冠状动脉解剖变异的CTA影像特征分析

目的:分析冠状动脉解剖变异的CT血管造影(computed tomography angiography,CTA)影像特征。方法:回顾分析2010年6月到2014年4月间PACS存储的12326例心脏CTA图像资料,记录解剖变异冠状动脉的名称、开口起源位置、数目、行程状态及终止部位表现及其与毗邻结构的关系。结果:共有700例心脏有冠状动脉解剖变异,以冠状动脉开口起源异常最多见,共622例(622/12326,5.05%),其中左和右冠状动脉开口高位350例(350/12326,2.84%),左和右冠状动脉开口于对侧窦166例(166/12326,1.35%),冠状动脉双开口70例(70/12326,0.57%),左和右冠状动脉开口于窦间36例(36/12326,0.29%);其次为数目异常29例(29/12326,0.24%),包括左、右单支冠状动脉19例(19/12326,0.15%)和冠状动脉分支(LCx)缺如10例(10/12326,0.08%);冠状动脉终止异常(冠脉动脉-动脉圆锥和/或肺动脉瘘)29例(29/12326,0.24%)。VR是显示冠状动脉解剖变异最重要的后处理方法。结论:冠状动脉解剖变异CTA表现复杂多样,心脏CTA能够准确显示冠状动脉解剖变异种类及其毗邻关系。     

Susceptibility-Weighted Imaging for the Noncontrast Evaluation of Hepatocellular Carcinoma: A Prospective Study with Histopathologic Correlation

Background

Specific morphologic features of hepatocellular carcinoma (HCC) on imaging have identifiable pathologic correlates as well as implications for altering surgical management and defining prognosis. In this study, we compared susceptibility-weighted imaging (SWI) to conventional techniques and correlated our findings with histopathology to determine the role of SWI in assessing morphologic features of HCC without using a contrast agent.

Methods

86 consecutive patients with suspected HCC were imaged with MRI (including T1, T2, T2*, and SWI) and subsequently CT. 59 histologically-proven HCC lesions were identified in 53 patients. Each lesion on each imaging sequence was evaluated by two radiologists, and classified with respect to lesion morphology, signal intensity relative to surrounding hepatic parenchyma, presence of a pseudocapsule, presence of venous invasion, and internal homogeneity.

Results

Histopathology confirmed pseudocapsules in 41/59 lesions. SWI was able to detect a pseudocapsule in 34/41 lesions; compared to conventional T1/T2 imaging (12/41) and T2* (27/41). Mosaic pattern was identified in 25/59 lesions by histopathology; SWI confirmed this in all 25 lesions, compared to T1/T2 imaging (13/25) or T2* (18/25). Hemorrhage was confirmed by histopathology in 43/59 lesions, and visible on SWI in 41/43 lesions, compared to T1/T2 (7/43) and T2* (38/43). Venous invasion was confirmed by histopathology in 31/59 patients; SWI demonstrated invasion in 28/31 patients, compared to T1/T2 (7/31) and T2* (24/31).

Conclusions

SWI is better at identifying certain morphologic features such as pseudocapsule and hemorrhage than conventional MRI without using a contrast agent in HCC patients.     

Prominent Vessel Sign on Susceptibility-Weighted Imaging in Acute Stroke: Prediction of Infarct Growth and Clinical Outcome

Background and Purpose

Predicting the risk of further infarct growth in stroke patients is critical to therapeutic decision making. We aimed to predict early infarct growth and clinical outcome from prominent vessel sign (PVS) identified on the first susceptibility-weighted image (SWI) after acute stroke.

Materials and Methods

Twenty-two patients with middle cerebral artery (MCA) infarction had diffusion-weighted imaging, SWI, MR angiography, and clinical evaluation using the National Institutes of Health Stroke Scale at 7–60 hours and 5–14 days after stroke onset. Late-stage clinical evaluation at 1 and 3 months used the modified Rankin Scale. The infarct area and growth were scored from 10 (none) to 0 (infarct or growth in all 10 zones) using the Alberta Stroke Program Early CT Score (ASPECTS) system.

Results

Infarct growth on the second MRI occurred in 13 of 15 patients with PVS on the first MRI and not in any patient without PVS (n=7; r=0.86, P<0.001). The extent of PVS was significantly correlated with infarct growth (r=0.82, P<0.001) and early-stage outcome (P=0.02). No between-group difference in late-stage clinical outcome was found.

Conclusion

PVS on the first SWI after acute MCA territory stroke is a useful predictor of early infarct growth. Extensive PVS within the large MCA territory is related to poor early-stage outcome and could be useful for clinical assessment of stroke.     

Assessment of Intratumoral Micromorphology for Patients with Clear Cell Renal Cell Carcinoma Using Susceptibility-Weighted Imaging

Background

Multiple treatment options exist for the management of renal cell carcinomas. Preoperative evaluation of clear cell renal cell carcinoma (CRCC) grades is important for deciding upon the appropriate method of therapy. We hypothesize that susceptibility weighted imaging (SWI) is sensitive enough to detect intratumoral microvessles and microbleeding in renal cell carcinoma, which can be used to grade CRCC.

Material and Methods

Retrospective reviews of 37 patients with pathologically proven CRCCs were evaluated. All patients underwent SWI examinations. The characteristics of intratumoral susceptibility signal intensity (ITSS) includes the likelihood of the presence of ITSS, morphology of ITSS, dominant structure of ITSS and ratio of ITSS area to tumor area, which were all assessed on SWI. The results were compared using the nonparametric Mann-Whitney test.

Results

ITSS was seen in all patients except 4 patients with low-grade CRCCs. There was no significant difference between low and high-grade CRCCs when looking at the likelihood of the presence of ITSS. There was a significant difference in the mean score of dominant structures between low and high-grade CRCCs. Specifically, more dominant vascular structures and less hemorrhage were seen in low-grade tumors (2.15±1.05) compared to high-grade tumors (1.27±0.47) (P<0.005). The ratio of ITSS area to tumor area was also significantly higher for the high-grade group (1.55±0.52) than that for the low-grade group (0.88±0.43) on SWI (P<0.005).

Conclusion

SWI is useful for grading CRCCs.     

An In Vitro and In Vivo Analysis of the Correlation between Susceptibility-Weighted Imaging Phase Values and R2* in Cirrhotic Livers

Objective

To establish a baseline of susceptibility-weighted imaging (SWI) phase value as a means of detecting iron abnormalities in cirrhotic liver and to analyze its relationship with R2*.

Materials and Methods

Sixteen MnCl₂ phantoms, thirty-seven healthy individuals and 87 cirrhotic patients were performed SWI and multi-echo T2*-weighted imaging, and the signal processing in NMR (SPIN) software was used to measure the radian on SWI phase images and the R2* on T2* maps. The mean minus two times standard deviation (SD) of Siemens Phase Unit (SPU) in healthy individuals was designated as a threshold to separate the regions of interest (ROIs) into high- and low-iron areas in healthy participants and cirrhotic patients. The SWI phase values of high-iron areas were calculated. The R2* values was measured in the same ROI in both healthy participants and patients.

Results

SWI phase values correlated linearly with R2* values in cases of MnCl₂ concentrations lower than 2.3 mM in vitro (r = −0.996, P<0.001). The mean value and SD of 37 healthy participants were 2003 and 15 (SPU), respectively. A threshold of 1973 SPU (−0.115 radians) was determined. The SWI phase value and R2* values had a negative correlation in the cirrhotic patients (r = −0.742, P<0.001). However, no similar relationship was found in the healthy individuals (r = 0.096, P = 0.576). Both SWI phase values and R2* values were found to have significant correlations with serum ferritin concentrations in 42 patients with blood samples (r = −0.512, P = 0.001 and r = 0.641, P<0.001, respectively).

Conclusion

SWI phase values had significant correlations with R2* after the establishment of a baseline on the phase image. SWI phase images may be used for non-invasive quantitative measurement of mild and moderate iron deposition in hepatic cirrhosis in vivo.     

巢湖及其支流浮游动物群落结构特征及水质评价

2013年9月至2014年6月对巢湖及柘皋河、杭埠河、南淝河3条支流的浮游动物进行了调查,共检出浮游动物297种,其中,原生动物124种,轮虫135种,枝角类29种,桡足类9种。南淝河浮游动物物种数最多,为203种,巢湖最少,为130种;巢湖及3条支流均以原生动物和轮虫物种数最多。浮游动物总密度为644 223 ind/L,柘皋河浮游动物密度最高,巢湖浮游动物密度最低,巢湖及3条支流原生动物密度占浮游动物总密度的比例均为最高;四个季节柘皋河浮游动物密度均为最高。浮游动物总生物量为253.14 mg/L,南淝河浮游动物生物量最高,杭埠河和巢湖浮游动物生物量较低;春季和冬季柘皋河浮游动物生物量最高,夏季和秋季南淝河浮游动物生物量最高。相较3条支流,巢湖浮游动物优势种数最少。依据理化指标,巢湖及3条支流为富营养或超富营养水平,营养水平为:南淝河巢湖柘皋河杭埠河。浮游动物群落结构和环境因子的冗余分析(RDA)表明,巢湖及3条支流浮游动物群落结构在四个季节均未能明显区分开,浮游动物群落和环境理化因子的相关性较小。     

肝外胆管解剖变异和先天发育异常MRCP研究

目的:归纳肝外胆管解剖变异和先天发育异常的MRCP(magnetic resonance cholangiopancreatography,MRCP)表现。方法:回顾分析2010年1月到2015年6月间PACS存储的6817例图像资料,首先判定图像质量,然后记录肝门区胆管分支汇入方式、胆囊管插入位置、胆管先天发育异常及其表现。结果:1590例存在肝外胆管解剖变异和先天发育异常。其中胆囊管汇入位置异常发生率14.72%(787/5347),肝门区胆管分支汇入状态异常发生率17.97%(961/5347)。包括肝门区胆管分支汇入状态正常,胆囊管汇入位置异常575例,发生率10.75%(575/5347)。胆囊管汇入位置正常,肝门区胆管分支汇入状态异常749例,发生率14.01%(749/5347)。胆囊管汇入位置和肝门区胆管分支汇入状态异常并存212例,发生率3.96%(212/5347)。先天性发育异常即先天胆管扩张症54例,发生率1.01%(54/5347)。结论:肝外胆管解剖变异和先天发育异常复杂多样,MRCP能够准确显示大部分解剖变异种类及其毗邻关系,但是受图像质量及所罹患病种制约。     

Rational Classification of Portal Vein Thrombosis and Its Clinical Significance

Portal vein thrombosis (PVT) is commonly classified into acute (symptom duration <60 days and absence of portal carvernoma and portal hypertension) and chronic types. However, the rationality of this classification has received little attention. In this study, 60 patients (40 men and 20 women) with PVT were examined using contrast-enhanced computed tomography (CT). The percentage of vein occlusion, including portal vein (PV) and superior mesenteric vein (SMV), was measured on CT image. Of 60 patients, 17 (28.3%) met the criterion of acute PVT. Symptoms occurred more frequently in patients with superior mesenteric vein thrombosis (SMVT) compared to those without SMVT (p<0.001). However, there was no significant difference in PV occlusion between patients with and without symptoms. The frequency of cavernous transformation was significantly higher in patients with complete PVT than those with partial PVT (p<0.001). Complications of portal hypertension were significantly associated with cirrhosis (p<0.001) rather than with the severity of PVT and presence of cavernoma. These results suggest that the severity of PVT is only associated with the formation of portal cavernoma but unrelated to the onset of symptoms and the development of portal hypertension. We classified PVT into complete and partial types, and each was subclassified into with and without portal cavernoma. In conclusion, neither symptom duration nor cavernous transformation can clearly distinguish between acute and chronic PVT. The new classification system can determine the pathological alterations of PVT, patency of portal vein and outcome of treatment in a longitudinal study.     

Next-Generation Sequencing of Microbial Communities in the Athabasca River and Its Tributaries in Relation to Oil Sands Mining Activities

The Athabasca oil sands deposit is the largest reservoir of crude bitumen in the world. Recently, the soaring demand for oil and the availability of modern bitumen extraction technology have heightened exploitation of this reservoir and the potential unintended consequences of pollution in the Athabasca River. The main objective of the present study was to evaluate the potential impacts of oil sands mining on neighboring aquatic microbial community structure. Microbial communities were sampled from sediments in the Athabasca River and its tributaries as well as in oil sands tailings ponds. Bacterial and archaeal 16S rRNA genes were amplified and sequenced using next-generation sequencing technology (454 and Ion Torrent). Sediments were also analyzed for a variety of chemical and physical characteristics. Microbial communities in the fine tailings of the tailings ponds were strikingly distinct from those in the Athabasca River and tributary sediments. Microbial communities in sediments taken close to tailings ponds were more similar to those in the fine tailings of the tailings ponds than to the ones from sediments further away. Additionally, bacterial diversity was significantly lower in tailings pond sediments. Several taxonomic groups of Bacteria and Archaea showed significant correlations with the concentrations of different contaminants, highlighting their potential as bioindicators. We also extensively validated Ion Torrent sequencing in the context of environmental studies by comparing Ion Torrent and 454 data sets and by analyzing control samples.     

超声弹性成像技术及其应用

超声弹性成像作为一种新的超声成像方法,它通过获取有关组织弹性信息进行成像,弥补了X射线、超声成像(US)、磁共振成像(MRI)、计算机断层扫描(CT)等传统医学成像模态不能直接提供组织弹性的不足,具有无创、简单、便宜、容易应用等优点,被广泛应用于临床,成为目前医学弹性成像的一个研究热点。本文介绍了弹性成像基本的原理,详细阐述了血管内超声弹性成像、超声振动声成像、超声剪切波弹性成像、瞬时弹性成像、心肌弹性成像等不同激励方式下的几种超声弹性成像的基本原理、成像方法、国内外目前的研究现状、成像优缺点等,叙述了超声弹性成像在乳腺检测、前列腺癌的检测、射频消融监测和检测、冠状动脉粥样硬化的治疗等临床应用,并总结了超声弹性成像的发展趋势。     

Detection of Endogenous Iron Reduction during Hepatocarcinogenesis at Susceptibility-Weighted MR Imaging: Value for Characterization of Hepatocellular Carcinoma and Dysplastic Nodule in Cirrhotic Liver

Objective

To investigate the value of susceptibility-weighted imaging (SWI) for characterization of hepatocellular carcinoma (HCC) and dysplastic nodule (DN).

Materials and Methods

Sixty-eight cirrhotic patients with 89 hepatocellular nodules underwent SWI. The radiological features of hepatocellular nodules on SWI were classified into three types: type A (iso- or hypointensity, and background liver siderosis), type B (hyperintensity, and background liver siderosis), or type C (hyperintensity, and no background liver siderosis). Intranodular and background liver iron content was quantified and correlated with SWI pattern. Prussian blue staining was performed to quantify intranodular and background liver iron content.

Results

Type A pattern (n = 12) contained 11 (91.7%) DNs and 1 (8.3%) HCC, Type B pattern (n = 66) comprised 1 (1.5%) DN and 65 (98.5%) HCCs (including 12 DN-HCCs and 53 overt HCCs), and type C pattern (n = 11) was exclusively seen in HCCs. The iron scores of DN-HCCs and overt HCCs were significantly lower than those of background livers [(0.091±0.30) VS (2.18±0.87), P = 0.000; (0.11±0.41) VS (2.16±0.97), P = 0.000; respectively]. There was no significant difference between iron scores of DNs and those of background livers [(1.92±0.29) VS (2.17±039), P = 0.191]. For lesion-based and patient-based analysis of HCCs (DN-HCCs and overt HCCs), type B pattern showed a sensitivity, specificity, accuracy, positive predicative value (PPV), and negative predicative value (NPV) of 84.4% and 84.4%, 91.7% and 75%, 85.4% and 83.8%, 98.5% and 98.2%, 47.8% and 23.1%, respectively.

Conclusion

SWI can provide valuable information for characterization of HCC and DN based on endogenous iron reduction during hepatocarcinogenesis.     

3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks.A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure^1,2, alterations in brain vasculature of a Alzheimer''s disease mouse model³, portal vein abnormalities in portal hypertensive and cirrhotic mice⁴, developmental steps in rat lymphatic maturation between immature and adult lungs⁵, immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury⁶.Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network, focusing specifically on the portal vein and intrahepatic bile duct. These casts can be visualized by clearing or macerating the tissue and can then be analyzed. This technique can be applied to virtually any vascular or ductal system and would be directly applicable to any study inquiring into the development, function, maintenance, or injury of a 3-dimensional ductal or vascular structure.     

小盐芥营养器官的结构特点与其盐渍环境的关系研究

利用石蜡切片法研究了盐生植物小盐芥(Thellungiella halophila)营养器官的解剖结构。结果表明：小盐芥根的初生结构中表皮细胞为1层,且细胞大而高度液泡化,根毛数量较少;皮层仅由外皮层和内皮层2层细胞构成,细胞大,排列紧密;根次生维管组织发达。茎的初生结构中外剀维管束8～10束,大小不等,呈一轮排列;髓和髓射线发达;茎次生结构中维管组织也很发达。根和茎的这些结构特点提高了植物体吸收、运输水分的能力,而且根的特殊结构和输导系统将盐分限制在根内,适应于盐渍环境所造成的渗透胁迫和干旱胁迫。小盐芥叶片较小,上、下表皮细胞各1层,细胞大而高度液泡化,叶肉中栅栏组织与海绵组织分化不明显,但叶绿体体积大、数目多,细胞间隙较大,通气性能好,光合效率高。这些特点对其适应干旱盐渍环境有重要意义。小盐芥上述结构特征与典型真盐生植物、旱生植物相去其远,其营养器官内也无盐腺、囊泡等泌盐结构。由此推论,小盐芥更倾向于似盐生植物(拒盐植物)。     

High-resolution Time-lapse Imaging and Automated Analysis of Microtubule Dynamics in Living Human Umbilical Vein Endothelial Cells

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes within individual endothelial cells (ECs). These processes are critical for homeostatic maintenance such as wound healing, and are also crucial in promoting tumor growth and metastasis. EC morphology is defined by the organization of the cytoskeleton, a tightly regulated system of actin and microtubule (MT) dynamics that is known to control EC branching, polarity and directional migration, essential components of angiogenesis. To study MT dynamics, we used high-resolution fluorescence microscopy coupled with computational image analysis of fluorescently-labeled MT plus-ends to investigate MT growth dynamics and the regulation of EC branching morphology and directional migration. Time-lapse imaging of living Human Umbilical Vein Endothelial Cells (HUVECs) was performed following transfection with fluorescently-labeled MT End Binding protein 3 (EB3) and Mitotic Centromere Associated Kinesin (MCAK)-specific cDNA constructs to evaluate effects on MT dynamics. PlusTipTracker software was used to track EB3-labeled MT plus ends in order to measure MT growth speeds and MT growth lifetimes in time-lapse images. This methodology allows for the study of MT dynamics and the identification of how localized regulation of MT dynamics within sub-cellular regions contributes to the angiogenic processes of EC branching and migration.     

荧光成像技术及其在生命科学中的应用

近年来,荧光成像技术发展迅速,其成像系统通常为目前最先进的分析检测仪器之一的激光共聚焦显微镜,荧光探针是荧光成像技术的核心之一。作为新兴光学成像技术,荧光成像技术在生命科学领域中应用广泛,可用于蛋白质及金属离子检测,肿瘤疾病的诊断,并为药物新剂型的研究提供了新思路。     

Cardiovascular Magnetic Resonance Imaging of Scar Development Following Pulmonary Vein Isolation: A Prospective Study

Aims

Cardiovascular magnetic resonance (MR) provides non-invasive assessment of early (24-hour) edema and injury following pulmonary vein isolation (by ablation) and subsequent scar formation. We hypothesize that 24-hours after ablation, cardiovascular MR would demonstrate a pattern of edema and injury due to ablation and the severity would correlate with subsequent scar.

Methods

Fifteen atrial fibrillation patients underwent cardiovascular MR prior to pulmonary vein isolation, 24-hours post (N = 11) and 30-days post (N = 7) ablation, with T2-weighted (T2W) and late gadolinium enhancement (LGE) imaging. Left atrial wall thickness, edema enhancement ratio and LGE enhancement were assessed at each time point. Volumes of LGE and edema enhancement were measured, and the circumferential presence of injury was assessed at 24-hours, including comparison with LGE enhancement at 30 days.

Results

Left atrial wall thickness was increased 24-hours post-ablation (10.7±4.1 mm vs. 7.0±1.8 mm pre-PVI, p<0.05). T2W enhancement at 24-hours showed increased edema enhancement ratio (1.5±0.4 for post-ablation, vs. 0.9±0.2 pre-ablation, p<0.001). Edema and LGE volumes at 24-hours were correlated with 30-day LGE volume (R = 0.76, p = 0.04, and R = 0.74, p = 0.09, respectively). Using a 16 segment model for assessment, 24-hour T2W had sensitivity, specificity, and accuracy of 82%, 63%, and 79% respectively, for predicting 30-day LGE. 24-hour LGE had sensitivity, specificity, and accuracy of 91%, 47%, and 84%.

Conclusions

Increased left atrial wall thickening and edema were characterized on cardiovascular MR early post-ablation, and found to correlate with 30-day LGE scar.     

藻胆素的构象变化及其对光吸收的影响

研究藻胆蛋白中藻胆素构象的变化对藻胆素光谱性质的影响,在光合作用原初过程的研究中有重要意义．由于四吡咯发色团构象的非同源性随机涨落,藻胆素的电子激发态能级呈类Boltzmann分布;藻胆素的电子－振动吸收跃迁谱带线型因子可描述为与构象随机分布因子有关的卷积形式;藻胆素构象的随机分布导致电子－振动吸收跃迁谱带的不对称增宽．     

Pelage Color Variation of Macaca arctoides and Its Evolutionary Implications

Stump-tailed macaques (Macaca arctoides) exhibit significant intraspecific variation in pelage color. Based on their pelage color and geographical distribution, they are classified into 2 subspecies: northern bright brown Macaca arctoides arctoides and southern black Macaca arctoides melanota. However, studies on the natural population are extremely scarce, and researchers have occasionally questioned the subspecific classification. We quantitatively examined pelage color variation of Macaca arctoides in 3 free-ranging populations in Thailand. Pelage color difference between populations is significant. The population distributed south of the Isthmus of Kra showed wide intrapopulational variation, including bright brown, dark brown, and completely black, whereas the northern populations primarily had dark brown hairs. Thus, we conclude that one cannot classify the color variants into subspecies. Further, we hypothesize that the distinctive polymorphism in southern Thailand resulted from geographical isolation caused by the Pleistocene eustatic fluctuations and subsequent recovery of land connection and subsequent gene flow.     

Role of Soft Matter in the Sandwich Vein of Dragonfly Wing in Its Configuration and Aerodynamic Behaviors

The microstructure of the main longitudinal veins of the dragonfly wing and the aerodynamic behaviors of the wing were investigated in this paper.The microstructure of longitudinal vein presents two circumferential chitin layers and a protein-fiber soft layer.The dragonfly wing is corrugated due to the spatial arrangement of longitudinal veins.It was found that the corrugation angle could significantly influence the lift/drag ratio across a range of attack angles by the wind tunnel experiments.The results of the finite element analysis indicate that the protein soft layer of vein facilitates the change of the corrugation angle by allowing substantial relative twisting deformation between two neighboring veins,which is not possible in veins without a soft sandwich layer.