosis diagnosis.

METHODS

In this feasibility proof-of-concept study, 18F-NaF μPET scan and μCT scan were obtained on Hispaniolan (Amazona ventralis) and orange-winged Amazon parrots (A amazonica). A different μPET scan protocol was used for each species. Images were reviewed by 3 observers for arterial calcification and radiotracer uptake indicative of atherosclerosis. A blood lipid profile was also performed. A subset of Hispaniolan Amazon parrots were euthanized after completion of the study, and the heart and arteries were collected for histopathology.

RESULTS

10 adult Hispaniolan and 8 adult orange-winged Amazon parrots were scanned. Atherosclerotic lesions were detected on both μCT and μPET scan in various arteries. The presence of streak artifacts and increased noise on μCT scan limited the ability to detect high-attenuation areas of arteries and obtain observer consensus except for 1 case of severe arterial calcification. μPET scan was overall more sensitive, had higher interobserver agreement in lesion scoring, and detected a higher number of lesions in both species, including in coronary arteries. On histopathology on 5 Amazon parrots, the majority (5/6) of clinically relevant atherosclerotic lesions and some preatheromatous lesions (1/3) were identified on μPET scan. No association between atherosclerosis detection on μPET scan and the lipid profile was observed.

CONCLUSIONS

This study established a safe and effective protocol for 18F-NaF molecular imaging of psittacine atherosclerosis, which proved to be more sensitive than CT scan.

CLINICAL RELEVANCE

18F-sodium fluoride PET scan allows for a more reliable and earlier diagnosis of atherosclerotic lesions in Amazon parrots.