Rubello Domenico, Rampin Lucia, Banti Elena, Massaro Arianna, Cittadin Silvia, Cattelan Anna Maria, Al-Nahhas Adil
Service of Nuclear Medicine - PET Unit, 'S. Maria della Misericordia' Hospital, Istituto Oncologico Veneto (IOV) - IRCCS, Viale Tre Martiri, Rovigo, Italy.
Nucl Med Commun. 2008 Apr;29(4):331-5. doi: 10.1097/MNM.0b013e3282f401d6.
To evaluate clinical efficacy of a dual-time acquisition protocol consisting of early 4 h and delayed 20-24 h imaging with anti-granulocyte scintigraphy (LeukoScan) in the diagnosis of infection in painful total knee arthroplasty (TKA).
Seventy-eight consecutive patients with TKA (12 bilateral) were prospectively enrolled in the study from August 2004 to July 2005. All the patients had clinical and biochemical suspicious of infection, except for the 12 patients with bilateral painless prosthesis who had no signs and symptoms of loosening and/or infection and were considered as controls. TKA prostheses had been implanted 4 months to 9.5 years before our studies. Forty-three patients were on antibiotic therapy at the moment of scintigraphic examination, and treatment was not discontinued. All patients underwent LeukoScan examination by performing both early 4 h and delayed 20-24 h imaging. In addition to planar imaging SPECT was performed in 18 cases. A decrease in radiotracer uptake from early to delayed LeukoScan imaging was interpreted as an unspecific finding (negative for infection), while an increasing uptake was interpreted as a positive finding for the presence of infection. Three-phase Tc-MDP bone scan was also routinely performed by standard technique. Sensitivity and specificity of early and delayed LeukoScan imaging were calculated.
Sensitivity for early and delayed imaging were 92.7%, while specificity was 78.4% for early imaging and 100% for delayed imaging approach. SPECT imaging did not add any significant information as regard to specificity in our experience. Eight false positive early scans were correctly diagnosed as negative at delayed imaging. Three false negative results were recorded. Sensitivity and specificity were similar when patients were on or off antibiotic therapy. Imaging was negative in all 12 controls.
Our results, based on a large group of patients, suggest that delayed LeukoScan imaging is important in identifying false positive results detect at early imaging. Thus, a dual-time, 4 h early and 20-24 h delayed LeukoScan imaging approach should be recommended to increase the diagnostic accuracy of the scintigraphy, with the exception of patients with a negative early LeukoScan examination, in whom the acquisition of delayed imaging appears unnecessary. In our experience, concomitant antibiotic therapy did not influence the diagnostic value of LeukoScan.
评估一种双时相采集方案（包括早期4小时和延迟20 - 24小时显像）联合抗粒细胞闪烁显像（白细胞扫描）在诊断疼痛性全膝关节置换术（TKA）感染中的临床疗效。
2004年8月至2005年7月，前瞻性纳入78例连续的TKA患者（12例双侧受累）。除12例双侧无痛假体患者无松动和/或感染的体征和症状并被视为对照组外，所有患者均有临床和生化方面感染可疑表现。在我们研究前，TKA假体已植入4个月至9.5年。43例患者在闪烁显像检查时正在接受抗生素治疗，且治疗未中断。所有患者均通过早期4小时和延迟20 - 24小时显像进行白细胞扫描检查。除平面显像外，18例患者还进行了单光子发射计算机断层扫描（SPECT）。白细胞扫描早期至延迟显像放射性示踪剂摄取减少被解释为非特异性表现（感染阴性），而摄取增加被解释为存在感染的阳性表现。还通过标准技术常规进行三相锝-亚甲基二膦酸盐（Tc-MDP）骨扫描。计算早期和延迟白细胞扫描显像的敏感性和特异性。
早期和延迟显像的敏感性均为92.7%，早期显像的特异性为78.4%，延迟显像方法的特异性为100%。根据我们的经验，SPECT显像在特异性方面未增加任何显著信息。8例假阳性早期扫描在延迟显像时被正确诊断为阴性。记录到3例假阴性结果。患者接受或未接受抗生素治疗时，敏感性和特异性相似。所有12例对照组患者显像均为阴性。
基于一大组患者的我们的结果表明，延迟白细胞扫描显像对于识别早期显像时检测到的假阳性结果很重要。因此，除早期白细胞扫描检查阴性的患者外，应推荐采用双时相、早期4小时和延迟20 - 24小时的白细胞扫描显像方法，以提高闪烁显像的诊断准确性，对于早期白细胞扫描检查阴性的患者，延迟显像似乎不必要。根据我们的经验，同时进行的抗生素治疗不影响白细胞扫描的诊断价值。
