Colorectal neoplasms always present with thickness of the intestinal wall or a soft tissue mass in the enteric cavity. Multi-slice computed tomography (MSCT) with high spatial resolution and advanced post-processing techniques can demonstrate the above signs of the tumor, and the invasive signs of adjacent structures and lymph node metastasis. Combined with three dimensional reformation images, MSCT shows a higher sensitivity than that of double contrast barium enema and electronic colonoscope. MSCT is promising in the diagnosis and preoperative evaluation of colorectal neoplasms.

Objective To study the effect of hypoxial endothelia cell conditional medium(HECCM)on the proliferation of pulmonary arterial muscle cell(PASMC).Methods MTT assay was used to test the proliferation,immuno-cytochemistry was used to identify the expression of ?-SM-actin.Results(1)HECCM could promote the proliferation of PASMC,down-regulate their expression of ?-SM-actin.(2)DDPH could up-regulate the expression of ?-SM-actin in PASMC which was time-dependant.Conclusions DDPH could reverse the phenotype transformation of PASMC exposed to HECCM,the action was time-dependant.After some time DDPH could reversly transform PASMC to the normal contractile phenotype.

Objective To investigate the effectiveness and feasibility of cardiovascular computed tomography angiography(CTA) in 128-slice DSCT with low tube voltage and low dosage contrast media in children with tetralogy of Fallot (TOF). Methods Forty patients with TOF were randomly divided into group A and group B by random number table method, patients in group A received a conventional scan with 80 kVp and contrast media of 1.2 ml/kg, patients in group B, 70 kVp and contrast media of 1.0 ml/kg were used. The injection time of the two groups were both fixed for 12 s. CT attenuation, image noise and signal-to-noise ratio (SNR) of ascending aorta, the main pulmonary artery, left ventricle and right ventricle were quantified. Radiation dose and volume of the contrast medium were recorded. Subjective image quality was assessed by two radiologists in consensus. The Student's t test was performed to analyse the differences between the two groups regarding CT attenuation, image noise, SNR, radiation dose and volume of the contrast medium. The image quality scores between the two groups were compared by using the Mann-Whitney U test. Results No significant difference was found in the attenuation, noise, SNR between the two groups in the same evaluated anatomic regions and no significant difference was found in the image quality. Effective dose (ED) was(0.17±0.05),(0.13±0.04)mSv respectively, there was significant reduction in group B than that in group A (t=2.48, P=0.019). The consumed iodine amount was(10.00±1.84),(8.29± 1.45) ml respectively, there was significant reduction between the two groups (t=2.89, P=0.007). Conclusions In children with TOF, the cardiovascular CTA with diagnostic quality can be adequately acquired with low tube voltage (70 kVp) and low concentration contrast media (1.0 ml/kg), there is significant reduction in radiation dose and contrast medium amount.

Objective To explore the optimal reconstruction windows in patients with heart rate (HR) over 91 (beats per minute) bpm, and to explore the feasibility of prospective ECG-gated DSCT coronary angiography.Methods Two hundred and thirty-two patients[body mass index (BMI):23-25 kg/m2, with stable HR, and average HR ≥91 bpm]with suspected or known coronary artery disease underwent retrospective ECG-gated DSCT coronary angiography.They were divided into 3 groups (A-C) according to the average HR of scanning.Images were reconstructed from 29% to 80% of the R-R interval in 3% increments.Two independent readers assessed the overall image quality by a five-point scale and determined the optimal reconstruction windows of each coronary segment and the ranges.Coronary arteries were segmented according to the guideline of the American Heart Association (AHA).The degree of interobserver agreement was determined by Kappa statistics.Results Three thousand three hundred and fortythree segments were considered to have diagnostic image quality in 232 patients.The ranges of optimal reconstruction windows of images were concentrated on 81%-61% and 51%-31%.In group A(91-95 bpm), there were 1183 segments in 83 patients, and the according proportions were 5.49%, 94.51%,respectively; In group B(96-100 bpm), there were 986 segments in 68 patients, and the according proportions were 0.20%, 99.80%, respectively; In group C(≥ 101 bpm), there were 1174 segments in 81 patients, and the according proportions were 0.17%, 99.83%, respectively.The optimal construction windows in 3274 segments out of 3343 segments in 232 patients were concentrated in 41%, ranged from 51%-31%.The image quality assessment in 3343 segments in 232 patients have a high inter-observe agreement (Kappa=0.883,P <0.05).Conclusion The optimal reconstruction windows of patients with stable HR(≥91 bpm) was concentrated in 41%, ranged from 51%-31%.When nothing except the window of data acquisition is considered, the prospective ECC,-gated DSCT coronary angingraphy can be used in patients with stable HR(≥91 bpm).

Objective To explore the application of low-dose prospective ECG-triggering dualsource CT (DSCT) angiography in infants and children with Kawasaki disease (KD).MethodsNineteen children diagnosed of Kawasaki disease underwent low-dose prospective ECG- triggering DSCT angiography (DSCTA) with free breathing and transthoracic echocardiogram (TTE).The overall imaging quality was graded on a five-point scale. Interobserver agreement in subjective image quality grading was assessed by Kappa statistics.The location,number and size of the aneurysms and dilations were recorded and compared with those of TTE.Pearson correlation analysis was used to evaluate the agreement on measurements between DSCTA and TTE.The average effective dose of DSCTA in all 19 children was calculated.ResultsDSCTA was performed successfully in all 19 children.A total of 91.5 ％ (226/247) segments permitted visualization with diagnostic image quality. Fifteen patients were diagnosed with coronary artery lesions. A total of 28 aneurysms and 15 arterial aneurysmal dilations were detected by DSCTA,while 19 aneurysms and 13 arterial aneurysmal dilations were found by TTE.TTE failed to detect 9 aneurysms (2 in the distal right coronary artery,2 in the posterior descending artery,1 in the middle of left anterior descending artery,1 in the middle of left circumflex artery,2 in the distal of LCX and 1 in the obtuse marginal branch)and 2 arterial aneurysmal dilations (1 at the diagonal branch and 1 at obtuse marginal branch). The concordance of DSCTA and TTE in measurement of diameter and length of these aneurysms and aneurysmal dilatations are good (0.63 ± 0.20) and (0.58 ± 0.20) cm vs ( 1.49 ± 0.83 ) and ( 1.22 ± 0.66) cm ( r =0.989 and 0.965,P ＜ 0.05 ).There was a good agreement on overall image quality ( Kappa =0.87 ). The mean effective dose was(0.24 ± 0.08) mSv.ConclusionProspective ECG-triggering DSCTA with very low effective radiation dose is safe,reliable and more sensitive than TTE on diagnosing of coronary artery lesions,especially in the distal lesions,in infants and children with KD.

Objective To explore the clinical value of dual-energy CT angiography (DE-CTA) in the diagnosis of carotid cavernous fistula. Methods Fourteen patients suspected of carotid cavernous fistula underwent DE-CTA between Dec. 2008 and Feb. 2010. Image post-processing of DE-CTA was performed with the dedicated software to obtain bone-removal and non bone-removal images. Four experienced radiologists evaluated image quality of DE-CTA, the number, location and size of fistulae and dilation of cerebral veins. The bone-removal and non bone-removal images were compared for displaying of fistulae and other related lesions. Kappa test was used to test the consistency of image quality evaluation between two radiologists. The sizes of fistulae were measured with bone-removal DE-CTA images and non bone-removal DE-CTA images respectively and their results were compared by using student's t-test and the correlation test. Results Twenty-eight intracranial internal carotid arteries of 14 patients showed acceptable image quality. Fourteen cases were diagnosed as carotid cavernous fistula with both bone-removal and non boneremoval DE-CTA images. Two patients presented with bilateral lesions, while 7 patients presented with left lesions and 5 patients had right lesions. Totally, sixteen fistulae lesions were detected in 14 patients. The mean size of fistulae was (0. 36 ±0. 10) mm by bone-removal images, whereas (0. 35 ±0. 11 ) mm by non bone-removal images. There was no significant difference between the two methods ( t = 0. 29, P ＞ 0. 05 ),and good correlation was found between the two methods ( r = 0. 97, P ＜0.05). Thirteen dilated cerebral veins in 8 cases were found by bone-removal images versus 9 dilated cerebral veins in 6 cases by non boneremoval images. Conclusions Image post-processing of DE-CTA is a simple and useful method to identify carotid cavernous fistula. DE-CTA is also useful for therapeutic planning.

Objective To evaluate feasibility and time efficiency of dual-source flash post-processing software (Bone Reading)for reconstruction of bronchial artery.Methods The imaging data of 70 patients with suspected bronchial artery dilatation who underwent bronchial artery-CTA were evaluated by 2 independent radiologists.First,the related contents of bronchial artery such as origination,number, type,route and lumen diameter were evaluated by multiple planar reconstruction (MPR),maximum intensity projection (MIP)and volume rendering technique (VRT).The results and process time were recorded.After a month,the post-processing software(Bone Reading)was used to evaluate the same contents.Results There was very good correlation between both readers for both reading methods without significant differences.There was significant difference of process time between with regular method and with Bone Reading (P<0.05)for both readers.Process time could be decreased by approximately 35%.Conclusion The application of CT software (Bone Reading)is feasible in the CTA of bronchial artery.This method may gain a significant time saving in comparison to regular method.

Objective To explore the clinical application of dual-soure CT(DSCT) in coronary artery.Methods 51 patients suspected with coronary artery disease underwent both DSCT coronary arteriography and selective coronary angiography(CAG), the DSCTA results were compared with that of CAG.Results DSCT coronary arteriography in 51 patients at any heart rate was successful.Coronary artery branches and part sub-branches were clearly displayed by DSCT angiography.Stenosis or obstruction of 166 coronary artery branchs in 51 patients were showed ,of them,150 branches were confirmed by CAG. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of DSCTA were 100%, 90%, 90.4%, 100% and 94.8% respectively.Conclusion DSCT is a valuable method in detecting the diseases of coronary artery with lower dose. The accuracy of the DSCT is approximate to the CAG.

Objective To compare the accuracy, image quality and radiation dose between prospective ECG?gated sequential and high?pitch acquisition on 128?slice dual?source CT (DSCT) angiography in infants and children with congenital heart disease (CHD). Methods Ninety?two children with CHD from October 2011 to February 2013 were prospectively enrolled and assigned into two groups according to random number table. Forty?six patients underwent DSCT angiography with sequential mode, and the other 46 patients were examined with high?pitch mode. With surgical and/or DSA results as the standard, the diagnostic accuracy and sensitivity of the two groups for the intracardiac structures, extracadiac and coronary artery anomalies were evaluated, and the comparison was analyzed by Fisher exact test. A 5?grade scoring system was used to interpret the image quality of intracardiac structures, great vessels and the proximal and middle segments of coronary arteries. Interobserver agreement on grades of image quality was assessed by Kappa statistics. The image quality scores were compared using the Mann?Whitney U test. The Student t test or the Mann?Whitney U test was used to analyze the differences between the two groups regarding to patients' age, weight , heat rate, CT attenuation, image noise and SNR in the ascending aorta and the pulmonary trunk as well as radiation dose. Results All 92 patients successfully underwent DSCT angiography. The diagnostic accuracies of intracardiac anomalies by high?pitch group and sequential group were 95.65%(88/92) and 99.28%(274/276), showed significant difference between the two groups (P<0.05), but no significant difference in the sensitivity of intracardiac anomalies (P>0.05) .There was no significant difference in the diagnostic accuracy and sensitivity of extracadiac anomalies between the two groups (P>0.05). The diagnostic accuracies of coronary artery anomalies by high?pitch group and sequential group were 93.48%(43/46) and 100.00%(46/46), showed no significant difference between the two groups (P>0.05), but there was significant difference in the sensitivity of coronary artery anomalies (50.00%(3/6) , 100.00% (11/11)) (P<0.05). There was excellent agreement for image quality scoring of the intracardiac structures, great vessels and the proximal and middle coronary arteries between the two observers (Kappa=0.81, 0.85, 0.85, P<0.05). The median image quality scores of extracardiac great vessels were both 5.00 in high?pitch group and sequential group, and there was no significant difference between the two groups (U=981.000, P>0.05). The median image quality scores of intracardiac structures and proximal and middle segments of coronary arteries respectively by high?pitch group were 4.00 and 3.00, and 5.00 and 4.00 respectively by sequential group. The image quality of intracardiac structures (U=594.500, P<0.05) and proximal and middle segments of coronary arteries (U=397.500, P<0.05) was significantly better in the sequential group than that in the high?pitch group. There was no significant difference between the two groups in CT attenuation, noise and SNR of the ascending aorta and pulmonary trunk. The mean effective doses of the high?pitch group and the sequential group were(0.27±0.11)and(0.39±0.17)mSv, and showed significant difference between the two groups (t=4.316, P<0.05). Conclusions Both sequential and high?pitch mode of 128?slice DSCT angiography provide high accuracy for the assessment of CHD in infants and children, while the high?pitch mode, though with some image quality declined, shows further significantly lower radiation dose.

Objective To investigate the value of prospectively electrocardiogram (ECG)-triggered high-pitch coronary computed tomography angiography at 70 kV and 30 mL contrast medium with Stellar detector dual-source CT.Methods 60 patients with the BMI<24.9 kg/m2 were randomized into two groups:Group A (30 cases)with the tube voltage of 70 kV and 30 mL contrast medi-um.Group B (30 cases)with the tube voltage of 100 kV and 50 mL contrast medium.All the patients were performed with a Stellar detector dual-source CT using a prospectively ECG triggered high-pitch spiral technique.The images of Group A were reconstructed with SAFIRE technique,while Group B were with FBP technique.The objective image quality includes CT attenuation,SNR, CNR.And radiation dose was also calculated.The subjective was evaluated by 4-scale point.Independent sample t test was used.Re-sults There was no difference for subjective image quality between the groups,A:(3.38±0.942),B:(3.50±0.682),(t=-0.562, P >0.05).The CT attenuation of the 70 kV group were higher than that of the 100 kV group for all the segments(P <0.01).The SNR and the CNR have no statistically significant difference between the groups (P >0.05).Compared with the 100 kV group,the radiation dose of the 70 kV group was reduced by 76.5% (A:0.19±0.023 mSv,B:0.81±0.101 mSv,P <0.01).Conclusion Using 70 kV with 30 mL contrast medium in Stellar detector dual-source CT coronary angiography for the patients with a normal BMI could obtain qualified diagnostic image with low radiation dose and contrast medium.