B型超声图像直方图的原理及临床应用

本文叙述了声像图的直方图形成原理及其分析方法。介绍了三种直方图取样方法,即:①点分析取样;②线分析取样;③面分析取样。描述了用以分析的谱线宽度、高次谱位、谱线包络线及统计数据等参数。 本法有助于鉴别各种液性、实质性、纤维化、钙化或结石及混合性病变。本法对超声诊断的量化分析具有十分重要的意义。     

Dosimetric Parameters in Partial Breast Irradiation Through Brachytherapy

The objective of this work is to evaluate biological models and dose homogeneity in a new partial breast irradiation method, the MammoSite RTS. The study is based on 11 patients who received the therapy. For each patient, we determined the dose volume distribution delivered to the breast. Based on these data, we estimate some important biological parameters. Eleven patients with early-stage, invasive, ductal breast cancer were treated using MammoSite RTS brachytherapy, which delivers radiation through a balloon placed in the lumpectomy bed. The radiation was provided by an Iridium-192 source, and 340 cGy were delivered per fraction twice daily. We calculated some commonly used dosimetric parameters, and evaluated the biological parameters tumor control probability (TCP) and normal tissue complication probability (NTCP). We also looked for correlations among these parameters. The average equivalent uniform dose (EUD), NTCP, and TCP were 43.66 Gy, 47.95%, and 91.78%, respectively. The coefficient of variation (CV) among the patients was very low for all 3 parameters. Two dose homogeneity indices (DHI and the S-index) are strongly correlated (r = −0.815). The area under the dose-volume histogram (DVH) and the treatment volume (TXV) also showed a strong correlation (r = 0.995, p < 0.0001). A simplified logit Poisson–EUD model is suitable for determining NTCP and TCP. Other factors such as the area under the DVH and dose homogeneity indices are also useful in planning radiotherapy treatments for early breast cancer.     

超声组织直方图频谱定量和彩色层换技术诊断分析肿块137例

目的 使用计算机photoshop技术，观察研究静态肿块组织特性以提高超声的诊断能力。方法 应用Interword智能图文管理系统，将B超获取的诊断图像，经二次处理软件包manage格式，对B超组织图像包块进行分析。结果 通过对肿块组织直方图测定和彩色变换处理，提供了频谱数据及彩色图像的信息，直方图各灰阶参数在诊断肿块组织特性中发挥了重要作用，为临床诊治提供了客观的半定量化指标。结论 应用此计算机技术，具有简便可行，且提高静态脏器及肿物性质的诊断能力。     

Clinical application of a new method that segments the region of interest into multiple layers for RF amplitude histogram analysis in the cirrhotic liver

Purpose We used texture analysis in conjunction with an alternative method of analyzing the amplitude histogram using a radiofrequency (RF) signal to differentiate ultrasonograms of normal and cirrhotic livers. This method segments the region of interest (ROI) into multiple layers (sub-ROIs). In each sub-ROI of a homogeneous medium, the histogram of enveloped-amplitude of RF backscattered echoes resembles a Rayleigh distribution. Theoretically, the values of the signal-to-noise ratio (SNR), skewness, and kurtosis for Rayleigh statistics are constant and independent of the mean scattering intensity, which is contributed by such undesirable effects as tissue attenuation, beam diffraction, and incident waveforms. These values, which averaged overall sub-ROI, should provide an unbiased estimator.Methods We studied 36 normal livers and 28 cirrhotic livers, all confirmed by clinical findings including laboratory and pathology data; the SNR, skewness, and kurtosis values of the disease groups were compared. At the same time, these values were estimated using the conventional method, which did not segment the ROI into multiple sub-ROIs. The unpaired t-test was used to determine statistical significance.Results With the new method, all values obtained from cirrhotic livers differed significantly from those obtained from normal livers, and the standard deviation of these values was smaller than those obtained using the conventional method.Conclusions These results suggest that the new method can be used to diagnose the cirrhotic liver objectively.This article is translated from the Japanese version, which was published in J Med Ultrasonics 2001;28:J25–33     

磁共振联合超声鉴别诊断子宫内膜间质肉瘤与变性子宫肌瘤

目的:应用磁共振联合超声鉴别诊断子宫内膜间质肉瘤（ESS）与变性子宫肌瘤。方法:回顾性分析ESS患者19例和变性子宫肌瘤患者36例。分析患者磁共振直方图（T2WI肿瘤最大层面直方图）及彩超检测结果特征,并对两种方法联合诊断的灵敏度与特异度进行分析。结果与结论:ESS患者与变性子宫肌瘤患者临床表现近似,但各具特征;ESS患者年龄更高,绝经女性所占比例更高,且肿物最大直径相对更大。超声检测肿瘤基本特征可见,ESS患者肿瘤边界模糊的比例更高,以中强度回声为主,瘤体结构多为实性,血流丰富,红色样变比例也较高。对比之下,变性子宫肌瘤患者回声多为低强度,肿瘤结构多为其他结构,血流稀疏,脂肪样变比例相对更高。同时,受试对象MRI检测T2W1肿瘤最大层面直方图相关参数,在ESS患者和变性子宫肌瘤患者中可见在平均值、方差、偏度、峰度以及几个不同的百分位数（P1、P10、P50、P90）的差异均存在统计学意义（P<0.05）。直方图（P50）联合超声检查的灵敏度和特异度均较高,效力最佳。     

楔形板在胸上段食管癌放疗中对TPS剂量分布影响探讨

目的：探讨楔形板在胸上段食管癌放疗应用中对TPS剂量分布的影响。方法：对胸上段食管鳞癌患者行螺旋CT扫描,获取病灶及其周围组织的三维数据,在TPS中设计加用头足向45°楔行板和不加楔形板的两个计划,计算并比较二者剂量体积直方图。结果：尽管两个计划形成的靶区剂量平均值非常接近,但剂量分布的均匀性有显著差别,不加楔形板时靶区剂量标准差为6．31;在前野加45°楔行板后靶区剂量标准差为4．45,显示采用楔形板后靶区剂量的离散性显著减小,即靶区剂量的分布更加均匀。结论：在常规照射方式的射野中加入楔形板来改善胸上段食管癌照射剂量分布是一种简单有效的方法。     

Septal unit activity and hippocampal EEG during the sleep-wakefulness cycle of the rat

The functional relationship between septal unit activity and hippocampal EEG was studied during the sleep-wakefulness cycle in chronically implanted unrestrained rats. Results were statistically analyzed in order to obtain the time interval and auto and crosscorrelation histograms. During REM sleep and restless wakefulness the hippocampal EEG showed a theta rhythm of 4–8 cps and the septal unit activity was characterized by the presence of rhythmic bursts with a frequency in every single instance similar to that of the hippocampus. The septal units showed a bimodal time interval histogram. Their autocorrelation histogram exhibited a sinusoidal pattern of decreasing amplitude. The crosscorrelation histogram of septal units and the hippocampal EEG also showed a sinusoidal pattern suggestive of the functional relationship between both neural structures. During slow wave sleep and quiet wakefulness there was a disappearance of the hippocampal theta rhythm and rhythmic septal unit bursts. The second mode was missing in the time interval histogram and the auto and crosscorrelation histograms showed an irregular pattern. It is concluded that medial septal nucleus and hippocampal temporal patterns of activity are similar during REM sleep and restless wakefulness.     

一种基于内容的医学图像检索方法的实现

介绍颜色相关图及其改进算法在医学图像检索中的应用,并与标准灰度直方图的检索效果做了比较.