乳腺钼靶X线机的认识与维修方法分析

美国HOLOGIC乳腺钼靶机为一种先进的钼靶机。该设备在使用中利用乳腺三维断层摄影、Selenia Dimensions数字化影像技术和HTC高通透性蜂窝状滤线栅技术,能够实现快速读取、刷新等功能,并能够在最小辐射剂量下获取优质影像。基于此,文章主要探讨乳腺钼靶X线机,阐述设备的工作原理,分析常见故障和故障检查方式,并探讨相应的故障维修方式。     

乳腺导管内乳头状瘤的MRI诊断价值探讨

目的 :探讨乳腺导管内乳头状瘤的MRI表现及其诊断价值。方法 :回顾性分析22例经手术和病理证实为乳腺导管内乳头状瘤的影像学资料。结果 :本组病例主要MRI表现可归纳为4种类型:边缘光滑结节型(45.4%,10/22)、不规则结节型(27.3%,6/22)、囊内结节型(18.2%,4/22)、导管扩张型隐匿性病变(9.1%,2/22)。乳腺导管内乳头状瘤的MRI形态学与血流动力学特点多样,部分与恶性肿瘤难以区分,但也具有一定特征性。结论 :MRI能较准确地发现与定位BIDP病灶,对临床诊断与术前评估具有重要意义。     

基于双视角乳腺X线图像的微钙化簇检测

本文提出了一种通过将两个视角的图像信息进行综合分析的方法,以降低乳腺X线图像中微钙化簇检测中的假阳性率.基于微钙化簇通常出现在两个视角图像中这一事实,文中提出了一种微钙化簇匹配技术:首先把MLO视角探测到的可疑微钙化簇通过空间位置关系找到CC视角中与其相对应的病变区域,形成微钙化簇对;然后对匹配后的每对微钙化簇提取面积、形态、灰度等簇特征,通过特征之间的相似度判断所对应微钙化簇的真伪.实验结果表明:本文的微钙化簇检测算法较单视角检测特异度增加了15%.     

体部线圈在MRI乳腺腋窝淋巴结扫描中应用

目的 :探讨体部相控阵线圈(Body matrix Coil)在解决常规MRI乳腺检查中腋窝淋巴结成像问题的价值。方法:搜集2012年6月至2013年6月间来我院做MRI乳腺检查患者50例,在使用常规乳腺线圈做乳腺扫描的同时,加盖BODY matrix线圈扫描腋窝部位,观察腋窝淋巴结显示情况及对整个图像质量、诊断结果的影响。结果 :加盖BODY matrix线圈对常规乳腺扫描图像质量无明显影响,且可以根据需要加做冠状位或横轴位显示双侧腋窝淋巴结。经比较,加盖BODY matrix线圈扫描比常规线圈扫描对腋窝淋巴结的检出率高,差异具有统计学意义。结论 :利用乳腺线圈加BODY matrix线圈的方法既不影响常规乳腺成像,又可以不同切面显示双侧腋窝组织,对诊断是否有腋窝淋巴结浸润具有很大价值。     

计算机X线摄影在临床诊断中的应用

介绍了计算机X线摄影(Computed Radiography简称CR)在现代临床诊断中的应用现状,对CR的工作原理、构成、图像数字化方法和CR图像的后期处理技术进行了阐述.与常规X线摄影相比,CR的工作原理是用成像板(Ima-ging Plate,IP)代替传统的增感屏/胶片来完成影像数据的存储,利用激光扫描技术读取存储于IP上的感光信号,然后借助计算机对读取的影像数据进行数字处理和输出.该方法不仅实现了X线摄影的数字化,而且可充分利用现代计算机网络技术,使医学诊断和存储达到网络化水平,极大地提高了医疗诊断效率,具有广阔的应用前景.     

微焦点放大摄影的数字化X射线影像系统

在新型软X射线机的基础上,继承原机某些部件设计成果,提出微焦点放大摄影数字化影像系统软X射线机解决方案,分析了X光放大摄影中的数据关系,并着重对各种数字化摄影的转换方式、关键器件作了重点探讨。     

医用数字X线设备DR和CR

医学影像技术随着数字化信息的发展也出现一些先进的数字影像设备,其中数字化放射摄影DR和计算机放射摄影CR是具有代表性的影像设备,本文着重介绍2种设备的成像原理及设备技术特点,并对DR和CR进行比较。DR等数字X线设备的出现,取消存储胶片的繁琐,便于传输、存储和远程诊断,促进远程放射学科的发展。     

X线层析摄影合成快速迭代重建方法的仿真及评价

X线层析摄影合成 (tomosynthesis)是在有限角投影情况下图像重建的主要方法之一。对X线层析摄影合成中的一种快速迭代重建方法进行了计算机对比仿真 ,结果表明该迭代方法的迭代次数大大小于传统方法 ,如直接重建法 (ART) ,而重建质量基本相同。在介绍了评价重建图像质量的几个参数后 ,对不同方法和迭代次数的图像重建结果进行了定量评估。     

钼靶X射线、超声及MRI对乳腺癌诊断的应用价值

目的:探讨钼靶X射线、超声及MRI对乳腺癌的临床诊断价值。方法:以117例疑似乳腺癌患者为研究对象,将钼靶X射线、超声及MRI检查结果与病理诊断结果对比,考察不同影像手段对各类乳腺疾病的诊断能力。结果:MRI对乳腺癌的敏感性、准确度等均优于钼靶X射线和超声,但特异性与钼靶X射线相当。与超声相比,钼靶X射线的特异性、阳性预测值较高,但在其他诊断能力相关的参数方面则无优势。结论 :钼靶X射线、超声及MRI在诊断乳腺疾病方面各有优劣,但钼靶X射线可作为乳腺癌临床初诊的首选手段,临床确诊时可联用多种影像手段。     

加热炉双交叉燃烧控制原理分析及实现

文章介绍了加热炉燃烧控制原理及实现策略．从生产实际的角度给出了解决方案。     

磁共振检查在幼年特发性关节炎早期诊断中的应用价值

目的:探讨磁共振在幼年特发性关节炎早期诊断中的应用价值。方法:回顾性分析我院49例经临床确诊为幼年特发性关节炎且X线平片无异常患儿早期膝关节、髋关节和骶髂关节的磁共振影像,观察受累关节早期改变。结果:49例膝关节中有47例发现有影像异常,31例髋关节中有17例有影像异常,31例骶髂关节中有13例有影像异常。受累关节以炎性改变为主,包括滑膜增生、关节积液和骨髓水肿等。结论:磁共振扫描可以清晰呈现JIA初期X线平片不易显示的关节滑膜增生、积液和骨髓水肿等早期改变,对其临床早期确诊和治疗具有重要参考价值。     

MRI与MSCT在坐骨股骨撞击综合征诊断中的应用价值分析

目的分析核磁共振成像(MRI)与多层计算机断层扫描(MSCT)在坐骨股骨撞击综合征诊断中的应用价值。方法回顾性收集2017年9月~2019年11月我院骨科收治的65例坐骨股骨撞击综合征患者的临床资料,所有患者均经手术治疗确诊,并且在术前均进行MRI和MSCT检查。比较MRI和MSCT对坐骨股骨撞击综合征患者的检出率及坐骨股骨间隙(IFS)、股方肌间隙(QFS)值、疾病相关指标、疾病相关病变影像征象检出率。结果MRI对坐骨股骨撞击综合征的检出率为92.31%,显著高于MSCT(78.46%,P=0.025)。MRI和MSCT对坐骨股骨撞击综合征患者健侧、患侧IFS和QFS值及股骨颈前倾角(FNA)、股骨小转子角(LTA)、股骨颈干角(CCD)、坐骨角(IA)值比较,差异均无统计学意义(P>0.05)。MRI和MSCT检测坐骨股骨撞击综合征患者健侧IFS和QFS值均显著高于患侧(P<0.05)。MRI对坐骨股骨撞击综合征患者关节面硬化的检出率(9.23%)低于MSCT(23.08%),对股方肌水肿和滑膜囊肿的检出率(66.15%和21.54%)高于MSCT(24.62%和6.15%,P<0.05)。结论MRI对坐骨股骨撞击综合征、组织水肿及囊肿的诊断检出率高于MSCT,对关节面硬化的诊断检出率低于MSCT,因此可将两种方法联合用于坐骨股骨撞击综合征的诊断。     

膝周慢性骨髓炎与骨肉瘤的低场MRI鉴别诊断

目的:探讨低场MRI对膝周慢性骨髓炎与骨肉瘤的鉴别诊断价值。方法:回顾性分析临床证实的膝周长骨慢性骨髓炎(15例)和骨肉瘤(6例)0.35T MRI资料并复习文献。结果:两组均有骨破坏及骨硬化。病变散在条片状分布,半影征、骨周大量积液征、窦道征为慢性骨髓炎较为特异的征象;而病变较连续分布并呈僵硬征及Codman三角征更多见于骨肉瘤。结论:熟悉膝周慢性骨髓炎与骨肉瘤的低场MRI表现特点有助于诊断及鉴别诊断。     

Protein kinases in mammary gland development and cancer

Protein kinases, the enzymes responsible for phosphorylation of a wide variety of proteins, are the largest class of genes known to regulate growth, development, and neoplastic transformation of mammary gland. Mammary gland growth and maturation consist of a series of highly ordered events involving interactions among several distinct cell types that are regulated by complex interactions among many steroid hormones and growth factors. The mammary gland is one of the few organ systems in mammals that complete their morphologic development postnatally during two discrete physiologic states, puberty and pregnancy. Thus, the mammary gland is an excellent model for studying normal development and the early steps of tumor formation. The susceptibility of the mammary gland to tumorigenesis is influenced by its normal development, particularly during stages of puberty and pregnancy. Numerous experimental and epidemiological studies have suggested that specific details in the development of the mammary gland play a critical role in breast cancer risk. Mammary gland development is characterized by dynamic changes in the expression and functions of protein kinases. Perturbations in the regulated expression or function of protein kinases or their associated signaling pathways can lead to malignant transformation of the breast. For example, overexpression of several receptor-tyrosine kinases, including human epidermal growth factor receptor and HER2/Neu, has been shown to contribute to the development of breast cancer. Since receptor-tyrosine kinases regulate several essential processes such as mitogenesis, motility, invasion, cell survival, and angiogenesis, targeting receptor-tyrosine kinases may have important implications in designing strategies against breast cancer.     

Apoptosis in normal and neoplastic mammary gland development

Apoptosis plays important roles in mammary development from early embryonic formation of the mammary gland to the regression that follows cessation of cycling. The most dramatic occurrence of apoptosis is found during mammary involution. Most of the secretory epithelium in the lactating breast undergoes apoptosis as the mammary gland regresses and is reorganized for another cycle of lactation. We used the morphology, biochemical changes, and gene expression detected in apoptotic mammary epithelium during involution as a model for studying cell death during other stages of mammary development and for approaching the failure of apoptosis found in mammary hyperplasia. Morphological studies and gene expression have suggested that apoptosis during involution is comprised of two phases: an early limited apoptosis in response to hormone ablation and later protease promoted widespread apoptosis in response to altered cell-matrix interactions and loss of anchorage. We examined protein expression during involution for changes associated with loss of hormone stimulation and altered cell-matrix interactions. One of the proteins whose expression is able to inhibit apoptosis, and is altered during mammary epithelial cell was the serine-threonine protein kinase, Akt 1. Akt 1 activation is common to hormone, growth factor, and anchorage-mediated survival of epithelial cells. We found regulated expression of activated Akt 1 in the mammary gland during involution. Akt 1 activation peaked in pregnancy and lactation, and decreased significantly during apoptosis in mammary involution. Mechanisms of Akt 1 action include modulation of the ratio bcl-2 family members implicated in control of apoptosis. Bcl-2 family proteins were also expressed in pattern consistent with Akt 1 regulation. These observations led us to examine expression of activated Akt 1 and bcl-2 family proteins in premalignant hyperplasias. Akt 1 activation was increased; expression of anti-apoptotic proteins bcl-2 and bcl-x was strongly increased while pro-apoptotic bax was greatly diminished in three different lines of transplantable premalignant mammary hyperplasia. This data suggest that activation of Akt 1 by hormone- or anchorage-mediated pathways regulates survival of mammary epithelium and can contribute to initiation of neoplasia. These data suggest that perturbation of normal cell turnover can contribute to initiation of neoplasia.     

MSCT和MRI对胫骨平台骨折的临床诊断价值

目的 :考察MRI和MSCT对胫骨平台骨折的临床诊断价值,以及其在胫骨平台骨折AO分型方面的指导价值。方法 :以我院2009年5月至2013年11月间收治的183例胫骨平台骨折患者为研究对象,对其MSCT和MRI检查结果进行汇总分析。对比分析两种影像手段对不同AO分型的胫骨平台骨折的诊断情况。结果 :经手术和联用其它检查手段,最终确诊AO分型中B型骨折患者96例(B1型46例、B2型31例、B3型19例),C型患者87例(C1型50例、C2型22例、C3型15例)。MSCT和MRI的诊断结果显示,MRI和CT在B1型、B2型、B3型、C2型的检出比例和确诊精度均相似,且差异无统计学意义(P>0.05)。但在C1和C3型骨折的检出比例和确诊精度方面,则以MRI较为理想,且差异具有统计学意义(P<0.05)。在合并伤方面,MSCT和MRI的检出情况接近,差异无统计学意义(P>0.05)。治疗效果显示,参考MSCT和MRI诊断结果制定的治疗方案合理、可靠,表明MSCT和MRI在对胫骨平台骨折的诊治具有明确的临床指导价值。结论 :MSCT和MRI对不同AO分型的胫骨平台骨折和其合并伤均有较好的诊断能力。     

Second-order stereology of benign and malignant alterations of the human mammary gland

The purpose of the present study was a quantitative characterization of the three-dimensional arrangement of the epithelial component of benign and malignant alterations of the female breast by combining stereology with stochastic geometry. Twenty cases of fibrous mastopathy and 20 cases of invasive ductal mammary cancer were studied at the light microscopic level. Segmentation of the epithelial tissue component was performed with an image analyser. From the resulting binary images, unbiased estimates of the covariance C(r) and the intensity V_v of the epithelial volume component were obtained automatically by computer. From these data, estimates of the correlation function k(r), of the pair correlation function g(r), of the radial distribution function RDF(r) and of the reduced second moment function K(r) of epithelial volume were determined. The estimates of C(r) and RDF(r) differed between groups, but these functions depend on spatial pattern and V_v. As carcinomas showed a significantly higher epithelial volume density V_v than mastopathies, estimation of C(r) and RDF(r) alone did not permit a safe distinction between possibly different types of spatial arrangement of epithelium in the benign and malignant lesions. Analysis of the estimates of k(r), g(r) and K(r), which are not influenced by V_v, showed definite interaction between epithelial volume elements, with clustering at short distances and repulsion at long distances. In both groups, the null hypothesis of purely random arrangement of epithelium had to be rejected. The clearest distinction between groups was obtained by estimation of g(r), which showed that short-range, tubular pattern as well as long-range, lobular architecture are better preserved in benign than in malignant lesions. The low interindividual scatter of k(r), g(r) and K(r) indicates a high biological significance of spatial pattern, which is presumably under strict genetic control. Potential uses of the method are: (i) the identification of biomathematical models which could contribute to a better understanding of the growth processes involved, (ii) conditional simulation of the underlying three-dimensional structures by computer, and (iii) supporting the diagnosis of mammary lesions with borderline histopathological appearance.     

Vascular remodelling during the normal and malignant life cycle of the mammary gland

The mammary gland life cycle is exemplified by massive, physiologically dictated changes in cell number and composition, architecture, and functionality. These drastic upheavals, by necessity, also involve the mammary endothelium, which undergoes angiogenic expansion during pregnancy and lactation followed by ordered regression during involution. In this review, we summarise data obtained using the Mercox methyl methacrylate corrosion cast technique to analyse the mammary gland vasculature during normal development and carcinogenesis. Concomitant with epithelial cell expansion, the mammary vasculature grows during the first half of pregnancy by sprouting angiogenesis whereas the last half of pregnancy and lactation are characterised by the non-proliferative intussusceptive angiogenesis. The vasculature of the lactating gland is composed of a well-developed capillary meshwork enveloping the secretory alveoli with basket-like honeycomb structures. During involution, regression of the vasculature is achieved by regional collapse of the honeycomb structures, capillary retraction, and endothelial attenuation. This process appears partly to involve apoptosis. However, an additional mechanism involving remodelling without cell death, which we have termed angiomeiosis, must exist to explain the morphological observations. Interestingly, in mammary tumours of neuT transgenic mice, both sprouting and intussusceptive angiogenesis was observed simultaneously in the same nodules, a finding with potential implications for cancer therapy. The underlying molecular mechanisms controlling angiogenic modulation in the mammary gland, particularly angiogenic regression and the endothelial:parenchymal interplay, are poorly understood. However, the data summarised in this review indicate that precisely these molecular mechanisms offer novel alternatives for specific and effective treatment of breast cancer.