ObjectiveTo investigate the feasibility and accuracy of dual energy CT (DECT) in detecting acute myocardial ischemic reperfusion injury in a swine model.Methods Acute myocardial ischemic reperfusion injury model was made by ligaturing the left anterior descending coronary artery (LAD)or the first diagonal artery ( D1 ) of swine heart,the first-pass contrast enhanced DECT was performed.And then pigs were sacrificed,and the hearts were removed,triphenyhetrazolium chloride staining was performed.The CT numbers of non-ischemic and ischemic regions were measured.In the short axis of the left ventricle,the ventricular wall was divided into 17 segments for analysis,segments with myocardial perfusion defect in DECT myocardial iodine maps,DECT ( 140,100 kV,weighted average 120 kV) were determined and compared with histopathology.The sensitivity,specificity and inter-modality agreement of DECT in detecting myocardial injury were calculated.One-way ANOVA test was used to analyze the differences between the CT number and weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV in ischemic and normal regions.ResultsPartial sparse or defective perfusion in the apical anterior and septal wall were demonstrated in DECT myocardial iodine maps.The CT number of injured myocardium was significantly lower than that of normal myocardium at 140,100 kV,weighted average 120 kV.The sensitivity,specificity of DECT myocardial iodine maps were 85.2％ (23/27),86.2％ (94/109),and Kappa value was 0.62,the sensitivity,specificity at 140 kV were 88.9％ (24/27),92.7％ (101/109),and Kappa value was 0.76,the sensitivity,specificity at 100 kV were 85.2％(23/27),89.0％ (97/109),and Kappa value was 0.67,the sensitivity,specificity at weighted average 120 kV were 88.9％ (24/27),91.7％ ( 100/109),and Kappa value was 0.74.There were no significant differences between the weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV and histopathological results ( F =0.419,P =0.741 ).ConclusionDECT myocardial iodine maps can detect acute myocardial ischemic reperfusion injury in a swine model and have a good correlation with histopathology.

Objective To evaluate the response of the lung tumor xenografts in nude mice to antiangiogenic treatment from perspectives of anatomic,vessel function,cellular and molecular level using the multimodality imaging techniques including optical imaging,dynamic contrast enhanced MRI(DCE-MRI)and diffusion weighted imaging(DWI).Methods The green fluorescent protein(GFP)was transplanted labeled using GFP-expressing NCI-H460 cells.After the transfection of GFP,NCI-H460 cells were implanted subcutaneously into nude mice.Ten days after implantion,12 nude mice whose tumor xenografts grew to 0.5-1.0 cm in the maximum diameter were randomly divided into 2 groups,and injected with phosphate-buffered saline and recombinant human endostatin respectively.Then the nude mice in the two groups underwent optical imaging,DCE-MRI and DWI.The volumes,photon counts,the quantitative MR vessel functional parameters including volume transfer constant(Ktrans),rate constant(Kep),volume of extravascular extracellular space(Ve)and maximum area under the enhancement curve(iAUC),and apparent diffusion coefficient(ADC)values of the tumors were recorded.Then tumors were collected and observed using the transmission electron microscopy and pathology examination,including HE staining,microvessel density(MVD)and the expressions of vascular endothelial cell growth factor(VEGF).The Kep and VEGF expressions in experimental group and control group were compared with x2 text,and other values were compared with t test.The Pearson and Spearman test were used for analyzing the correlation of values in the two groups.Results Seven days after inoculation,the fluorescence signals were detected and grew with the growth of the tumors.On the 7 day after starting therapy,the photon counts of experimental group and control group were(2.51 ± 2.43)× 1010(photon/sec)and(5.77 ± 3.25)× 1010(photon/sec),respectively with no significant differences(t =1.964,P ＞0.05).Two sample t test showed that the tumor volumes in experimental group were smaller than those in control group[(365 ± 56)vs(987 ± 265)mm3,t =0.001,P ＜ 0.01].There was a positive correlation(r =0.673,P ＜ 0.05)between the photon counts and the volumes of the tumors.The mean Ktrans,Kep,Ve and iAUC of experimental group were:(0.055 ±0.012)min-1,0.335(0.184—0.894)min-1,0.297 ± 0.041 and 7.334 ± 3.930,and those for control group were:(0.117 ± 0.027)rin-1,0.417(0.324-1.736)min-1,0.326:±:0.062 and 13.280 ± 4.245.There were significant differences of Krans and iAUC(t =5.155,2.518,P ＜ 0.05)between experimental group and control group.And there was a positive correlation(r =0.715,P ＜ 0.0 1)between the values of iAUC and MVD,but not the expressions of VEGF(r =0.484,P ＞ 0.05).The values of ADC in experimental group were higher than that in control group[(791 ± 38)× 10-6 vs(737 ± 43)×10-6 mm2/s],and there were significant differences(t =-2.299,P ＜ 0.05).Two sample t test showed that the MVD in experimental group were lower than that in control group[(11.9 ± 4.8)vs(19.2 ±4.3)item/hpf,t =2.774,P ＜ 0.05].The VEGF expressions in experimental group were lower than that in control group(x2 =4.000,P ＞ 0.05).It was observed that some cells in experimental group had degenerated and apoptotic signs by the electron microscopy.Conclusions Evaluating the response of lung tumor xenografts to antiangiogenic treatment at anatomical,vessel functional,cellular and molecular level using the multimedality imagings is applicable.And it will be in favour of evaluating the therapeutic effect promptly.

Objective To investigate the feasibility and accuracy of dual energy CT myocardial iodine maps in detecting acute myocardial infarction in canine model. Methods Myocardial ischemia model was made by ligaturing left anterior descending coronary arteries (LAD) after thoracotomy in six dogs, while another 3 dogs undergoing thoracotomy not ligaturing LAD as control group. Before and three hours after operation, dual-source CT (DSCT) was performed, followed by resting 99Tcm-MIBI single photon emission computed tomography myocardial perfusion imaging. Then, dogs were sacrificed, and the hearts were removed, triphenyltetrazolium chloride staining and conventional HE staining were performed. CT number of non-ischemic and ischemic regions were measured and analyzed. The wall of the left ventricle in the short axis was divided into 17 segments, the segments of myocardial perfusion defect in DSCT myocardial iodine maps, SPECT, and pathology were determined. Student t test was used to analyze the difference of CT number between infarcted and non-infarcted myocardium. Kappa test was used for the accuracy of DSCT myocardial iodine maps and SPECT in detecting myocardial ischemia according to the pathological results. Results No abnormal regions were detected using DSCT myocardial iodine maps in preoperative control and infarction group. After thoracotomy, partial sparse or defective perfusion was consistently noted in six dogs' apical anterior and partition wall in both DSCT myocardial iodine maps and SPECT. In the infarcted group, the attenuation of infarction region (34.75 ± 16.66) HU was significantly decreased compared with preoperative measurements ( 123. 18 ± 15.38 ) HU ( t = 10. 526, P ＜ 0. 01 ); decreased perfusion in the infarcted region was also noted in the DSCT myocardial iodine maps and SPECT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT myocardial iodine maps and SPECT were 85.0% (34/40) , 84. 1% (95/113) ,65.4% (34/52) ,94. 0%(95/101) ,and 82. 5% (33/40), 90. 3% ( 102/113 ) ,75.0% (33/44) ,93.6% ( 102/109 ), respectively.Kappa values were 0. 63 and 0. 71 for the agreement of DSCT myocardial iodine maps and SPECT.Conclusion DSCT myocardial iodine maps is comparable diagnostic accuracy with rest SPECT myocardial perfusion imaging in detection of acute myocardial infarction in a canine model.

Objective To study the value of breast vascularity in differential diagnosis of benign and malignant breast lesions. Methods The data of 37 patients with benign and malignant breast lesions in the Second Hospital of Shanxi Medical University from February 2017 to November 2017 were respectively analyzed. The number, diameter, length and breast-feeding arteries of bilateral breast vessel were recorded in the maximal intensity projection (MIP) of magnetic resonance imaging (MRI) and were scored according to Sardanellie. The patients were divided into the benign group and the malignant group according to the pathological results. Besides, ≥2 cm group and <2 cm group was also divided according to the maximum diameter of lesions. The differences in number and score of vascularity in both groups were compared. And the diagnostic efficacy of MRI was evaluated based on Sardanellie score and breast-feeding arteries. Results There were no significant differences in the number and score of vascularity between bilateral breast in benign breast lesions group (1.11 ±0.35 vs. 1.22 ±0.45, t= 0.19, P= 0.85; 0.89 ±0.38 vs. 0.95 ±0.21, t= 0.25, P=0.80). The number and score of vascularity of the affected side were higher than those of the healthy side in breast malignant lesions group (2.61 ±1.29 vs. 0.61 ±0.21, t= 6.18, P= 0.00; 1.78 ±0.65 vs. 0.61 ±0.21, t=6.30, P=0.00 respectively). The number and score of vascularity were statistically different between benign and malignant breast lesions (t= 8.57, P< 0.001; t= 12.61, P< 0.001). The number of vascularity in the malignant group was higher than that in the benign group with the maximum diameter of lesion<2 cm (1.27 ± 0.59 vs. 2.57±0.98, t=90.5, P< 0.05), and there was no significant difference in the scores of vascularity in the malignant group and the benign group (1.09 ±0.43 vs. 1.86 ±0.38, t= 87.0, P> 0.05); The number and score of vascularity in the malignant group were higher than those in the benign group with the maximum diameter ≥2 cm (0.92±0.63 vs. 2.64±1.50, t=47.5, P<0.05; 0.92±0.33 vs. 1.73±0.79, t=53.5, P< 0.05). There was no significant improvement in the diagnostic efficacy of MRI based on the score of vascularity and positive breast-feeding arteries in the identification of benign and malignant lesions when the maximum diameter of lesions were<2 cm, and it had a high diagnostic efficacy when the maximum diameter of lesions were ≥2 cm. Conclusions The vascularity of breast can be clearly seen by using breast dynamic contrast enhanced (DCE) MRI. The increase and score of vascularity in the differential diagnosis of benign and malignant breast lesions have a certain application value. The positive of breast-feeding arteries may increase the diagnostic efficiency of MRI.

Objective:To evaluate the diagnostic value of spectral CT calcium suppression (CaSupp) technique in acute and chronic thoracolumbar compression fractures.Methods:A total of 31 patients with thoracolumbar compression fractures were given spectral CT and MR scans from March to October 2020 in the Second Hospital of Shanxi Medical University. Acute and chronic vertebral fractures were diagnosed by doctor A and B based on CaSupp diagram, and the consistency between the two doctors was evaluated by Kappa test. CT values of fractured vertebra and adjacent normal vertebra were measured on conventional CT and CaSupp graphs respectively, and the CT value difference between fractured vertebra and adjacent vertebra was calculated. Independent sample t-test was used to compare the conventional CT value and CT value difference, CaSupp CT value and CT value difference between acute and chronic fractured vertebra. Using MRI as the gold standard, the ROC curves were drawn to evaluate the subjective diagnostic efficacy of physicians and the diagnostic efficacy of each quantitative parameter. DeLong test was used to compare the area under the curve (AUC) of each quantitative parameter in pairs. Results:The number of vertebral bodies in acute and chronic compression fractures diagnosed by MRI was 48 and 11 respectively. The Kappa value of subjective diagnosis of acute and chronic vertebral fractures by doctors A and B was 0.782, and the AUC, sensitivity, specificity were 0.882 and 0.857, 85.4% and 89.6%, 90.9% and 81.8%, respectively. The differences of conventional CT value, CaSupp CT value and CaSupp CT value difference between acute and chronic compression fractures were statistically significant (all P<0.05), and the AUC values of conventional CT value, CaSupp CT value, conventional CT value difference and CaSupp CT value difference were 0.824, 0.930, 0.706 and 0.934, respectively. Pair comparison showed that the AUC of the CaSupp CT value and CaSupp CT value difference was greater than that of conventional CT value difference, with statistically significant differences ( Z=2.014, P=0.044, Z=2.028, P=0.043), while there were no statistically significant differences between other AUC values (all P>0.05). Conclusion:The dual-layer detector spectral CT CaSupp technique has high value in differentiating acute and chronic thoracolumbar compression fractures, and the CaSupp CT value and CaSupp CT value difference are recommended for diagnosis.