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 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 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 study the clinical value of color Doppler ultrasonography in the persistent sciatic artery.Methods The ultrasonographic images of eleven patients with persistent sciatic artery diagnosed by CT angiography or digital subtraction angiography were retrospective analyzed,the ultrasonographic features were summarized.Results The sciatic artery showed the enlarged internal iliac artery,which continued into the thigh in a posterior location,the sciatic artery described a tortuous course toward the knee,slowly filling normal-appearing popliteal artery in 8 cases,there were no connection with popliteal artery in 1 cases.The common femoral artery and superficial femoral artery was dysplasia in 7 patients,which was thinner than the popliteal artery.Conclusions The ultrasonography is the effective imaging method for diagnosis of the persistent sciatic artery.

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.

Researches have shown that melatonin is neuroprotectant in ischemia/reperfusion-mediated injury. Although melatonin is known as an effective antioxidant, the mechanism of the protection cannot be explained merely by antioxidation. This study was devoted to explore other existing mechanisms by investigating whether melatonin protects ischemia/reperfusion-injured neurons through elevating autophagy, since autophagy has been frequently suggested to play a crucial role in neuron survival. To find it out, an ischemia/reperfusion model in N2a cells was established for examinations. The results showed that autophagy was significantly enhanced in N2a cells treated with melatonin at reperfusion onset following ischemia and greatly promoted cell survival, while autophagy blockage by 3-MA led to the shortened N2a cell survival as assessed by MTT, transmission electron microscopy, and laser confocal scanning microscopy. Besides, the protein levels of LC3II and Beclin1 were remarkably increased in ischemia/reperfusion-injured N2a in the presence of melatonin, whereas the expression of p-PKB, key kinase in PI3K/PKB signaling pathway, showed a decrease when compared with untreated subjects as accessed by immunoblotting. Taken together these data suggest that autophagy is possibly one of the mechanisms underlying neuroprotection of melatonin.

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.