The Application Of Three-phase Bone Scintigraphy In Combination With SPECT/CT In Differential Diagnosis Of Periprosthetic Infection And Prosthetic Loosening

Objective:To analyze the imaging features of three-phase bone imaging combined with SPECT / CT fusion images in the differential diagnosis of prosthesis loosening and peripheral infection,and to compare the diagnostic efficacy in peripheral infection with laboratory tests.To discuss the value of three-phase bone imaging combined with SPECT / CT fusion image in differential diagnosis of peripheral infection and aseptic loosening of prosthesis.Methods:Subjects: 106 patients who has been hip and knee replacement surgery 4 months to 11 years from December 2012 to November 2016.There are pain,joint movement disorders and other symptoms,suspected to be peripheral infection or prosthesis loosening.Laboratory examination: to detect high-sensitivity C-reactive protein in serum samples by immune fluorescence dry quantitative method,for erythrocyte sedimentation rate measurement with the Westergren method.SPECT/CT: SPECT blood-pool phase,delayed phase,SPECT tomography and CT tomography were obtained respectively.SPECT/CT fusion images were obtained by image fusion technique.Hypersensitive C-reactive protein>10mg/L as positive;erythrocyte sedimentation rate>30mm/H as positive,either or both positive as positive,both negative as negative.Periprosthetic Infection Diagnostic Criteria: Replacement of the joint blood flow and/or pool phase showed abnormal radioactive concentration around the soft tissue of the prosthesis.Prosthesis Loosening diagnostic criteria:(1)blood flow is negative,blood pool is negative or weakly positive,no diffuse radioactive uptake in the delayed phase surrounding the prosthesis.(2)the femoral head was divided into three zones(I,II,III)by horizontal and vertical lines,and the proximal femur was divided into 7 regions.In the three zones of the acetabulum,the delayed phase and the SPECT / CT zone I were radioactive,with or without the radioactive enrichment of the II and III regions,all were found to be acetabular prosthesis loosening.In the 7 divisions of the femoral prosthesis and the femoral interface,radioactivity was concentrated in region 1 and/or 7,as well as radioactive concentrators in Region 4,the prosthesis was diagnosed stem loose.(3)delayed phase and SPECT/CT tomography showed at both ends of the prosthesis or distal bone radioactivity increased,increased bone density of the increased radioactive parts in CT,prosthesis and adjacent bone may have a gap between.Final diagnosis: The prosthesis is diagnosed by loose focal seen in the revision of prosthesis.Meet the following one diagnosed as the prosthesis infection:(1)the formation of sinus connected with the prosthesis;(2)the formation of pus around the prosthesis;(3)specimens or liquid obtained in tissue surrounding prosthesis be microbial developed or pathological inflammatory exudate.The sensitivity,accuracy and specificity of the two diagnostic methods were calculated by comparing the results of three-phase bone imaging with the SPECT/CT fusion images and laboratory examination with revision.The diagnostic efficacy of two methods was statistically Analysis.And run the two test results and intraoperative diagnosis of consistency test(Kappa test).Results:1.Three-phase bone imaging combined with SPECT/CT fusion images and laboratory tests to diagnose the results106 cases of pain after arthroplasty and other symptoms of the patient,was diagnosed as 60 cases of periprosthetic infection in the revision,the three-phase bone imaging combined with SPECT/CT diagnosis of prosthesis around the infection of 56 cases,misdiagnosed as prosthesis loosening in 4 cases;laboratory diagnosis of prosthesis infection in 43 cases,misdiagnosed as prosthesis loosening in 17 cases.Revision diagnosis of prosthesis loosening in 44 cases,the three-phase bone imaging combined with SPECT / CT fusion imaging diagnosis of prosthesis loosening of 36 cases,misdiagnosed as peripheral infection in 8 cases;laboratory diagnosis of prosthesis loosening of the 21 cases,misdiagnosed as periprosthetic infection in 23 cases.The sensitivity,specificity and accuracy of detecting infection were 93.33%(56/60),82.61%(38/46),88.67%(94/106)and 71.67%(43/60),47.82%(22/46),61.32%(65/106),respectively.The positive images of early phase(blood flow-pool phase)can be diagnosed in patients with periprosthetic infection.For patients with loose prosthesis,the delayed phase and SPECT/CT should be considered to confirm diagnosis.For possibility of chronic suppurative limited infection,the three-phase bone scintigraphy in combination with SPECT/CT fusion image combined with laboratory results analysis can improve the diagnostic sensitivity in periprosthetic infection.2.Abnormal concentration of 36 cases of patients with revision-confirmed prosthesis loosening in SPECT / CT correct diagnosis.26 cases of hip and femoral head replacement patients,14 cases showed hip I area concentration,14 cases showed hip II area concentration,8 cases showed hip area III concentration;femoral area 1 concentration 6 cases,3 cases of femur 7 area,5 cases of femoral 4/5 area concentration;10 cases of knee arthroplasty after the prosthesis side of the focus of the point of point or linear radioactive concentration.3.Statistic analysis of three-phase bone imaging combined with SPECT/CT and laboratory tests and revision-confirmed diagnosisThere was a significant difference in the specificity of three-phase bone imaging combined with SPECT/CT fusion images and laboratory tests in the diagnosis of periprosthetic infection(p <0.05).The coincidence(Kappa)of the three-phase bone scintigraphy combined with SPECT / CT fusion images was 0.767> 0.75,and the consistency(Kappa)of laboratory examination and intraoperative diagnosis was 0.198 <0.4.Conclusions:1.Three-phase bone imaging combined with SPECT/CT closer to the results of intraoperative diagnosis compared with the results of laboratory tests,is the effective method of clinical diagnosis of periprosthetic infection and loosening.Laboratory tests can be used as screening and auxiliary diagnostic means2.Positive images of the early phase(blood-pool phase)is crucial to diagnosing periprosthetic infection.For patients with loose prosthesis,the delayed phase and SPECT / CT fusion images are needed to further confirm the diagnosis.3.Delayed phase images and SPECT / CT can fix loose parts which match the loose lesions seen in the revision.4.Three-phase bone imaging combined with SPECT / CT fusion images of other causes(such as spinal diseases,etc.)of arthroplasty regional pain after replacement has good diagnostic value.