A proposed method for the automatic interpretation of images obtained by computer tomography]

A preliminary study is described relative to the possibility of using methods of automatic image interpretation in the field of biomedical images. These general methods are capable of recognizing characteristic shapes inside the image. In this paper the structures are described and interpreted. These methods are capable of outlining shapes which are important from a clinical point of view--e.g., spine, vertebrae. They can also evaluate the shapes by plausible methods, to explain the meaning of the whole image. A feasibility study is described concerning the automatic recognition of vertebral contour in axial CT images. The results suggest that the employed techniques can be used in real diagnostic applications.     

A new method for measuring coronary artery diameters with CT spatial profile curves

PurposeCoronary artery vascular edge recognition on computed tomography (CT) angiograms is influenced by window parameters. A noninvasive method for vascular edge recognition independent of window setting with use of multi-detector row CT was contrived and its feasibility and accuracy were estimated by intravascular ultrasound (IVUS).MethodsMulti-detector row CT was performed to obtain 29 CT spatial profile curves by setting a line cursor across short-axis coronary angiograms processed by multi-planar reconstruction. IVUS was also performed to determine the reference coronary diameter. IVUS diameter was fitted horizontally between two points on the upward and downward slopes of the profile curves and Hounsfield number was measured at the fitted level to test seven candidate indexes for definition of intravascular coronary diameter. The best index from the curves should show the best agreement with IVUS diameter.ResultsOf the seven candidates the agreement was the best (agreement: 16 ± 11%) when the two ratios of Hounsfield number at the level of IVUS diameter over that at the peak on the profile curves were used with water and with fat as the background tissue. These edge definitions were achieved by cutting the horizontal distance by the curves at the level defined by the ratio of 0.41 for water background and 0.57 for fat background.ConclusionsVascular edge recognition of the coronary artery with CT spatial profile curves was feasible and the contrived method could define the coronary diameter with reasonable agreement.     

A novel method for automatic determination of different stages of multiple sclerosis lesions in brain MR FLAIR images.

It is very important to detect stages of multiple sclerosis (MS) lesions in order to exactly quantify involved voxels. In this paper, a novel method is proposed for automatic detection of different stages of MS lesions in the brain magnetic resonance (MR) images, in fluid attenuated inversion recovery (FLAIR) studies. In the proposed method, firstly, MS lesion voxels are segmented in FLAIR images based on adaptive mixtures method (AMM) and Markov Random Field (MRF) model. Then, signal intensity of each lesion voxel is modeled as a linear combination of signals related to the normal and also abnormal parts, in the voxel. By applying an optimal threshold, voxels with new intensities are primarily classified into two stages: previously destructed (chronic) and on going destruction (acute) lesions. Finally, the acute lesions, according to their activities, are classified, by another optimal threshold, into two new stages, early and recent acute. Evaluation of the proposed method was performed by manual segmentation of chronic and enhanced (early) acute lesions in gadolinium enhanced T1-weighted (Gad-E-T1-w) images by studying T1-weighted (T1-w) and T2-weighted (T2-w) images, using similarity criteria. The results showed a good correlation between the lesions segmented by the proposed method and by experts manually. Thus, the suggested method is useful to reduce the need for paramagnetic materials in contrast enhanced MR imaging which is a routine procedure for separation of acute and chronic lesions.     

Influence of physical fitness and activity behavior on retinal vessel diameters in primary schoolchildren

Retinal vessel alterations have been shown to be associated with cardiovascular risk factors and physical inactivity as early as childhood. In this context, the analysis of physical activity in children has solely been based on questionnaire assessments. The study aimed to examine the association of physical fitness performance and self‐reported physical activity with retinal vessel diameters in young children. Three hundred ninety‐one primary schoolchildren [7.3 years (SD 0.4)] were examined in this cross‐sectional study. The primary outcome was endurance performance measured with the 20‐m shuttle run. The additional tests consisted of a 20‐m sprint, jumping sidewards and balancing backwards. Retinal microcirculation was assessed using a static retinal vessel analyzer. Parents completed questionnaires about physical and sedentary activities. Endurance performance was associated with narrower retinal venular diameters [?0.9 (95%CI: ?1.8; ?0.1) measuring units (mu)/ unit shuttle run, P = 0.04] and a higher arteriolar to venular ratio [0.003 (?0.001; 0.006)/unit shuttle run, P = 0.06]. The sprint performance was associated with narrower retinal arterioles [4.7 (0.8; 8.6) mu/unit sprint, P = 0.02]. Indoor playing activity correlated with narrower retinal venules [?0.04 (?0.07; ?0.01) mu/per unit, P = 0.02]. Our data suggest that objectively measured endurance performance relates with better retinal vessel health in early childhood.     

基于元启发策略的肿瘤调强放疗自动计划方法

目的提出一种基于元启发策略的放疗自动计划方法(ATP-STAR),并验证其有效性。方法ATP-STAR方法的主要过程为先对优化参数进行向量化编码,采用高斯卷积修正优化参数,再利用模拟退火选择备选优化参数向量集,结合射野通量优化,并行探索最优的优化参数组合,实现计划自动试错。选取20例肿瘤个体化差异较大的病例进行方法测试。邀请具备5年以上临床工作经验的物理师进行人工计划设计。人工计划和ATP-STAR计划均基于开源matRad计划系统完成,射野及处方剂量与临床治疗计划保持一致。分析不同病种ATP-STAR与人工计划的靶区和危及器官剂量学差异。结果对靶区而言,ATP-STAR计划的均匀性优于人工计划(脑瘤:z=2.28,P=0.022;肺癌:z=2.29,P=0.022;肝癌:z=2.11,P=0.035),脑瘤和肝癌ATP-STAR计划的适形性与人工计划相当,肺癌ATP-STAR计划的适形性略差于人工计划(z=2.29,P=0.022)。对脑瘤的危及器官而言,相比于人工计划,ATP-STAR计划的左眼晶状体Dmean平均受量由2.19 Gy降至1.76 Gy(z=2.28,P=0.022),左视神经Dmean由11.36 Gy降至10.22 Gy(z=2.28,P=0.022),右视神经Dmax由32.92 Gy降至29.97 Gy(z=2.10,P=0.036),垂体Dmax由39.53 Gy降至35.21 Gy(z=2.29,P=0.022)。对肺癌的危及器官而言,ATP-STAR计划的脊髓Dmax平均受量由38 Gy降至31.17 Gy(z=2.12,P=0.034),双肺Dmean由8.51 Gy降至8.07 Gy(z=2.29,P=0.022),心脏Dmean由3.21 Gy降至2.69 Gy(z=2.29,P=0.022)。对肝癌的危及器官而言,ATP-STAR计划的脊髓Dmax由18.19 Gy降至14.76 Gy(z=2.11,P=0.035),肝脏Dmean由15.61 Gy降至14.45 Gy(z=2.11,P=0.035),肾脏Dmean由4.76 Gy降至4.04 Gy(z=2.10,P=0.036)。结论ATP-STAR方法较少依赖人工计划设计经验,易于推广,有望改善调强放疗计划质量及一致性,并节省临床人力和时间成本。     

一种测定过氧化氢酶活性的新方法

建立了一种测定过氧化氢酶活性的新方法－钼酸铵法，并应用于测定经ＨＰＬＣ分离纯化的细菌过氧化氢酶活性，对分离得到的５个峰酶活尾进行了比较，峰２酶比活力达到３６．８８ｍｍｏｌ．ｍｉｎ＾－１．ｍｇ＾－１蛋白，酶活性明显高于其它峰。结果表明，该方法是一种灵敏，简便、快速及实用的测定细菌过氧化氢酶活性的检测方法。     

A method for determination of upper extremity kinematics

Kinematic analysis of the upper extremity has been conducted using a wide variety of techniques, philosophies, and analytic methods. We describe a simple, marker-based three-dimensional video analytic technique that borrows concepts from lower extremity kinematic analysis. A sequential rotation order about orthogonal axes is described, although alternate methods are examined as well. The method has been verified by application to a mechanical model. In certain positions, gimbal lock may occur, and a different sequence of rotational decomposition may be required. Agreement on standardization of technique would assist in the dissemination of upper extremity scientific data.     

鼠药毒饵中毒鼠强的气相色谱测定方法

毒鼠强是一种剧毒速效灭鼠药，用这种鼠药拌粮食做成的毒饵在不少地方使用，因投毒、误服造成多起中毒事故。毒饵中鼠药成分的分析鉴定对于中毒病人的诊断与治疗都具有实际意义。所建方法对样品的预处理简单，回收率在８６％以上。该方法已用于与两次中毒事故有关的毒饵中鼠药的测定。有助于中毒病人的诊断与治疗。另外，还提出了测定毒饵中鼠药回收率的简易方法。     

A novel method for the determination of x-ray mass attenuation coefficients

A new and an accurate method to determine the mass attenuation coefficient, μ_m, of low energy x-rays employing proportional counter and radioactive source is described. This method incorporates all the recent suggestions of Creagh and Hubbell. A rigid good geometry arrangement, the gating of channels of the spectrometer at FWHM position of the photopeak, the selection of absorber foils, are all done after detailed investigations, in order to minimize the effect of small angle scattering and multiple scattering on the μ_m value. The method is studied in detail using aluminium as an absorber since it is a standard reference material. The results at each step are presented to demonstrate the credibility of our method. From these results we conclude that the ‘best value’ for μ_m can be obtained for those thicknesses which lie in the transmission (T) range 0.5 ⩾ T ⩾ 0.25. The measured values of μ_m for copper, silver and for materials such as nylon, teflon, lucite and mylar agree closely with the standard theoretical values indicating the validity of our method.     

HPLC法测定石杉科植物中石杉碱甲的含量

目的：建立用高效液相色谱法（ＨＰＬＣ）测定石杉科植物中石杉碱甲（ｈｕｐｅｒｚｉｎｅ Ａ）含量的方法。方法与结果：按照常规的方法提取出石杉总生物碱,用ＨＰＬＣ对总碱直接进行分析。色谱条件下如：Ｓｐｈｅｒｉｓｏｒｂ Ｃ１８分析柱,检测波长２３１．３ｎｍ,甲醇：水（８５：１５,体积分数）作为流动相,流速１ｍｌ／ｍｉｎ。外标法测定。该方法的一范围是０．４１～６．１５ｍｇ／Ｌ,平均加祥回收率为９９．７２％～     

A multi-scale method for automatic correction of intensity non-uniformity in MR images

In this paper, a novel multi-scale method for coil sensitivity profile correction is presented based on wavelet transform. A magnetic resonance (MR) image can be decomposed into two spaces by the wavelet transform: approximate space and residual space. The approximate templates in approximate space can be thought of as multi-scale sensitivity profiles of the surface coil for coil correction. When we choose a suitable filter for decomposition, one of the sensitivity profiles should be optimal among the multi-scale sensitivity profiles. The optimal sensitivity profile can be chosen automatically by an analysis of the contents of the two spaces. The multi-scale method does not rely on any data other than the image generated by the MR scanner. The experiment showed promising results based on one-dimensional simulation and images of phantom and human images.