Improved bulk myocardial motion suppression for navigator-gated coronary magnetic resonance imaging

PURPOSE: To evaluate the impact of a new, cross-correlation based method for compensation of respiratory induced motion of the heart using an individually adapted three-dimensional (3D) translation or affine transformation approach. MATERIALS AND METHODS: A total of 32 patients underwent a routine cardiac MR examination. In each patient, a calibration scan was performed during free-breathing to register breathing-related motion within a 3D ellipsoid registration kernel covering the entire heart. Three navigators were employed for all three spatial dimensions (feet-head, anterior-posterior, and left-right) and the optimal translatory correction factors for each spatial dimension were determined. In addition, the cross-correlations for different motion models (no compensation, fixed 1D-translation, adapted 3D-translation, and affine transformation) were calculated. RESULTS: The mean correction factor for the feet-head direction was 0.45 +/- 0.13. Though the mean correction factors for the anterior-posterior and left-right direction were nearly zero (-0.01 +/- 0.08 and 0.02 +/- 0.09, respectively), the correction factors exceeded the amount of 0.1 in 12 (19%) and in 19 patients (30%), respectively. All motion compensation models showed significantly higher cross-correlations when compared to "no compensation" (P < 0.05). In particular, the affine transformation algorithm achieved the highest cross-correlation values (88.3 +/- 5.1%) with a significant increase compared to fixed 1D translation (84.7 +/- 6.5%, P < 0.05). CONCLUSION: A considerable number of patients demonstrated relevant breathing-related movement of the heart in the anterior-posterior or left-right direction in addition to the predominant breathing-related movement in the feet-head direction. Thus, it is recommended to compensate for all three spatial dimensions. The affine transformation algorithm combined with three navigators significantly improved breathing-related cardiac motion compensation when compared to the conventionally applied 1D translation with a fixed correction factor.     

心脏三维标测中配准方法的研究

目的对标测导管采集点与计算机断层（CT）或核磁共振（MR）成像建立的三维心脏模型进行配准。方法现有的方法通常是以三维标测点空间和CT/MR数据模型空间都是正交为前提,因此这些方法通常只调整三维平移、旋转和拉伸等9个自由度来实现配准。而我们的研究表明,这2个空间不一定同时正交。因此引入了基于12个自由度的仿射变换模型和相应的迭代最近点算法来实现配准,并研究了如何把该算法与手术操作结合起来。结合OpenGL,我们用Visual C＋＋ 6.0软件实现了该配准方法。结果仿真结果表明：平均误差由配准前的40像素降到了配准后的1.5像素;进一步的动物实验验证了该算法的有效性。结论本文提出的三维标测配准算法能够实现心脏三维标测中的配准。     

鼠曲草TLC鉴别及质量检查项目研究

目的建立简单快捷的鼠曲草药材质量控制方法和标准。方法通过对3个不同产地的鼠曲草药材进行TLC鉴别、水溶性浸出物、醇溶性浸出物、水分以及灰分测定的研究,建立其质量控制标准。结果确定了鼠曲草TLC鉴别、水分、灰分和水溶性浸出物、醇溶性浸出物的测定方法,制定了其质量控制标准。结论研究结果表明本研究制定的鼠曲草药材质量控制标准,可为山东省以及其他地区使用和检验提供依据。     

鼠曲草乙酸乙酯部位化学成分Ⅱ

目的:研究鼠曲草乙酸乙酯部位化学成分。方法:采用硅胶柱色谱、Sephadex LH-20等分离纯化手段相结合对鼠曲草进行分离纯化。通过理化性质和波谱数据(1H-NMR,13C-NMR)进行结构鉴定。结果:从鼠曲草中分离鉴定了13个化合物,分别鉴定为咖啡酸乙酯(1),原儿茶酸乙酯(2),对羟基肉桂酸(3),4-羟基苯乙酮(4),原儿茶酸(5),3-(4’-formylphenoxy)-4-methoxybenzaldehyde(6),desmethylyangonine-4’-glucopyranoside(7),4’-hydroxydehydrokawain(8),绿原酸(9),1,4,5-三咖啡酰奎宁酸(10),1,5-二咖啡酰奎宁酸(11),1,5-二咖啡酰奎宁酸甲酯(12),1,3-二咖啡酰奎宁酸(13)。结论:化合物1,2,4~7,10为首次从鼠曲草属植物中分离得到,化合物3,8为首次从菊科植物中分离得到。     

Correcting eddy current and motion effects by affine whole‐brain registrations: Evaluation of three‐dimensional distortions and comparison with slicewise correction

Eddy‐current (EC) and motion effects in diffusion‐tensor imaging (DTI) bias the estimation of quantitative diffusion indices, such as the fractional anisotropy. Both effects can be retrospectively corrected by registering the strongly distorted diffusion‐weighted images to less‐distorted T2‐weighted images acquired without diffusion weighting. Two different affine spatial transformations are usually employed for this correction: slicewise and whole‐brain transformations. However, a relation between estimated transformation parameters and EC distortions has not been established yet for the latter approach. In this study, a novel diffusion‐gradient‐direction–independent estimation of the EC field is proposed based solely on affine whole‐brain registration parameters. Using this model, it is demonstrated that a more distinct evaluation of the whole‐brain EC effects is possible if the through‐plane distortion was considered in addition to the well‐known in‐plane distortions. Moreover, a comparison of different whole‐brain registrations relative to a slicewise approach is performed, in terms of the relative tensor error. Our findings suggest that for appropriate intersubject comparison of DTI data, a whole‐brain registration containing nine affine parameters provides comparable performance (between 0 and 3%) to slicewise methods and can be performed in a fraction of the time. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.     

高效液相色谱法同时测定鼠曲草中槲皮素与木犀草素的含量

目的：建立高效液相色谱法同时测定鼠曲草中槲皮素与木犀草素的含量。方法：采用Diamonsil C18(2)色谱柱（4.6 mm×250 mm, 5 μm）,以甲醇-0.4%磷酸（42∶58）为流动相,检测波长为360 nm,柱温为30℃,流速为1 mL·min-1,进样量为20 μL。结果：槲皮素、木犀草素浓度分别在3.588-35.880 μg·mL-1（R2=0.9996）,1.294-12.940 μg·mL-1（R2=0.9994）范围内与峰面积积分值呈良好的线性关系,平均回收率（n=6）分别为99.51% （RSD=0.31%）、99.74%（RSD=2.28%）。不同产地的鼠曲草中槲皮素和木犀草素的含有量范围分别为0.39- 0.58 mg·g-1、0.17-0.27 mg·g-1。结论：该方法操作简便,结果准确,重复性良好,可作为鼠曲草中槲皮素和木犀草素含量的测定方法,对鼠曲草的质量控制有一定的参考价值。     

Bidirectional elastic image registration using B-spline affine transformation

A registration scheme termed as B-spline affine transformation (BSAT) is presented in this study to elastically align two images. We define an affine transformation instead of the traditional translation at each control point. Mathematically, BSAT is a generalized form of the affine transformation and the traditional B-spline transformation (BST). In order to improve the performance of the iterative closest point (ICP) method in registering two homologous shapes but with large deformation, a bidirectional instead of the traditional unidirectional objective/cost function is proposed. In implementation, the objective function is formulated as a sparse linear equation problem, and a sub-division strategy is used to achieve a reasonable efficiency in registration. The performance of the developed scheme was assessed using both two-dimensional (2D) synthesized dataset and three-dimensional (3D) volumetric computed tomography (CT) data. Our experiments showed that the proposed B-spline affine model could obtain reasonable registration accuracy.     

模板匹配法在原位杂交图像中的应用

目的：自动寻找一杂交图像中感兴趣的分析区域,方法;采用图像处理方法中的ＳＤＡ模板匹配法,对原全杂交图像中的相似目标自动匹配定位,结果：通过搜索空间,提高了匹配速度,同时利用中值滤波、仿射变换保持了匹配精度。结论：表明该方法抗灰度变化强,相似程度在一定范围内的目标都能够准确匹配,基本满足我们研究需要。     

Multi‐modal robust inverse‐consistent linear registration

Registration performance can significantly deteriorate when image regions do not comply with model assumptions. Robust estimation improves registration accuracy by reducing or ignoring the contribution of voxels with large intensity differences, but existing approaches are limited to monomodal registration. In this work, we propose a robust and inverse‐consistent technique for cross‐modal, affine image registration. The algorithm is derived from a contextual framework of image registration. The key idea is to use a modality invariant representation of images based on local entropy estimation, and to incorporate a heteroskedastic noise model. This noise model allows us to draw the analogy to iteratively reweighted least squares estimation and to leverage existing weighting functions to account for differences in local information content in multimodal registration. Furthermore, we use the nonparametric windows density estimator to reliably calculate entropy of small image patches. Finally, we derive the Gauss–Newton update and show that it is equivalent to the efficient second‐order minimization for the fully symmetric registration approach. We illustrate excellent performance of the proposed methods on datasets containing outliers for alignment of brain tumor, full head, and histology images. Hum Brain Mapp 36:1365–1380, 2015. © 2014 Wiley Periodicals, Inc .     

Mechanisms of relaxant action of a crude hexane extract of Gnaphalium liebmannii in guinea pig tracheal smooth muscle

We investigated the mechanisms of action of Gnaphalium liebmannii which is used as a folk medicine in México for treating various respiratory diseases such as gripe, fever, asthma, cough, cold, bronchitis, expectorating, and bronchial affections. The tension changes of guinea pig tracheal segments were isometrically recorder on a polygraph. Hexane extract of Gnaphalium liebmannii was the most active relaxant extract (IC(30)=54.23+/-19.79 microg/mL with 99.5+/-3.2 % of relaxation), followed by dichloromethane extract (IC(30)=120.22+/-5.27 microg/mL) and methanol extract (IC(30)=190.25+/-30.02 microg/mL). Hexane extract produced a parallel rightward shift of the concentration-response curve of carbachol in a competitive manner (pA(2)=-2.4), but did not modify the concentration-response curves for histamine. The relaxant effect of hexane extract of Gnaphalium liebmannii was unaffected by the presence of propranolol (3x10(-6)M) or glibenclamide (10 microM). However hexane extract produced a leftward shifts of the concentration-response curve of forskolin (10(-8) to 10(-3)M), nitroprusside (10(-10) to 10(-6)M), isoproterenol (3x10(-10) to 3x10(-5)M) and aminophylline (10(-11) to 10(-2)M). The above results suggest that Gnaphalium liebmannii induce relaxation of the tracheal muscle, probably via phosphodiesterase inhibition. The bronchodilator effect of Gnaphalium liebmannii might explain in part their traditional use as anti-asthmatic remedy.