Clinical value of 18F-FDG PET/CT imaging in evaluation of antineutrophil cytoplasmic antibody-associated vasculitis / 中华核医学与分子影像杂志

ABSTRACT

Objective To explore the clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT in assessing antineutrophil cytoplasmic antibody-associated vasculitis (AAV).Methods Fifteen patients (7 males,8 females,age (66±11) years) with AAV between January 2015 and June 2017 were retrospectively analyzed.There were 6 patients diagnosed as granulomatosis with polyangiitis (GPA),7 diagnosed as microscopic polyangiitis (MPA) and 2 diagnosed as eosinophilic granulomatosis with polyangiitis (EGPA).All patients underwent 18 F-FDG PET/CT and the image features were observed and analyzed.The maximum standardized uptake value (SUVmax) of the positive lesion was measured.The relationship between the SUVmax and C reactive protein (CRP) was analyzed with Pearson correlation.The SUVmax and the number of lesion sites were compared by two-sample t test between the CRP-elevated and CRP-normal patients.Results A total of 56 lesions in the 14 of 15 AAV patients were detected by PET/CT.The positive findings distributed in 15 tissues and organs,including the nasopharynxes (n =9),lungs (n =9),kidneys (n =8),spleen (n =6),lymph nodes (n =6),bone marrow (n =4),skin (n =3),prostate (n =2),aortas (n =2),vertebral soft tissues (n =2),orbita (n =1),parotid gland (n =1),thyroid gland (n =1),liver (n =1) and pancreas (n=1).The 60.7％ (34/56) of lesions were clinically unsuspected occult lesions.GPA lesions mainly invaded the nasopharynxes,lungs and kidneys;MPA lesions mainly invaded the kidneys and spleen;EGPA lesions mainly invaded the nasopharynxes,lymph nodes and bone marrow.There was no significant correlation between the level of CRP and the SUVmax of AAV lesions (r=0.462,P＞0.05).No differences in the SUVmax were observed between patients with elevated CRP levels and those with normal CRP levels (t=1.451,P＞0.05).But more lesion sites were observed in patients with elevated CRP (t=3.456,P＜0.05).Conclusions 18F-FDG PET/CT shows positive findings in multiple sites in AAV patients,including clinically unsuspected sites.This imaging technique may be a useful tool for diagnosis and evaluation of AAV.