RESUMO
PURPOSE: To compare the contribution of the (18)F-FDG-PET/CT acquisition at 180 min and at 60 min in suspicion of large vessel vasculitis (LVV). MATERIAL AND METHODS: A prospective study including 23 patients was performed. PET/CT was acquired at 60 and 180 min (early and delayed scan) after (18)F-FDG injection. A visual analysis was performed at the supra-aortic trunks (SAT), thoracic aorta (TA), abdominal aorta (AA), iliac arteries (IA) and femoral/tibioperoneal arteries (FTA). Intensity (0-3) and uptake pattern (diffuse/linear) were assessed in the 115 vascular regions. RESULTS: There was no FDG uptake in the early and delayed acquisition in 20/115 vascular regions (17.4%). Of the 95 regions (82.6%) showing FDG uptake at the early, delayed or both acquisitions, intensity did not change in the delayed acquisition in 46 and changed in 49. Of the 49 regions in which the intensity changed, it decreased in 36 and increased in 13 (TA:8, SAT:5). AA, IA and FTA intensity did not increase in any of the cases. Uptake pattern at the TA in the early acquisition was diffuse in 16 patients. In 7, it changed to linear and in 9 the uptake disappeared. The early pattern was linear in 7 patients and 6 of them showed increased intensity in the delayed acquisition and in 1 remained the same. CONCLUSION: The 180 min delayed FDG-PET/CT acquisition provides a more detailed visualized of the vessel wall, showing the washout of the blood pool activity. Therefore, it may contribute to a more accurate diagnosis of LVV.
Assuntos
Fluordesoxiglucose F18/farmacocinética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/farmacocinética , Tomografia Computadorizada por Raios X , Vasculite/diagnóstico , Vasculite/metabolismo , Idoso , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de TempoRESUMO
AIM: To assess the calcification process of the carotid plaque by (18)F-sodium fluoride PET/CT imaging. MATERIAL AND METHODS: A prospectively designed study including 15 patients in whom an atheroma plaque was detected by contrast enhanced CT scan during a neurological work-up was performed. A total of 29 plaques, 19 asymptomatic and 10 symptomatic, were studied. An (18)F-sodium fluoride PET/CT scan was acquired 180min after the i.v. injection of 370 MBq of (18)F-sodium fluoride in all the patients. The images obtained were analyzed visually according to the intensity of the uptake. RESULTS: All the plaques showed (18)F-sodium fluoride uptake, regardless of the intensity. However, the plaques of the symptomatic group showed a level of 2 or greater intensity while the intensity in 6 of the 19 in the asymptomatic group was lower than 2. CONCLUSIONS: Although the study is limited by the small number of cases, the results show the feasibility of the technique to study the calcification of the atheroma using (18)F-sodium fluoride and suggest an association between symptomatology and higher uptake of (18)F-sodium fluoride. Thus, these results encourage us to continue this study, with the inclusion of a larger number of patients.
