Objective To investigate the effect of intravenous thrombolytic therapy with urokinase on the neurological function and the concentration of serum matrix metalloproteinase 9 (MMP-9) in the patients with acute cerebral infarction.Methods The patients with acute cerebral infarction were divided into the experimental and control groups.The experimental group included 27 patients who were complied with thrombolytic criterion within 4.5 hours after stroke and were firstly treated by intravenous thrombolytic therapy with urokinase by 100 million units after 24 h and 300 mg aspirin by oral.The control group included 27 cases that were directly administrated by 300 mg aspirin 4.5 hours later after stroke.After 24 h,the two groups were administrated with other same conventional treatments such as neurotrophy,improvement of microcirculation,and control of blood-fat.The neurological function and dynamic concentration of serum MMP-9 were observed before treatment and after treatment.Results After treatment,the neurological deficit evaluation score in both groups was gradually reduced with the treatment time,and the neurological deficit evaluation score in the experimental group was significantly lower than that in the control group at the 1 st,3rd,and 14th day,respectively[(10.97 ± 1.53) Score vs (15.67 ±1.78)Score,t =8.35,P =0.03;(8.15 ± 1.40) Score vs(12.72 ± 3.31) Score,t =6.62,P =0.03; (5.87 ± 1.03) Score vs (11.92 ±2.05) Score,t =13.70,P =0.01].After treatment,the concentration of serum MMP-9 in both groups was reduced with the treatment time,and serum MMP-9 in the experimental group was significantly lower than that in the control group at the 1st,3rd,and 14th day,respectively[(282.84 ±37.51) ng/ml vs (316.90±36.75)ng/ml,t =3.37,P =0.00;(309.11±37.71)ng/mlvs (348.39 ±15.26) ng/ml,t =5.02,P=0.04;(264.68±31.91)ng/ml vs (302.81 ±36.30)ng/ml,t =4.10,P =0.03].Conclusions Intravenous thrombolytic therapy with urokinase can effectively reduce the neurological deficit and the produce of MMP-9 in patients with acute cerebral infarction.

Objective To evaluate the diagnostic values of MSCT for detecting atherosclerotic plaques on New Zealand rabbits models in comparison with pathologic results. Methods Fifteen New Zealand rabbits were enrolled in this study, including 5 with balloon injury and high-fat diet ( group A), 5 with high-fat diet only (group B) and 5 with regular feed (group C). 16th week late, contrast-enhanced MSCT scan was performed in all rabbits with 16 slice MSCT (16-MSCT) in group A and 64 slice MSCT (64-MSCT) in group B and C. The CT and pathological findings were compared in a double-blind manner. The sensitivities and specificities of 16-MSCT and 64-MSCT for detecting atherosclerotic plaques were evaluated by using Fisher test and x2 test. Results Sixty and seventy-five images on 16-MSCT and 64-MSCT had corresponding pathological slices. The sensitivities for the detection of plaques on 16-MSCT and 64-MSCT were 41.5% (22/53) and 64. 9% (24/37), and spocificities of 85. 7% (6/7) and 89. 5% (34/38), respectively. Conclusions 64-MSCT has a higher sensitivity in the detection of atherosclerotic plaques than 16-MSCT. Both scanners can be used to preclude the diagnosis of atherosclerosis.

0bjective To determine the optimal contrast protocols for 64.slice spiral CT coronary angiography in order to reduce the volume of contrast injection.Methods One hundred fifty pailents scheduled to undergo 64-slice spiral CT coronary angiography were prospectively randomized into the following five groups with different injection protocols:group l:uniphasic injection without a flush;group 2:biphasic injection with a flush;group 3,group 4 and group 5:triphasic injection with a diluted contrast material with 3:7.5:5.7:3 contrast/saline ratio respectively.Attenuation was measured in the right atrium,right ventricle,left atrium,left ventricle,ascending aorta,fight coronary artery and left coronary artery and analyzed with single factor variance test(ANOVA).The quality the coronary artery images was evaluated and compared using person Chi-Square.Results The total contrast material vohme were (67.0±5.3)ml,(59.9±4.9)ml,(62.9±3.2)ml,(69.2 4±5.7)ml and(70.9 4-4.6)ml in five groups respectively(F=27.43,P<0.01).Image quali～scores of coronary arteries were significant different among five groups(X2=18.81,P<0.05).There were signiflcandy differences in artifacts of the superior vena cava among five groups(X2=31.44,P<0.01).The artifacts in the superior vena cava in group 1 was the most,and in group 2 was the least.The mean enhancement values of right and left coronary arteries in group 2 were significantly greater than those in other groups(F=2.47 and 4.10,P<0.05).The visualization of both left ventricle and right ventricle cavities W88 the best in group 3.Conclusion Biphasic injection and triphasic injection are better than uniphasic injection for 64-slice spiral CT coronary angiography and triphasic injecfion is better than biphasic injection for the visualization of both left ventricle and right ventricle cavities.

Objective To study the correlation between morphological characteristics of coronary artery calcified plaques and luminal stenosis of local coronary artery segments with 64-slice computed tomography.Methods One hundred and eleven patients who had undergone 64-slice computed tomographic coronary angiography(CTCA)and conventional coronary angiography(CAG)were retrospectively analyzed.The calcified plaques were classified as punctate,nodular,strip-like and nubbly in long-axis view of coronary artery lumen,and were classified as crescent,semilunar,round moon and circinate in short-axis view.The morphologic characteristics of these calcified plaques on CTCA were retrospectively analyzed and compared with luminal stenosis of CAG results.Results Among 528 calcified coronary segments which were analyzed in 111 patients,there were 383(72.5%)punctate calcified plaque segments and 145(27.5%)of non-punctate plaques.There were 34(23.4%,34/145)non-punctate calcified plaques which caused severe stenosis(≥75%),including 4(11.8%)nodular,8(23.5%)stripe-like and 22(64.7%)nubbly calcified plaques on the long-axis view,and 0(0.0%)cresent,8(23.5%)semilunar,18(52.9%)round moon and 8(23.5%)circinate calcified plaques on the short-axis view.The ratios of different morphological coronary artery calcifications which caused severe stenoses were significantly different with each other(all P＜0.01).Conclusion Different figures of coronary artery calcified plaques demonstrate different degrees of stenoses of local coronary artery lumen.Severe stenoses were mostly caused by nubbly calcified plaque on long-axis view,round moon and circinate calcified plaque on short-axis view.

Objective To analyze the image quality of coronary arteries by dual-source computed tomography (DSCT) in children with congenital heart disease(CHD). Methods Image quality of coronary arteries were scored by two radiologists with an ordinal grading system. Score 3 or 4 was considered to be good image quality and diagnostic. Score differences among 3 groups of various baseline heart rate levels, 3 groups of various age levels and 4 coronary branches were analyzed by using ANOVA. Multiple linear regression analysis was used to test the effects of age, heart rate, tube voltage, tube current, pitch, contrast volume, contrast injection rate on the coronary image scores. Results A total of 72 consecutive patients were enrolled. 71.2% (205/288) of coronary artery branches was good enough for diagnosis. Image quality of left main coronary artery (LM, score 3.64±0.49), left anterior descending (LAD, score 2.97±0.40), right coronary artery (RCA, score of 2.82±0.70), left circumflex (LCX, score 2.76±0.73) were in a descending order (F=29.00, P<0.01). Image scores of age groups of 0--1 years old (2.80±0.65), >1--3 years old (2.81±0.74), >3--14 years old (3.58±0.52) were in an ascending order (F= 20.16,P<0.01). Image scores of heart rate groups of<100 bpm (3.54±0.56),100--150 bpm (2.86± 0.70) and >150 bpm (2.81±0.63) were in a descending order (F=16.72, P<0.01). Multiple linearregression analysis demonstrated that multiple impact factors affected image quality of LM, LAD, LCX and RCA. Age(r=0.013 ,P<0.01)and contrast volume(r=0.292, P<0.01)had positive correlation with LM score. Age(r=0.509, P<0.01) and voltage (r=0.292, P=0.011) had positive correlation with LAD score. Heart rate(r= -0.179, P<0.05) had negative correlation with LAD score. Age (r=0.063, P< 0.01) had negative correlation with LCX score. Age (r=0.486,P<0.01) and voltage (r=0.220, P<0.05) had positive correlation with RCA score. Conclusions Dual-source CT could clearly shows coronary arteries of children with CHD over the age of 3 or with heart rate less than 100 bpm. Limitations of Dual-source CT coronary angiography for CHD children included young age and fast heart rate.