99Tcm-MDP imaging for the diagnosis of joint infection after total hip arthroplasty / 中华核医学与分子影像杂志

ABSTRACT

Objective To investigate the value of 99Tcm-MDP imaging for the differential diagnosis between infection and aseptic loosening after total hip arthroplasty.Methods During February 2008 to August 2011,74 patients (32 males,42 females,average age (64.3±11.2) years) with hip pain after arthroplasty underwent 3-phase (blood flow,blood pool and bone phases) 99Tcm-MDP imaging.All patients had measurements of serum C reactive protein (CRP) and erythrocyte sedimentation rate (ESR).Joint infection was defined as either increased peri-prosthetic soft tissue activity during perfusion and blood pool phases or increased peri-prosthetic bone activity during uptake phase,or positive in all 3 phases.Aseptic loosening was defined as having negative 99Tcm-MDP in all 3 phases.Clinical diagnosis was chosen as the gold standard.The blood flow-pool imaging was compared with the serum examinations.x2 test was used for statistical analysis.Results There were 74 symptomatic joints in 74 patients,including 24 joint infections and 50 aseptic loosening.For the detection of peri-prosthetic infection,combined perfusion-blood-pool phase was more accurate than bone uptake phase (90.5％ (67/74) vs 55.4％ (41/74) ;x2=23.159,P＜0.001),with the sensitivity of 91.7％ (22/24)vs 70.8％ (17/24) and specificity of 90.0％ (45/50) vs 48.0％ (24/50),respectively.The blood flow-pool imaging was also more accurate than CRP (73.0％ (54/74) ;x2 =7.656,P＜0.05) and ESR (71.6％ (53/74) ; x2 =8.633,P＜0.05),respectively.Conclusion 99Tcm-MDP perfusion/blood flow-pool imaging is an accurate modality for differentiating peri-prosthetic infection from aseptic loosening in patients with hip pain after arthroplasty.