Abdominal aortic aneurysm (AAA) is a common fatal aortic disease.The rupture of AAA is the procession affected by multiple factors.Besides physiological,pathological and biochemical changes,morphological and biomechanical alteration can also influence this procession.The progress of rupture risk evaluation through morphological and biomechanical characteristics of AAA were reviewed in this article.

Changes in respiratory function before and after CPB in 40 children with state of left-to-right shunt of VSD were studied. Among the cases, 20 of them were with pulmonary hypertension (PH group ) and 20 without PH (control group). Before CPB, resist ante of inspira tion (RI) and resistance of expiration (RE)in PH group (23.87?7.53,42.98?12.1) were significantly higher than those of control group(RI 17.95?7.53,RE 34.95?5.13);compliance of lung-thorax(CLT) in PH group(11.58?4.87) was significantly lower than that of control group(14.32?1.99). After CPB. both RI (30.94?11.89) and RE(46.43?9.9) in PH group were greatly higher than those in control group (28.00?9.29,46.43?9.9);CLT (10.98?4.6) was lower than that of control group (12.3?2.68). In PH group,the PaO_2 decreased and the magnitude of A-aDO2 increased much more than those in control group. The results suggest that respiratory function in the children with PH might not be improved immediately after CPB separation.

Objective To evaluate the methods and the factors of affecting imaging quality of 3D CE MRA of carotid arteries.Methods 3D CE MRA in 48 patients were performed using 1.5T super conductive MR scanner,cervical and lumbar combination phased array coils. All patients were examined using intravenous injection Gd-DTPA and breath-hold 3D FLASH sequence. Results Imaging quality was satisfied in 46/48 patients (96%). MIP and MPR could clearly showed normal anatomy. The site,size and stenosis degree of the lesion were also demonstrated. Compared to surgery,DSA and/or ultrasound results , in 23 patients, the sensitivity and specificity of 3D CE MRA were 100% and 100% respeectively for the lesion of carotid arteries. Conclusion High quality images of 3D CE MRA mainly depends on determining the best acquisition delay time,optimizing injection volume and rate of contrast material,using reasonable sequence parameters and skilled level of operators.

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 study the value of dual-source CT(DSCT)in assessing aortic mechanical valve with 3D cardiovascular imaging technique.Methods Thirty-four patients with mechanical aortic valve transplantation were enrolled.Nineteen cases transplanted with On-x valve and 15 cases with St jude valre.CT scan was performed in all 34 patients and MRI scan in 30 patients.The CT imaging quality of On-x valve with St jude valve was compared by two independent samples Wilcoxon rank test.Two independent sampies test was used to compare tlle valve angle in the two kinds of valve and also in the same group.The relative functional index of left ventricle in CT and MR analysis by paired-samples t Test. Results The image quality was dirided into three grades.Six hundred and eighty phases in all 34 patients.which included 391 phases with grade 1,171 phases with grade 2 and 118 phases with grade 3.There were no significant different between two kinds of mechanical valve in image quality(image quality of grade 1:Z=-1.084,P=0.286;grade 2:Z=-0.088,P=0.945;grad 3:Z=-1.045,P=0.319).The mean bileaflet angle of 34 cases was 82.0°±4.4°in completely opening and 34.5°±5.7°in completely closing.The mean radian gradient over openess and closure was 47.5°±7.5°.The radian gradient of St iude group(55.0°±1.8°)was obviously larger than On-x group(41.5°±4.1°)(t=-11.732,P=0.000).But,there were no significant difference between dual-source CT and 1.5 T MR when evaluate the left ventrical fuction,including EF[MR.EF(57.2-1-2.8)%,CT-EF(57.9±2.8)%,f:-0.496,P=0.623],EDV[MR-EDV (121.6±9.1)ml,CT-EDV(132.9±11.2)ml,t=-1.198,P:0.240],ESV[MR-ESV(55.1±6.9)ml,CT-ESV(59.5±7.6)ml,t=-1.094,P=0.283],myocardium mass at ED[MR-Myo.mass (155.5 ±12.6)g,CT-Myo.mass(147.9±11.6)g,t=1.823,P=0.079]and CO[MR-CO(5.7±0.4)ml/min,CT-CO(5.9±0.5)ml/min,t=-3.211,P=0.775].Conclusions Dual source CT with 3D cardiovascular imaging technique is valuable and effective for evaluating aortic mechanical valve.The shape of the whole valve and movement of bileaflet reappears well.With the postprocessing software,it allows evaluating aortic mechanical valve function,reliable measurements of opening and closing leaflet angles and left ventrieal function.

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.

ObjectiveTo assess the performance of dual-source CT (DSCT) for left atrial volume and function evaluation and compare this performance to that of cardiac cine MR ( CMR ),which was considered as the standard reference technique.Methods Forty-nine patients referred for CT coronary angiography were enrolled in this study.DSCT data sets and FIESTA cines of the vertical long axis covering the left atrium and the short axis covering the left ventricle were obtained on the same day without additional medicine.All images were analyzed to obtain left atrial volume at different time and its function values.All the parameters were corrected by body surface area.Inter-modality agreement was tested through linear regression and Bland-Altman analyses.Repeated measurements were performed to determine inter-observer variation.ResultsThe indexed measurements of DSCT and CMR were (47.4 ± 11.1 ) and (46.2 ± 9.7 )ml/m2 for LAVmax,( 22.2 ± 6.9) and ( 21.3 ± 5.8 ) ml/m2 for LAVmin,( 34.8 ± 8.8 ) and ( 33.6 ± 7.8 )ml/m2 for LAVp,(24.0 ±5.7)and(21.5 ±5.0) ml/m2 for LARV,(11.6 ±3.9)and(10.9 ±3.9) ml/m2 for LAPV,(12.4 ±3.9)and(10.7 ±3.6) ml/m2 for LAAV,(22.6 ±8.4)and(21.0 ±6.4) ml/m2 for LACV,(52.8 ± 7.4) ％ and ( 54.5 ± 6.3 ) ％ for LAEF,respectively.The correlation coefficients between DSCT and CMR measurements for LAVmax,LAVmin,LAVp,LARV,LAPV,LAAV,LACV and LAEF were 0.89,0.90,0.90,0.80,0.82,0.80,0.76 and 0.78,respectively.However,DSCT slightly overestimated LAVmax,LAVmin,LAVp,LARV,LAPV,LAAV and LACV,and the deviation was 1.2,0.9,1.1,0.3,0.1,0.2 and 0.4 ml/m2,respectively.Compared with CMR,DSCT slightly underestimated LAEF of about 0.6％.Interobserver variation was lower in DSCT examination than CMR for the measurements of left atrial function.ConclusionDSCT provided accurateand reproducible measurements of left atrial volume and function.

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 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.

PurposeTo determine the feasibility and accuracy of dual source CT (DSCT) in assessing myocardial delayed-enhancement and left ventricular wall thickness of hypertrophic cardiomyopathy (HCM) in comparison with cardiac magnetic resonance (CMR).Materials and MethodsEighty patients with HCM confirmed by clinical diagnosis were enrolled in the study. DSCT images and CMR images were acquired at the arterial and lag phases. According to 17-segment model provided by American Heart Association, the left ventricular wall thickness and location of delayed-enhancement were verified, and the correlation of these two methods were analyzed in terms of the diagnosis of myocardial delayed enhancement (MDE).Results1360 myocardial segments for 80 patients were assessed. The left ventricular wall thickness determined by DSCT was significantly correlated with MR results (r=0.88,P<0.01). DSCT and MDE showed substantial agreement on per-patient (n=74,Kappa=0.751,P<0.05) and per-segment (n=1238, Kappa=0.746,P<0.01) levels. For dense myocardial delayed enhancement, CT findings were significantly correlated with those of CMR (r=0.89, P<0.01), but CT scan slightly underestimated the lesion scope of fibrosis. Bland-Altman analysis showed that CT and MRI were different in measuring the lesion volume of myocardial delayed enhancement (mean standard deviation was 2.71%).ConclusionThe cardiac CT examination provides comprehensive information in coronary artery and myocardial assessment, and MDE-DSCT is also effective in the diagnosis of myocardial fibrosis in HCM since it can be used in assessing myocardial fibrosis.