Sinogram restoration for low-dose cerebral perfusion CT images / 南方医科大学学报

In clinical cerebral perfusion CT examination, repeated scanning the region of interest in the cine mode increases the radiation dose of the patients, while decreasing the radiation dose by lowering the scanning current results in poor image quality and affects the clinical diagnosis. We propose a penalized weighted least-square (PWLS) method for recovering the projection data to improve the quality of low-dose cerebral perfusion CT imaged. This method incorporates the statistical distribution characteristics of brain perfusion CT projection data and uses the statistical properties of the projection data for modeling. The PWLS method was used to recover the data, and the Gauss-Seidel (GS) method was employed for iterative solving. Adaptive weighting is introduced between the original projection data and the projection data after PWLS restoration. The experimental results on the clinical data demonstrated that the PWLS-based sinogram restoration method improved noise reduction and artifact suppression as compared with the conventional noise reduction methods, and better retained the edges and details to generate better cerebral perfusion maps.

Changes in IL-17 and TGF-β1 levels in serum and bronchoalveolar lavage fluid and their clinical significance among children with asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the changes in the levels of interleukin-17 (IL-17) and transforming growth factor beta 1 (TGF-β1) in serum and bronchoalveolar lavage fluid (BALF) and their clinical significance among children with asthma.</p><p><b>METHODS</b>Fifty-six children with asthma were divided into moderate or severe asthma (n=37) and mild asthma groups (n=19) and 18 children without asthma were selected as the control group. Cells in BALF were counted under a microscope. The levels of IL-17 and TGF-β1 in serum and BALF were measured using ELISA.</p><p><b>RESULTS</b>were no significant differences in total cell count and percentage of macrophages between the two asthma groups and the control group (P>0.05). The percentages of neutrophils, eosinophils and epithelial cells in BALF were significantly higher in the two asthma groups than in the control group (P<0.05). The two asthma groups had significantly higher levels of IL-17 and TGF-β1 in serum and BALF than the control group (P<0.05), and the moderate or severe asthma group had significantly higher levels of IL-17 and TGF-β1 in serum and BALF than the mild asthma group (P<0.05). Levels of IL-17 and TGF-β1 in serum were significantly positively correlated with those in BALF (r=0.935 and 0.943, P<0.05 for both). In children with asthma, serum IL-17 level was significantly positively correlated with the percentage of neutrophils, eosinophils and epithelial cells in BALF (r=0.802, 0.799, and 0.674, P<0.05 for all), and a significant positive correlation was also seen between serum levels of IL-17 and TGF-β1 (r=0.878, P<0.05).</p><p><b>CONCLUSIONS</b>Levels of IL-17 and TGF-β1 in serum and BALF are elevated in children with asthma. IL-17 and TGF-β1 may be involved in the occurrence and development of asthma, and they play important roles in asthma attack and aggravation.</p>