Objective To assess the value of dual-source computed tomography angiography (DSCTA)in detecting intracranial aneurysms by comparing with conventional and three-dimensional DSA.Methods In this study,95 patients with subarachnoid hemorrhage(SAH)underwent both DSCTA and DSA examination.The detection rate,size,and ratio of the neck to the dome(N/D ratio)of the aneurysrns were evaluated.Statistical analysis was performed using a paired sample Student's t-test for the comparisons of the value of N/D and 2 Related Samples test for long axis.Results A total of 67 aneurysms in 63 patients at DSA and 64 aneurysms in 60 patients at DSCTA were detected,respectively;whereas no aneurysm was detected in 32 patients at DSA.Compared with DSA,the overall sensitivity.specificity,positive predictive value,and negative predictive value of DSCTA on a per-aneurysm basis were 94.2%,100.0%,100.0%,and 91.4%,respectively.For the aneurysms larger than 3 mm,the sensitivity and specificity of DSCTA in detecting intracranial aneurysms were equal to those of DSA:For aneurysms smaller than 3 mm,however,the sensitivity and specificity of DSCTA is 80.0% and 100.0%.The N/D ratio for DSA and DSC:TA was 0.46±0.14 and 0.51±0.18.respectively,and the median of long axis was 4.9 mm and 4.8 mm.respectively.There was no significant difierence in the N/D ratio(t=3.20;P＞0.05)and the long axis(Z=-1.309;P＞0.05)between DSA and DSCT.Condusions Compared with conventional and three-dimensional digital subtraction angiography,DSCTA has high sensitivity and specificity in the detection of intracranial aneurysms,especially for detection of snlall aneurysnm(＜3 mm).It can be used as a routine screening technique.

Objective To evaluate the clinical values of dual energy lung perfusion using dual-source CT. Methods Fifty-four patients who underwent chest contrast-enhanced CT were included in this study from May to August in 2007. Dual energy CT scanning was performed in all patients. The patients were divided into four groups: normal group, exudation lesion group, mass lesion group, and pulmonary embolism group. Imaging appearances of dual energy CT perfusion in four groups were analyzed. Results Dual energy CT showed symmetrical homogeneous perfusion in healthy subjects (n = 14), exudation lesions (n =10) appeared as low perfusion, In mass lesions (n =27), peripheral masses presented as local perfusion defect, central masses appeared as segmental perfusion defect because of the involvement of hilar vessels,and pulmonary embolism (n = 3) appeared as perfusion defect in corresponding pulmonary segment.Conclusion Dual energy CT scanning can be used to show the pulmonary perfusion status and assess the pulmonary perfusion abnormalities in central lung cancer and pulmonary embolism.

clues for interpretation of myocardial ischemia.

Objective To investigate the feasibility of the adaptive cardio sequence prospective ECG-gated dual-source CT coronary angiography (CTCA).Methods Thirty one patients underwent prospective ECG-gated dual-source CTCA. The patients were divided into two groups: group A, heart rate ≤ 75 times / minutes, 70% of R-R interval was chose; group B, heart rate> 75 times / minutes, 40% of R-R interval was chose. Two experienced radiologists assessed the image quality of 15 segments of coronary arteries in a double blinded fashion in a four score scale. Student t test was used to compare the image quality between two groups. CT dose index(CTDIvol) and effective dose(ED) were also calculated for both groups. Results 437 segments of coronary arteries in 31 patients were included this analysis, 408 segments (93.4%) had assessable image quality, while 29 segments (6.6%) had non assessable image quality. Of 226 segments in group A, 12 segments (5.3%) had non assessable image quality; however, 17 segments (8.1%) of 211 segments in group B had non assessable image quality. The average score of image quality was 3.57±0.64 in 31 patients. There was no statistical difference for mean image quality of group A (3.65±0.39) and group B (3.41±0.43)( t=1.62,P=0.12 ) . There was a statistical difference for mean image quality for segment 10 on a per segment basis ( t = 3.8 ,P＜0.05). CTDIvol and ED were (18.88±5.04) mGy and (4.31±1.05) mSv, respectively.Conclusion Adaptive cardio sequence prospective ECG-gated dual source CT can acquire assessable image quality of coronary artery with lower radiation dose to the patients, which has the potential to be a routine CTCA technique.

Objective:To investigate the effects of resistance exercise on mitochondrial function, muscle attenuation and muscle fiber morphology in quadriceps femoris of aged rats.Methods:The 18-month-old male rats were randomly divided into five groups( n=8, each): control(not exercise), 0% weight-bearing, 30% weight-bearing, 50% weight-bearing, and 70% weight-bearing exercise.After maximum resistance running, intermittent race table resistance exercise with 0%, 30%, 50%, 70% maximum load were performed.The treadmill placement slope was 35°, the running speed was 15 m/min, and exercise was performed every other day.At the end of the 8 th week, the mitochondrial membrane potential of quadriceps femoris muscle was measured, cytosol contents of cytochrome C(Cyt c), apoptosis-inducing factor(AIF), and apoptotic protein(Smac/DIABLO)were measured, and the morphology and structure of muscle fibers were observed. Results:Compared with the control group, the mitochondrial ΔΨmt was increased in the 0%, 30%, 50% and 70% maximum load groups, with a significant difference in the increment in the 0%, 30% and 50% maximum load groups( t=7.412, 5.611, 6.213, all P<0.01).Compared with the 0% maximum load group, the percentage of cells with mitochondrial ΔΨmt was statistically significantly decreased in the 30% maximum load group(10.6%)( t=9.356, P<0.05), while the percentage of cells with mitochondrial ΔΨmt was statistically significantly increased in the 70% maximum load group(10.03%)( t=8.341, P<0.05).Compared with the control group, the contents of Cyt c, AIF and Smac/DIABLO in the cytoplasm of quadriceps femoris of aged rats with 8-week resistance exercise were decreased, among which the contents of Cyt c and Smac/DIABLO were statistically significantly decreased in the three groups of 0%, 30%, and 50% maximum load( t=8.324, 7.516, and 6.871, all P<0.05), as well as the decrement in AIF of the three groups of 0%, 30%, and 50% maximum load was statistically significant( t =9.434, 8.78, and 7.342, all P<0.05).Compared with the control group, the vacuolar area of muscle fibers was extremely significantly decreased in the 0%, 30%, and 50% maximum load groups( t =5.567, 6.784, and 7.432, P<0.01); the protein content in the quadriceps femoris muscle was very significantly increased in the 30%, 50%, and 70% maximum load groups( t =7.478, 6.765, and 4.564, all P <0.01).Compared with the 0% maximum load group, the protein content in the quadriceps femoris muscle was very significantly increased in the 30%, 50%, and 70% maximum load groups( t=9.236, 8.342, and 6.456, all P<0.01). Conclusions:Low and medium weight-bearing resistance exercise can improve the mitochondrial function of quadriceps femoris, reduce the femoral quadriceps mitochondria-released proapoptotic proteins Cyt c, AIF, and Smac/DIABLO, and reduce the incidence of quadriceps femoris apoptosis.Low and medium weight-bearing resistance exercise can increase the protein content of muscle fibers, reduce the vacuolar area of muscle fibers, maintain muscle mass, and delay the occurrence of sarcopenia.