Objective:To study the feasible training model of graduate students with professional degree. Methods:According to the purpose of training-clinical skills of graduate students with professional degree in department of radiology, we have made several ways to ensure the procedural and standardization of the training from course setting, multiple level clinical operation training, the ability of study and evaluation system. Results:To introduce the mode by using evaluation system and to standardize the steps. Conclusion:The model which includes proper course setting, multiple level clinical operation training, the ability of study and evaluation system can enhance the clinical skill training and advance the professionalism of the students.

Objective:To avoid the redundant computation based on the convolution operation in the traditional wavelet transform, and to remove the baseline wander noise existing in the course of collecting the ECG signal. Methods: Use the lifting wavelet transform with two wavelets, and constitute the ECG signal with the noise removed after decomposing, setting the subband coefficient including the noise to zero, and rebuilding. Results:Use MATLAB to remove the baseline wander noise in the ECG signal and bw provided by the MIT-BIH database, and the results show that the baseline wander was removed effectively. Conclusion:The baseline wander noise in the ECG signal can be removed accurately though the method mentioned above, the waveform information in the original ECG signal can be maintained effectively, and subsequently, that can provide help for detecting the characteristic parameters in the ECG signal.

This paper introduces an infusion remote-control system based on wireless data-transfer.It can realize such functions as the accurate control of the infusion speed,humanized prompt,central monitoring,wardship and management.Ultrasonic adopted to detect the flux,the lower MCU can fulfill such functions as control,display and storage,which can also perform real-time wireless communication with the upper PC to facilitate remote control.

Objective To analyse the flow characteristics in the true lumen and false lumen,and the relationship between the flow characteristics and the collapse degree of the true lumen using MRI.Methods Eleven patients with acute Stanford type B aortic dissection were examined by true FISP、3D CE MRA、PC cine MRI on a Siemens Sonata 1.5 T.Not only the quantitative data on the hemodynamics such as peak velocity,average velocity,average flow volume,forward volume,retrograde volume and net volume,and the area of the true lumen and false lumen can be acquired,but also the blood flow model,ie the velocity-mapping.Then we analysed the relationship between the flow characteristics and the collapse degree of the true lumen.Results The average area of the false lumen in the proximal descending aorta(about 2 cm distal to the entry)was(8.10±2.93)cm2,and(2.59±0.93)cm2 of the true lumen in the same slice (P＜0.05).The average velocity in the false lumen,(2.81±0.73)cm/s,was significantly lower than in the true lumen[(15.52±2.84)cm/s,P＜0.01],wheras the average flow(36.32±5.37)ml/s,was not significantly difierent(P＞0.05)from the average flow in the false lumen(37.62±24.58)ml/s.The velocity-mapping curve looked like same in the true and false lumen in this level.And in the abdominal aorta(about the level of the hepatic hilar),the average flow(10.46±5.57)cm/s was significantly lower(P＜0.05)than in true lumen[(4.04±2.96)cm/s].At this level,the direction of blood flow in the true lumen was retrograde(upward)in the mid and late systolic phase in six patients,and normal in the diastolic phase and early systolic phase,that was to say,bidirectional blood flow can be caught in the true lumen of the abdominal aorta.The collapse degree of the true lumen was closely correlated with the the average velocity and the flow volume in the false Iumen,and the coefficient correlation and P value were 0.931 and 0.000,0.926 and 0.000 respectively.Conclusions PC cine MRI can quantitatively measure the peak velocity,average velocity,average flow volume,forward volume,retrograde volume and net volume,and combined with 3D CE MRA can evaluate the collapse degree of the true lumen.It is important for clinical application in the diagnosis,therapeutic management and the therapeutic opportunity choice of the acute Stanford type B aortic dissection.

Objective To investigate the diagnostic performance of stress cardiac magnetic resonance(CMR) for evaluating low-risk patients with suspected acute coronary syndrome(ACS).Methods Twenty-two patients with low risk of suspected ACS were prospectively and consecutively enrolled in this study.Diagnostic performance of stress CMR was compared with single-photon emission computed tomography(SPECT) for diagnosis of myocardial ischemia with coronary angiography (CAG) as the reference method.Results On the patient-based level analysis,the diagnostic performance of CMR for detection of ACS was sensitivity 93% and specificity 75%.The corresponding value of SPECT was 79%,63%.The area under the ROC (AUC) of CMR was 0.897, which was slightly superior to that of SPECT at 0.723 (P=0.19).On the per-vessel assessment, the diagnostic value of CMR was sensitivity 89%,specificity 87%, while the corresponding value of SPECT was 68%,83%.The AUC of CMR was 0.923,which was significantly higher than that of SPECT at 0.774 (P<0.05).Furthermore, the AUC of CMR was significantly superior to that of SPECT with AUC being 0.900 and 0.553 in the left anterior descending (LAD) vessels (P=0.009 6).Conclusion Stress perfusion CMR has excellent diagnostic performance in low risk ACS patients.Compared with SPECT,stress perfusion CMR performed better in the low-risk ACS populations.

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 investigate cell-killing and bystander effects on gallbladder cancer (GBC-SD) cells transferred with double suicide genes (CD and HSV-tk). Methods CD and HSV-tk genes were transfected into PA317 cells using lipofectamine. GBC-SD cells were infected with viral supernatant. GBC-SD/CD+tk cells were treated with 5-FC and/or GCV. GBC-SD/CD+tk and GBC-SD were inoculated subcutaneously into the nude mice respectively and treated with GCV and 5-FC for 21 days. Results The killing effect of 5-FC and GCV in combination on GBC-SD/CD+tk cells is more effective than using 5-FC or GCV alone. The local bystander effect is significant while the distant bystander effect was not obvious. Conclusion The cell-killing efficacy of chemotherapy on GBC-SD transfected with double suicide gene was significantly increased, and the bystander effect was obvious.

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 the morphological characteristics of large and small infrarenal abdominal aortic aneurysm (AAA) with 64-slice spiral CT angiography (CTA). Methods Forty-five patients with infrarenal true AAA underwent CTA. The morphological characteristics of AAA were evaluated. The patients were divided into two groups: small AAA (diameter<5 cm, n=20) and large AAA (diameter≥5.0 cm, n=25). The clinical risk factors and morphological characteristics between small and large AAA were compared. The correlation between the size of AAA and the other morphological characteristics was analyzed. Results Compared to patients with small AAA, those with large AAA showed lower systolic blood pressure and larger prevalence of smoking (P＜0.05). The length of aneurysms body, diameter of proximal and distal neck, the prevalence of thrombus in posterior wall, and aneurysm wall calcification score in large AAA were significantly larger than those of small AAA (P＜0.05). The length of AAA was positively correlated with proximal neck angle (r=0.418, P＜0.01) and diameter (r=0.411, P＜0.01), whereas negatively correlated with entry angle (r=-0.478, P＜0.01)and proximal neck length (r=-0.562, P＜0.01). Conclusion The size of infrarenal AAA is associated with the other morphological characteristics.

Objective To investigate the feasibility of comprehensive assessment of the whole aorta and coronary arteries (CA) simultaneously with high-pitch 128-slice dual-source CT ECG-gated FLASH protocol.Methods A total of 48 consecutive patients with suspected aortic diseases underwent CTA examination of the whole aorta and CA using a ECG-gated FLASH CT protocol (pitch =3.2) without heart rate (HR) control.Aorta,aortic valves and CA were shown with different post-processing modalities.The image quality of the aorta,aortic valves and CA was evaluated and compared according to HR (low HR group ≤ 65 bpm,high HR group ＞ 65 bpm).The scan time,effective dose and contrast medium volume were recorded.Inter-observer differences were calculated by Kappa test.Differences between groups were analyzed by Mann-Whitney test with count data and variance test with measurement data.Results All examinations were completed successfully.The image quality was acceptable in the aorta,aortic valve (100％,48/48) and CA (94.0％,551/586).Percentage of diagnostic quality images was slightly higher in low HR group (94.7％,232/245,93.5％,319/341,Z =-2.504,P ＜ 0.05).Inter-reader reproducibility was 95.8％ (46/48) in the aorta and aortic valve,96.6％ (566/586) in CA,yielded good agreement (Kappa =0.81 and 0.89).The mean attenuation of aorta and CA were higher than 300 HU,especially in low HR group (357.0-446.0) HU.Except proximal segment of right CA,the CNR of whole aorta and coronary arteries were significantly higher in the low HR group (24.5-29.0) than that in the high HR group (20.0-23.1,P ＜0.05).SNR of the whole aorta was higher in the low HR group (13.7-17.9) than the high HR group (11.5-13.9,P ＜ 0.05).The mean scan time was (1.56 ± 0.08) s,effective dose was (4.12 ± 1.23) mSv (2.77-6.77 mSv),and contrast medium volume was (72.8 ± 2.1) ml.Conclusions CT angiography of whole aorta and coronary arteries could be performed simultaueously within 2 seconds with CT ECG-gated FLASH protocol.The images were of diagnostic quality for aortic and CA disease with low dose of radiation and contrast media.However,high HR could decrease the image quality of CA.