Objective To investigate the feasibility and clinical value of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV in chest CT scan.Methods A total of 60 patients of clinical diagnosis with lung tumor were enrolled.Those patients were randomly divided into test group and control group.Control group underwent a scan protocol with lateral scout scan combined with Care Dose 4D and Care kV,while anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV were performed in test group.The signal-to-noise ration (SNR),contrast-to-noise ratio (CNR),and overall image quality of two groups of images and diseased tissues were analyzed and evaluated by two high-grade radiologists using double-blind method.Effective doses (E) were also calculated.Results All the 60 patients had successfully completed the chest CT scans.Test group overall image quality (4.57 ± 0.45) and control group overall image quality (4.73 ± 0.45) had no statistically significant difference (P ＞ 0.05).The control group image SNR,CNR and diseased tissue SNR,CNR compared with test group had no statistical significance difference (P ＞ 0.05).The difference of the volume CT dose index (CTDIvol),dose-length product (DLP) and effective dose (E) of test group and control group was statistically significant (t =8.514,8.464,8.464,P ＜ 0.001).Compared with control group,the effective dose of test group decreased by 33.3％.Conclusions Compared with lateral scout scan,the technology of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV can decrease radiation dose without reducing the image quality.This technology can therefore be considered as a regular imaging modality for chest CT scan.

Objective To assess the value of cardiac magnetic resonance (CMR) imaging in left ventricular structure and function in patients with end stage renal disease (ESRD).Methods Twenty-five patients with ESRD and 10 healthy subjects underwent CMR.Left ventricular end diastolic volume(EDV),end-diastolic diameter(EDD),end-systolic volume(ESV),end-systolic diameter(ESD),stroke volume(SV),ejection fraction(EF),LVM and interventricular septum (IVS) thickness were measured and compared.The parameters from CMR and 2DTTE were compared.Results The EF in patients with ESRD was significantly lower than that in controls (P＜0.001),while ESV,ESD,IVS and LVM were respectively higher than these in controls (P＜0.05).There was no significant difference (P＞0.05) in ESV between CMR and 2DTTE,but EF of CMR was significantly higher than this of 2DTTE (P＜0.05).There was no significant difference (P =0.296) in left ventricular systolic functional category.Bland-Altman plots showed a good agreement between the two methods.Conclusion CMR is a helpful tool to assess left ventricular structure and function in patients with ESRD.

Objective To explore the clinical application value of second-generation dual-source CT combined with intelligent modulation and iterative reconstruction in emergency aortic dissection imaging.Methods A total of 40 emergency patients with clinical suspected aortic dissection were included in this study.Conventional scanning was performed in the control group,and large-pitch intelligent modulation and iterative reconstruction were performed in the test group.The mean CT value,mean noise,signal noise ratio(SNR),contrast noise ratio(CNR),effective dose,image quality and aortic root image quality were evaluated and analyzed.Results Totally 40 patients successfully completed CT aortic dissection imaging.There was no difference in image quality between the two groups (P＞ 0.05).The quality of aortic root images in the test group was better than that in the control group,and the difference was statistically significant(x2=22.556,P＜0.05).The mean CT value and mean noise of aorta in the control group were slightly higher than those in the test group.However,SNR and CNR in the test group were higher than those in the control group,and the difference was statistically significant (t =-21.042,-15.924,8.530,11.495,P＜0.05).The effective dose of the control group [(10.59±3.89)mSv] was significantly higher than that [(6.39±0.81) mSv] of the test group,the difference was statistically significant (t =-12.327,P＜0.05).Conclusions The combined intelligent modulation technique and iterative reconstruction technique with dual-source CT large pitch scanning can meet the requirements of image quality and reduce the effective dose,and can be used as a conventional imaging method for emergency CT of aortic dissection.

Objective:To investigate the clinical characteristics and structural and functional cardiac changes in heart failure with preserved ejection fraction(HFpEF)complicated with atrial fibrillation(AF)in elderly patients.Methods:As a cross-sectional study, 835 patients with HFpEF aged ≥60 years admitted to the Department of Geriatric Cardiovascular Medicine of the First Hospital of Lanzhou University between April 2009 and December 2020 were divided into an HFpEF+ AF group(267 cases)and an HFpEF group(568 cases)according to whether they had AF in addition to HFpEF, and their cardiac structure and function were evaluated.The optimal cutoff point of the ratio of the peak early diastolic velocity(E)to the maximum early diastolic velocity(e')of the mitral annulus(E/e')was analysed using the receiver operating characteristic(ROC)curve.The HFpEF+ AF group was divided into two subgroups, E/e'>11 and E/e'≤11, and differences in their clinical presentation, cardiac structural and function, and the relationship between the left and right heart were compared.Results:Compared with the HFpEF group, the left atrial volume index(LAVi)was larger[(60.0±23.3)ml/m 2vs.(43.9±19.0)ml/m 2, t=10.130, P<0.01]and the left ventricular ejection fraction(EF), mitral annular septal systolic velocity(s' S)and E/e' were smaller than in the HFpEF+ AF group(all P<0.01), whereas the right ventricular diameter(RVD), right atrial diameter(RAD)and area(RAA), tricuspid regurgitation velocity(TRv), and pulmonary arterial systolic pressure(PASP)in the HFpEF+ AF group were all greater than those in the HFpEF group(all P<0.05).In the E/e'>11 subgroup of HFpEF+ AF, the prevalence of hypertension, coronary heart disease and diabetes were higher, AF courses were shorter, and the decline of s' was more severe(all P<0.05).Furthermore, E/e' was independently correlated with LAVi, as was LAVi with PASP( t=2.114, 1.963, P=0.034, 0.042).The above-mentioned features were similar to those in the HFpEF group.The E/e'≤11 subgroup had a higher proportion of women, longer duration of AF than the E/e'>11 subgroup(median: 5 years vs.1 year, P=0.003), more noticeable enlargement of the right ventricle and right atrium, higher TRv and PASP( P<0.05). Conclusions:In elderly patients with HFpEF complicated with AF, the left atrial volume is increased further, and left ventricular systolic function and right heart morphology show serious deterioration, suggesting there might be two phenotypes of HFpEF+ AF with different pathophysiological mechanisms.