基于S-G滤波的超声造影分析参数灌注成像

为弥补以往超声造影定量分析软件将感兴趣区(ROI)作为均质的整体区域进行分析的不足,提出一种基于S-G滤波器的在时域内直接处理数据平滑问题的定量分析方法,针对ROI区域内部像素点进行灌注成像参数分析,快速并可最大限度地保留原始有用信息。首先获得超声造影的原始DICOM动态医学数据,获取ROI内每个像素点的时间强度曲线,用S-G滤波器对时间强度曲线进行分析,得到反映灌注时相和灌注强度的多项定量分析参数,如到达时间(AT)、达峰时间(TTP)、达峰强度(PI)、平均通过时间(MTT)、曲线下面积(AUC)和上升斜率(RS)等;然后再对像素点参数分别进行彩色编码并以不同颜色显示,从而准确量化和直观显示超声造影的各项灌注参数。为评估该分析方法的稳定性,比较3位研究者分别对15个肝细胞癌病灶的分析结果。经统计,所有参数的组间相关系数(ICC)>0.80,验证了该方法的可行性和稳定性。     

近红外荧光散射断层成像的研究进展

近红外荧光光学断层成像(FODT)是以合适的荧光探针作为标记物或对比剂，用特定波长的红光激发荧光染料，使其发出波长长于激发光的近红外荧光，通过测量媒质边界处有限点的荧光强度，考虑光子在组织中传播的散射特性，来重建出组织内部的荧光光学特性的分布图像以及组织光学参数。这种成像方式具有无电离辐射、染料稳定、可长期监测和设备简单、成本低等优点，在肿瘤检测、基因表达、蛋白质分子检测和药物受体定位等方面有着很大的应用潜力。在给出近红外荧光散射断层成像典型系统的基础上，详述了近红外荧光在组织中的频域传播模型和重建算法；介绍了两家研究机构在此领域的研究进展；讨论了将该成像方法应用于临床的进一步的发展方向。     

CT灌注成像对正常前列腺的血流动力学研究

目的 应用CT灌注成像对正常前列腺的血流灌注特点进行前瞻性研究.方法 应用GE lightspeed 8 slices螺旋CT对30例正常前列腺进行CT灌注成像.在工作站对灌注原始图像进行处理,在原始图上分别沿前列腺外周区和中央腺画出感兴趣区(ROI),对所有ROI的血流量(BF)、血容量(BV)、对比剂平均通过时间(MTY)和毛细血管表面通透性(PS)进行统计学分析.结果 正常前列腺外周区的BF、BV、MTT和PS分别为(10.57±5.65)ml/(100ml·min)、(2.71±1.34)ml/100ml、(22.36±4.12)s及(12.31±7.78)ml/(100 ml·min),中央腺依次为(9.92±4.08)ml/(100 ml·min)、(3.03±1.37)ml/100 ml、(23.78±3.73)s及(14.06±9.08)ml/(100ml·min).将整个层面的前列腺组织设为一个ROI,前列腺外周区与中央腺的灌注参数之间差异无统计学意义(P值分别为0.690、0.825、0.433和0.853).对正常前列腺的BF和年龄进行相关性分析,P=0.600.结论 正常前列腺为低血流灌注器官,随年龄增长,前列腺在正常情况下的灌注量无明显改变.     

近红外荧光散射断层成像的研究进展

近红外荧光光学断层成像(FODT)是以合适的荧光探针作为标记物或对比剂,用特定波长的红光激发荧光染料,使其发出波长长于激发光的近红外荧光,通过测量媒质边界处有限点的荧光强度,考虑光子在组织中传播的散射特性,来重建出组织内部的荧光光学特性的分布图像以及组织光学参数。这种成像方式具有无电离辐射、染料稳定、可长期监测和设备简单、成本低等优点,在肿瘤检测、基因表达、蛋白质分子检测和药物受体定位等方面有着很大的应用潜力。在给出近红外荧光散射断层成像典型系统的基础上,详述了近红外荧光在组织中的频域传播模型和重建算法;介绍了两家研究机构在此领域的研究进展;讨论了将该成像方法应用于临床的进一步的发展方向。     

基于预扫描正则化与稀疏约束重建的低剂量CT灌注成像

CT灌注成像中患者会受到长时间的X线照射,在灌注前预先扫描一幅正常剂量图像,在后续灌注过程中进行低剂量采集,将所获低剂量图像与参考图像做减影并进行滤波处理以获得灌注信息,然后叠加到正常剂量图像中,可以非常显著地降低CT灌注成像中辐射剂量,然而,当剂量非常低的时候,重建图像会受到噪声与伪影干扰。本文基于类似的预扫描正则化数据采集方案,分别进行正常剂量和低剂量预扫描,然后利用相同的低剂量进行后续灌注过程的扫描,将所采集低剂量数据与预扫描的低剂量数据在投影域作差,然后在重建中引入稀疏性约束,以获得更准确的灌注信息重建,重建后的灌注信息最后同样叠加到正常剂量图像中。本文采用一套人脑CT灌注图像进行模拟实验,结果表明在同样剂量下,本文所提新方法重建结果所包含的灌注信息更准确,时间衰减曲线与正常剂量情况的吻合度更高,而且平均过渡时间可重复性好。     

基于感兴趣区约束的并行磁共振成像重建算法

目的：并行磁共振成像利用敏感度编码降低成像所需的梯度编码步数，从而缩短数据扫描时间，本文旨在提出一种磁共振并行成像重建新算法，提高加速因子较大时的图像重建质量。材料与方法：获得精确的空间敏感度分布是提高其图像重建质量的关键之一。但是由于可用于估计的数据较少，敏感度分布中总是存在一定的噪声与伪影干扰，根据理想的敏感度分布应该在成像区域外取值为零这一特点，本文提出带感兴趣区约束的并行成像算法，首先基于区域生长和形态学方法提取出成像物体的外部轮廓构造感兴趣区，然后将该区域外的敏感度置零后引人并行重建算法，以避免成像区域外的伪影与噪声对重建的影响。结果：通过8通道线圈并行采集的体模数据重建实验表明，在加速因子取4时，本文算法可以更有效地抑制重建图像中的噪声及伪影，实现高质量的图像重建。结论：通过在并行成像算法中引人带感兴趣区的约束。可使加速因子较大时并行磁共振成像的图像重建质量获得一定的提升。     

扩散峰度成像对外周带前列腺癌的诊断价值

目的探讨扩散峰度成像(DKI)主要的3个参数对外周带前列腺癌的诊断价值。方法对40例外周带前列腺癌患者进行常规MRI扫描和DKI序列扫描,以病理检测为金标准,观测指标包括外周带肿瘤区域和非肿瘤区域平均表观扩散系数(ADC)值、各项异性(FA)值及平均峰度(MK)值。应用双样本t检验比较肿瘤区域和非肿瘤区域间DKI各参数值的差异,应用ROC曲线分析DKI各参数对外周带前列腺癌的诊断效能。结果外周带前列腺癌的FA及MK值均明显高于正常外周带组织,差异具有极显著性统计学意义(P0.01),而ADC值明显低于正常组织,差异具有极显著性统计学意义(P0.01)。DKI的3个参数(ADC值、FA值及MK值)诊断前列腺癌的ROC曲线下面积分别为0.966、0.871和0.998。结论 DKI的3个参数(ADC值、FA值及MK值)对于外周带前列腺癌均具有诊断意义,而MK值是敏感性及特异性俱佳的参数。     

结构光方法在荧光分子断层成像系统的三维轮廓重构中的应用

荧光分子断层成像系统需要获取成像物体的三维表面轮廓,用于荧光团浓度重建的前向模型,本文提出了基于结构光方法的成像物体的三维表面轮廓重构。首先利用8比特格雷码对图像进行编码,再将编码后的图像投射到成像对象,这时经成像物体的三维表面轮廓调制后的图像再通过二值化、解码、插值和轮廓重构等步骤最后输出三维表面轮廓。圆柱物体和小鼠实验表明,该方法可以较好地重构成像物体的三维表面轮廓,并且具有硬件系统简单、易实现等优点。     

基于双波长近红外成像方法的血氧含量检测

为了对生物组织血氧含量分布进行成像,利用760 nm和850 nm的双波长近红外差分探测方法,研制了血氧含量检测系统,并首次使用吲哚菁绿 (ICG) 和散射体作为仿体设计实验。首先测量了牛奶的光密度差ΔOD随牛奶浓度差Δc的变化值。接着将ICG溶解在稀释了40倍的牛奶中,用不同浓度梯度稀释ICG,得到一系列ΔOD-Δc曲线,用一次函数拟合曲线,根据方差(SSE)、均方根(RMSE)和确定系数(R²)确定系统分辨率。然后改变散射介质浓度,研究它对系统测量的影响。最后选择30名健康测试者进行在体实验,测量手掌血氧含量的空间分布以及动态时间变化。结果表明,牛奶和ICG在双波长光源下的吸收系数之比分别接近1∶1和2.5∶1,因此可以用牛奶模拟组织中的水、脂肪、某些色素等,用ICG模拟血液中的脱氧血红蛋白;系统分辨率为1.6×10^-5 mg/mL的ICG浓度变化;弱散射介质的浓度与系统的动态响应范围成负相关,与系统的灵敏度成正相关;扎住手腕后,手掌血氧含量从1逐渐降低至0.3±0.105,松开橡皮筋后,血氧含量逐渐恢复至0.97±0.018。以上结果说明该系统具有测量可行性,将在组织血氧检测方面拥有良好的应用价值。     

基于图像融合技术提高磁探测电阻抗成像质量的研究

为了提高磁探测电阻抗成像(magnetic detection electrical impedance tomography,MDEIT)中图像分辨率,提出了一种基于图像融合技术提高磁探测电阻抗成像质量的研究。通过利用水平集方法对预处理后的CT图像进行分割,获得结构信息图像;采用CT图像建立模拟肺水肿病变仿真模型,并利用传统灵敏度矩阵算法进行重建,获得MDEIT功能信息图像;利用小波融合算法进行图像融合以获得结构—功能融合图像,并对融合结果进行分析。仿真结果表明,结构信息图像与功能信息图像相融合的图像效果较好。融合图像中重建电导率信息分布更清晰,并且可以实现在实际组织中对病变组织位置和大小精准定位,从而使磁探测电阻抗成像质量得到很大提升,为磁探测电阻抗成像的临床应用奠定了基础。     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.     

Hypo- und Hypermagnesämie aus kardiologischer Sicht

Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.     

Environmental risk factors and their role in the management of atopic dermatitis

Introduction: The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors.

Areas covered: We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD.

Expert commentary: The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures.     

Class II HLA in Georgia Caucasus Tbilisi Georgians and their Mediterranean ancestry: The Usko Mediterranean languages

Georgia (or Sakartvelo in its own language) is a South Caucasus Mts. country with its easternmost part is enigmatically named Iberia, like the Iberian Peninsula, which may refer to rivers “Kura” and “Ebro” or their valleys respectively. Most of their inhabitants speak Georgian which is included within Dene-Caucasian group and Usko-Mediterranean subgroup of languages. The latter includes Basque, Berber, ancient Iberian-Tartessian, Etruscan, Hittite, Minoan Lineal A and others. In the present paper, HLA class II -DRB1 and -DQB1 alleles has been studied and extended haplotypes calculated. Most frequent haplotypes are also of Mediterranean origin (i. e.: (A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*51)-DRB1*13:01-DQB1*06:03, or (A*24-B*35)-DRB1*01:01-DQB1*05:01) and DA genetic distances show that closest world populations to Georgians are Mediterraneans. Georgians also show common extended haplotypes ((A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*13)-DRB1*07:01-DQB1*02:01 and (A*03-B*35)-DRB1*11:01-DQB1*03:01) with Svan people, a secluded population in North Georgia mountains. We can conclude that Georgians belong to a very old Mediterranean substratum according to both linguistics (Usko Mediterranean languages) and HLA genetics.     

HLA genes in Amerindians from Mexico San Vicente Tancuayalab Teenek/Huastecos

Huastecos or Teenek Amerindians are presently living at North East Mexico (San Luis Potosi State). They have probably one of the most ancient culture of Mexico and Central America together with Mayas and Olmec groups with which also show close relationships. Proximity to Atlantic Ocean/Mexican Gulf originated that Spaniards had very early contact with them at about 1519 CE or before. In the present paper we have aimed to study HLA gene profile which may be useful for HLA and disease epidemiology and transplant programs in Teeneks. HLA-DRB1*04:07, -DRB1*14:06 and -DRB1*04:11 have been found in high frequency like in other Amerindian groups. High frequency typical Amerindians HLA extended haplotypes have been found, such as A*02-B*35-DRB1*04:07-DQB1*03:02; A*68-B*39-DRB1*04:07-DQB1*03:02 and A*02-B*39-DRB1*04:07-DQB1*03:02; also new haplotypes have been described, like A*02-B*52-DRB1*04:11-DQB1*03:02, A*68-B*35-DRB1*14:02-DQB1*03:01 and A*68-B*40-DRB1*16:02-DQB1*03:01. Genetic proximity is observed not only to linguistically close Mayans, but also to Mazatecans, Mixtecans and Zapotecans, who speak an altogether different languages; it shows once more that genes and languages do not correlate. This population was greatly diminished after European contact between 1500 and 1600 years CE; in fact, North and South America First Inhabitants population was brought from 80 down to 8 million people because of diseases (i.e.: measles, smallpox or influenza), slavery and war.     

État de l’art : nouveaux anticoagulants et transfusion

Direct oral anticoagulants (DOAC) are indicated for stroke prevention in atrial fibrillation and for the prevention and treatment of venous thromboembolism. As any anticoagulant, they are associated with a bleeding risk. Management of DOAC-induced bleeding is challenging. Idarucizumab, antidote for dabigatran, is currently available and is part of the therapeutic strategy, whereas antidotes for anti-Xa agents are under development. Activated or non-activated prothrombin concentrates are proposed, although their efficacy to reverse DOAC is uncertain. We propose an update on DOAC-associated bleeding management, integrating the availability of idarucizumab and the critical place of DOAC concentration measurements.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.