ABSTRACT
Objective:To establish a method for correction of tail vein extravasation based on PET images and to improve the accuracy of SUV.Methods:The simulation method was established by phantom on Nano PET/CT and images were reconstructed by a three-dimensional ordered-subsets exception maximum algorithm. PET images were analyzed by using the Interview Fusion 1.0 software. The optimal scanning time and the ROI delineated method were found. The accuracy of the simulation method was verified by comparing the activity of simulation method with the mice tail activity measured by the dose calibrator directly on Kunming (KM) mouse ( n=11). Using the simulation method, the impact of extravasation on SUV was proved. Independent-sample t test was used to analyze data. Results:Ten minutes was selected as the optimal scanning time and SUV max 42% threshold was selected as the ROI delineated method. The specific correction formula was as follows: actual activity=image activity/(4.48× V+ 77.05)×100 (0.3 MBq/ml≤leakage concentration<6.5 MBq/ml); actual activity=image activity/(6.65× V+ 71.10)×100 (6.5 MBq/ml<leakage concentration≤14.8 MBq/ml). In the verification experiment, the difference rate between simulated and standard activity was (6.10±2.43)%. In actual operation verification, SUV was underestimated by (6.07±2.67)%. The corrected SUV (0.276±0.078) was not significantly different from the standard SUV (0.277±0.078; t=0.99, P=0.353), while the uncorrected SUV (0.264±0.078) was significantly lower than the standard SUV ( t=7.02, P<0.001). Conclusion:The correction calculation method based on PET images can realize the accurate correction of tail vein leakage activity and the SUV results of animal imaging.
ABSTRACT
Objective To explore the advantages of computer assisted total knee arthroplasty(TKA)by comparing the post-operative 1 year short term effect of the computer assisted TKA and the conventional TKA .Methods A total of 60 patients from September 2013 to September 2014 were randomly divided into two groups and performed TKA by adopting the computer-assisted technology and the conventional technology respectively .The KSS score ,WOMAC score ,Oxford score and long-leg weight-bearing X-ray before operation and at postoperative 1 year were performed for each case and the statistical analysis was conducted . Results All cases were followed up for an average of 12 months (12—14 months) .The mechanical limb axis in the navigation as-sisted group was —0 .033o± 1 .470o ,which in the traditional group was 0 .600o± 2 .989o(t= —1 .711 ,P<0 .05);the proportions of within 3o varus/valgus force lines were 86 .70% and 73 .30% respectively ,the KSS scores were 88 .80 ± 3 .71 and 82 .63 ± 4 .15;the postoperative WOMAC scores were 23 .57 ± 3 .64 and 30 .00 ± 4 .89 respectively ;the Oxford scores were 18 .53 ± 3 .66 and 21 .83 ± 3 .99 ,the differences between the two groups were statistically significant (P<0 .005) .Conclusion TKA by computer navigation guidance can obtain more accurate lower limb force lines ,moreover the navigation group has more advantages in the clinical rehabili-tation effect .