Objective To compare the iodine contrast agent dosage,radiation dose and image quality in CT pulmonary angiogra-phy (CTPA)with low tube voltage and high tube current in 64-slice spiral CT.Methods 60 patients with suspected pulmonary em-bolism in our hospital were randomly chosen and divided into three groups:Group Ⅰ:20 patients,using 120 kV,180 mA,contrast dose of 70 mL.Group Ⅱ:20 patients,using 100 kV,280 mA,contrast dose of 50 mL.Group Ⅲ:20 patients,using 80 kV,automat-ic tube current modulation techniques (300-500 mA),comparative dose of 30 mL.CT values and image noise of three pulmonary central areas and a segment branch were measured in each group.Objective indicators,subjective image quality assessment,CT dose index volume (CTDIvol),dose-length product (DLP)and effective absorbed dose (ED)were compared in three groups to evaluate the value of low kV,high mA with low-contrast dose in CTPA.Analysis of variance and t-test was used for data analysis.Results Compared with those of the standard method of CTPA,all pulmonary dry in two groups of low dose were well displayed.There was no statistical significance between each two groups in image quality score (P > 0.05),but was statistical significance in CT values, noise,SNR and CNR (P < 0.01).The CT radiation dose,CTDIvol and DLP of Group Ⅱ and Group Ⅲ were significantly lower than those of Group Ⅰ (P < 0.01).Conclusion Compared with traditional methods,low dose contrast agent injections under 80 kV could reduce the dose of contrast agent and the effect of hardening artifacts due to contrast agent in superior vena cava on right pul-monary artery.It is helpful to reduce the risk of contrast induced nephropathy and reduce patients’exposure to X-ray radiation.

Objective To investigate the effect of vacuum-assisted closure(VAC)on the circulating number of endothelia progenitor cell(EPCs)in diabetic patients with mild to moderate degrees of ischemic foot ulcer and their related factors. Methods A total of 84 diabetic patients with foot ulcer duration for at least 4 weeks and ankle brachial index(ABI)0.5~0.9 were selected and divided into and assigned to two groups according to 2: 1 randomization:vacuum-assisted closure(VAC)treatment group(n=56)and Non-VAC treatment group(n=28). The control group (NC) was composed of 18 patients who had normal glucose tolerance and lower extremity ulcer without arteriovenous disease. VAC was performed on the ulcer wound after debridement for 1 week in both VAC group and NC group,and the patients in Non-VAC group received conventional treatment process. The circulating number of EPCs was measured before and after various treatments and the influencing factors of their changes were analyzed. Results After VAC treatment,the circulating number of EPCs significantly increased in both VAC group and NC group[(85.3 ± 18.1)vs(34.1 ± 12.5)/106cells,(119.9 ± 14.4)vs(66.1 ± 10.6)/106cells,both P<0.05]. By contrast,the circulating number of EPCs had no significant change in Non-VAC group[(45.2 ± 19.4)vs(34.7 ± 16.8)/106cells, P>0.05]. In addition,the circulating levels of vascular endothelial growth factor(VEGF)and the protein expressions of VEGF and stromal cell-derived factor-1α(SDF-1α)in the granulation tissue also significantly increased after VAC treatment in both VAC group and NC group,but no significant change in Non-VAC group. Compared with Non-VAC group,the changes of VEGF and SDF-1α levels in the sera and granulation tissue were all significantly higher in both VAC group and NC group(P<0.05 or P<0.01). There were no significant differences in changes of the circulating number of EPCs, and VEGF and SDF-1α in the sera and granulation tissue between VAC group and NC group. Correlation analysis showed that the change of the circulating number of EPCs was correlated with the changes of VEGF and SDF-1α levels in the sera and granulation tissue of VAC group and NC group(P<0.05). Conclusion VAC treatment may increase the circulating number of EPCs in diabetic patients with mild to moderate ischemic foot ulcer as in non-diabetic controls,which may be attributed to the upregulation of systemic and local VEGF and SDF-1α levels.