Objective:To investigate the training of writing research paper for graduate students majoring in medical imaging, therefore improving international academic communication. Methods: Analyzing the problems existed in English paper writing for the graduate students majoring in medical imaging. According to the feature of English paper writing in the field of medical imaging, the new teaching model was used and the problem-based-learning method was introduced.Results: The new training model of English research paper writing is practical and helpful for graduate students majoring in medical imaging to improve their writing skill and research ability.Conclusion: The training of English research paper writing is efficient for graduate students majoring in medical imaging. The training process can lay good foundation for their future research careers.

Objective To investigate the feasibility of coronary CT angiography in single cardiac cycle and to analyze the image quality and radiation dose in patients with high heart rate(HR) using 256-row detector CT. Methods Ninety-two consecutive patients between October and November 2015 who were suspected coronary artery disease underwent coronary CT angiography(CCTA) were enrolled, which was performed with a 256-row detector CT(Revolution CT, GE Healthcare) using prospective ECG-triggered volume CCTA within a single cardiac cycle with snapshot freeze(SSF) technique. The patients were grouped by HR during CT scans: group A(80—89 bpm, n=56), group B(90—99 bpm, n=20), and group C(≥100 bpm, n=16). Image quality was compared before and after using SSF technique reconstructions in seventy-four patients. The image quality of coronary artery was evaluated blindly by 2 experienced radiologists using a four-point scale based on the 18-segment model according to the Society of Cardiovascular Computed Tomography guidelines. The differences in age, body mass index, heart rate and CT dose index volume,effective dose(ED) among the three groups were compared by using ANOVA analysis or Kruskal-Wallis test, the image quality and interpretability using χ2 test. Comparisons of image quality between standard and SSF were performed with paired Wilcoxon rank sum test. Kappa coefficient was used to test inter-observer agreement. Results A total of 1 065 coronary artery segments, 98.97%(1 054/1 065) met the requirements for diagnosis. No significant difference was found(χ2=1.274, P=0.563) for the diagnostic image quality of coronary artery segments among the 3 groups with 98.64%(651/660), 99.57%(232/233), 99.42%(171/172), respectively. Significant difference(χ2=68.811, P<0.05) was found for diagnostic image quality before and after using SSF with increase from 90.29%(772/855) to 99.44%(881/886). Image quality was improved with the use of SSF reconstructions and the diagnostic segments were also increased. The median of ED for group A, B and C was 2.03, 1.93, 2.37 mSv, respectively. There was no significant difference in ED among group A, B and group C(H=2.412,P>0.05). Conclusions Single cardiac cycle scan is feasibility for coronary CT angiography in patients with high heart rate using 256-row detector CT. This scan mode can maintain the diagnostic image quality with low radiation dose. SSF technique can improve the image quality.

Objective The optimal treatment for chronic type B dissection remains controversial. The purpose of this study was to report early and mid-term results of thoracic endovascular aortic repair (TEVAR) of chronic type B aortic dissection. Methods Methods From June 2001 to September 2007, 84 patients with chronic type B aortic dissection received TEVAR. The time between onset of dissection and TEVAR was (13.9 ± 22.0) months (ranged 1 - 120 months). All patients were followed for 6 - 86 months [mean (33.2 ± 19.2) months]. Results The entry tear was completely sealed in 77 cases ( 91.7% ) during TEVAR. The incidence of incomplete seal was 8.3%. One-month mortality was 1. 2%. One patient had retrograde type A dissection 1 month after operation. Four patients received a second TEVAR during follow-up :3 for endoleaking and 1 for newly formed intima tear. Seven patients (8.3%) died during follow-up: 3 thoracic aorta rupture due to endoleaking, 1 abdominal aorta rupture caused by continuous dilation of the abdominal aorta, unrelated to aortic dissection deaths in 2 and 1 died of unknown cause. The Kaplan Meier actuarial survival curve showed a 7-year survival rate of 84.4%. Conclusion Early and mid-term results showed that TEVAR was effective in treating chronic type B aortic dissection. Endoleak was the main cause of death during follow-up. With increasing of physician's experience and refinement of the stent-graft, results are likely to improve in the future.

Objective To evaluate low-dose CT coronary angiography with prospective electrocardiogram (ECG)-triggering using dual-source CT scanner.Methods Sixty-eight patients who underwent coronary CT angiography using a dual-source CT scanner were divided into 2 groups: group A (38 cases) and group B (30 cases).Prospective ECG-triggering sequence scan mode was employed for group A.Inclusion criteria included: heart rate <70 bpm, sinus rhythm, and heart rate fluctuation less than 10 bpm.Data acquisition was set at 70% of the RR-interval.Retrospective ECG-gating helical scan was performed for group B.Inclusion criteria included heart rates < 70 bpm and sinus rhythm.The exclusion criteria included heart failure and serious arrhythmias.In both groups, patients with a BMI≥24 kg/m2 were examined with a tube voltage of 120 kV, whereas patients with a BMI <24 kg/m2 were examined with a tube voltage of 100 kV.All images were transferred to a workstation for further processing and analysis.The imaging quality was evaluated.The imaging quality of coronary artery segments were compared with rank sum test between the two groups, and the radiation dose were compared with t test.Results A total of 476 coronary artery segments were evaluated in group A and 372 segments were evaluated in group B.The mean score of imaging quality for coronary artery segments in group A was 3.48±0.59 and that in group B was 3.53±0.58.There was no statistical difference in imaging quality between the two groups (Z=-1.432, P=0.187).The effective dose was on average (2.51±0.54) mSv (range 1.3--3.3 mSv) in group A, whereas on average (14.55±3.54) rosy (range 7.1--20.2 mSv) in group B.There was a statistical difference between the two groups (t=18.484, P=0.000).Conclusions Low-dose prospective ECG-triggering sequence scan in dual-source CT coronary angiography is feasible in patients with low heart rate and regular cardiac rhythm.This scan mode can substantially reduce radiation doses while preserving good diagnostic image quality.

Objective To prospectively evaluate the influence of average heart rate,heart rate variability and ECG editing on image quality of 64-slice CT coronary angiography(CTCA)in patients with atrial fibrillation(AF).Methods Fifty patients who were diagnosed with AF underwent respective ECG-gating 64-slice CTCA Image quality(good,moderate,poor)were evaluated on vessel segment level pre-and post ECG editing.Chi-square test was performed to compare the image quality in patients with various average heart rate,heart rate variability,and pre-and post ECC editing.Pearson correlation analysis was performed to test the relationship between the image quality and average heart rate and heart rate variability.Sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)were calculated by using the conventional angiography as the standard reference.Results The average heart rate of the fifty AF patients was(89±23)beat/min,with variability of(18.2±6.1)beat/min.Finally,24(3.4%)segments were considered to have poor image quality in 6(12.0%)patients.Image quality decreased significantly(P＜0.05)at the average heart rate of over 100 beats per minute(11 segments)or the standard deviation of heart rate of over 24 beats per minute(11 segments).There was significant correlation between the mean heart rate and the image quality for all segments,the RCA,and distal section of coronary artery(r=0.50,0.55,0.53,0.49,0.42,0.44;P＜0.05).Heart rate variability was also significant correlated with the image quality.There was significant difference on image quality pre-and post ECG editing(P=0.013).The respective overall sensitivity,specificity,NPV,PPV values were 100%(6/6),93.2%(41/44),100%(41/41),and 66.7%(6/9).Conclusion ECG editing can improve the success rate and the image quality of 64-slice CTCA effectively in patients with AF within a certain range of average heart rates and heart rate variability.

Objective To investigate the application of low-dose adaptive sequence scan of dual-source CT coronary angiography in patients with high heart rate and evaluate the image quality.Methods Seventy-two patients who underwent coronary CT angiography with heart rate> 70 bpm were divided into 2 groups.Group A was adaptive sequence scan, and Group B was retrospective ECG-gating helical scan.Examinations were performed on a dual-source CT scanner (Somatom Definition) .All images were transferred to a workstation for further processing and analysis.The image quality was evaluated using same criteria.The image quality of coronary artery segments was compared in two groups using rank sum test, and the radiation dose was compared using t test Results A total of 501 coronary artery segments were evaluated in group A and 400 segments in group B.The mean ranks in image quality of coronary artery segments in group A was 475.42, whereas 420.41 in group B.There was a statistical difference in image quality between the two groups (Z= - 3.509,P=0.000).The effective dose was on average (6.2±0.9) mSv in group A, whereas on average (14.7±1.9) mSv in group B, there was a statistical difference between the two groups(t= - 27.011, P=0.000).Conclusions Adaptive sequence scan in dual-source CT coronary angiography is feasible in patients with high heart rates.This scan mode can substantially reduce radiation dose and maintain the diagnostic image quality.

Objective:To evaluate the feasibility and diagnostic efficacy of the coronary fractional flow reserve derived from CT (CT-FFR) measurement method based on tracer pharmacokinetic principle.Methods:A total of 130 patients (159 coronary artery vessels) who were admitted to Beijing Anzhen Hospital from January 2015 to March 2019 were included in this study retrospectively. All patients had completed coronary CT angiography (CCTA) and invasive coronary angiography with invasive FFR. Subjective assessment of stenosis degree was performed on CCTA images and non-invasive FFR measurement was performed by using a tracer-kinetics based on CT-FFR measurement method. The Bland-Altman method was used to evaluate the diagnostic consistency of the two methods. Compared with the invasive FFR results, the sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve (AUC) of tracer-kinetics based on CT-FFR results for the diagnosis of coronary ischemic lesions were evaluated. All cases were divided into two heart rate groups:>65 bpm and ≤65 bpm. The diagnostic efficacy of tracer-kinetics based on CT-FFR in different heart rate groups was evaluated. χ 2 test and DeLong test were used to compare diagnostic performance in different evaluation methods and heart rate groups. Logistic regression analysis was used to evaluate the impact of factors such as heart rate, image thickness, image enhancement, and noise on the accuracy of diagnosis. Results:Bland-Altman analysis showed that the average difference between the two methods was -0.01. (-0.11-0.10). Compared with invasive FFR results, the tracer-kinetics based on CT-FFR method had a diagnostic sensitivity of 92.4%, specificity of 82.1%, positive predictive value of 87.6%, negative predictive value of 88.7%, and the area under ROC curve (AUC) value was 0.94. Compared with the diagnostic efficacy of luminal stenosis evaluated based on CCTA images, the difference was significantly statistical ( P<0.05). The diagnostic performance of CT-FFR had no statistically significant difference between the two heart rate groups. Factors such as heart rate, image thickness, image enhancement, and noise had no significant effect on the diagnostic accuracy of the tracer-kinetics based on CT-FFR method. Conclusions:The tracer-kinetics based on CT-FFR method may quickly complete the non-invasive FFR measurement on CCTA images with image quality that meets the needs of clinical diagnosis. It has a good diagnostic performance in the diagnosis of coronary ischemic lesions even for those cases with a faster heart rate. The diagnostic accuracy of tracer-kinetics based on CT-FFR method is not significantly affected by factors such as heart rate, image thickness, image enhancement, and image noise.

Atractylodis rhizoma is a perennial herb of the Asteraceae family,which mainly divided into A.chinensis(DC)Koidz and Atractyiodes lancea(Thunb)DC,with the effects of strengthening the spleen,drying dampness,brightening the eyes,etc.Atractylodis rhizoma is mainly used in the clinical treatment of spleen deficiency and dampness,night blindness,eye fatigue and other symptoms.According to the clinical effect,and modern pharmacological researches have confirmed,the Chinese herbal medicine Atractylodis rhizoma contains a variety of active ingredients,such as volatile oils,alkynes,glycosides,etc.In recent years,pharmacological studies on Atractylodis rhizoma have found that atractylodin in polyalkynes has good activity in anti-inflammation,treatment of bacterial resistance,and inhibition of cholangiocarcinoma cell migration,and its high biological activity may be related to the conjugated enyne structure.Therefore,this article summarizes the studies on chemical components and pharmacological effects of polyalkynes in Atractylodis rhizoma that have been published in recent years,and comprehensively expounds the research progress of polyalkynes in Atractylodis rhizoma,so as to provide reference for scientific researchers and promote the in-depth development and utilization of the medicinal value of Atractylodis rhizoma.

Objective To evaluate the feasibility and accuracy of cardiac CT (CCT) in quantitation of extracellular volume (ECV) fraction in patients with heart failure, with 3 T Cardiac MR (CMR) as the reference. Methods Twenty?eight patients with variety reasons of heart failure were enrolled in this study. ECVs was calculated, the correlation between CCT and CMR ECV value and other cardiac function parameters (left ventricular end systolic volume LVESV, left ventricular end diastolic volume LVEDV, cardiac output CO and ejection fraction LVEF, and clinical bio?marker BNP) was determined. Interclass correlation coefficient (ICC) was used to evaluate the agreement of measurement by two radiologists. Results The average of ECV on CCT and CMR was 33% ± 8% and 31% ± 6%, respectively. A good correlation was revealed between myocardial ECV at CCT and that at CMR (r=0.854, P<0.001). Bland?Altman analysis between CCT and CMR showed a small bias (4.6%), with 95% limits of agreement of-18.2% to 27.4%. ICC for ECV at CCT was excellent (ICC=0.910). For both CCT and CMR, ECV was inversely related to LVEF. The radiation dose for CCT?ECV was (1.60±0.04) mSv. Conclusions ECV at CCT and that at CMR showed good correlation, suggesting the potential for myocardial tissue characterization using CCT. However, CCT?ECV would possibly overestimate the extent of ECV.

Objective To analyze the correlation between calcification factors and fractional flow reserve derived from CT (CT?FFR). And to evaluate the diagnostic efficacy of CT?FFR in coronary artery lesions with calcification compared with that of invasive FFR. Methods Sixty?five patients (74 coronary artery vessels) who were admitted to Beijing Anzhen Hospital from July 2014 to December 2016 were included in this study retrospectively. All patients had completed CCTA (coronary CT angiography), coronary angiography and invasive FFR measurements, and had coronary lesions contain calcifications. The evaluation of CCTA data included quantitative analyses of plaque components, coronary artery stenosis, and CT?FFR measurements. The patients′basic data were grouped and compared according to the FFR values. The measurement data was tested by independent?samples t tests, and the categorical data were analyzed by χ2 tests. Quantitative measurements of plaques were compared between groups using independent?sample t tests or rank sum tests based on FFR and CT?FFR values. The reproducibility of CT?FFR measurement software was evaluated by inter?class correlation coefficient (ICC) and the Youden index was calculated to determine the threshold for CT?FFR diagnosis of ischemia. Pearson or Spearman correlation analyses were used to assess the correlations between CT plaque quantitative indicators, CT?FFR and invasive FFR. Multivariate logistic regression analysis was used to analyze the predictors of ischemia by FFR and CT?FFR. In contrast to invasive FFR results, the sensitivity, specificity, negative predictive value, positive predictive value (PPV) of CT?FFR in the diagnosis of coronary ischemic lesions were evaluated, and the diagnostic consistency was evaluated by the Bland?Altman method. Results Compared with invasive FFR, CT?FFR had a more significant correlation with calcification volume and ratio of calcification in plaques (r=-0.519 and－0.547, respectively, both P=0.001). Multivariate logistic regression analysis showed that plaque length was a predictor of invasive FFR in the diagnosis of pathological ischemia ( OR=1.13, 95%CI : 1.05—1.23, P=0.002), and was associated with CT?FFR to determine pathological ischemia. In addition to plaque length ( OR=1.10, 95%CI : 1.02—1.18, P=0.010), the predictor also included ratio of calcification in plaque ( OR=1.09, 95%CI: 1.03—1.15, P=0.003). Compared with invasive FFR results, the diagnostic sensitivity of CT?FFR was 79.1%, the specificity was 80.6%, the PPV was 85.0%, and the area under the ROC curve was 0.78. The result for the diagnosis of ischemia lesion by using CT?FFR had significant statistical differences with the results by according coronary artery stenosis (χ2=10.05, P=0.002; χ2=34.71, P=0.001; χ2=7.65, P=0.006; Z=2.10, P=0.029). The Bland?Altman analysis showed a mean difference of －0.01 (-0.26—0.25) between the CT?FFR and the invasive FFR. Conclusions There is no significant correlation between the proportion of calcification components of coronary plaque and the presence or absence of myocardial ischemia, but the proportion of calcification in plaque will affect the result that is evaluated by CT?FFR. However, compared with CT?based stenosis evaluation, CT?FFR can still significantly improve the ability of CCTA to diagnose ischemia lesion with calcification.