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Objective To investigate the added value of CTAC for improving image quality and diagnostic efficiency of bone imaging in SPECT/CT.Methods Seventy-five patients (47 males,28 females,(56.6± 12.8) years) with abnormal uptake in planar whole-body bone scintigraphy underwent SPECT/CTfor differentiation of malignant from benign spinal lesions.NAC and CTAC SPECT images were classified based on 5-point scale (5:excellent,4:good,3:adequate,2:suboptimal,1:inadequate).The diagnostic confidence for both NAC and CTAC SPECT images were classified based on 4-point scale (4:definite,3:certain,2:equivocal,1:uninterpretable).The pathological results after surgery were used as gold standard to evaluate the added diagnostic value of CTAC for spinal lesions.Wilcoxon-signed rank sum test was used for data analysis.Results CTAC improved the image quality in 37.3％ (28/75) of patients,and downgraded in 2.7％ (2/75) of patients.The remaining 45 patients were unchanged (60.0％,45/75).SPECT with CTAC could significantly improve the image quality (z=-4.747,P＜0.001),but the overall diagnostic confidence was not increased (z=-1.000,P＞0.05).Conclusion CTAC can improve the image quality of spinal SPECT,especially useful in imaging with poorer quality,but it has no significant incremental value in diagnostic confidence.
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Objective To investigate the value of 99Tcm-Duramycin SPCET/CT in the detection of vulnerable plaque (VP) in atherosclerotic (AS) rabbit models.Methods Sixteen New Zealand male rabbits were randomly divided into three groups:group A (sham-operated group,n =4),group B (stable plaque group,n =4) and group C (VP group,n =8).Group A was fed on normal diet,and the other 2groups were fed on cholesterol diet for 12 weeks.Femoral artery dissection sham-operation was done in group A and group B,while balloon-induced abdominal aorta wall injury was produced in group C after 2 weeks'feeding.Animals were injected with 99Tcm-Duramycin (74 MBq/kg) and then SPECT/CT imaging was performed at the end of 4,8,and 12 weeks,respectively.Abdominal aortas were explanted for ex vivo imaging and histological characterization of plaque.The apoptosis index (AI) was calculated.One-way analysis of variance was used to analyze data.Results There was no radioactive uptake by the abdominal aorta in each group at the end of 4 weeks and no uptake in group A and group B at the end of 8 weeks.There was slightly uptake radioactive uptake by the abdominal aorta in group B at the end of 12 weeks and in group C at the end of 8 weeks.There was intense uptake at the lesions of AS rabbits in group C at the end of 12 weeks,and the T/NT value significantly higher than that of the other two groups (3.40±0.22 vs 2.12±0.65,2.68±0.18,F=198.775,P＜0.05).The result was confirmed in the ex vivo imaging of the explanted aorta.The AI of group C was significantly higher than that of group A and B ((25.4±6.32) ％ vs (0±0.02)％,(5.3± 1.97)％,F=70.260,P＜0.05).Conclusions 99Tcm-Duramycin scimigraphy could identify the apoptosis of VP in the rabbit AS models.It is a promising non-invasive method to diagnose AS plaques.
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Objective To investigate the imaging characteristics of both intra- and extrathoracic sarcoidosis on 18F-FDG PET/CT.Methods From 2007 Aug.to 2009 Nov.,22 patients( 10 males,12 females) with sarcoidosis,confirmed by pathological study and clinical follow-up,underwent 18 F-FDG PET/CT imaging.The imaging patterns of intrathoracic and extrathoracic lesions were analyzed.The patterns were classified as the typical or atypical ( symmetrical or asymmetrical FDG accumulation and enlargement of hilar lymph nodes) based on PET and CT separately.Nonparametric McNemar test,independent t-test and Fisher exact test were applied for statistical analysis.Results For typical pattern vs atypical pattem identification,PET was significantly different from CT ( 18 and 4 vs 12 and 10,P =0.031 ).In those with atypical pattern demonstrated by CT alone at hilar region,PET showed either symmetrical or asymmetrical accumulation of FDG.Except for mediastinal lymph nodes involvement,lung parenchyma was the second common site ( 19/22,86.4％ ),followed by lymph nodes at abdomen and (or) pelvis ( 12/22,54.5％ ).Conclusion The imaging characteristics of both intra- and extrathoracic sarcoidosis on 18F-FDG PET/CT may be helpful for the diagnosis of atypical sarcoidosis on CT image alone.