18 F-FDG PET/CT imaging for haemophilic arthropathy compared with clinical, radiological and power Doppler sonographic characteristics of 20 haemophilia patients

Repeated joint bleeding in haemophilia patients may lead to haemophilic arthropathy with marked inflammation and synovitis. This study investigated the potential of F-fluorodeoxyglucose positron emission tomography-computed tomography ( F-FDG PET/CT) as a novel diagnostic method for haemophilic arthropathy. We recruited 20 adult haemophilia patients who reported history of hemarthroses in the shoulder, elbow, hip, knee, or ankle joints. All joints were assessed by power Doppler ultrasonography and radiography, and graded by hyperaemia score and Pettersson score, respectively. Joint pain was evaluated by visual analogue score (VAS). Range of motion (ROM), Haemophilia Joint Health Score (HJHS) and annual joint bleeding rate (AJBR) were recorded. Finally, all participants had whole-body F-FDG PET/CT, and maximum standardized uptake value (SUVmax) of the joints being studied was measured. Thirteen patients had severe haemophilia, and seven had moderate haemophilia. The mean age was 36 years. PET SUVmax showed significant correlations with VAS, ROM, Pettersson score, hyperaemia score, HJHS score and AJBR in all large joints except hip. Joints with pain, hyperaemia and radiographic changes were found to have higher SUVmax than those without these features. Using Youden's index, the optimal cut-off value for early radiographical arthropathy was found to be between 1.9 and 2.0. Our study indicates that F-FDG PET/CT imaging correlated well with various conventional diagnostic techniques. It also demonstrated high sensitivity and specificity for early radiographic arthropathy. F-FDG PET/CT imaging may quantitatively evaluate disease activity of most large joints in a single examination and help detect early haemophilic arthropathy.