WorldWideScience

Sample records for 2d multi-slice mri

  1. Predictive Modelling of Cardiac 2D Multi-Slice MRI with Simultaneous Resolution of Cardiac and Respiratory Motion

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Ólafsdóttir, Hildur; Darkner, Sune;

    2009-01-01

    This paper introduces a novel approach to modelling of volumetric cardiac magnetic resonance imaging (MRI) with simultaneous resolution of cardiac and respiratory motion. The major challenge is that the inherent slow nature of MRI prevents obtaining real-time volumetric images of the heart with...... respiratory bellow and a vectorcardiogram, and utilizes a combination of deformation modelling and pixel intensity modelling. We demonstrate that this approach reliably models volumetric cardiac MRI for any combination of cardiac and respiratory phase....

  2. Ultrafast multi-slice spatiotemporally encoded MRI with slice-selective dimension segmented.

    Science.gov (United States)

    Zhang, Ting; Chen, Lin; Huang, Jianpan; Li, Jing; Cai, Shuhui; Cai, Congbo; Chen, Zhong

    2016-08-01

    As a recently emerging method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has a high robustness to field inhomogeneity and chemical shift effect. It has been broadened from single-slice scanning to multi-slice scanning. In this paper, a novel multi-slice SPEN MRI method was proposed. In this method, the slice-selective dimension was segmented to lower the specific absorption rate (SAR) and improve the image quality. This segmented method, dubbed SeSPEN method, was theoretically analyzed and demonstrated with phantom, lemon and in vivo rat brain experiments. The experimental results were compared with the results obtained from the spin-echo EPI, spin-echo SPEN method and multi-slice global SPEN method proposed by Frydman and coauthors (abbr. GlSPEN method). All the SPEN images were super-resolved reconstructed using deconvolution method. The results indicate that the SeSPEN method retains the advantage of SPEN MRI with respect to resistance to field inhomogeneity and can provide better signal-to-noise ratio than multi-slice GlSPEN MRI technique. The SeSPEN method has comparable SAR to the GlSPEN method while the T1 signal attenuation effect is alleviated. The proposed method will facilitate the multi-slice SPEN MRI to scan more slices within one scan with better image quality. PMID:27301072

  3. Ultrafast multi-slice spatiotemporally encoded MRI with slice-selective dimension segmented

    Science.gov (United States)

    Zhang, Ting; Chen, Lin; Huang, Jianpan; Li, Jing; Cai, Shuhui; Cai, Congbo; Chen, Zhong

    2016-08-01

    As a recently emerging method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has a high robustness to field inhomogeneity and chemical shift effect. It has been broadened from single-slice scanning to multi-slice scanning. In this paper, a novel multi-slice SPEN MRI method was proposed. In this method, the slice-selective dimension was segmented to lower the specific absorption rate (SAR) and improve the image quality. This segmented method, dubbed SeSPEN method, was theoretically analyzed and demonstrated with phantom, lemon and in vivo rat brain experiments. The experimental results were compared with the results obtained from the spin-echo EPI, spin-echo SPEN method and multi-slice global SPEN method proposed by Frydman and coauthors (abbr. GlSPEN method). All the SPEN images were super-resolved reconstructed using deconvolution method. The results indicate that the SeSPEN method retains the advantage of SPEN MRI with respect to resistance to field inhomogeneity and can provide better signal-to-noise ratio than multi-slice GlSPEN MRI technique. The SeSPEN method has comparable SAR to the GlSPEN method while the T1 signal attenuation effect is alleviated. The proposed method will facilitate the multi-slice SPEN MRI to scan more slices within one scan with better image quality.

  4. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, M.B.; Ólafsdóttir, H; Larsson, H.B.W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising off-line computer intensive analyses of variance and clustering in an annotated training set, the presented method is capable of providing registration without any manual interaction in ...

  5. Multi-slice MRI with the dynamic multi-coil technique.

    Science.gov (United States)

    Juchem, Christoph; Nahhass, Omar M; Nixon, Terence W; de Graaf, Robin A

    2015-11-01

    To date, spatial encoding for MRI is based on linear X, Y and Z field gradients generated by dedicated X, Y and Z wire patterns. We recently introduced the dynamic multi-coil technique (DYNAMITE) for the generation of magnetic field shapes for biomedical MR applications from a set of individually driven localized coils. The benefits for B0 magnetic field homogenization have been shown, as well as proof of principle of radial and algebraic MRI. In this study the potential of DYNAMITE MRI is explored further and the first multi-slice MRI implementation in which all gradient fields are purely DYNAMITE based is presented. The obtained image fidelity is shown to be virtually identical to that of a conventional MRI system with dedicated X, Y and Z gradient coils. Comparable image quality is a milestone towards the establishment of fully functional DYNAMITE MRI (and shim) systems.

  6. Value of MRI with sliding multi-slice technique for staging ovarian carcinoma

    International Nuclear Information System (INIS)

    Objective: To analyze the technical characteristics of sliding multi-slice magnetic resonance imaging (SMS-MRI), and to evaluate the value of staging ovarian carcinoma by SMS-MRI. Methods: Pre-operative SMS-MRI of chest, abdomen and pelvis was performed on 15 patients with ovarian carcinoma. Sequences included TSE T2WI, SMS TIRM and fat-suppressed contrast-enhanced SMS FLASH. The SMS-MRI was analyzed and staged according to FIGO's classification by two radiologists. The location of tumor, local invasion of uterus and fallopian tube or other pelvic tissues, peritoneum metastasis, lymph node metastasis and distal metastasis were recorded. The results were compared with operative and pathological findings. Results: The pathological diagnosis was serous cystadenocarcinoma (9), mucinous cystadenocarcinoma (2), endometrioid carcinoma (2), clear cell carcinoma (1) and granular cell carcinoma (1) at stage II (2), stage III (10) and stage IV (3). The accuracy of SMS-MRI staging was 100% (15/15). The tumor location, involvement of uterus and fallopian tubes as well as distant metastasis were accurately demonstrated by SMS-MRI. Conclusion: SMS-MRI can be a faster one-stop examination with good image quality. SMS-MRI is an alternative imaging method of staging ovarian carcinoma. (authors)

  7. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Ólafsdóttir, Hildur; Larsson, Henrik B. W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising computer intensive analyses of variance and clustering in an annotated training set off-line, the presented method is capable of providing registration without any manual interaction...... is verified and stabilised using perfusion specific prior models of pose and shape estimated from training data. Qualitative and quantitative validation of the method is carried out using 2000 clinical quality, short-axis, perfusion MR slice images, acquired from ten freely breathing patients with acute...... myocardial infarction. Despite evident perfusion deficits and varying image quality in the limited training set, a leave-one-out cross validation of the method showed a mean point to curve distance of 1.25+/-0.36 pixels for the left and right ventricle combined. We conclude that this learning-based method...

  8. Recurrent Fully Convolutional Neural Networks for Multi-slice MRI Cardiac Segmentation

    OpenAIRE

    Poudel, Rudra P K; Lamata, Pablo; Montana, Giovanni

    2016-01-01

    In cardiac magnetic resonance imaging, fully-automatic segmentation of the heart enables precise structural and functional measurements to be taken, e.g. from short-axis MR images of the left-ventricle. In this work we propose a recurrent fully-convolutional network (RFCN) that learns image representations from the full stack of 2D slices and has the ability to leverage inter-slice spatial dependences through internal memory units. RFCN combines anatomical detection and segmentation into a si...

  9. Functional Study of the Heart using MRI and Multi-slice CT (MSCT

    Directory of Open Access Journals (Sweden)

    "Sh. Akhlaghpour

    2005-08-01

    Full Text Available Introduction & Background: By using newer imaging techniques (MRI and MSCT, it is possible to perform functional studies of the heart including, wall mo-tion, chamber volume evaluation, and myocardial mass and wall thickness. While MRI had recently been introduced as the gold standard method for the morphological and functional studies of the heart, recent advances in the number of detectors, rotation time, and reconstruction protocols made Multislice CT (MSCT another new application for functional studies of the heart too. Ordinary raw data for coro-nary CT angiography is sufficient for these functional studies. Apart from the point that which technique is to be used to get a standard and reproducible meas-urement, a proper imaging strategy is necessary. To use MSCT, various softwares are available for these studies. By the use of these two modalities, valvular evaluations are also possible as addressed in many recent publications. In this article the strategy for functional study of the heart is presented and some case studies are also discussed.

  10. MRI in soils: determination of water concent changes due to root water uptake by means of a multi-slice-multi-echo sequence (MSME)

    NARCIS (Netherlands)

    Pohlmeier, A.; Vergeldt, F.; Gerkema, E.; As, van H.; Dusschoten, van D.; Vereecken, H.

    2010-01-01

    Root water uptake by ricinus communis (castor bean) in fine sand was investigated using MRI with multiecho sampling. Before starting the experiments the plants germinated and grew for 3 weeks in a cylindrical container with a diameter of 9 cm. Immediately before the MRI experiments started, the cont

  11. The Application of Multi-slice Spiral CT and MRI in Diagnosis of Facial Paralysis%CT、MRI在周围性面瘫诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    汪建华; 田建明; 左长京; 马小龙; 王志锋; 曾新力

    2011-01-01

    目的 探讨多层螺旋CT与MRI技术在周围性面瘫的定位及病因诊断中的价值.方法 回顾性分析68例周围性面瘫患者的CT、MRI资料,分析总结影像学在周围性面瘫的定位、定性诊断中的意义.结果 本组68例周围性面瘫中影像学能明确定位45例(66.2%).病因分别是耳部先天畸形时伴面神经管异常2例,外伤性面瘫25例,慢性中耳乳突炎合并胆脂瘤10例,肿瘤11例及Bell's面瘫20例.除Bell's面瘫影像学无异常发现外,其他均准确发现病变并提示诊断.结论 合理运用CT、MRI技术,对耳部先天性发育畸形、脑外伤、慢性中耳乳突炎及肿瘤所致的周围性面瘫具有重要的诊断意义.%Objective To investigate the value of multi-slice spiral CT and MRI in diagnosis of pcripheral facial paralysis . Methods Imaging data of 68 patients with peripheral facial paralysis were analyzed retrospectively. The values of CT and MRI in localizing and qualitative diagnosing peripheral facial paralysis were summarized. Results In present study,45 of 68 cases(66. 2% ) of peripheral facial paralysis could be evaluated accurately in the etiology by CT and MRI,including congenital malformations of ear ( n= 2 ) ,traumatic facial paralysis ( n= 25) , chronic tympanitis with cholestcatoma( n= 10) and tumors( n= 11 ) , but Bell ' s facial paralysis ( n=20) was no of positive imaging findings . Conclusion CT and MRI are of significance for congenital ear deformities, traumaticbrain injury, chronic tympanitis with cholesteatomas , and tumors-induced peripheral facial paralysis.

  12. MSCT和MRI对浸润性宫颈癌术前分期的价值对比%Comparison of multi-slice spiral CT and MRI in the diagnosis of pre-surgicai staging of invasive cervical cancer

    Institute of Scientific and Technical Information of China (English)

    邱书珺; 陆晓兰; 蒋小平; 王家强; 顾倩

    2012-01-01

    目的:对比浸润性宫颈癌在MSCT和MRI上表现差异及术前分期价值.方法:搜集有手术病理结果证实的宫颈癌82例,术前行CT检查74例,行MRI检查63例,以术后病理分期为标准,计算并比较CT、MRI对不同期宫颈癌的诊断符合率;对比分析两组图像上肿瘤大小、阴道或穹窿侵犯、宫体侵犯以及宫旁侵犯,分别计算并比较诊断符合率、敏感度及特异度.结果:对≤Ⅰ B1期宫颈癌,CT和MRI诊断符合率分别为47.56%、70.73%,Ⅰ B2~ⅡA期分别为80.49%、87.80%,≥ⅡB期分别为91.46%、82.93%.在显示肿瘤方面,MRI对≤4cm癌肿、阴道或穹窿侵犯方面的显示优于CT;CT对宫体侵犯诊断灵敏度高,对盆腔转移淋巴结的诊断优于MRI.结论:对≤Ⅰ B1和Ⅰ B2~ⅡA的早中期浸润性宫颈癌术前行MRI检查更有价值;而对于≥ⅡB的晚期浸润性宫颈癌行MSCT检查则更具有价值.%Objective:To retrospectively evaluate the significance of MRI and multi-slice Spiral CT (MSCT) for pre-treatment staging of invasive cervical cancer. Methods:82 patients with biopsy-proven cervical cancer were enrolled in this study. 74 patients underwent CT and 63 underwent MRI before surgery. Using surgicopathologic findings as the reference standard, to compare the accuracy of CT and MRI in various stages of cervical cancer, Tumor size, infiltration of vagina or fornix,corpus and parametrium involvement found in these 2 groups were compared and analysed,and the sensitivity,specificity and accuracy were calculated. Results:For stage ≤I Bl ,the diagnostic accuracy was 47. 56% for CT and 70. 73% for MRI; for stage I B2 ~ H A, the accuracy was 80. 49% and 87. 80% respectively; for advanced stage (≤ II B),it was 91. 46% and 82. 93% respectively. MRI was superior to CT for delineating cervical carcinoma with the size smaller than 4. 0cm and infiltration of vagina or fornix. CT is superior to MRI for the diagnosis of pelvic lymph node

  13. Whole left ventricular functional assessment from two minutes free breathing multi-slice CINE acquisition

    Science.gov (United States)

    Usman, M.; Atkinson, D.; Heathfield, E.; Greil, G.; Schaeffter, T.; Prieto, C.

    2015-04-01

    Two major challenges in cardiovascular MRI are long scan times due to slow MR acquisition and motion artefacts due to respiratory motion. Recently, a Motion Corrected-Compressed Sensing (MC-CS) technique has been proposed for free breathing 2D dynamic cardiac MRI that addresses these challenges by simultaneously accelerating MR acquisition and correcting for any arbitrary motion in a compressed sensing reconstruction. In this work, the MC-CS framework is combined with parallel imaging for further acceleration, and is termed Motion Corrected Sparse SENSE (MC-SS). Validation of the MC-SS framework is demonstrated in eight volunteers and three patients for left ventricular functional assessment and results are compared with the breath-hold acquisitions as reference. A non-significant difference (P > 0.05) was observed in the volumetric functional measurements (end diastolic volume, end systolic volume, ejection fraction) and myocardial border sharpness values obtained with the proposed and gold standard methods. The proposed method achieves whole heart multi-slice coverage in 2 min under free breathing acquisition eliminating the time needed between breath-holds for instructions and recovery. This results in two-fold speed up of the total acquisition time in comparison to the breath-hold acquisition.

  14. Enhancement of the low resolution image quality using randomly sampled data for multi-slice MR imaging

    OpenAIRE

    Pang, Yong; Yu, Baiying; Zhang, Xiaoliang

    2014-01-01

    Low resolution images are often acquired in in vivo MR applications involving in large field-of-view (FOV) and high speed imaging, such as, whole-body MRI screening and functional MRI applications. In this work, we investigate a multi-slice imaging strategy for acquiring low resolution images by using compressed sensing (CS) MRI to enhance the image quality without increasing the acquisition time. In this strategy, low resolution images of all the slices are acquired using multiple-slice imag...

  15. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    OpenAIRE

    Arathi T; Latha Parameswaran

    2014-01-01

    Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different a...

  16. Comparison of the Value of Multi-slice Spiral CT and MRI in the Diagnosis of Biliary Obstructive Diseases%多排螺旋CT、MRI在诊断胆道梗阻性病变中价值比较

    Institute of Scientific and Technical Information of China (English)

    孙永峰

    2015-01-01

    目的:探讨多排螺旋CT及MRI在胆道梗阻性病变患者中的临床诊断价值差异。方法选取112例经手术病理检查确诊的胆道梗阻性病变患者为研究对象,均行多排螺旋CT及MRI检查,详细记录检查结果。以手术病理检查结果为“金标准”,评估多排螺旋CT及MRI在胆道肠梗阻性疾病中的定位、定性诊断符合率差异。结果①多排螺旋CT病灶定位符合率为95.5%,同MRI的97.3%对比无统计学意义(P>0.05);②MRI定性诊断胆道梗阻性疾病的准确率为91.1%,显著高于多螺旋CT的77.7%,差异具有统计学意义(P0.05). ②The accuracy rate of MRI in qualitative diagnosis ofbiliary obstructive diseases was 91.1% which was significantly higher than 77.7% ofmulti-slice spiral CT, and the difference was statistically significant (P<0.05).Conclusion To apply multiple-sequence MRI in diagnosis of patients with suspected biliary obstructiv diseases, the accuracy rate of location and qualitative diagnosis is relatively higher, which is beneficial to improve the accuracy and effectiveness of early diagnosis and has positive on saving consultation hours and carrying out the follow-uptreatmentsmoothly. It is worthy of clinical promotion.

  17. Dynamic bowtie filter for cone-beam/multi-slice CT.

    Directory of Open Access Journals (Sweden)

    Fenglin Liu

    Full Text Available A pre-patient attenuator ("bowtie filter" or "bowtie" is used to modulate an incoming x-ray beam as a function of the angle of the x-ray with respect to a patient to balance the photon flux on a detector array. While the current dynamic bowtie design is focused on fan-beam geometry, in this study we propose a methodology for dynamic bowtie design in multi-slice/cone-beam geometry. The proposed 3D dynamic bowtie is an extension of the 2D prior art. The 3D bowtie consists of a highly attenuating bowtie (HB filled in with heavy liquid and a weakly attenuating bowtie (WB immersed in the liquid of the HB. The HB targets a balanced flux distribution on a detector array when no object is in the field of view (FOV. The WB compensates for an object in the FOV, and hence is a scaled-down version of the object. The WB is rotated and translated in synchrony with the source rotation and patient translation so that the overall flux balance is maintained on the detector array. First, the mathematical models of different scanning modes are established for an elliptical water phantom. Then, a numerical simulation study is performed to compare the performance of the scanning modes in the cases of the water phantom and a patient cross-section without any bowtie and with a dynamic bowtie. The dynamic bowtie can equalize the numbers of detected photons in the case of the water phantom. In practical cases, the dynamic bowtie can effectively reduce the dynamic range of detected signals inside the FOV. Furthermore, the WB can be individualized using a 3D printing technique as the gold standard. We have extended the dynamic bowtie concept from 2D to 3D by using highly attenuating liquid and moving a scale-reduced negative copy of an object being scanned. Our methodology can be applied to reduce radiation dose and facilitate photon-counting detection.

  18. Dynamic bowtie filter for cone-beam/multi-slice CT.

    Science.gov (United States)

    Liu, Fenglin; Yang, Qingsong; Cong, Wenxiang; Wang, Ge

    2014-01-01

    A pre-patient attenuator ("bowtie filter" or "bowtie") is used to modulate an incoming x-ray beam as a function of the angle of the x-ray with respect to a patient to balance the photon flux on a detector array. While the current dynamic bowtie design is focused on fan-beam geometry, in this study we propose a methodology for dynamic bowtie design in multi-slice/cone-beam geometry. The proposed 3D dynamic bowtie is an extension of the 2D prior art. The 3D bowtie consists of a highly attenuating bowtie (HB) filled in with heavy liquid and a weakly attenuating bowtie (WB) immersed in the liquid of the HB. The HB targets a balanced flux distribution on a detector array when no object is in the field of view (FOV). The WB compensates for an object in the FOV, and hence is a scaled-down version of the object. The WB is rotated and translated in synchrony with the source rotation and patient translation so that the overall flux balance is maintained on the detector array. First, the mathematical models of different scanning modes are established for an elliptical water phantom. Then, a numerical simulation study is performed to compare the performance of the scanning modes in the cases of the water phantom and a patient cross-section without any bowtie and with a dynamic bowtie. The dynamic bowtie can equalize the numbers of detected photons in the case of the water phantom. In practical cases, the dynamic bowtie can effectively reduce the dynamic range of detected signals inside the FOV. Furthermore, the WB can be individualized using a 3D printing technique as the gold standard. We have extended the dynamic bowtie concept from 2D to 3D by using highly attenuating liquid and moving a scale-reduced negative copy of an object being scanned. Our methodology can be applied to reduce radiation dose and facilitate photon-counting detection. PMID:25051067

  19. Use of marginal distributions constrained optimization (MADCO) for accelerated 2D MRI relaxometry and diffusometry

    Science.gov (United States)

    Benjamini, Dan; Basser, Peter J.

    2016-10-01

    Measuring multidimensional (e.g., 2D) relaxation spectra in NMR and MRI clinical applications is a holy grail of the porous media and biomedical MR communities. The main bottleneck is the inversion of Fredholm integrals of the first kind, an ill-conditioned problem requiring large amounts of data to stabilize a solution. We suggest a novel experimental design and processing framework to accelerate and improve the reconstruction of such 2D spectra that uses a priori information from the 1D projections of spectra, or marginal distributions. These 1D marginal distributions provide powerful constraints when 2D spectra are reconstructed, and their estimation requires an order of magnitude less data than a conventional 2D approach. This marginal distributions constrained optimization (MADCO) methodology is demonstrated here with a polyvinylpyrrolidone-water phantom that has 3 distinct peaks in the 2D D-T1 space. The stability, sensitivity to experimental parameters, and accuracy of this new approach are compared with conventional methods by serially subsampling the full data set. While the conventional, unconstrained approach performed poorly, the new method had proven to be highly accurate and robust, only requiring a fraction of the data. Additionally, synthetic T1 -T2 data are presented to explore the effects of noise on the estimations, and the performance of the proposed method with a smooth and realistic 2D spectrum. The proposed framework is quite general and can also be used with a variety of 2D MRI experiments (D-T2,T1 -T2, D -D, etc.), making these potentially feasible for preclinical and even clinical applications for the first time.

  20. 2D dose distribution images of a hybrid low field MRI-γ detector

    Science.gov (United States)

    Abril, A.; Agulles-Pedrós, L.

    2016-07-01

    The proposed hybrid system is a combination of a low field MRI and dosimetric gel as a γ detector. The readout system is based on the polymerization process induced by the gel radiation. A gel dose map is obtained which represents the functional part of hybrid image alongside with the anatomical MRI one. Both images should be taken while the patient with a radiopharmaceutical is located inside the MRI system with a gel detector matrix. A relevant aspect of this proposal is that the dosimetric gel has never been used to acquire medical images. The results presented show the interaction of the 99mTc source with the dosimetric gel simulated in Geant4. The purpose was to obtain the planar γ 2D-image. The different source configurations are studied to explore the ability of the gel as radiation detector through the following parameters; resolution, shape definition and radio-pharmaceutical concentration.

  1. 2D and 3D MRI features of classic bladder exstrophy

    International Nuclear Information System (INIS)

    The bladder exstrophy–epispadias complex (EEC) represents a spectrum of rare and surgically correctable congenital anomalies. Classic bladder exstrophy (CBE) stands between epispadias and cloacal exstrophy (CE) in the severity spectrum, and is the most commonly encountered type. CBE involves congenital defects of the bladder, abdominal wall, pelvic floor, and bony pelvis. With the growing understanding of the detrimental effects of radiation in children, magnetic resonance imaging (MRI) is progressively been utilized in the preoperative work-up and post-surgical follow-up of these patients. MRI provides valuable information for planning and evaluating the optimal surgical techniques for closure of CBE. The aim of this paper is to provide a review of the two- (2D) and three-dimensional (3D) MRI features of CBE including a detailed analytical description of the anatomy of the pelvic floor in affected patients

  2. Neurovascular coupling to D2/D3 dopamine receptor occupancy using simultaneous PET/functional MRI

    DEFF Research Database (Denmark)

    Sander, Christin Y; Hooker, Jacob M; Catana, Ciprian;

    2013-01-01

    This study employed simultaneous neuroimaging with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to demonstrate the relationship between changes in receptor occupancy measured by PET and changes in brain activity inferred by fMRI. By administering the D2/D3...... dopamine receptor antagonist [(11)C]raclopride at varying specific activities to anesthetized nonhuman primates, we mapped associations between changes in receptor occupancy and hemodynamics [cerebral blood volume (CBV)] in the domains of space, time, and dose. Mass doses of raclopride above tracer levels...... caused increases in CBV and reductions in binding potential that were localized to the dopamine-rich striatum. Moreover, similar temporal profiles were observed for specific binding estimates and changes in CBV. Injection of graded raclopride mass doses revealed a monotonic coupling between neurovascular...

  3. Registration of 2D x-ray images to 3D MRI by generating pseudo-CT data

    Science.gov (United States)

    van der Bom, M. J.; Pluim, J. P. W.; Gounis, M. J.; van de Kraats, E. B.; Sprinkhuizen, S. M.; Timmer, J.; Homan, R.; Bartels, L. W.

    2011-02-01

    Spatial and soft tissue information provided by magnetic resonance imaging can be very valuable during image-guided procedures, where usually only real-time two-dimensional (2D) x-ray images are available. Registration of 2D x-ray images to three-dimensional (3D) magnetic resonance imaging (MRI) data, acquired prior to the procedure, can provide optimal information to guide the procedure. However, registering x-ray images to MRI data is not a trivial task because of their fundamental difference in tissue contrast. This paper presents a technique that generates pseudo-computed tomography (CT) data from multi-spectral MRI acquisitions which is sufficiently similar to real CT data to enable registration of x-ray to MRI with comparable accuracy as registration of x-ray to CT. The method is based on a k-nearest-neighbors (kNN)-regression strategy which labels voxels of MRI data with CT Hounsfield Units. The regression method uses multi-spectral MRI intensities and intensity gradients as features to discriminate between various tissue types. The efficacy of using pseudo-CT data for registration of x-ray to MRI was tested on ex vivo animal data. 2D-3D registration experiments using CT and pseudo-CT data of multiple subjects were performed with a commonly used 2D-3D registration algorithm. On average, the median target registration error for registration of two x-ray images to MRI data was approximately 1 mm larger than for x-ray to CT registration. The authors have shown that pseudo-CT data generated from multi-spectral MRI facilitate registration of MRI to x-ray images. From the experiments it could be concluded that the accuracy achieved was comparable to that of registering x-ray images to CT data.

  4. Visual grading of 2D and 3D functional MRI compared with image-based descriptive measures

    Energy Technology Data Exchange (ETDEWEB)

    Ragnehed, Mattias [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences, Division of Radiological Sciences/Radiology, Faculty of Health Sciences, Linkoeping (Sweden); Leinhard, Olof Dahlqvist; Pihlsgaard, Johan; Lundberg, Peter [Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Linkoeping University, Division of Radiological Sciences, Radiation Physics, IMH, Linkoeping (Sweden); Wirell, Staffan [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University Hospital, Department of Radiology, Linkoeping (Sweden); Soekjer, Hannibal; Faegerstam, Patrik [Linkoeping University Hospital, Department of Radiology, Linkoeping (Sweden); Jiang, Bo [Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Smedby, Oerjan; Engstroem, Maria [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden)

    2010-03-15

    A prerequisite for successful clinical use of functional magnetic resonance imaging (fMRI) is the selection of an appropriate imaging sequence. The aim of this study was to compare 2D and 3D fMRI sequences using different image quality assessment methods. Descriptive image measures, such as activation volume and temporal signal-to-noise ratio (TSNR), were compared with results from visual grading characteristics (VGC) analysis of the fMRI results. Significant differences in activation volume and TSNR were not directly reflected by differences in VGC scores. The results suggest that better performance on descriptive image measures is not always an indicator of improved diagnostic quality of the fMRI results. In addition to descriptive image measures, it is important to include measures of diagnostic quality when comparing different fMRI data acquisition methods. (orig.)

  5. Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong Hoon; Goo, Hyun Woo; Yoon, Chong Hyun [University of Ulsan College of Medicine, Asan Medical Center, Ulsan (Korea, Republic of)

    2004-09-15

    In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.

  6. Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay

    International Nuclear Information System (INIS)

    In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection

  7. Design of a 2D MRI compatible robot for performing prostate cancer treatment using therapeutic ultrasound

    OpenAIRE

    Yiallouras, Christos

    2015-01-01

    Therapeutic ultrasound is a promising treatment method for many common cancers, including prostate cancer. Magnetic resonance image (MRI) guidance of therapeutic ultrasound permits targeting and monitoring of therapy. In this thesis a prototype MRI compatible positioning device for the treatment of prostate cancer using therapeutic ultrasound is presented. The accuracy, MRI compatibility and functionality of the positioning device was evaluated in in vitro experiments (using gel phantoms and ...

  8. How will the introduction of multi-slice CT affect patient doses?

    International Nuclear Information System (INIS)

    Imaging protocols for patients undergoing CT examinations on a conventional single section scanner (GE CT/i) were compared with those developed after a multi-slice scanner (GE LightSpeed) was introduced into clinical practice. For multi-slice CT, the reduction in patient scan time was a more than a factor of two for head scans, and approximately 25% for body scans. The number of images available for review on the multi-slice CT system increased by approximately 40%. Use of this multi-slice CT scanner resulted in an effective dose of 1.2 mSv for head examinations and 9.1 mSv for body examinations. The increase in patient effective dose after the introduction of multi-slice CT was approximately 30% for head CT examinations and 150% for body examinations. Higher patient doses were due to a shorter CT geometry, x-ray beam profiles that are greater than the detector width, and the use of a pitch ratio of only 0.75. Since multi-slice CT offers major reductions in scan time as well as improved image quality, it is anticipated that both individual and collective doses from CT will continue to increase for the foreseeable future. (author)

  9. Simultaneous multi-slice Turbo-FLASH imaging with CAIPIRINHA for whole brain distortion-free pseudo-continuous arterial spin labeling at 3 and 7 T.

    Science.gov (United States)

    Wang, Yi; Moeller, Steen; Li, Xiufeng; Vu, An T; Krasileva, Kate; Ugurbil, Kamil; Yacoub, Essa; Wang, Danny J J

    2015-06-01

    Simultaneous multi-slice (SMS) or multiband (MB) imaging has recently been attempted for arterial spin labeled (ASL) perfusion MRI in conjunction with echo-planar imaging (EPI) readout. It was found that SMS-EPI can reduce the T1 relaxation effect of the label and improve image coverage and resolution with little penalty in signal-to-noise ratio (SNR). However, EPI still suffers from geometric distortion and signal dropout from field inhomogeneity effects especially at high and ultrahigh magnetic fields. Here we present a novel scheme for achieving high fidelity distortion-free quantitative perfusion imaging by combining pseudo-continuous ASL (pCASL) with SMS Turbo-FLASH (TFL) readout at both 3 and 7 T. Bloch equation simulation was performed to characterize and optimize the TFL-based pCASL perfusion signal. Two MB factors (3 and 5) were implemented in SMS-TFL pCASL and compared with standard 2D TFL and EPI pCASL sequences. The temporal SNR of SMS-TFL pCASL relative to that of standard TFL pCASL was 0.76 ± 0.10 and 0.74 ± 0.11 at 7 T and 0.70 ± 0.05 and 0.65 ± 0.05 at 3T for MB factor of 3 and 5, respectively. By implementing background suppression in conjunction with SMS-TFL at 3T, the relative temporal SNR improved to 0.84 ± 0.09 and 0.79 ± 0.10 for MB factor of 3 and 5, respectively. Compared to EPI pCASL, significantly increased temporal SNR (pbrain distortion-free quantitative mapping of cerebral blood flow at high and ultrahigh magnetic fields.

  10. Comparison of 4D flow and 2D velocity-encoded phase contrast MRI sequences for the evaluation of aortic hemodynamics.

    Science.gov (United States)

    Bollache, Emilie; van Ooij, Pim; Powell, Alex; Carr, James; Markl, Michael; Barker, Alex J

    2016-10-01

    The purpose of this study was to compare aortic flow and velocity quantification using 4D flow MRI and 2D CINE phase-contrast (PC)-MRI with either one-directional (2D-1dir) or three-directional (2D-3dir) velocity encoding. 15 healthy volunteers (51 ± 19 years) underwent MRI including (1) breath-holding 2D-1dir and (2) free breathing 2D-3dir PC-MRI in planes orthogonal to the ascending (AA) and descending (DA) aorta, as well as (3) free breathing 4D flow MRI with full thoracic aorta coverage. Flow quantification included the co-registration of the 2D PC acquisition planes with 4D flow MRI data, AA and DA segmentation, and calculation of AA and DA peak systolic velocity, peak flow and net flow volume for all sequences. Additionally, the 2D-3dir velocity taking into account the through-plane component only was used to obtain results analogous to a free breathing 2D-1dir acquisition. Good agreement was found between 4D flow and 2D-3dir peak velocity (differences = -3 to 6 %), peak flow (-7 %) and net volume (-14 to -9 %). In contrast, breath-holding 2D-1dir measurements exhibited indices significantly lower than free breathing 2D-3dir and 2D-1dir (differences = -35 to -7 %, p < 0.05). Finally, high correlations (r ≥ 0.97) were obtained for indices estimated with or without eddy current correction, with the lowest correlation observed for net volume. 4D flow and 2D-3dir aortic hemodynamic indices were in concordance. However, differences between respiration state and 2D-1dir and 2D-3dir measurements indicate that reference values should be established according to the PC-MRI sequence, especially for the widely used net flow (e.g. stroke volume in the AA).

  11. Detection of irregular, transient fMRI activity in normal controls using 2dTCA: comparison to event-related analysis using known timing

    OpenAIRE

    Morgan, Victoria L.; John C Gore

    2009-01-01

    When events occur spontaneously during the acquisition of a series of images, traditional modeling methods for detecting functional MRI activation detection cannot be employed. The two-dimensional Temporal Clustering Algorithm, 2dTCA, has been shown to accurately detect random, transient activations in computer simulations without the use of known event timings. In this study we applied the 2dTCA technique to detect the timings and spatial locations of sparse, irregular, transient activations...

  12. Improvement of Efficiency and Flexibility in Multi-slice Helical CT

    Institute of Scientific and Technical Information of China (English)

    SUN Wen-wu; CHEN Si-ping; ZHUANG Tian-ge

    2008-01-01

    One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method.

  13. Multi-slice computed tomography assessment of bronchial compression with absent pulmonary valve

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yu-Min; Sun, Ai-Min; Wang, Qian; Zhu, Ming; Qiu, Hai-Sheng [Shanghai Children' s Medical Center and Shanghai Jiao Tong University Medical School, Department of Radiology, Shanghai (China); Jaffe, Richard B. [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States); Liu, Jin-Fen [Shanghai Children' s Medical Center, Department of Cardiothoracic Surgery, Shanghai (China); Gao, Wei [Shanghai Children' s Medical Center and Shanghai Jiao Tong University Medical School, Department of Cardiology, Shanghai (China); Berdon, Walter E. [Children' s Hospital of New York, Department of Radiology, New York, NY (United States)

    2014-07-15

    Absent pulmonary valve is a rare cardiovascular anomaly that can result in profound tracheobronchial compression. To demonstrate the advantage of multi-slice CT in diagnosing tracheobronchial compression, its severity as related to the adjacent dilated pulmonary arteries, and associated lung and cardiac lesions. We included children with absent pulmonary valve who were reviewed by multi-slice CT during a 17-year period. The number and locations of stenoses and lung lesions were noted and the severity of stenosis was categorized. The diameter of the pulmonary artery was measured and associated cardiac defects were demonstrated. Thirty-one children (14 girls and 17 boys) were included. Of these, 29 had ventricular septal defect and 2 had an intact ventricular septum. Twenty-nine children (94%) had tracheobronchial compression, judged to be mild in nine children (31%), moderate in 10 (34%) and severe in 10 (34%). The different locations of the stenosis (carina, main bronchi, lobar and segmental bronchi) were observed. And the number and location of lung lesions demonstrated that the right middle and left upper and lower lobes were often affected. The diameter of the pulmonary artery in these children was well above normal published values, and Spearman rank correlation analysis showed a correlation between the size of the pulmonary artery and the severity of the tracheobronchial stenosis. Nineteen children (61%) underwent surgery and 4 of these children had a multi-slice CT post-operative follow-up study. Absent pulmonary valve can cause significant morbidity and mortality in children. Multi-slice CT can accurately depict areas of tracheobronchial compression, associated lung lesions and cardiac defects, helping to direct the surgeon. (orig.)

  14. Functional MRI of the pharynx in obstructive sleep apnea (OSA) with rapid 2-D flash sequences; Funktionelle MRT des Pharynx bei obstruktiver Schlafapnoe (OSA) mit schnellen 2D-FLASH-Sequenzen

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, L. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Muenchen (Germany); Guenther, E. [Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenkranke, Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Muenchen (Germany); Gauger, J. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Muenchen (Germany); Nitz, W. [Siemens Medizintechnik, Erlangen (Germany); Kastenbauer, E. [Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenkranke, Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Muenchen (Germany); Reiser, M. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Muenchen (Germany)

    1996-03-01

    Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an in-plane resolution of 2.67x1.8 mm were achieved. The mobility of the tongue, soft palate and pharyngeal surface could be clearly delineated. The MRI findings correlated well with the clinical examinations. We propose ultrafast MRI as a reliable and non-invasive method of evaluating pharyngeal obstruction and their levels. (orig.) [Deutsch] Die funktionelle Bildgebung des Pharynx war bisher eine Domaene der Hochfrequenzroentgenkinematographie, der Computertomographie (CT) und der ultraschnellen Computertomographie. Die Entwicklung moderner Techniken in der Magnetresonanztomographie (MRT) fuehrte zu neuen Ansaetzen in der Diagnostik pharyngealer Dysfunktionen. Ziel der vorliegenden Studie war die Implementierung neuer schneller MR-Sequenzen, um Verschlussmechanismen entlang des Pharnyxschlauches bei Patienten mit obstruktiver Schlafapnoe (OSA) zu untersuchen. 16 Patienten mit OSA und 6 gesunde Probanden wurden an einem 1,5-T-Ganzkoerpermagnetresonanztomographen (`Vision`, Siemens Medizintechnik, Erlangen

  15. Detection of malignant right coronary artery anomaly by multi-slice CT coronary angiography

    International Nuclear Information System (INIS)

    Coronary artery anomalies occur in 0.3-0.8% of the population and infer a high risk for sudden cardiac death in young adults. Diagnosis is usually established during coronary angiography, which is hampered by poor spatial visualization. Magnetic resonance imaging is an alternative, but it is not feasible in the presence of metal objects or claustrophobia. In this report, a 15-year-old boy experienced ventricular fibrillation and was successfully resuscitated. Cardiac catheterization was inconclusive, and pacemaker implantation prohibited the use of MR imaging. Multi-slice CT coronary angiography revealed a malignant anomalous right coronary artery. (orig.)

  16. Small intestinal lipomas:Diagnostic value of multi-slice CT enterography

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To analyze the clinical and imaging features of the small intestinal lipomas and to evaluate the diagnostic value of multi-slice computed tomography(CT) enterography.METHODS:Fourteen cases(one had two intestinal lesions) of surgically confirmed lipomas of the small intestine were retrospectively analyzed.The location,size,clinical and radiological aspects were discussed.RESULTS:Twelve patients presented with abdominal pain,of whom three complained of paroxysmal colic.Melena or bloody stools was mentione...

  17. Exploiting sparsity and low-rank structure for the recovery of multi-slice breast MRIs with reduced sampling error.

    Science.gov (United States)

    Yin, X X; Ng, B W-H; Ramamohanarao, K; Baghai-Wadji, A; Abbott, D

    2012-09-01

    It has been shown that, magnetic resonance images (MRIs) with sparsity representation in a transformed domain, e.g. spatial finite-differences (FD), or discrete cosine transform (DCT), can be restored from undersampled k-space via applying current compressive sampling theory. The paper presents a model-based method for the restoration of MRIs. The reduced-order model, in which a full-system-response is projected onto a subspace of lower dimensionality, has been used to accelerate image reconstruction by reducing the size of the involved linear system. In this paper, the singular value threshold (SVT) technique is applied as a denoising scheme to reduce and select the model order of the inverse Fourier transform image, and to restore multi-slice breast MRIs that have been compressively sampled in k-space. The restored MRIs with SVT for denoising show reduced sampling errors compared to the direct MRI restoration methods via spatial FD, or DCT. Compressive sampling is a technique for finding sparse solutions to underdetermined linear systems. The sparsity that is implicit in MRIs is to explore the solution to MRI reconstruction after transformation from significantly undersampled k-space. The challenge, however, is that, since some incoherent artifacts result from the random undersampling, noise-like interference is added to the image with sparse representation. These recovery algorithms in the literature are not capable of fully removing the artifacts. It is necessary to introduce a denoising procedure to improve the quality of image recovery. This paper applies a singular value threshold algorithm to reduce the model order of image basis functions, which allows further improvement of the quality of image reconstruction with removal of noise artifacts. The principle of the denoising scheme is to reconstruct the sparse MRI matrices optimally with a lower rank via selecting smaller number of dominant singular values. The singular value threshold algorithm is performed

  18. Comparison of 3D turbo spin-echo SPACE sequences with conventional 2D MRI sequences to assess the shoulder joint

    International Nuclear Information System (INIS)

    Highlights: • 3D SPACE and conventional 2D TSE MRI for assessment of the shoulder joint were compared. • Concordance for most pathologys was substantial to almost perfect. • Examination time could be reduced up to 8 min (27%). • Regarding rotator cuff injuries an additional sagittal T2w TSE sequence in 3D protocol is recommended. - Abstract: Purpose: To determine the accuracy and reliability of three-dimensional (3D) T1- and proton density (PD)-weighted turbo spin-echo (TSE) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) compared with conventional 2D sequences in assessment of the shoulder-joint. Materials and methods: Ninety-three subjects were examined on a 3-T MRI system with both conventional 2D-TSE sequences in T1-, T2- and PD-weighting and 3D SPACE sequences in T1- and PD-weighting. All examinations were assessed independently by two reviewers for common pathologies of the shoulder-joint. Agreement between 2D- and 3D-sequences and inter-observer-agreement was evaluated using kappa-statistics. Results: Using conventional 2D TSE sequences as standard of reference, sensitivity, specificity, and accuracy values of 3D SPACE were 81.8%, 95.1%, and 93.5% for injuries of the supraspinatus-tendon (SSP), 81.3%, 93.5%, and 91.4% for the cartilage layer and 82.4%, 98.5%, and 97.5% for the long biceps tendon. Concordance between 2D and 3D was almost perfect for tendinopathies of the SSP (κ = 0.85), osteoarthritis (κ = 1), luxation of the biceps tendon (κ = 1) and adjacent bone marrow (κ = 0.92). Inter-observer-agreement was generally higher for conventional 2D TSE sequences (κ, 0.23–1.0), when compared to 3D SPACE sequences (κ, −0.33 to 1.0) except for disorders of the long biceps tendon and supraspinatus tendon rupture. Conclusion: Because of substantial and almost perfect concordance with conventional 2D TSE sequences for common shoulder pathologies, MRI examination-time can be reduced by nearly 40

  19. Comparison of 3D turbo spin-echo SPACE sequences with conventional 2D MRI sequences to assess the shoulder joint

    Energy Technology Data Exchange (ETDEWEB)

    Kloth, Jost Karsten, E-mail: jost.kloth@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany); Winterstein, Marianne, E-mail: marianne.winterstein@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany); Akbar, Michael, E-mail: michael.akbar@med.uni-heidelberg.de [Orthopedic and Trauma Surgery, University Hospital Heidelberg, Schlierbacher Landstraße 200a, D-69118 Heidelberg (Germany); Meyer, Esther, E-mail: esther.meyer@siemens.com [Siemens Healthcare, Erlangen (Germany); Paul, Dominik, E-mail: dominik.paul@siemens.com [Siemens Healthcare, Erlangen (Germany); Kauczor, Haus-Ulrich, E-mail: hans-ulrich.kauczor@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany); Weber, Marc-André, E-mail: marcandre.weber@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany)

    2014-10-15

    Highlights: • 3D SPACE and conventional 2D TSE MRI for assessment of the shoulder joint were compared. • Concordance for most pathologys was substantial to almost perfect. • Examination time could be reduced up to 8 min (27%). • Regarding rotator cuff injuries an additional sagittal T2w TSE sequence in 3D protocol is recommended. - Abstract: Purpose: To determine the accuracy and reliability of three-dimensional (3D) T1- and proton density (PD)-weighted turbo spin-echo (TSE) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) compared with conventional 2D sequences in assessment of the shoulder-joint. Materials and methods: Ninety-three subjects were examined on a 3-T MRI system with both conventional 2D-TSE sequences in T1-, T2- and PD-weighting and 3D SPACE sequences in T1- and PD-weighting. All examinations were assessed independently by two reviewers for common pathologies of the shoulder-joint. Agreement between 2D- and 3D-sequences and inter-observer-agreement was evaluated using kappa-statistics. Results: Using conventional 2D TSE sequences as standard of reference, sensitivity, specificity, and accuracy values of 3D SPACE were 81.8%, 95.1%, and 93.5% for injuries of the supraspinatus-tendon (SSP), 81.3%, 93.5%, and 91.4% for the cartilage layer and 82.4%, 98.5%, and 97.5% for the long biceps tendon. Concordance between 2D and 3D was almost perfect for tendinopathies of the SSP (κ = 0.85), osteoarthritis (κ = 1), luxation of the biceps tendon (κ = 1) and adjacent bone marrow (κ = 0.92). Inter-observer-agreement was generally higher for conventional 2D TSE sequences (κ, 0.23–1.0), when compared to 3D SPACE sequences (κ, −0.33 to 1.0) except for disorders of the long biceps tendon and supraspinatus tendon rupture. Conclusion: Because of substantial and almost perfect concordance with conventional 2D TSE sequences for common shoulder pathologies, MRI examination-time can be reduced by nearly 40

  20. The clinical application of multi-slice spiral CT angiography in abdominal aortic disease

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To evaluate the clinical application of multi-slice spiral CT angiography(MSCTA) in the assessment of abdominal aortic disease. Methods: Fifty-four patients underwent multi-slice spiral CT angiography of abdomen. Contrast agent (Omnipaque 300 I g/L) 1.5 ml/kg was injected and the injection rate was 3 ml/s. The delay time was determined by bolus tracking technique,Tll level abdominal aorta was set as the target vessel and the threshold was 180-200 Hu, slice width was 3 mm and with a pitch of 4-6.Original data were transferred to working-station to perform functional reconstruction. Results: Ten cases were normal, twenty-eight cases were abdominal aortic aneurysms, five abdominal aortic dissecting aneurysms (Debakay type Ⅲ ) and eleven aortic sclerosis. SSD showed the body of aneurysm and the relationship between aneurysm and adjacent blood vessel, MIP better displayed calcification of blood vessel wall and condition of the stent, MPR demonstrated true and false lumen, rupture site of abdominal aorta intima and mural thrombus. Conclusion: MSCTA axial and reconstruction image can show the extent of abdominal aortic disease and the relationship with adjacent blood vessels. It is a safe, simple and non-invasive examination method.

  1. Effect of Task-Correlated Physiological Fluctuations and Motion in 2D and 3D Echo-Planar Imaging in a Higher Cognitive Level fMRI Paradigm

    Science.gov (United States)

    Ladstein, Jarle; Evensmoen, Hallvard R.; Håberg, Asta K.; Kristoffersen, Anders; Goa, Pål E.

    2016-01-01

    Purpose: To compare 2D and 3D echo-planar imaging (EPI) in a higher cognitive level fMRI paradigm. In particular, to study the link between the presence of task-correlated physiological fluctuations and motion and the fMRI contrast estimates from either 2D EPI or 3D EPI datasets, with and without adding nuisance regressors to the model. A signal model in the presence of partly task-correlated fluctuations is derived, and predictions for contrast estimates with and without nuisance regressors are made. Materials and Methods: Thirty-one healthy volunteers were scanned using 2D EPI and 3D EPI during a virtual environmental learning paradigm. In a subgroup of 7 subjects, heart rate and respiration were logged, and the correlation with the paradigm was evaluated. FMRI analysis was performed using models with and without nuisance regressors. Differences in the mean contrast estimates were investigated by analysis-of-variance using Subject, Sequence, Day, and Run as factors. The distributions of group level contrast estimates were compared. Results: Partially task-correlated fluctuations in respiration, heart rate and motion were observed. Statistically significant differences were found in the mean contrast estimates between the 2D EPI and 3D EPI when using a model without nuisance regressors. The inclusion of nuisance regressors for cardiorespiratory effects and motion reduced the difference to a statistically non-significant level. Furthermore, the contrast estimate values shifted more when including nuisance regressors for 3D EPI compared to 2D EPI. Conclusion: The results are consistent with 3D EPI having a higher sensitivity to fluctuations compared to 2D EPI. In the presence partially task-correlated physiological fluctuations or motion, proper correction is necessary to get expectation correct contrast estimates when using 3D EPI. As such task-correlated physiological fluctuations or motion is difficult to avoid in paradigms exploring higher cognitive functions, 2

  2. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears*

    Science.gov (United States)

    Chagas-Neto, Francisco Abaeté; Nogueira-Barbosa, Marcello Henrique; Lorenzato, Mário Müller; Salim, Rodrigo; Kfuri-Junior, Maurício; Crema, Michel Daoud

    2016-01-01

    Objective To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition. PMID:27141127

  3. The clinical value of combined use of MR imaging and multi-slice spiral CT in limb salvage surgery for orthopaedic oncology patients: initial experience in nine patients

    International Nuclear Information System (INIS)

    The purpose of this prospective study was to evaluate the value of the combined use of MR imaging and multi-slice spiral CT for limb salvage surgery in orthopaedic oncology patients. Nine consecutive patients with lower/upper limb malignant bone tumours (7 osteosarcomas and 2 chondrosarcomas) were treated with limb-salvaging procedures. Preoperative planning including determination of the osteotomy plane and diameters of the prosthesis was performed basing on the preoperative CT and MR images. The histopathology was performed as golden diagnostic criteria to evaluate the accuracy of CT and MR-based determination for tumour’s boundary. The tumour extension measured on MRI was consistent with the actual extension (P>0.05, paired Student’s t test), while the extension measured on CT imaging was less than the actual extension. The length, offset and alignment of the affected limb were reconstructed accurately after the operation. An excellent functional outcome was achieved in all patients. In the present study, MRI was found to be superior to CT for determining the tumour extension, combined use of MRI and CT measurement provided high precision for the fit of the prosthesis and excellent functional results

  4. Computer aided diagnosis of osteoporosis using multi-slice CT images

    Science.gov (United States)

    Takahashi, Eiji; Saita, Shinsuke; Kawata, Yoshiki; Niki, Noboru; Ito, Masako; Nishitani, Hiromu; Moriyama, Noriyuki

    2010-03-01

    The patients of osteoporosis comprised about 11 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. The development of Multislice CT technology made it possible to perform the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer screening which may lead to its early detection. We develop an automatic extraction algorithm of vertebra, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the computer aided diagnosis of osteoporosis.

  5. Optimization of scanning parameters for multi-slice CT colonography: Experiments with synthetic and animal phantoms

    International Nuclear Information System (INIS)

    AIM: To determine the optimal collimation, pitch, tube current and reconstruction interval for multi-slice computed tomography (CT) colonography with regard to attaining satisfactory image quality while minimizing patient radiation dose. MATERIALS AND METHODS: Multi-slice CT was performed on plastic, excised pig colon and whole pig phantoms to determine optimal settings. Performance was judged by detection of simulated polyps and statistical measures of the image parameters. Fat and muscle conspicuity was measured from images of dual tube-current prone/supine patient data to derive a measure of tube current effects on tissue contrast. RESULTS: A collimation of 4x2.5 mm was sufficient for detection of polyps 4 mm and larger, provided that a reconstruction interval of 1.25 mm was used. A pitch of 1.5 allowed faster scanning and reduced radiation dose without resulting in a loss of important information, i.e. detection of small polyps, when compared with a pitch of 0.75. Tube current and proportional radiation dose could be lowered substantially without deleterious effects on the detection of the air-mucosal interface, however, increased image noise substantially reduced conspicuity of different tissues. CONCLUSION: An optimal image acquisition set-up of 4x2.5 mm collimation, reconstruction interval of 1.25 mm, pitch of 1.5 and dual prone/supine scan of 40/100 mA tube current is proposed for our institution for scanning symptomatic patients. Indications are that where CT colonography is used for colonic polyp screening in non-symptomatic patients, a 40 mA tube current could prove satisfactory for both scans

  6. Optimization of scanning parameters for multi-slice CT colonography: Experiments with synthetic and animal phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Embleton, K.V. E-mail: k.embleton@man.ac.uk; Nicholson, D.A.; Hufton, A.P.; Jackson, A

    2003-12-01

    AIM: To determine the optimal collimation, pitch, tube current and reconstruction interval for multi-slice computed tomography (CT) colonography with regard to attaining satisfactory image quality while minimizing patient radiation dose. MATERIALS AND METHODS: Multi-slice CT was performed on plastic, excised pig colon and whole pig phantoms to determine optimal settings. Performance was judged by detection of simulated polyps and statistical measures of the image parameters. Fat and muscle conspicuity was measured from images of dual tube-current prone/supine patient data to derive a measure of tube current effects on tissue contrast. RESULTS: A collimation of 4x2.5 mm was sufficient for detection of polyps 4 mm and larger, provided that a reconstruction interval of 1.25 mm was used. A pitch of 1.5 allowed faster scanning and reduced radiation dose without resulting in a loss of important information, i.e. detection of small polyps, when compared with a pitch of 0.75. Tube current and proportional radiation dose could be lowered substantially without deleterious effects on the detection of the air-mucosal interface, however, increased image noise substantially reduced conspicuity of different tissues. CONCLUSION: An optimal image acquisition set-up of 4x2.5 mm collimation, reconstruction interval of 1.25 mm, pitch of 1.5 and dual prone/supine scan of 40/100 mA tube current is proposed for our institution for scanning symptomatic patients. Indications are that where CT colonography is used for colonic polyp screening in non-symptomatic patients, a 40 mA tube current could prove satisfactory for both scans.

  7. Multi-slice spiral CT angiography: clinical application and the evaluation

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical application of multi-slice spiral CT angiography (MSCTA) in diagnosis of vascular diseases. Methods: Imaging materials of multi-slice spiral CT angiography of 73 cases were retrospectively analyzed, including 27 cases of intracranial vascular CTA, 8 of carotid CTA, 10 of pulmonary artery CTA, 6 of coronary artery CTA, 11 of aortic CTA, and 11 of low extremity artery CTA. After the raw data was reconstructed by overlapping slice-chickness, the axial images were uploaded to workstation for post data processing, and were then evaluated and reconstructed using 3D software including maximum intensity projection (MIP), shaded surface display (SSD), and volume rendering technique (VRT). Results: The blood vessels were successfully demonstrated in 71 cases out of 73. Abnormality was found in 63 cases out of 71. The intracranial CTA showed aneurysm in 7 cases, arteriovenous malformation in 5, carotid-cavernous fistula in 2, cerebral vascular occlusion in 2, astrocytoma in 2, and meningioma in 3. The carotid CTA revealed carotid stenosis in 4 cases, vertebral artery stenosis in 2 and a post-bracket implantation subclavian artery. In pulmonary artery CTA, pulmonary artery embolism and 5 cases of pulmonary artery involved with lung cancer were seen in 3 cases. In coronary artery CTA, coronary artery stenosis were shown in 3 cases. The aortic CTA demonstrated aortic dissection in 4, aortic stenosis calcification in 5, aortic aneurysm in 2, liver cancer in 2, renal artery stenosis in 2, and Budd-Chiari syndrome in 2. CTA of low extremity artery revealed external iliac artery occlusion in 2 and femoral artery stenosis in 5. Conclusion: By combining axial images with various reconstructed with adjacent organs can also be evaluated. MSCTA is of convenience, reliability, safety and noninvasive. (authors)

  8. Complex and magnitude-only preprocessing of 2D and 3D BOLD fMRI data at 7 T.

    Science.gov (United States)

    Barry, Robert L; Strother, Stephen C; Gore, John C

    2012-03-01

    A challenge to ultra high field functional magnetic resonance imaging is the predominance of noise associated with physiological processes unrelated to tasks of interest. This degradation in data quality may be partially reversed using a series of preprocessing algorithms designed to retrospectively estimate and remove the effects of these noise sources. However, such algorithms are routinely validated only in isolation, and thus consideration of their efficacies within realistic preprocessing pipelines and on different data sets is often overlooked. We investigate the application of eight possible combinations of three pseudo-complementary preprocessing algorithms - phase regression, Stockwell transform filtering, and retrospective image correction - to suppress physiological noise in 2D and 3D functional data at 7 T. The performance of each preprocessing pipeline was evaluated using data-driven metrics of reproducibility and prediction. The optimal preprocessing pipeline for both 2D and 3D functional data included phase regression, Stockwell transform filtering, and retrospective image correction. This result supports the hypothesis that a complex preprocessing pipeline is preferable to a magnitude-only pipeline, and suggests that functional magnetic resonance imaging studies should retain complex images and externally monitor subjects' respiratory and cardiac cycles so that these supplementary data may be used to retrospectively reduce noise and enhance overall data quality.

  9. Genetic association of glutathione peroxidase-1 with coronary artery calcification in type 2 diabetes: a case control study with multi-slice computed tomography

    Directory of Open Access Journals (Sweden)

    Fujimoto Kei

    2007-09-01

    Full Text Available Abstract Background Although oxidative stress by accumulation of reactive oxygen species (ROS in diabetes has become evident, it remains unclear what genes, involved in redox balance, would determine susceptibility for development of atherosclerosis in diabetes. This study evaluated the effect of genetic polymorphism of enzymes producing or responsible for reducing ROS on coronary artery calcification in type 2 diabetes (T2D. Methods An index for coronary-arteriosclerosis, coronary artery calcium score (CACS was evaluated in 91 T2D patients using a multi-slice computed tomography. Patients were genotyped for ROS-scavenging enzymes, Glutathione peroxidase-1 (GPx-1, Catalase, Mn-SOD, Cu/Zn-SOD, as well as SNPs of NADPH oxidase as ROS-promoting elements, genes related to onset of T2D (CAPN10, ADRB3, PPAR gamma, FATP4. Age, blood pressure, BMI, HbA1c, lipid and duration of diabetes were evaluated for a multivariate regression analysis. Results CACS with Pro/Leu genotype of the GPx-1 gene was significantly higher than in those with Pro/Pro (744 ± 1,291 vs. 245 ± 399, respectively, p = 0.006. In addition, genotype frequency of Pro/Leu in those with CACS ≥ 1000 was significantly higher than in those with CACS OR = 3.61, CI = 0.97–13.42; p = 0.045 when tested for deviation from Hardy-Weinberg's equilibrium. Multivariate regression analyses revealed that CACS significantly correlated with GPx-1 genotypes and age. Conclusion The presence of Pro197Leu substitution of the GPx-1 gene may play a crucial role in determining genetic susceptibility to coronary-arteriosclerosis in T2D. The mechanism may be associated with a decreased ability to scavenge ROS with the variant GPx-1.

  10. Multi-slice CT angiography by triple-phase enhancement in preoperative evaluation of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    XIAO Xi-gang; HAN Xue; SHAN Wei-dong; LI An-yuan

    2005-01-01

    Background Triple-phase enhancement of multi-slice computed tomography (MSCT) has markedly improved the diagnostic accuracy of hepatocellular carcinoma (HCC), and MSCT angiography (MSCTA) has been proved useful in detecting vascular anatomy noninvasively. This study aimed to explore the value of MSCTA by triple-phase enhancement in preoperative evaluation of HCC.Methods Fifty-six consecutive cases of primary HCC scheduled for resection were studied with MSCTA by triple-phase enhancement. The raw data images were processed on a workstation for multiplanar reconstruction (MPR) and three-dimensional (3D) reconstruction. The findings after processing of the data were compared with those after surgery or intraoperative sonography. Results The false positive rate of MSCTA by triple-phase enhancement was 10.1% and its false negative rate was 4.3% in detecting HCC. No significant difference was observed in MSCTA and surgery or intraoperative sonography in detecting vascular anatomy anomalies and pathologic variations, whereas significant difference was found in detecting bile duct invasion with MSCT compared to intraoperative sonography.Conclusions MSCTA by triple-phase enhancement not only improves the detection of HCC, but also provides valuable preoperative information about hepatic vascular architecture and parenchyma. MSCTA by triple-phase enhancement is worthy of application as a non-invasive method in preoperative evaluation of HCC.

  11. Multi-slice spiral CT appearances of pulmonary infections after liver transplantation

    International Nuclear Information System (INIS)

    Objective: To investigate multi-slice spiral CT (MSCT) appearances of pulmonary infections after liver transplantation (LT) and the diagnostic values of MSCT. Methods: The clinical data and CT images of liver transplantation receptors were reviewed from 2001 August to 2007 June, the types, onset time and CT appearances of pulmonary infections were analyzed retrospectively. Chi square test was used for the statistics. Results: The incidence rate of pulmonary infections after LT was 32.9% (174/529), the mortality was 9.8% (17/174), The incidence of bacterial infection, fungus or associated fungus infection, and virus or associated virus infection were 17.2% (n=91), 14.7% (n=78)and 2.3% (n=12)respectively, the pulmonary infections were seen in 64.7%, 28.7% and 6.6% of patients 1 to 30 days, 31-90 days and after 90 days following LT. Consolidations (n=32), ground-glass opacities (n= 22), nodules (n=10), reticular or lineal opacities (n=4) were found in 45 patients who had CT examination, there were no statistic differences in incidence rate between bacterial infection and mycotic infection (P>0.05). Conclusion: Pulmonary bacterial and fungus infection are common after LT, and often present as the mixed infection, the high risk period for infection is within 30 days after LT, thoracic CT scan is very important for characterizing the pulmonary infections after LT. (authors)

  12. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  13. The comparative study between multi-slice spiral CT angiography and color flow ultrasonography in hepatic and splenic trauma

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical value of multi-slice spiral CT angiography and color flow ultra- sonography in hepatic and splenic trauma. Methods Thirty-six cases of hepatic and splenic trauma were collected, the MSCT were analyzed and compared with that of color flow ultrasonography. Results: Seventeen cases were Hepatic trauma including nine cases of hepatic contusion, six cases of sub-envelope hematoma, two cases of both sub-envelope hematoma and hepatic contusion. Nineteen cases were splenic trauma including nine cases of splenic contusion, ten cases of sub-envelope hematoma. Conclusion: Multi-slice spiral CT angiography show hepatic and splenic trauma clearer than that of color flow ultrasonography, and can provide reliable basis for clinic diagnosis and therapy. (authors)

  14. Experimental Study of Multi-slice Spiral CT Perfusion Imaging in VX2 Soft-tissue Tumor of Rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jingfeng; WANG Renfa; WANG Min; LI Yonggang; YANG Haitao

    2006-01-01

    An experimental animal model of malignant soft-tissue tumor was established to investigate the applied value of multi-slice spiral CT perfusion imaging preliminarily. Ten New Zealand white rabbits which were implanted with VX2 tumor in either proximal thigh were subjected to CT plain scan and perfusion scan two weeks later respectively, then the original perfusion images were transmitted to AW4.0 Workstation. The functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were computed and analyzed. All the values of BF, BV and PS in VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those in the normal muscular tissues significantly. It was suggested that multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, and can give a quantitative assessment to angiogenesis and blood perfusion of soft-tissue tumors.

  15. The application of multi-slice CT and image post processing techniques in diagnosing of pulmonary embolism

    International Nuclear Information System (INIS)

    Objective: To characterize the pulmonary embolism (PE) on multi-slice CT pulmonary angiography, and to evaluate the role of multi-slice CT pulmonary angiography (CTPA) in the diagnosis of PE. Methods: Forty-five patients with PE confirmed by CTPA were retrospective analyzed. Images were reconstructed with maximal intensity projection (MIP), multiple planar reconstruction (MPR) and volume rendering technique (VRT). The display of pulmonary arteries and the ability of detecting embolisms were compared among the three different reconstruction techniques. Results: MPR images showed superiority to MIP and VRT images in displaying embolisms (P<0.05). Conclusion: MPR images were better than those of MIP and VRT, but provided poor three-dimensional information; MIP and VRT were more straightforward than MPR in displaying large branches of pulmonary artery. MPR combined with MIP and VRT could help to accurately establish PE diagnosis. (author)

  16. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta

    OpenAIRE

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2015-01-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient’s age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases. Brain bleeding volume i...

  17. Correction of misaligned slices in multi-slice cardiovascular magnetic resonance using slice-to-volume registration

    OpenAIRE

    Hawkes David J; Schnabel Julia A; Netsch Thomas; Pinder Richard J; Chandler Adam G; Hill Derek LG; Razavi Reza

    2008-01-01

    Abstract A popular technique to reduce respiratory motion for cardiovascular magnetic resonance is to perform a multi-slice acquisition in which a patient holds their breath multiple times during the scan. The feasibility of rigid slice-to-volume registration to correct for misalignments of slice stacks in such images due to differing breath-hold positions is explored. Experimental results indicate that slice-to-volume registration can compensate for the typical misalignments expected. Correc...

  18. Is correction necessary when clinically determining quantitative cerebral perfusion parameters from multi-slice dynamic susceptibility contrast MR studies?

    Science.gov (United States)

    Salluzzi, M.; Frayne, R.; Smith, M. R.

    2006-01-01

    Several groups have modified the standard singular value decomposition (SVD) algorithm to produce delay-insensitive cerebral blood flow (CBF) estimates from dynamic susceptibility contrast (DSC) perfusion studies. However, new dependences of CBF estimates on bolus arrival times and slice position in multi-slice studies have been recently recognized. These conflicting findings can be reconciled by accounting for several experimental and algorithmic factors. Using simulation and clinical studies, the non-simultaneous measurement of arterial and tissue concentration curves (relative slice position) in a multi-slice study is shown to affect time-related perfusion parameters, e.g. arterial-tissue-delay measurements. However, the current clinical impact of relative slice position on amplitude-related perfusion parameters, e.g. CBF, can be expected to be small unless any of the following conditions are present individually or in combination: (a) high concentration curve signal-to-noise ratios, (b) small tissue mean transit times, (c) narrow arterial input functions or (d) low temporal resolution of the DSC image sequence. Recent improvements in magnetic resonance (MR) technology can easily be expected to lead to scenarios where these effects become increasingly important sources of inaccuracy for all perfusion parameter estimates. We show that using Fourier interpolated (high temporal resolution) residue functions reduces the systematic error of the perfusion parameters obtained from multi-slice studies. Preliminary results associated with this paper were presented at ISMRM 12th Scientific Meeting and Exhibition, Kyoto, Japan, 2004.

  19. Assessment of the arteriovenous cerebrovascular system by multi-slice CT. A single-bolus, monophasic protocol

    Energy Technology Data Exchange (ETDEWEB)

    Klingebiel, R.; Zimmer, C. [Charite CM, Humboldt Univ., Berlin (Germany). Neuroradiology Section; Rogalla, P.; Kivelitz, D. [Charite CM, Humboldt Univ., Berlin (Germany). Dept. of Radiology; Bohner, G. [Charite CM, Humboldt Univ., Berlin (Germany). Neuroradiology Section; Goetze, R. [Charite CM, Humboldt Univ., Berlin (Germany). Dept. of Radiology; Lehmann, R. [Charite CM, Humboldt Univ., Berlin (Germany). Neuroradiology Section

    2001-11-01

    Purpose: We present a protocol for the non-invasive angiographic assessment of the arterial and venous cerebrovascular (CV) system by multi-slice CT. Material and Methods: Data acquisition was performed in a multi-slice CT scanner with a scan range from the carotid bifurcation to the vertex and manual scan start following i.v. administration of 120 ml iodinated contrast medium with a flow rate of 4 ml/s. This protocol was applied in 12 patients with symptoms of acute CV insufficiency. Results: In all patients, comprehensive imaging of the arteriovenous CV system was achieved including the common carotid bifurcation, the third segment of the major cerebral arteries, the dural sinus and the internal cerebral veins. Various CV pathologies, such as a territorial artery occlusion, a thrombotic obstruction of the internal carotid artery, an intracranial arteriovenous malformation and a sinus vein thrombosis, were successfully evaluated. Conclusion: Comprehensive assessment of the arteriovenous CV system is possible by the use of a single-bolus, monophasic multi-slice scan technique.

  20. Self-navigation with compressed sensing for 2D translational motion correction in free-breathing coronary MRI: a feasibility study.

    Directory of Open Access Journals (Sweden)

    Gabriele Bonanno

    Full Text Available PURPOSE: Respiratory motion correction remains a challenge in coronary magnetic resonance imaging (MRI and current techniques, such as navigator gating, suffer from sub-optimal scan efficiency and ease-of-use. To overcome these limitations, an image-based self-navigation technique is proposed that uses "sub-images" and compressed sensing (CS to obtain translational motion correction in 2D. The method was preliminarily implemented as a 2D technique and tested for feasibility for targeted coronary imaging. METHODS: During a 2D segmented radial k-space data acquisition, heavily undersampled sub-images were reconstructed from the readouts collected during each cardiac cycle. These sub-images may then be used for respiratory self-navigation. Alternatively, a CS reconstruction may be used to create these sub-images, so as to partially compensate for the heavy undersampling. Both approaches were quantitatively assessed using simulations and in vivo studies, and the resulting self-navigation strategies were then compared to conventional navigator gating. RESULTS: Sub-images reconstructed using CS showed a lower artifact level than sub-images reconstructed without CS. As a result, the final image quality was significantly better when using CS-assisted self-navigation as opposed to the non-CS approach. Moreover, while both self-navigation techniques led to a 69% scan time reduction (as compared to navigator gating, there was no significant difference in image quality between the CS-assisted self-navigation technique and conventional navigator gating, despite the significant decrease in scan time. CONCLUSIONS: CS-assisted self-navigation using 2D translational motion correction demonstrated feasibility of producing coronary MRA data with image quality comparable to that obtained with conventional navigator gating, and does so without the use of additional acquisitions or motion modeling, while still allowing for 100% scan efficiency and an improved ease

  1. Multi-slice CT in the planning of nephron-sparing interventions for renal cell carcinoma: prospective study correlated with histopathology; Multi-Slice-CT in der Planung der organerhaltenden Operation des Nierenzellkarzinoms: Prospektive histopathologisch korrelierte Studie

    Energy Technology Data Exchange (ETDEWEB)

    Hallscheidt, P. [Forschungsschwerpunkt Radiologische Diagnostik und Therapie des Deutschen Krebsforschungszentrums, Heidelberg (Germany); Abt. Radiodiagnostik der Radiologischen Klinik der Univ. Heidelberg (Germany); Schoenberg, S.; Zuna, I. [Forschungsschwerpunkt Radiologische Diagnostik und Therapie des Deutschen Krebsforschungszentrums, Heidelberg (Germany); Schenk, J.P. [Abt. Radiodiagnostik der Radiologischen Klinik der Univ. Heidelberg (Germany); Petirsch, O.; Riedasch, G. [Urologische Klinik und Poliklinik der Univ. Heidelberg (Germany)

    2002-07-01

    Objective: For nephron sparing surgery of renal cell carcinoma knowledge of the intrarenal extension of the tumor and infiltration of the renal pelvis, the intrarenal vessels and the perinephric fat is essential. This question is much more difficult to answer compared to the description of staging parameters. Aim of this study is to evaluate the value of multi-slice CT in planning of nephron sparing surgery. Material and Methods: In a prospective study 46 patients with suspected renal cell carcinoma underwent a triphasic multi-slice CT (unenhanced, delay 30 s and 120 s). A reconstructed slice thickness of 2 mm in the arterial and parenchymal phase was used to create volume rendered 3D-reconstructions. Based on the source data and multiplanar reconstructed images the extent of the renal cell carcinoma was assessed in terms of size, hilar infiltration, arterial and venous invasions, capsula infiltration and perirenal growth. The results of two blinded readers were correlated with histopathological staging and intraoperative findings. Results: 36 carcinomas were evaluated histopathologically. 10 patients showed no renal cell carcinoma histopatholologically. Multi-slice CT allowed us to diagnose the localization and size of all tumors correctly. Infiltration into perinephric fat was correctly excluded in 24/30 and 8/30 cases. Infiltration of the renal pelvis could be excluded in 17/24 and 12/24 cases. The state of venous infiltration could be correctly diagnosed in 29/30 and 27 /30 carcinomas. Conclusion: Despite of the high temporal and spatial resolution of multi-slice CT, which allows the delineation of intrarenal arteries as well as renal hilus and the veins, the evaluation of tumor infiltration into the renal hilus, the intrarenal vessels and the perinephric fat remains a diagnostic problem. For planning of nephron sparing surgery, a knowledge of the infiltration in these structures is essential. (orig.) [German] Ziel: Fuer die Planung der organerhaltenden

  2. Multi-slice spiral CT perfusion imaging of chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Objective: To evaluate the diagnostic value of multi-slice spiral CT (MSCT) perfusion imaging in chronic obstructive pulmonary disease (COPD). Methods: Twenty COPD patients and 20 volunteers underwent 8-row detector spiral CT (MSCT) perfusion imaging using cine scan mode with 5 mm slice thickness, 0.5 s rotation time and a total scan time of 45 s with 5 s intervals. 60 ml contrast agent (300 nag I/ml) were administered at a rate of 4 ml/s from the forearm superficial vein. The imaging data were transferred to a workstation. A time-density curve and pseudo-color map were generated automatically with GE CT perfusion 3 software, the blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were measured. Results: Time-density curve was flatter and the peak of the curve was obviously lower in COPD patients than the volunteers. The BF, BV, PS in COPD patients was (24.77±11.49) ml·min-1·100 g-1, (2.48±1.02) ml/100 g and (2.75±1.13) ml· min-1·100 g-1 respectively. In volunteers was (290.14±107.59) ml·min-1·100 g-1, (16.51 ± 5.98) ml/100 g, (8.80±3.03) ml·min-1·100 g-1 respectively. The MTT in COPD patients and volunteers was (10.58±4.85) s and (4.50±1.71)s respectively. The BF, BV and PS in COPD patients was lower than the volunteers, the MTY was higher (P<0.01). Conclusion: MSCT perfusion imaging is helpful for the diagnosis of COPD. (authors)

  3. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

    International Nuclear Information System (INIS)

    Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

  4. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xin, E-mail: Xin.Liang@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); College of Stomatology, Dalian Medical University (China); Jacobs, Reinhilde, E-mail: Reinhilde.Jacobs@uz.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Hassan, Bassam, E-mail: b.hassan@acta.n [Department of Oral Radiology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); Li Limin, E-mail: Limin.Li@uz.kuleuven.b [Department of Paediatric Dentistry and Special Dental Care, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Pauwels, Ruben, E-mail: Ruben.Pauwels@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Corpas, Livia, E-mail: LiviaCorpas@gmail.co [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Souza, Paulo Couto, E-mail: Paulo.CoutoSouza@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Martens, Wendy, E-mail: wendy.martens@uhasselt.b [Department of Basic Medical Sciences, Faculty of Medicine, University of Hasselt, Diepenbeek (Belgium); Shahbazian, Maryam, E-mail: Maryam.Shahbazian@student.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Alonso, Arie, E-mail: ariel.alonso@uhasselt.b [Department of Biostatistics and Statistical Bioinformatics, Universiteit Hasselt (Belgium)

    2010-08-15

    Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

  5. Multi-slice CT for visualization of pulmonary embolism using perfusion weighted color maps

    International Nuclear Information System (INIS)

    Purpose: The purpose of our preliminary study was to evaluate the feasibility of a new technique for the perfusion weighted color display of the density of lung parenchyma derived from multi-slice CT (MSCT) data sets of clinical routine examinations for visualization of pulmonary embolism (PE). Materials and Methods: Imaging of patients with suspected PE was performed on a commercially available MSCT (Somatom Volume Zoom; Siemens, Forchheim, Germany) after intravenous application of 120 cc of contrast-medium using a power injector. Scan parameters were 140 kV and 100 mAs, using a thin collimation of 4x1 mm and a table speed of 7 mm (pitch: 1.75). Derived from thin collimation axial slices (slice thicknesseff. 1.25 mm, reconstruction increment 0.8 mm), a new image processing technique was deployed. Based on these source images, an automated 3D-segmentation of the lungs was performed followed by threshold based extraction of major airways and vascular structures. The filtered volume data were color encordes and finally overlayed onto the original CT images. This color encoded display of parenchymal density distribution of the lungs was shown in axial, coronal and sagittal plans orientation. In four patients with excluded PE as well as in two patients with proven PE this new technique was performed. Results: In the four patients that were considered negative regarding PE on MSCT, lung densitometry showed a homogeneous distribution of color encoded densities without circumscribed decreased or increased areas, beside the usually present gravity-dependent gradient in ventro-dorsal direction. In the two patients with proven PE, low density values on perfusion weighted color maps were found distally to the occluded pulmonary arteries. (orig.)

  6. Multi-slice CT for visualization of acute pulmonary embolism: single breath-hold subtraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, J.E.; Mahnken, A.H.; Spuentrup, E.; Guenther, R.W. [Dept. of Diagnostic Radiology, Univ. of Technology, Aachen (Germany); Klotz, E.; Ditt, H. [Siemens Medical Solutions, Computed Tomography, Forchheim (Germany)

    2005-01-01

    Purpose: the purpose of our preliminary animal study was to evaluate the feasibility of a new subtraction technique for visualization of perfusion defects within the lung parenchyma in segmental and subsegmental pulmonary embolism (PE). Materials and methods: in three healthy pigs, PE were artificially induced by fresh human clot material. Within a single breath-hold, CT angiography (CTA) was performed on a 16-slice multi-slice CT scanner (SOMATOM Sensation 16; Siemens, Forchheim, Germany) before and after intravenous application of 80 mL of contrast-medium, followed by a saline chaser. Scan parameters were 120 kV and 100 mAs{sub eff.}, using a collimation of 16 x 1.5 mm and a table speed/rot. of 36 mm (pitch: 1.5; rotation time: 0.5 s). A new 3D subtraction technique was developed, which is based on automated segmentation, non-linear spatial filtering and non-rigid registration. Data were analysed using a color-encoded ''compound view'' of parenchymal enhancement and CTA information displayed in axial, coronal and sagittal orientation. Results: subtraction was technically feasible in all three data sets. The mean scan time for each series was 4.7 s, interscan delay was 14.7 s, respectively. Therefore, an average breath-hold of approximately 24 s was required for the overall scanning procedure. Downstream of occluded segmental and subsegmental arteries, perfusion defects were clearly assessable, showing lower or missing enhancement compared to normally perfused lung parenchyma. In all pigs, additional peripheral areas with triangular shaped perfusion defects were delineated, considered typical for PE. Conclusions: our initial results from the animal model studied slow that perfusion imaging of PE is feasible within a single breath-hold. It allows a comprehensive assessment of perfusion deficits as the direct proof of a pulmonary embolus, can be combined with an indirect visual quantification of the density changes in the adjacent lung tissue

  7. Multi-slice computed tomography for diagnosis of combined thoracoabdominal injury

    Institute of Scientific and Technical Information of China (English)

    Jun Liu; Weidong Yue; Dingyuan Du

    2015-01-01

    Purpose:To investigate the diagnostic value of multi-slice computed tomography (MSCT) for combined thoracoabdominal injury.Methods:A retrospective study was conducted to analyze the clinical data and MSCT images of 68 patients who sustained a combined thoracoabdominal injury associated with diaphragm rupture,and 18 patients without diaphragm rupture.All the patients were admitted and treated in the Chongqing Emergency Medical Center (a level Ⅰ trauma center) between July 2005 and February 2014.There were 71 males and 15 females with a mean age of 39.1 years (range 13-88 years).Among the 86 patients,40 patients suffered a penetrating injury,46 suffered a blunt injury as a result of road traffic accident in 21 cases,fall from a height in 16,and crushing injury in 9.The Mscr images were retrospectively reviewed by two radiologists.The results of CT diagnosis were compared with surgical findings and/or follow-up results.Results:Among the 86 cases,diaphragm discontinuity was found in 29 cases,segmental nonrecognition of the diaphragm in 14,diaphragmatic hernia in 21,collar sign in 14,dependent viscera sign in 18,elevated abdominal organs in 21,bowel wall thickening and/or hematoma in 6,and pneumoperitoneum in 8.CT diagnostic accuracy for diaphragm rupture was 88.4% in the right side and 90.7% in the left side.cT diagnostic accuracy for hemopneumothorax,pulmonary contusion,mediastinal hemorrhage,kidney and adrenal gland injuries was 100%,while for liver,spleen and pancreas injuries was 96.5%,96.5%,94.2% respectively.Conclusion:To reach an early diagnosis of combined thoracoabdominal injury,surgeons and radiologists should be familiar with all kinds of images which might show signs of diaphragm rupture,such as diaphragm discontinuity,segmental nonrecognition of the diaphragm,dangling diaphragm sign,diaphragm herniation,collar sign,dependent viscera sign,and elevated abdominal organs.

  8. The value of multi-slice spiral CT in the preoperative assessment of living renal donor

    International Nuclear Information System (INIS)

    Objective: The purpose of this study is to assess the value of multi-slice spiral CT (MSCT) in the preoperative evaluation of living renal donor as a all in one modality. Methods: Thirty-six potential living renal donors underwent the examination using a GE light VCT scanner. Informed consent was obtained from all participants. The plain scan, early arterial phase, late arterial phase and excretory phase scans are performed in the former 25 donors (injection rate 5 rolls, total volume 100 mi, tube tension 120 kV). While in the later 11 donors (2 ml/s 40 ml +4 ml/s 60 ml), the scanning protocol included the plain scan ( 100 kV), vascular phase and excretory phase scans (100 kV). The excretory phase data were used in the reconstruction of CT urography in both groups. All images were reviewed by one radiologist and one urologist, and the findings of MSCT were compared with intraoperative findings for 33 donors, to investigate the utilities of MSCT in assessing renal vascularity, urinary tract and lesions of renal parenchyma. When discrepancies are found between the two reviewers, consensus was obtained via discussion. Au data was statiscally processed with SPSS for Windows. Results: MSCT angiography is in accordance with intraoperative findings in demonstrating the anatomy of renal arteries and renal vein trunk, accesary arteries, early branching of renal artery. The findings from CTA are highly in accordance with the intraoperative findings, which facilitate intraoperative ligation and reduce relevant complications. CTU demonstrates the anatomy of urinary, tract in good agreement with the intraoperative findings. The image quality of 3D vascularity and CTU between the two groups, scored 4.4 ± 1.2 vs 4.2 ± 1.3 and 4.6 ± 0.8 vs 4.4 ± 0.9 respectively, no statistical between-groups difference was found (Z=-0.89, -0.47, P>0.05). Conclusion: MSCT multiphase scanning combined with CTA and CTU play a important role in the evaluation of living renal donor, which

  9. Multi-slice and dual-source CT in cardiac imaging. Principles - protocols - indications - outlook. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Ohnesorge, B.M. [Siemens Medical Solutions Group China, Beijing (China); Flohr, T.G. [Siemens Medical Solutions, Forchheim (Germany). Div. CT Physics and Applications Development; Becker, C.R.; Reiser, M.F. [Muenchen Univ. Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Knez, A [Muenchen Univ. Klinikum Grosshadern (Germany). Section Head Imaging

    2007-07-01

    Cardiac diseases, and in particular coronary artery disease, are the leading cause of death and morbidity in industrialized countries. The development of non-invasive imaging techniques for the heart and the coronary arteries has been considered a key element in improving patient care. A breakthrough in cardiac imaging using CT occurred in 1998, with the introduction of multi-slice computed tomography (CT). Since then, amazing advances in performance have taken place with scanners that acquire up to 64 slices per rotation. This book discusses the state-of-the-art developments in multi-slice CT for cardiac imaging as well as those that can be anticipated in the future. It serves as a comprehensive work that covers all aspects of this technology, from the technical fundamentals and image evaluation all the way to clinical indications and protocol recommendations. This fully reworked second edition draws on the most recent clinical experience obtained with 16- and 64-slice CT scanners by world-leading experts from Europe and the United States. It also includes 'hands-on' experience in the form of 10 representative clinical case studies, which are included on the accompanying CD. As a further highlight, the latest results of the very recently introduced dual-source CT, which may soon represent the CT technology of choice for cardiac applications, are presented. This book will not only convince the reader that multi-slice cardiac CT has arrived in clinical practice, it will also make a significant contribution to the education of radiologists, cardiologists, technologists, and physicists-whether newcomers, experienced users, or researchers. (orig.)

  10. Assessment of left atrial volume and mechanical function in ischemic heart disease: a multi slice computed tomography study

    DEFF Research Database (Denmark)

    Kühl, Jørgen Tobias; Kofoed, Klaus F; Møller, Jacob E;

    2010-01-01

    and mechanical function with Multi Slice Computed Tomography (MSCT) in patients with ischemic heart disease. Furthermore, the LA and left ventricular (LV) function was evaluated in relation to signs of clinical heart failure. METHODS AND RESULTS: MSCT was performed in 40 patients with sinus rhythm and ischemic...... heart disease. We enrolled 20 patients with reduced LV ejection fraction (LVEF=45%) and 20 with preserved LVEF (>45%). LA volumes, reservoir, channel and pump function were measured. Interobserver variation for LA volume measures was 1.5% (SD: 6.6%). In patients with reduced LVEF, LA volumes were larger...

  11. Evaluation of Blood Flow Patterns of Solitary Pulmonary Nodules with Dynamic Multi-slice Spiral Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    LIShenjiang; XIAOXiangsheng; LIHuimin; LIUShiyuan; LIChengzhou; ZHANGChenshi; TAOZhiwei; YANGChunshan

    2004-01-01

    To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT) for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and differentiating solitary pulmonary nodules (SPNs). Methods: 37 patients with SPNs (diameter0.01). SFN-to-aorta ratio in inflammatory SPNs (20.78%±4.14) was significantly higher than that in benign (2.00%±2.26) and malig nant (14.63%±6.22) SPNs (P0.01). Conclusion: MSCT provides quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and is applicable diagnostic method for differentiating SPNs.

  12. Hepatic focal nodular hyperplasia in children: Imaging features on multi-slice computed tomography

    Institute of Scientific and Technical Information of China (English)

    Qing-Yu Liu; Wei-Dong Zhang; Dong-Ming Lai; Ying Ou-yang; Ming Gao; Xiao-Feng Lin

    2012-01-01

    AIM:To retrospectively analyze the imaging features of hepatic focal nodular hyperplasia (FNH) in children on dynamic contrast-enhanced multi-slice computed tomography (MSCT) and computed tomography angiography (CTA) images.METHODS:From September 1999 to April 2012,a total of 218 cases of hepatic FNH were confirmed by either surgical resection or biopsy in the Sun Yat-sen Memorial Hospital of Sun Yat-sen University and the Cancer center of Sun Yat-sen University,including 12 cases (5.5%) of FNH in children (age ≤ 18 years old).All the 12 pediatric patients underwent MSCT.We retrospectively analyzed the imaging features of FNH lesions,including the number,location,size,margin,density of FNH demonstrated on pre-contrast and contrastenhanced computed tomography (CT) scanning,central scar,fibrous sepia,pseudocapsule,the morphology of the feeding arteries and the presence of draining vessels (portal vein or hepatic vein).RESULTS:All the 12 pediatric cases of FNH had solitary lesion.The maximum diameter of the lesions was 4.0-12.9 cm,with an average diameter of 5.5 ± 2.5 cm.The majority of the FNH lesions (10/12,83.3%) had well-defined margins.Central scar (10/12,83.3%) and fibrous septa (11/12,91.7%) were commonly found in children with FNH.Central scar was either isodense (n =7) or hypodense (n =3) on pre-contrast CT images and showed progressive enhancement in 8 cases in the equilibrium phase.Fibrous septa were linear hypodense areas in the arterial phase and isodense in the portal and equilibrium phases.Pseudocapsule was very rare (1/12,8.3%) in pediatric FNH.With the exception of central scars and fibrous septa within the lesions,all 12 cases of pediatric FNH were homogenously enhanced on the contrast-enhanced CT images,significantly hyperdense in the arterial phase (12/12,100.0%),and isodense in the portal venous phase (7/12,58.3%) and equilibrium phase (11/12,91.7%).Central feeding arteries inside the tumors were observed on CTA images for all

  13. Qualitative and quantitative assessment of wrist MRI at 3.0T - Comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jee Young [Dept. of Radiology, Chungang Univ. Hospital, School of Medicine, Chungang Univ. (Korea, Republic of); Yoon, Young Cheol [Dept. of Radiology, Samsung Medical Center, School of Medicine, Sungkyunkwan Univ. (Korea, Republic of)], e-mail: ycyoon@skku.edu; Jung, Jin Young [Dept. of Radiology, Saint Paul' s Hospital, The Catholic Univ. (Korea, Republic of); Choe, Bong-Keun [Dept. of Preventive Medicine, School of Medicine, Kyung Hee Univ., Seoul (Korea, Republic of)

    2013-04-15

    Background: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated. Purpose: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T. Material and Methods: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed. Results: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial. Conclusion: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for

  14. Interpolated Compressed Sensing for 2D Multiple Slice Fast MR Imaging

    OpenAIRE

    Yong Pang; Xiaoliang Zhang

    2013-01-01

    Sparse MRI has been introduced to reduce the acquisition time and raw data size by undersampling the k-space data. However, the image quality, particularly the contrast to noise ratio (CNR), decreases with the undersampling rate. In this work, we proposed an interpolated Compressed Sensing (iCS) method to further enhance the imaging speed or reduce data size without significant sacrifice of image quality and CNR for multi-slice two-dimensional sparse MR imaging in humans. This method utilizes...

  15. The relationship between the appearances of colorectal tumor in multi-slices spiral CT and the pathologic histology

    International Nuclear Information System (INIS)

    Objective: To evaluate the relationship between the appearances of colorectal tumor in multi-slices spiral-CT and the pathologic histology. Methods: 92 patients with colorectal tumor, who had undergone preoperative MSCT examination, were reviewed retrospectively. The detail information of their appearances in multi-slices spiral CT, the pathologic histology, lymph node metastasis and pericolonic infiltration were analyzed. All the patients were cleaned intestine tracts and were given an enema (2.5% iso-osmia mannitol solution) before undergoing plain scan and portal venous phase enhanced scan with 64-slices spiral-CT Patients were classified into five types according to pathology: well-differentiated, moderately differentiated, poorly differentiated adencarcinoma, mucinous adenocarcinoma and signet-ring cell carcinoma. And then each group's CT features in plain and enhanced scan, lymph node metastasis, remote metastasis and infiltration were analyzed. Eventually, they were categorized into three groups based on their pathology of statistics. The first group was the poorly differentiated adencarcinoma, the second mucinous adenocarcinoma and signet-ring cell carcinoma, and the third well-differentiated and moderately differentiated adenocarcinoma. Results Of all these cases, 74 cases were of moderately differentiated adencarcinoma, and 4 cases of well differentiated adencarcinoma, 6 cases of poorly differentiated adencarcinoma, 7 cases of mucinous adenocarcinoma, only 1 case was of signet-ring cell carcinoma In first group, the average CT value in plain scanning was 41.00±6.39Hu, and 74.83±9.48Hu after contrast enhancement. In second group, the CT value was 39.00±3.46Hu and 73.66±11.66Hu respectively. In third group, the CT value was 44.83±5.95Hu and 85.05±10.47Hu respectively. Statistically significant difference existed comparing the first group with those of the other two groups (p<0.05). Each group's ratio of lymph node metastasis was 50% in first group, 37

  16. Dynamic enhanced multi-slice spiral CT in evaluation of blood flow patterns of solitary pulmonary nodules with enhancement

    Institute of Scientific and Technical Information of China (English)

    LI Shenjiang; XIAO Xiangsheng; LIU Shiyuan; LI Huimin; LI Chengzhou; ZHANG Chenshi; TAO Zhiwei; YANG Chunshan

    2004-01-01

    Objective To investigate the methods of dynamic enhanced multi-slice spiral CT in evaluation of blood flow patterns of solitary pulmonary nodules (SPNs) with enhancement. Methods Seventy eight patients with SPNs (≤4 cm) with strong enhancement underwent dynamic multi-slice spiral CT (Marconi Mx8000) scan before and after contrast enhancement by injecting contrast material with a rate of 4 mL/s. For the 40 patients in protocol one, one scan was obtained every 2 seconds during 15-45 and 75- 105 seconds after injection, while for the 38 patients in protocol two, one scan was obtained every 2 seconds during 11-41 and 71-101 seconds. For all the patients, one scan was obtained every 30 seconds during 2 9 minutes. The section thickness was 2.5 mm for lesions ≤3 cm and 5 mm for lesions >3 cm. Standard algorithm was used in the image reconstruction. Precontrast and postcontrast attenuation on every scan was recorded. The perfusion,peak height, ratio of peak height of the SPN to that of the aorta and mean transit time were calculated. Results The peak height, perfusion, ratio of peak height of the SPN to that of the aorta and mean transit time in malignant SPNs were 34. 85 Hu±10.87 Hu, 30. 37 ml/(min· 100 g)±11. 14 ml/(min · 100 g), 13. 78%±3.96%, 14.19 s±6.19 s respectively in protocol one, while those in protocol two were 36.62 Hu±10.75 Hu,30.01 ml/(min · 100 g)±8.10 ml/(min · 100 g), 14.70 %±4.71%, 13.91 s±4.82 s respectively. No statistically significant differences were found between the peak height (t = 0. 673, P = 0. 503), perfusion (t =0.152, P=0.880), ratio of peak height of the SPN to that of the aorta (t 0.861, P 0.393) and mean transit time (t= 0. 199, P=0. 843) in malignant SPNs measured in protocol one and those measured in protocol two. All mean transit time in protocol two (36/36) were obtained, but only part of them (25/32) were ob tained in protocol one. Conclusion Dynamic enhanced multi-slice spiral CT is a non-invasive method for

  17. MRI and 2D-CSI MR spectroscopy of the brain in the evaluation of patients with acute onset of neuropsychiatric systemic lupus erythematosus

    International Nuclear Information System (INIS)

    MRI and 2D-CSI spectroscopy were performed in eight patients with systemic lupus erythematosus who presented with acute onset of neuropsychiatric lupus (NP-SLE), and in seven normal controls to evaluate for differences in metabolic peaks and metabolic ratios between the two groups. Also, the interval change of the metabolic peaks and their ratios during treatment in the NP-SLE patient group was evaluated. Metabolic peaks for N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and lactate/lipids (LL) and their ratios (NAA/Cr, NAA/Cho, Cho/Cr, LL/Cr) were determined at initial presentation and 3 and 6 months later. In the eight lupus patients compared to the seven normal controls, NAA/Cho ratios were lower at presentation (1.05 vs 1.25; p = 0.004) and decreased even further at the three month follow-up (0.92 vs 1.05; p = 0.008). In contrast, both Cho/Cr (1.42 vs 1.26; p = 0.026) and LL/Cr ratios (0.26 vs 0.19; p = 0.002) were higher in the lupus patients at presentation compared to the controls and did not significantly change at three and six months follow-up. The NAA/Cr ratios were lower in the lupus patients compared to the controls at presentation but the difference was not statistically significant. However, the mean NAA/Cr significantly decreased from the initial examination to the three month follow-up (1.42 vs 1.32; p = 0.049) but did not significantly change from the three to the six month follow-up examinations. The NAA/Cr, Cho/Cr, and NAA/Cho ratios varied significantly (p < 0.05, p < 0.05, p < 0.05, respectively) between the 17 different locations measured in the brain in all eight patients and seven controls. Both the NAA/Cr ratios and the Cho/Cr ratios were also significantly lower in the gray matter than in the white matter (p < 0.0001) in both patients and controls, whereas the LL/Cr and NAA/Cho ratios were not significantly different. In conclusion, 2D-CSI MR spectroscopy may be useful in the early detection of metabolic CNS changes in NP

  18. MRI and 2D-CSI MR spectroscopy of the brain in the evaluation of patients with acute onset of neuropsychiatric systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Sundgren, P.C.; Jennings, J.; Gebarski, S.; Pang, Y.; Maly, P. [University of Michigan Health Systems, Department of Radiology, Ann Arbor, MI (United States); Attwood, J.T.; McCune, W.J. [University of Michigan Health Systems, Department of and Rheumatology, Ann Arbor, MI (United States); Nan, B. [University of Michigan Health Systems, School of Public Health, Ann Arbor, MI (United States)

    2005-08-01

    MRI and 2D-CSI spectroscopy were performed in eight patients with systemic lupus erythematosus who presented with acute onset of neuropsychiatric lupus (NP-SLE), and in seven normal controls to evaluate for differences in metabolic peaks and metabolic ratios between the two groups. Also, the interval change of the metabolic peaks and their ratios during treatment in the NP-SLE patient group was evaluated. Metabolic peaks for N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and lactate/lipids (LL) and their ratios (NAA/Cr, NAA/Cho, Cho/Cr, LL/Cr) were determined at initial presentation and 3 and 6 months later. In the eight lupus patients compared to the seven normal controls, NAA/Cho ratios were lower at presentation (1.05 vs 1.25; p = 0.004) and decreased even further at the three month follow-up (0.92 vs 1.05; p = 0.008). In contrast, both Cho/Cr (1.42 vs 1.26; p = 0.026) and LL/Cr ratios (0.26 vs 0.19; p = 0.002) were higher in the lupus patients at presentation compared to the controls and did not significantly change at three and six months follow-up. The NAA/Cr ratios were lower in the lupus patients compared to the controls at presentation but the difference was not statistically significant. However, the mean NAA/Cr significantly decreased from the initial examination to the three month follow-up (1.42 vs 1.32; p = 0.049) but did not significantly change from the three to the six month follow-up examinations. The NAA/Cr, Cho/Cr, and NAA/Cho ratios varied significantly (p < 0.05, p < 0.05, p < 0.05, respectively) between the 17 different locations measured in the brain in all eight patients and seven controls. Both the NAA/Cr ratios and the Cho/Cr ratios were also significantly lower in the gray matter than in the white matter (p < 0.0001) in both patients and controls, whereas the LL/Cr and NAA/Cho ratios were not significantly different. In conclusion, 2D-CSI MR spectroscopy may be useful in the early detection of metabolic CNS changes in NP

  19. An improved spatial tracking algorithm applied to coronary veins into Cardiac Multi-Slice Computed Tomography volume

    Science.gov (United States)

    Garcia, Marie-Paule; Toumoulin, Christine; Garreau, Mireille; Kulik, Carine; Boulmier, Dominique; Leclercq, Christophe

    2008-01-01

    This paper describes an enhanced vessel tracking algorithm. The method specifity relies on the coronary venous tree extraction through Cardiac Multi-Slice Computed Tomography (MSCT). Indeed, contrast inhomogeneities are a major issue in the data sets that necessit a robust tracking procedure. The method is based on an existing moment-based algorithm designed for coronary arteries into MSCT volume. In order to extract the whole path of interest, improvements concerning progression strategy are proposed. Furthermore, the original procedure is combinated with an automatic recentring method based on ray casting. This enhanced method has been tested on three data sets. According to the first results, the method appears robust to curvatures, contrast inhomogeneities and low contrast blood veins. PMID:19163593

  20. Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

    Directory of Open Access Journals (Sweden)

    Shu-qing ZHOU

    2011-06-01

    Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

  1. 心脏二尖瓣病变的多层螺旋CT诊断%Multi-slice Spiral Computed Tomography in the Diagnosis of Mitral Valve Diseases

    Institute of Scientific and Technical Information of China (English)

    吴丽娜; 鹿强

    2016-01-01

    本文从心脏二尖瓣多层螺旋CT研究方法、正常解剖的螺旋CT表现、二尖瓣血流动力特征及心肌改变、二尖瓣膜病螺旋CT表现四个方面分析了心脏二尖瓣病变螺旋CT的诊断价值,并简要介绍了MDCT/EBCT、MRI与US技术在心脏二尖瓣病变诊断方面的优缺点及展望。%This paper analyzed the clinical value of the multi-slice computed tomography in the diagnosis of heart mitral valve diseases in four aspects: the research method of multi-slice CT in heart mitral valve diseases, the manifestations of multi-slice CT in the normal anatomy, the characteristics of hemodynamics and myocardial changes in mitral valve diseases, and the manifestations of multi-slice CT in mitral valve diseases. The paper also brielfy introduced the pros and cons as well as the development prospect of the application of multi-detector computed tomography/electron-beam computed tomography and magnetic resonance imaging and ultrasonography in the diagnosis of mitral valve diseases.

  2. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    NARCIS (Netherlands)

    X. Liang; I. Lambrichts; Y. Sun; K. Denis; B. Hassan; L. Li; R. Pauwels; R. Jacobs

    2010-01-01

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G,

  3. Role of multi-slice CT coronary angiography in evaluating the different patterns of coronary artery disease in patients with unstable angina

    Directory of Open Access Journals (Sweden)

    Gamal Eldine M. Niazi

    2015-09-01

    Conclusion: Non-invasive multi-slice CT coronary angiography is a reliable technique of high ability to detect coronary artery disease and estimate the degree of obstruction, number of affected arteries and the pattern of their affection and can be used in workup in patients with unstable angina.

  4. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT) Part I. On subjective image quality

    NARCIS (Netherlands)

    X. Liang; R. Jacobs; B. Hassan; L.M. Li; R. Pauwels; L. Corpas; P.C. Souza; W. Martens; A. Alonso; I. Lambrichts

    2010-01-01

    Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileo

  5. MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jisook; Cha, Jang Gyu [Soonchunhyang University Bucheon Hospital, Department of Radiology, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Young Koo [Soonchunhyang University Bucheon Hospital, Department of Orthopedics, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Bo Ra [Soonchunhyang University Bucheon Hospital, Department of Biomedical Statistics, Wonmi-gu, Bucheon-si (Korea, Republic of); Jeon, Chan Hong [Soonchunhyang University Bucheon Hospital, Division of Rheumatology, Department of Internal Medicine, Wonmi-gu, Bucheon-si (Korea, Republic of)

    2016-07-15

    To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs. (orig.)

  6. Preliminary Reports on the Accuracy of Coronary CT-Angiography Using 64-slice Multi-slice Spiral CT (MSCT in Iran

    Directory of Open Access Journals (Sweden)

    "A. Arjmand Shabestari

    2005-08-01

    Full Text Available Introduction & Background: Coronary artery disease (CAD is the leading cause of death in many western countries. Its prevalence and incidence among Irani-ans particularly in the urban areas are increasing. Ac-cording to the newest Tehran annual mortality re-port, the most common cause of death in Tehran is cardiovascular disease. Diagnostic gold standard in CAD is fluoroscopic coronary angiography (FCA us-ing catheterization. Nevertheless, it is an invasive method and in recent years, some non-invasive or less-invasive imaging modalities such as MRI and CT scans have been used to investigate CAD. One of the most attractive new methods in this regard is Coro-nary CT-Angiography (CCTA, which has gained considerable attention. Multi-slice spiral CT (MSCT scanners with simultaneous acquisition of multiple (up to 64 slices in less than half a second of gantry rotation time (in our study, 0.33 second, have be-come available, resulting in minimally-invasive coro-nary artery imaging. The purpose of this study is to determine the diagnostic accuracy of a new 64-slice MSCT scanner in the diagnosis of coronary artery and/or bypass grafts occlusion or hemodynamically significant stenosis. Parients & Methods: This investigation is underway in patients undergoing elective FCA. A 64-channel per rotation MSCT scanner (Somatom Sensation 64, Siemens Medical Systems, Forchheim, Germany, with 0.6 mm collimation, 0.33 second gantry rotation time and 120 KVp was used to perform CCTA. Ap-proximately 70-90 mL of a nonionic contrast medium was injected intravenously. All coronary artery seg-ments, according to American Heart Association (AHA classification & nomenclature system were analyzed. Patients who had undergone previous coronary artery bypass grafts (CABGs, or used coro-nary stents were enrolled in the study, as well. MSCT scans were carried out within 10 days of catheteriza-tion, and the most dramatically stenotic lesions were analyzed in CCTA by a semi

  7. Cerebral gliomas: prospective comparison of multivoxel 2D chemical-shift imaging proton MR spectroscopy, echoplanar perfusion and diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Developments in MRI have made it possible to use diffusion-weighted MRI, perfusion MRI and proton MR spectroscopy (MRS) to study lesions in the brain. We evaluated whether these techniques provide useful, complementary information for grading gliomas, in comparison with conventional MRI. We studied 17 patients with histologically verified gliomas, adding multivoxel proton MRS, echoplanar diffusion and perfusion MRI the a routine MRI examination. The maximum relative cerebral blood volume (CBV), minimum apparent diffusion coefficient (ADC) and metabolic peak area ratios in proton MRS were calculated in solid parts of tumours on the same slice from each imaging data set. The mean minimum ADC of the 13 high-grade gliomas (0.92±0.27 x 10-3 mm2/s) was lower than that of the four low-grade gliomas (1.28±0.15 x 10-3 mm2/s) (P<0.05). Means of maximum choline (Cho)/N-acetylaspartate (NAA), Cho/creatine (Cr), Cho/Cr in normal brain (Cr-n) and minimum NAA/Cr ratios were 5.90±2.62, 4.73±2.22, 2.66±0.68 and 0.40±0.06, respectively, in the high-grade gliomas, and 1.65±1.37, 1.84±1.20, 1.61±1.29 and 1.65±1.61, respectively, in the low-grade gliomas. Significant differences were found on spectroscopy between the high- and low-grade gliomas (P<0.05). Mean maximum relative CBV in the high-grade gliomas (6.10±3.98) was higher than in the low-grade gliomas (1.74±0.57) (P<0.05). Echoplanar diffusion, perfusion MRI and multivoxel proton MRS can offer diagnostic information, not available with conventional MRI, in the assessment of glioma grade. (orig.)

  8. Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography

    DEFF Research Database (Denmark)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas;

    2012-01-01

    dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty......-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir...... between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P ...

  9. Measurements of patient chest dose for multi-slice X-ray CT examinations using PIN photodiode dosimeters

    International Nuclear Information System (INIS)

    Organ and tissue doses delivered during chest CT examinations were measured as a function of scanning parameters including tube current, slice thickness, and pitch of the multi-slice CT scanner. Measurements were carried out by using a chest dosimetry phantom that incorporated lung and vertebra models, and by putting PIN photodiode dosimeters into the phantom at sites of the esophagus or stomach, lung, bone marrow, and skin. Absorbed doses at each site in the phantom measured for a constant scan area indicated that these values could be precisely calculated from the value obtained at any scanning parameter by using inverse proportionality of dose to pitch and the data of x-ray intensity as a function of tube current and slice thickness measured for the CT scanner used. Relative dose at each site was found to be constant regardless of the scanning parameters, indicating that the dose value at each site could be calculated from that measured at only one point in the phantom. Effective doses and effective dose equivalents were estimated from organ or tissue doses for chest CT examinations, and were found to be 1.5 to 3 times larger than the average values of effective dose equivalent appearing in the literature. (author)

  10. Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

  11. Correlation of coronary artery stenosis evaluation with left heart structure and function by multi-slice computed tomography.

    Science.gov (United States)

    Song, L N; Cao, A D; Niu, Y J; Liu, N

    2014-08-07

    The aim of this study was to determine the impact of multi-slice computed tomography (MSCT) evaluation of coronary artery stenosis on left heart structure and systolic function. Coronary artery CT angiography was performed in 200 patients diagnosed with coronary heart disease, and then according to the AHA coronary artery 17-segment fractionation method, the Gensini score (GS) was determined for every narrow segment, and one-stop assessment of the correlation between left heart structure and function was performed. After the grouping of GS quartiles from low to high, there were differences between different patients with regard to LVDD, LADD, LVEDV, LVESV, MM, LVEF, and FS, while no difference in SV and CO. GS showed linear negative correlation with LVEF and FS, and linear positive correlation with LVDD, LADD, LVEDV, LVESV, and MM, while no correlation with SV and CO. That is, GS of coronary artery stenosis was negatively correlated with left ventricular systolic function and positively correlated with myocardial mass. The narrower the coronary artery, the worse the cardiac function and the higher the myocardial hypertrophy. Coronary artery stenosis was one of the important causes of the decrease in left ventricular systolic function and cardiac remodeling.

  12. Investigation of an image artefact induced by projection noise inhomogeneity in multi-slice helical computed tomography

    Science.gov (United States)

    Hsieh, Jiang

    2003-02-01

    The introduction of multi-slice helical computed tomography has fundamentally changed the way radiologists view CT images. Increasing numbers of clinical cases are examined with advanced visualization tools, such as maximum intensity projection, multi-planar reformation and volume rendering. It has been discovered that new image artefacts, which do not appear in the traditional two-dimensional reconstructed images, become visible in images generated by these new tools. In this paper, we investigate the causes of one such artefact, the Venetian blind artefact, which appears as bright-and-dark bands superimposed on three-dimensional images. We demonstrate that such an artefact is caused by the periodical noise variation in the reconstructed images. The image noise variation is, in turn, caused by the interaction of the noise inhomogeneity in the projections with the helical weights. An analytical formula is developed that accurately predicts the presence of such artefacts. Based on our analysis, several approaches are proposed for the artefact reduction or elimination.

  13. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta.

    Science.gov (United States)

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2016-04-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient's age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases.  Brain bleeding volume is the dependent variable, obtained through slice thickness of 5 mm and ABC/2 method with software measurement in MSCT Scan device. The independent variable of this study is the patient's age. The result of the study was the average brain's bleeding volume of 21.76 ml ± 2.48 ml (range of 1.04 ml to 94.73 ml).The slice thickness using ABC/2 method, has a significant correlation with brain's bleeding volume in MSCT Scan examination, with correlation coefficient value r of 0.79. Brain bleeding volume in patients who have ages lower than 50 years and more or equal to 50 years were (18.93 ± 3.26) ml and (23.53 ± 3.47) ml respectively. There is no correlation between age and brain's bleeding volume in haemorrhagic stroke cases, with p value of 0.18, r = 0.19. PMID:26573030

  14. Radiological patterns of primary graft dysfunction after lung transplantation evaluated by 64-multi-slice computed tomography: a descriptive study.

    Science.gov (United States)

    Belmaati, Esther Okeke; Steffensen, Ida; Jensen, Claus; Kofoed, Klaus F; Mortensen, Jann; Nielsen, Michael B; Iversen, Martin

    2012-06-01

    We evaluated the diagnostic value of high-resolution computed tomography (HRCT) images generated from 64 detector multi-slice CT scanners (HRCT(64-MSCT) imaging) in relation to primary graft dysfunction (PGD) after lung-transplantation (LUTX) in a pilot study. PGD has mortality rates ranging from 17 to 50% over a 90-day period. Detailed HRCT lung images, reconstructed using 64-MSCT, may aid diagnostic and therapeutic efforts in PGD. Thirty-two patients were scanned four times within a year post-LUTX, in a single-centre prospective study. HRCT lung images were reviewed, evaluated and scored by two observers, for ground-glass (GG) opacities, consolidation, septal thickening (ST) and pulmonary embolism. Image and PGD scores were compared in each patient. GG and consolidation changes were largely present up until 2 weeks post-LUTX, and markedly reduced by the 12th week. ST was predominantly found in patients with PGD. There were no vascular changes found at CT angiographies. The most severe cases of GG opacities and consolidation were found in patients with PGD. ST seems to be an important indicator of PGD. HRCT(64-MSCT) imaging may be a useful tool for the identification of pathological features of PGD not detected by classical evaluation in patients undergoing LUTX. PMID:22378316

  15. Low-dose multi-slice CT (LMCT) assessment of pulmonary emphysema in public-school teachers

    International Nuclear Information System (INIS)

    Although rates of emphysematous change in smokers have been reported previously, the precise effects of smoking on emphysematous change have not been established because the study subjects of previous reports were heterogeneous. This study was designed to determine the incidence of emphysematous change identified by low-dose multi-slice CT (LMCT) imaging in public-school teachers. We reviewed 1776 consecutive subjects (ages from 31 to 61 years) who had undergone LMCT scanning during health care examinations. In addition, their replies to questionnaires about smoking were obtained. Emphysematous change was found by LMCT imaging in 22 male smokers. In these 22 smokers, the scores of emphysematous change according to Goddard's method was well correlated with smoking history. According to the questionnaires, the smoking rates of male and female teachers were 56.7% and 4%, respectively. Eighty-five percent of the teachers worked in offices separated from smokers. Most smokers wished to quit smoking and most teachers knew the risk of nicotine as well as the rate of smoking among high school students. However, knowledge of the relationships between smoking and lung cancer, myocardial infarction, and subarachnoid hemorrhage were not adequate. Our present study clearly demonstrated the incidence of emphysematous change in school teachers. In addition, early exposure to information about the risks of smoking is believed to be important for students, but school teachers did not have enough of such information. (author)

  16. A comparative study of accuracy of linear measurements using cone beam and multi-slice computed tomographies for evaluation of mandibular canal location in dry mandibles

    OpenAIRE

    Naser, Asieh Zamani; Mehr, Bahar Behdad

    2013-01-01

    Background: Cross- sectional tomograms have been used for optimal pre-operative planning of dental implant placement. The aim of the present study was to assess the accuracy of Cone Beam Computed Tomography (CBCT) measurements of specific distances around the mandibular canal by comparing them to those obtained from Multi-Slice Computed Tomography (MSCT) images. Materials and Methods: Ten hemi-mandible specimens were examined using CBCT and MSCT. Before imaging, wires were placed at 7 locatio...

  17. A comparative study of accuracy of linear measurements using cone beam and multi-slice computed tomographies for evaluation of mandibular canal location in dry mandibles

    OpenAIRE

    Asieh Zamani Naser; Bahar Behdad Mehr

    2013-01-01

    Background: Cross- sectional tomograms have been used for optimal pre-operative planning of dental implant placement. The aim of the present study was to assess the accuracy of Cone Beam Computed Tomography (CBCT) measurements of specific distances around the mandibular canal by comparing them to those obtained from Multi-Slice Computed Tomography (MSCT) images. Materials and Methods: Ten hemi-mandible specimens were examined using CBCT and MSCT. Before imaging, wires were placed at 7 loc...

  18. Application of the FDK algorithm for multi-slice tomographic image reconstruction; Aplicacao do algoritmo FDK para a reconstrucao de imagens tomograficas multicortes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo Roberto, E-mail: pcosta@if.usp.b [Universidade de Sao Paulo (IFUSP), SP (Brazil). Inst. de Fisica. Dept. de Fisica Nuclear; Araujo, Ericky Caldas de Almeida [Fine Image Technology, Sao Paulo, SP (Brazil)

    2010-08-15

    This work consisted on the study and application of the FDK (Feldkamp- Davis-Kress) algorithm for tomographic image reconstruction using cone-beam geometry, resulting on the implementation of an adapted multi-slice computed tomography system. For the acquisition of the projections, a rotating platform coupled to a goniometer, an X-ray equipment and a digital image detector charge-coupled device type were used. The FDK algorithm was implemented on a computer with a Pentium{sup R} XEON{sup TM} 3.0 processor, which was used for the reconstruction process. Initially, the original FDK algorithm was applied considering only the ideal physical conditions in the measurement process. Then some artifacts corrections related to the projections measurement process were incorporated. The implemented MSCT system was calibrated. A specially designed and manufactured object with a known linear attenuation coefficient distribution ({mu}(r)) was used for this purpose. Finally, the implemented MSCT system was used for multi-slice tomographic reconstruction of an inhomogeneous object, whose distribution {mu}(r) was unknown. Some aspects of the reconstructed images were analyzed to assess the robustness and reproducibility of the system. During the system calibration, a linear relationship between CT number and linear attenuation coefficients of materials was verified, which validate the application of the implemented multi-slice tomographic system for the characterization of linear attenuation coefficients of distinct several objects. (author)

  19. Contrast investigation of multi-slice spiral CT perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits

    Institute of Scientific and Technical Information of China (English)

    Jingfeng Zhang; Renfa Wang; Min Wang; Jing Zhang; Jinmei Sang

    2005-01-01

    Objective: To perform a contrast investigation of multi-slice spiral CT (MSCT) perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits, and discuss the applicative value of multi-slice spiral CT perfusion imaging in soft-tissue tumors. Methods: 8 Newzealand white rabbits were implanted with 0.1 ml VX2 tumor tissue suspension in bilateral proximal thighs. 14 days and 21 days later, CT plain scan and perfusion scan were performed on these rabbits respectively, then the images were transmitted to AW4.0 workstation, the functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time(MTT) and permeability surface (PS) were computed and analyzed. Subsequently, the rabbits were sacrificed, the tumors of which were taken out for pathological examination. The correlation between MSCT functional parametric images and pathological findings was analyzed.Results: All the values of BF, BV and PS of VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those of the normal muscular tissues significantly ( P < 0.001). Conclusion: Multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, which can give a quantitative assessment to blood perfusion and angiogenesis of soft-tissue tumors.

  20. Changes of cerebrospinal fluid circulation dynamics after cerebral trauma monitored with MRI 2D-phase contrast cine%磁共振2D-PC cine法监测外伤后脑脊液循环动力学改变

    Institute of Scientific and Technical Information of China (English)

    岳翠; 郏潜新; 欧阳林; 王文浩; 陈懿; 肖玉辉; 何平

    2011-01-01

    Objective To evaluate the application of MRI 2D-phase contrast cine technique (MR 2D-PC cine) in monitoring the changes of cerebrospinal fluid (CSF) circulation dynamics. Methods MR 2D-PC cine was performed in 40 cases which were considered to have changes in CSF circulation dynamics and 40 healthy volunteers. The average velocity and the net forward volume of CSF were measured and compared with the results measured by lumbar puncture. Results In cerebral trauma patients,the average velocity was 1. 100 (0. 895 -1.420)cm/s and the net forward volume was 0.073 (0.017 -0.124) ml in a cardiac cycle. In healthy volunteers, the average velocity was 1.306 (1.210 -1.360)cm/s and the forward volume was 0.081 (0.062-0.258)ml in a cardiac cycle. The average velocity of CSF in cerebral trauma patients was slower (P < 0.05) and net forward volume was less (P <0.05) than that in volunteer. Conclusion MR 2D-PC cine can quantitatively monitor the changes of CSF circulation after trauma and provide evidence for clinical treatment.%目的 运用MRI二维相位对比序列(2D-PC cine)法监测外伤后脑脊液动力学的改变.方法 采用MRI 2D-PC cine法序列,以编码流速20 cm/s,于枕骨大孔水平测量40例健康志愿者与40例脑外伤后临床怀疑脑循环动力学异常患者的脑脊液流速、流量,并与腰穿结果 相对照,比较两组脑脊液流速、流量之间有无差异.结果 外伤组平均流速为1.100 (0.895~1.420) cm/s,一个心动周期内净流量为0.073(0.017 ~0.124)ml,正常组平均流速为1.306 (1.210~1.360) cm/s,一个心动周期内平均净流量为0.081(0.062~0.258)ml.外伤组平均流速及净流量均小于对照组(P<0.05).结论 MRI 2D-PC cine能早期无创的发现脑外伤后颅内压增高患者脑脊液流体动力学的改变,对于脑外伤后患者脑脊液循环改变的监测、治疗及预后评价有重要指导意义.

  1. Solitary pulmonary nodules: comparison of multi-slice computed tomography perfusion study with vascular endothelial growth factor and microvessel density

    Institute of Scientific and Technical Information of China (English)

    BAI Rong-jie; CHENG Xiao-guang; QU Hui; SHEN Bao-zhong; HAN Ming-jun; WU Zhen-hua

    2009-01-01

    Background The solitary pulmonary nodule (SPN) is one of the most common findings on chest radiographs. The objectives of clinical practice are to differentiate malignant nodules from benign nodules in the least invasive way and to make a specific diagnosis. This study was aimed to evaluate the correlation between perfusion imaging features and microvessel density (MVD) and vascular endothelial growth factors (VEGF) in SPNs using multi-slice computed tomography (MSCT); and to provide the theoretical basis for SPN blood flow pattern and blood flow quantitative features.Also, the study called for the discussion of the method's clinical application value in the differential diagnosis of benign and malignant SPNs.Methods Sixty-eight patients with SPN underwent multi-location dynamic contrast enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s) MSCT. Precontrast and postcontrast attenuations on every scan was studied. Perfusion, peak height, and the ratio of the peak height of the SPN to that of the aorta were analyzed. Perfusion was calculated using the maximum gradient of the time-density curves (TDC) and the peak height of the aorta. The quantitative parameters (perfusion, peak height, ratio of peak height of the SPN to that of the aorta) of the blood flow pattern were compared with MVD and the VEGF expression of immunohistochemistry.Results The perfusion peak heights of malignant ((96.15±11.55) HU) and inflammatory ((101.15±8.41) HU) SPNs were significantly higher than those of benign ((47.24±9.15) HU) SPNs (P<0.05, P<0.05). Ratios of SPN-to-aorta of malignant and inflammatory SPNs were significantly higher than those of benign SPNs (P<0.05, P<0.05). No significant differences were found between the peak height and SPN-to-aorta ratio of malignant SPNs and inflammatory SPNs (P>0.05, P>0.05). The precontrast densities of inflammatory SPNs were lower than those of malignant SPNs (P<0.05).Perfusion values

  2. Multi-slice spiral CT 3D reconstruction of extrahepatic feeding arteries in hepatocellular carcinoma:its clinical applications

    International Nuclear Information System (INIS)

    Objective: To discuss the feasibility of displaying the extrahepatic feeding arteries in hepatocellular carcinoma with the help of multi-slice spiral CT 3D reconstruction and to assess the clinical value of this technique. Methods: Triple-phase enhanced CT scanning with a 64-slice spiral CT scanner was performed in 89 patients with advanced primary hepatocellular carcinoma (HCC). Three-dimensional reconstruction techniques, including maximum intensity projection (MIP) and volume rendering (VR), with arterial phase images, were used to display the origination and course of both the intrahepatic and extrahepatic supplying arteries of HCC. The results were compared with the angiographic findings. Results: Of 59 cases with massive type HCC, extrahepatic supplying arteries were found in 33. In 21 cases of diffuse type HCC four showed extrahepatic supplying arteries,and in nine cases of nodular type HCC only one had extra-hepatic supplying arteries. The HCC could get their extrahepatic blood supply via eight pathways. A total of 44 extrahepatic supplying arteries were detected,and 19 anomalously originated hepatic arteries were found. Conclusion: The extrahepatic supplying arteries in hepatocellular carcinoma are common findings and their supplying pattern are extremely varied, which may be associated with the type and location of the tumors. Three-dimensional reconstruction technique with the help of triple-phase enhanced CT scanning on a 64-slice spiral CT scanner can provide excellent images as vivid and ideal as angiography can afford. Therefore,the times of angiography examination, the use of contrast media as well as the dose of radiation to both the patients and the physicians can be reduced as far as possible. The detailed information about extrahepatic blood supply is very useful for improving the therapeutic result of HCC. (authors)

  3. Accuracy and reliability of quantitative measurements in coronary arteries by multi-slice computed tomography: Experimental and initial clinical results

    International Nuclear Information System (INIS)

    AIM: To evaluate the accuracy of non-invasive measurements within coronary arteries by multi-slice computed tomography (MSCT). We present experimental as well as clinical data. MATERIALS AND METHODS: Silicon tubes simulating coronary arteries (outer diameter 6 mm, lumen diameter within stenotic area 2 mm) were used for experimental studies. Clinical data were derived from 15 patients in whom vessel diameters were assessed by MSCT, intracoronary ultrasound (ICUS) and quantitative coronary angiography (QCA). MSCT were performed in a Somatom Volume ZoomTMCT system (Siemens, Forchheim, Germany) at 2 collimated slice widths (2.5 mm, 1.0 mm). RESULTS: Outer silicon tube diameters were overestimated by MSCT (6.56 mm ± 0.32 mm). All measurements revealed significantly better results on 1.0 collimation compared to 2.5 mm collimation (outer diameter: 6.36 mm ± 0.22 mm vs 6.76 mm ± 0.27 mm, P < 0.0001; lumen diameters: 1.83 mm ± 0.14 mm vs 1.51 mm ± 0.19 mm,P < 0.0001). The comparison of vessel diameters within human coronary arteries revealed comparable results between ICUS and MSCT (4.89 mm ± 0.67 mm vs 4.91 mm ± 0.71 mm, P = 0.79,r = 0.79, P < 0.0001). QCA-measurements showed significantly lower results (3.67 ± 0.71, P < 0.0001,r = 0.62, P < 0.001). CONCLUSIONS: Experimental as well as initial clinical results indicate acceptable reliability and accuracy of quantitative measurements by MSCT, when using thin collimated slice widths. Partial volume effects lead to a systematic overestimation of vessel size. MSCT has the potential to become an important non-invasive diagnostic tool in patients with coronary artery disease. Schroeder, S. et al. (2001)

  4. The role of multi slice computed tomography in the evaluation of acute non-cardiac chest pain

    Directory of Open Access Journals (Sweden)

    Sandra Vegar Zubović

    2012-12-01

    Full Text Available Introduction: Differential diagnosis of acute chest pain encompasses a broad spectrum of illnesses which are most likely followed by benign outcomes (pneumonia, pneumothorax, pleurisy, pericardial effusion, hiatus hernia, but also illnesses of lethal outcomes (pulmonary embolism, myocardial infarction, aortic dissection,thoracic aortic aneurysms, thoracic aortic aneurysm rupture, etc. Illnesses associated with benign and lethal outcomes may present very similar if not the same symptoms, resulting in a diffi cult establishment of accurate diagnosis.Methods: During the period of one year, 123 patients presented with non-cardiac acute chest pain were referred for the multi slice computed tomography (MSCT examination. Scanning of thorax was conductedin two series: unenhanced and contrast-enhanced, using a window for pulmonary parenchyma and mediastinum.Results: From a total number of patients 21.1% had normal results while the other 79.9% had pathological results. Out of the total number of patients with pathological result MSCT established potentially lethal outcome for 35.0%, out of which 83.7% was contributed to vascular territory of pulmonary artery, while 16.3% was contributed to aorta.Conclusion: MSCT scanning, owe to its ability of simultaneous analysis of vascular and non-vascular thoracic structures, represents a very effi cient and reliable method for establishing accurate diagnosis and appropriatetriage of patients with acute chest pain. Accurate and effi cient diagnosis enables benefi cial outcome for the patient in this group of illness. MSCT enables the differentiation of etiological factors, which present as acute onset of non-cardiac chest pain.

  5. Peripheral pulmonary nodules: Relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF expression

    Directory of Open Access Journals (Sweden)

    Cheng Xiao-Ling

    2008-06-01

    Full Text Available Abstract Background The aim of this study is to investigate the relationship between16-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF (vascular endothelial growth factor expression in patients with benign and malignant pulmonary nodules, and differential diagnosis between benign and malignant pulmonary nodules. Methods Sixty-four patients with benign and malignant pulmonary nodules underwent 16-slice spiral CT perfusion imaging. The CT perfusion imaging was analyzed for TDC (time density curve, perfusion parametric maps, and the respective perfusion parameters. Immunohistochemical findings of MVD (microvessel density measurement and VEGF expression was evaluated. Results The shape of the TDC of peripheral lung cancer was similar to those of inflammatory nodule. PH (peak height, PHpm/PHa (peak height ratio of pulmonary nodule to aorta, BF (blood flow, BV (blood volume value of peripheral lung cancer and inflammatory nodule were not statistically significant (all P > 0.05. Both showed significantly higher PH, PHpm/PHa, BF, BV value than those of benign nodule (all P 0.05. In the case of adenocarcinoma, BV, BF, PS, PHpm/PHa, and MVD between poorly and well differentiation and between poorly and moderately differentiation were statistically significant (all P 0.05. PH, PHpm/PHa, BV, and PS of benign nodule were significantly lower than those of peripheral lung cancer (all P Conclusion Multi-slice spiral CT perfusion imaging closely correlated with tumor angiogenesis and reflected MVD measurement and VEGF expression. It provided not only a non-invasive method of quantitative assessment for blood flow patterns of peripheral pulmonary nodules but also an applicable diagnostic method for peripheral pulmonary nodules.

  6. The investigation of the lateral atlanto-dental interval of atlanto-axial joint by multi-slice spiral CT

    International Nuclear Information System (INIS)

    Objective: To explore imaging features of the lateral atlanto-dental interval (LADI) of atlanto-axial joint and its value in the diagnosis of atlanto-axial joint dislocation/subluxation. Methods: Two hundred and forty healthy volunteers without atlanto-axial joint dysfunction and 32 patients with torticollis and/or functional impairment at atlanto-axial.joint were enrolled into this study. All subjects were examined with multi-slice CT in both neutral and max rotation positions to the left/right. Clinical endpoints including VBLADI, variance range of the VBLADI and asymmetric conditions were evaluate. χ2 test is used to evaluate the variance of incidence of bilateral LADI asymmetry in different age groups, Pearson-test (2-tailed) is used to evaluate the correlation between VBLADI and rotary function of atlanto-axial joint, precise test of fourfold table is used to compare normal group with patient groups. Results: (1) In the normal control group: asymmetry of bilateral LADI were observed in 204 among 240 (85.00%) healthy volunteers including 60 youngsters (95% of ∣ VBLADI ∣ were 0.850 mm, 2.450 mm in the young (95% in the young and in the adult respectively. There was no correlation between VBLADI(-2.146 to 2.114 mm, Median 0.000 mm) and LA (22.949° to 44.649°, Median 34.500°), RA (25.284° to 45.334°, Median 35.300°), VLRA (-11.643° to 8.623°, median 0.000°) respectively in normal people (r=-0.030, -0.005, 0.026, P>0.05). (2) In the study with 32 patients including 25 youngsters (95% in group AALSD and group AACD than in abnormal group (P<0.01), but there is no difference between group AARD and normal group (P=0.738). Conclusion: The imaging finding of 'asymmetry of bilateral LADI' may be either a physiological variation or a pathological condition, clinical manifestations and other imaging findings should be evaluated to make a diagnosis. (authors)

  7. Low-dose multi-slice CT with three dimensional rendering of the tendons of foot and ankle

    International Nuclear Information System (INIS)

    Objective: To study the feasibility and reasonability of low-dose multi-slice CT (MSCT) with three dimensional rendering of the tendons of foot, and ankle. The statistical methods including ANOVA and Kruskal-Wallis H was used. Methods: Forty-five consecutive patients with fractures of foot and ankle were enrolled and evenly grouped into A(80 kV, 100 mAs), B (110 kV, 60 mAs) and C (130 kV, 60 mAs). The MSCT scanning range was 6 slices of 1.0 mm. The CT value and standard deviation (SD) of the muscle and the CTDIvol were recorded. The image quality of volume rendering of the tendons was blindly evaluated. Results: The CT value of muscle in group A (71.6±12.0) HU was significantly higher than group B [(66.8±9.2) HU, P=0.010] and C [(66.1±7.1) HU, P=0.004]. The SD average values were 11.9, 6.1 and 7.0 HU for three groups, and there were significant differences among the three groups (F= 37.142, P=O.0000). Group A had the highest SD value, group C had the lowest. SD; CTDIvol average value were (3.01±0.08), (4.63±0.11), (7.02±0.24) mGy respectively, which were significant different among the three groups (H =39.185, P=0.000). Group A had the lowest CTDIvol, while group C had the highest CTDIvol. Volume rendering of the tendons was evaluated as 2.3±0.5, 3.7±0.5, 4.8± 0.4, and there were significant differences among the three groups (H=72.779, P=0.000). Group A had the worst VR images, while group C had the best VR images. All VR images in Group B were good for diagnosis. Conclusion: The protocol of 110 kV, 60 mAs, and 1 mm × 6 with three-dimensional volume rendering would be enough for evaluating the tendons of foot and ankle. (authors)

  8. Study of low dose and dynamic multi-slice CT about obstructive sleep apnea syndrome in sleeping

    International Nuclear Information System (INIS)

    Objective: To perform Low dose dynamic MSCT(multi-slice CT) in sleeping obstructive sleep apnea syndrome (OSAS) patients correcting the imprecise measure values in waking state, and to exactly analyse the location and extension of the dynamic changes about the condition. Methods: Sixteen OSAS patients were scanned both in waking and naturally sleeping period (end phase of inspiration and expiration). Measured at the narrowest part of the retropalatal (RP) and retroglossal (RG) and 5 mm under the tip of epiglottis at the epiglottal (EPG)at the end period of inspiration in sleeping, respectively, and compared the accurate position of the narrowest or occlusive level in 3 phases. All patients were also scanned using cine mode at the narrowest level at the end period of inspiration in sleeping to show the pharyngeal cavity changes during sleep. Results: The smallest XSA of RP region (Mw=47.50 mm2, Me=73.00 mm2, Mi=2.00 mm2; Zwe=2.897, Pwe=0.003; Zwi=4.192, Pwiie=4.538, Piew=8.00 mm, Me=9.50 mm, Mi=1.50 mm; Zwe=1.933, Pwe=0.056; Zwi=3.720, Pwiie=4.230, Piew=8.00 mm, Me=9.00 mm, Mi=1.00 mm; Zwe=1.210, Pwe=0.246; Zwi=4.203, Pwiie=4.557, Piew=4.00 mm3, Me=5.50 mm3, Mi=1.50 mm3; Zwe=1.576, Pwe=0.125; Zwi=3.532, Pwiie=4.077, Piew=7.00 mm, Me=6.00 mm, Mi=10.50 mm; Zwe=0.557, Pwe=0.603; Zwi=2.541, Pwi=0.011; Zie=2.852, Pie=0.004) and RG regions (Mw=5.00 mm, Me=3.00 mm, Mi=9.50 mm; Zwe=0.747, Pwe=0.482; Zwi=2.657, Pwi=0.007; Zie=3.075, Pie=0.001), were different between inspiration and expiration of sleeping or awake. The dynamic cine CT scan during sleeping could show pharyngeal change, clearly. Conclusion: At the end period of inspiration in sleeping, the location of narrow or obstructive of airway is the most precise and sensitive and the false negative at the waking could be obviously reduced. Low dose MSCT scan reduced exposure and expense. (authors)

  9. Comparative study of myocardial perfusion imaging and 64 multi-slice spiral CT for the diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

    Objective: To compare the diagnostic value of myocardial perfusion imaging (MPI) and 64 multi-slice spiral CT (64-MSCT) for coronary artery disease (CAD). Methods: Fifty-two patients with suspected or known CAD were included in the study. Each patient underwent both stress and rest MPI, MSCT as well as conventional coronary angiography (CAG) within 1 month. The stress and rest MPI were scored by a 5-grade criteria (0-4) based on 17 coronary artery segments. The difference between summed stress and rest scores > 1 was defined as myocardial ischemia. Stenosis in one main vessel or one main branch of the main vessel ≥50% was defined as myocardial ischemia by MSCT. CAG was used as the reference for comparison. Statistical analysis was performed using SPSS 13.0 software. Kappa value was used to test the accordance of MPI and MSCT results. χ2 test was used to evaluate the difference between MPI and MSCT results. Results: The patient-based sensitivity, specificity, positive and negative predictive values and accuracy of MPI and MSCT for the diagnosis of CAD were 86.7% (26/30), 77.3% (17/22),83.9% (26/31), 81.0% (17/21), 82.7% (43/52) and 83.3% (25/30), 86.4% (19/22), 89.3%( 25/28), 79.2% (19/24), 84.6% (44/52), respectively. The vessel-based sensitivity, specificity, positive and negative predictive values and accuracy of MPI and MSCT were 74.5% (38/51), 81.0% (85/105), 65.5% (38/58), 86.7% (85/98), 78.8% (123/156) and 90.2% (46/51), 88.6% (93/105),79.3 % (46/58), 94.9% (93/98), 89.1% (139/156), respectively. There was no statistically significant difference between MPI and MSCT for either patient or lesion-based diagnosis (χ2 =0.44, 0.21, both P>0.05). 96.0% (24/25) patients with both abnormal MPI and MSCT positive were validated by CAG while 83.3% (15/18) patients with both MPI and MSCT negative were excluded by CAG. Conclusions: Both MPI and MSCT are reliable diagnostic modalities for CAD. They also provide complementary diagnostic value to each other. (authors)

  10. Investigation on the optical scan condition for imaging of multi-slice spiral CT liver perfusion in rats

    Institute of Scientific and Technical Information of China (English)

    BAI Rong-jie; WANG Jin-e; JIANG Hui-jie; HAO Xue-jia; DONG Xu-peng; HUANG Ya-hua; WEI Lai

    2013-01-01

    Background Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions,and is usually performed as an adjunct to a conventional CT examination because of its high temporal and spatial resolution,simple protocol,good reproducibility,and ability to measure hemodynamic changes of liver tissues at the capillary level.Experimental rat models,especially those of induced liver cancer,are often used in studies of hemodynamic changes in liver cancer.Carcinogenesis in rats has a similar pathological progression and characteristics resembling those in human liver cancer; as a result,rat models are often used as ideal animal models in the study of human liver cancer.However,liver perfusion imaging in rats is difficult to perform,because rats' livers are so small that different concentrations,flow rates,and dose of contrast agents during the CT perfusion scanning can influence the quality of liver perfusion images in rats.The purpose of this study,therefore,was to investigate the optimal scan protocol for the imaging of hepatic perfusion using a deconvolution mathematical method in rats by comparing the results of rats in different injection conditions of the contrast agent,including concentration,rate and time.Methods Plain CT scan conditions in eighty 2-month-old male Wistar rats were 5.0 mm slice thickness,5.0 mm interval,1.0 pitch,120 kV tube voltage,60 mA tube current,512×512 matrix,and FOV 9.6 cm.Perfusion scanning was carried out with different concentrations of diatrizoate (19%,38%,57%,and 76%),different injection rates (0.3 and 0.5 mi/s),and different injection times (1,2-3,4-5,and 6 seconds).The above conditions were randomly matched and adjusted to determine the best perfusion scan protocol.Thrae-phase contrast-enhanced scanning was performed after CT perfusion.Histological examination of the liver tissues with hematoxylin and eosin stains was done after CT scanning.Results When the concentration of the

  11. Interpolated compressed sensing for 2D multiple slice fast MR imaging.

    Directory of Open Access Journals (Sweden)

    Yong Pang

    Full Text Available Sparse MRI has been introduced to reduce the acquisition time and raw data size by undersampling the k-space data. However, the image quality, particularly the contrast to noise ratio (CNR, decreases with the undersampling rate. In this work, we proposed an interpolated Compressed Sensing (iCS method to further enhance the imaging speed or reduce data size without significant sacrifice of image quality and CNR for multi-slice two-dimensional sparse MR imaging in humans. This method utilizes the k-space data of the neighboring slice in the multi-slice acquisition. The missing k-space data of a highly undersampled slice are estimated by using the raw data of its neighboring slice multiplied by a weighting function generated from low resolution full k-space reference images. In-vivo MR imaging in human feet has been used to investigate the feasibility and the performance of the proposed iCS method. The results show that by using the proposed iCS reconstruction method, the average image error can be reduced and the average CNR can be improved, compared with the conventional sparse MRI reconstruction at the same undersampling rate.

  12. Diagnosis of pulmonary embolism and the underlying venous thrombosis by multi-slice CT; Diagnostik der Lungenembolie und zugrundeliegender Venenthrombosen in der Mehrzeilen-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Kopka, L.; Funke, M.; Funke, C.; Grabbe, E. [Abt. Roentgendiagnostik I, Georg-August-Univ. Goettingen (Germany)

    2001-06-01

    To determine the value of multi-slice CT for the diagnosis of acute pulmonary embolism and an underlying venous thrombosis. Methods: 70 patients with clinically suspected acute pulmonary embolism were examined. Using multi-slice CT a combined examination of the pulmonary arteries and the veins of the lower limb, pelvis and abdomen was performed. Only one single bolus of 150 ml iopromid 300 was injected into a cubital vein with a flow of 4 ml/s. First, the pulmonary arteries were scanned with a slice thickness of 2.5 mm and a pitch of 1.5. On arrival of the contrast medium at the popliteal veins, indicated by bolus trakking, the veins of the lower limbs up to the end of the inferior vena cava were imaged using a slice thickness of 3.75 mm and a pitch of 1.5. The results could be compared with a ventilation-perfusion scan in 48 cases, with a Doppler ultrasound examination in 46 cases, and with a venography in 10 cases. Furthermore, the image quality of all arterial and venous regions was subjectively assessed. Results: In all patients who underwent multi-slice CT the pulmonary arteries as well as the veins of the lower half of the body could be recorded completely. Regarding the pulmonary arteries the image quality showed excellent results for the central and segmental arteries. The region up to the 3rd division in subsegmental branches could be sufficiently judged. More peripherally, a diagnostic assessment was not possible. The image quality of the veins was excellent in all sections, except the calf, where a reliable diagnosis could not be made. The comparison with the other techniques confirmed the superiority of multi-slice CT concerning the central and segmental pulmonary arteries and the veins from the popliteal vein to the inferior vena cava. In contrast, peripheral pulmonary emboli can be detected more certainly in ventilation/perfusion scans. The veins of the calf can be evaluated more reliably with venography. (orig.) [German] Evaluation der Moeglichkeiten

  13. Depiction of the triangular fibro-cartilage in patients with ulnar-sided wrist pain: comparison of direct multi-slice CT arthrography and direct MR arthrography

    International Nuclear Information System (INIS)

    To compare direct multi-slice CT arthrography (MSCT-AG) and direct MR arthrography (MR-AG) of the wrist with regard to the depiction of the triangular fibro-cartilage (TFC). Fifteen consecutive patients with ulnar-sided wrist pain suspicious for TFC tear underwent both MSCT-AG and MR-AG of the wrist. Images obtained were evaluated by two radiologists in a blinded fashion for the depiction of six anatomical areas (radial, central and ulnar portion on the proximal and distal side) of the TFC by means of a five-point scoring system (1excellent visibility to 5= not visible). Scores for MSCT-AG and MR-AG were compared using the Student's t-test. Mean scores for MSCT-AG and MR-AG, respectively, were 2.5/2.0, 3.2/2.5 and 2.8/2.4 for the radial, central and ulnar portion of the TFC on its proximal side, and 2.7/2.0, 3.1/2.3 and 2.9/2.4 for the radial, central and ulnar portion on its distal side (n=15). Paired Student's t-test showed no significant difference between MSCT-AG and MR-AG (P>0.05). In a first, small series, depiction of the TFC with MSCT-AG is comparable to that of MR-AG. Further evaluation of direct multi-slice CT arthrography of the wrist in a larger patient population would be promising. (orig.)

  14. Establishing models of portal vein occlusion and evaluating value of multi-slice CT in hepatic VX2 tumor in rabbits

    Institute of Scientific and Technical Information of China (English)

    Yue-Yong Qi; Li-Guang Zou; Ping Liang; Dong Zhang

    2007-01-01

    AIM: To establish models of portal vein occlusion of hepatic VX2 tumor in rabbits and to evaluate the value of multi-slice CT.METHODS: Forty New Zealand rabbits were divided into 4 groups according to digital table: Immediate group (group A; transplantation of tumor immediately after the portal vein occlusion), 3-wk group (group B;transplantation of tumor at 3 wk after the portal vein occlusion), negative control group (group C) and positive control group (group D), 10 rabbits in each group.Hepatic VX2 tumor was transplanted with abdominal-embedding innoculation immediately after the portal vein occlusion and at 3 wk after the portal vein occlusion.Meanwhile, they were divided into negative control group (Left external branch of portal vein was occluded by sham-operation, and left exite was embedded and inoculated pseudoly) and positive control group (Transplanted tumor did not suffer from the portal vein occlusion). All rabbits were scanned with multi-slice CT.RESULTS: All 40 animals were employed in the final analysis without death. Tumor did not grow in both immediate group and 3-wk group. In 3-wk group, left endite was atrophied and growth of tumor was inhibited.The maximal diameter of tumor was significantly smaller than that in positive control group (2.55 ± 0.46 vs3.59 ± 0.37 cm, t = 5.57, P < 0.001). Incidences of metastasis in the liver and lung were lower in 3-wk group than those in positive control group (10% vs 40%, and 90% vs 100%, respectively). The expression intensities of the vascular endothelium growth factor (VEGF) in groups A, B, C and D were 0.10 ± 0.06, 0.66 ± 0.21, 0.28± 0.09 and 1.48 ± 0.32, respectively. VEGF expression level in the test group A was significantly lower than that in the negative control group C (t = 5.07; P < 0.001).In addition, VEGF expression in the test group B was significantly lower than that in the positive control group D (t = 6.38; P < 0.001). Scanning with multi-slice CT showed that displaying rate of

  15. Clinical application of multi-slice spiral CT urography in traumatic urine leaka%外伤性尿漏多层螺旋CT诊断

    Institute of Scientific and Technical Information of China (English)

    俞国有

    2012-01-01

    Objective To explore the diagnostic value of multi-slice CT in the urine leakage. Methods 20 cases of urine leaks confirmed by clinical diagnosis underwent spiral CT plain scanning and triphasic dynamic enhancement scanning. The CT features on axial images and multiplanar reformation (MPR). maximum intensity projection (MIP) and volume rendering (VR) were reviewed. Results The breakage in renal parenchyma, subcapsular hematoma of kidney, prerenal fascia thickening appeared in 15 cases with pelvis leak affected by trauma. The excretory phase could detect 2 cases wfth ureteral leakage. 3 cases with bladder leak had the defect of posterior wall. Encapsulated effusion in rectal bladder space and eggshell-like calcification of the wall could be found, the contrast agent inpoured the urinary vesicle through the defect of the bladder wall. Conclusion Since the multi-slice CT urography (MSCT) examination clearly shows the leakage, the site of urine leakage. the scope of urinary vesicle. and other complications. it can be used as a preferred diagnostic method of urinary leakage.%目的 探讨多层螺旋CT对肾盂、输尿管及膀胱外伤性尿漏的诊断价值.方法 搜集20例经临床证实发生尿漏患者多层螺旋CT检查.全部行增强三期扫描.运用多种CT后处理技术(MPR、VR、MIP)综合分析其MSCT特点.结果 20例患者中,肾盂尿漏15例,输尿管尿漏2例,膀胱尿漏3例,排泄期表现为对比剂外渗,各种后处理技术可以清晰显示漏口的部位及范围,并可合并显示肝脾破裂、肾实质破裂、肾包膜下血肿、肾周间隙积液、骨盆多发骨折等.结论 MSCT延迟增强扫描能清晰显示尿漏的部位、漏口和并发症,对尿漏的诊断和选择治疗方案提供重要依据,可以作为尿漏诊断首选方法.

  16. Evaluation of 2D multiband EPI imaging for high-resolution, whole-brain, task-based fMRI studies at 3T: Sensitivity and slice leakage artifacts.

    Science.gov (United States)

    Todd, Nick; Moeller, Steen; Auerbach, Edward J; Yacoub, Essa; Flandin, Guillaume; Weiskopf, Nikolaus

    2016-01-01

    Functional magnetic resonance imaging (fMRI) studies that require high-resolution whole-brain coverage have long scan times that are primarily driven by the large number of thin slices acquired. Two-dimensional multiband echo-planar imaging (EPI) sequences accelerate the data acquisition along the slice direction and therefore represent an attractive approach to such studies by improving the temporal resolution without sacrificing spatial resolution. In this work, a 2D multiband EPI sequence was optimized for 1.5mm isotropic whole-brain acquisitions at 3T with 10 healthy volunteers imaged while performing simultaneous visual and motor tasks. The performance of the sequence was evaluated in terms of BOLD sensitivity and false-positive activation at multiband (MB) factors of 1, 2, 4, and 6, combined with in-plane GRAPPA acceleration of 2× (GRAPPA 2), and the two reconstruction approaches of Slice-GRAPPA and Split Slice-GRAPPA. Sensitivity results demonstrate significant gains in temporal signal-to-noise ratio (tSNR) and t-score statistics for MB 2, 4, and 6 compared to MB 1. The MB factor for optimal sensitivity varied depending on anatomical location and reconstruction method. When using Slice-GRAPPA reconstruction, evidence of false-positive activation due to signal leakage between simultaneously excited slices was seen in one instance, 35 instances, and 70 instances over the ten volunteers for the respective accelerations of MB 2×GRAPPA 2, MB 4×GRAPPA 2, and MB 6×GRAPPA 2. The use of Split Slice-GRAPPA reconstruction suppressed the prevalence of false positives significantly, to 1 instance, 5 instances, and 5 instances for the same respective acceleration factors. Imaging protocols using an acceleration factor of MB 2×GRAPPA 2 can be confidently used for high-resolution whole-brain imaging to improve BOLD sensitivity with very low probability for false-positive activation due to slice leakage. Imaging protocols using higher acceleration factors (MB 3 or MB 4

  17. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xin, E-mail: Xin.Liang@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); College of Stomatology, Dalian Medical University (China); Lambrichts, Ivo, E-mail: Ivo.Lambrichts@uhasselt.b [Department of Basic Medical Sciences, Histology and Electron Microscopy, Faculty of Medicine, University of Hasselt, Diepenbeek (Belgium); Sun Yi, E-mail: Sunyihello@hotmail.co [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Denis, Kathleen, E-mail: kathleen.denis@groept.b [Department of Industrial Sciences and Techology-Engineering (IWT), XIOS Hogeschool Limburg, Hasselt (Belgium); Hassan, Bassam, E-mail: b.hassan@acta.n [Department of Oral Radiology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); Li Limin, E-mail: Limin.Li@uz.kuleuven.b [Department of Paediatric Dentistry and Special Dental Care, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Pauwels, Ruben, E-mail: Ruben.Pauwels@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Jacobs, Reinhilde, E-mail: Reinhilde.Jacobs@uz.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium)

    2010-08-15

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G, Accuitomo 3D, i-CAT, Galileos, Scanora 3D) and one MSCT scanner (Somatom Sensation 16). A 3D surface bone model was created from the six systems. The reference (gold standard) 3D model was obtained with a high resolution laser surface scanner. The 3D models from the five systems were compared with the gold standard using a point-based rigid registration algorithm. Results: The mean deviation from the gold standard for MSCT was 0.137 mm and for CBCT were 0.282, 0.225, 0.165, 0.386 and 0.206 mm for the i-CAT, Accuitomo, NewTom, Scanora and Galileos, respectively. Conclusion: The results show that the accuracy of CBCT 3D surface model reconstructions is somewhat lower but acceptable comparing to MSCT from the gold standard.

  18. Rapid assessment of myocardial infarct size in rodents using multi-slice inversion recovery late gadolinium enhancement CMR at 9.4T

    Directory of Open Access Journals (Sweden)

    Hausenloy Derek J

    2011-09-01

    Full Text Available Abstract Background Myocardial infarction (MI can be readily assessed using late gadolinium enhancement (LGE cardiovascular magnetic resonance (CMR. Inversion recovery (IR sequences provide the highest contrast between enhanced infarct areas and healthy myocardium. Applying such methods to small animals is challenging due to rapid respiratory and cardiac rates relative to T1 relaxation. Methods Here we present a fast and robust protocol for assessing LGE in small animals using a multi-slice IR gradient echo sequence for efficient assessment of LGE. An additional Look-Locker sequence was used to assess the optimum inversion point on an individual basis and to determine most appropriate gating points for both rat and mouse. The technique was applied to two preclinical scenarios: i an acute (2 hour reperfused model of MI in rats and ii mice 2 days following non-reperfused MI. Results LGE images from all animals revealed clear areas of enhancement allowing for easy volume segmentation. Typical inversion times required to null healthy myocardium in rats were between 300-450 ms equivalent to 2-3 R-waves and ~330 ms in mice, typically 3 R-waves following inversion. Data from rats was also validated against triphenyltetrazolium chloride staining and revealed close agreement for infarct size. Conclusion The LGE protocol presented provides a reliable method for acquiring images of high contrast and quality without excessive scan times, enabling higher throughput in experimental studies requiring reliable assessment of MI.

  19. 多层螺旋CT对颌骨放射性骨坏死的诊断价值%DIAGNOSTIC VALUE OF MULTI-SLICE SPIRAL CT FOR OSTERORADIONECROSIS OF JAW

    Institute of Scientific and Technical Information of China (English)

    林颖; 曹代荣; 游瑞雄; 江飞; 郑义浩

    2014-01-01

    Objective:To investigate the diagnostic value of multi-slice spiral CT for osteoradionecrosis of jaws (ORNJ). Methods:The CT ifndings of 27 cases ORNJ that were conifrmed by surgery and pathology were retrospectively analyzed. Results: The main CT ifndings of ORNJ were limited bone destruction and sequestration.Conclusions:Multi-slice spiral CT can clearly display location and appearance of lesions, sequestration, periosteal reaction and soft tissue mass formation. So multi-slice spiral CT has important value for diagnosis and differential diagnosis of ORNJ.%目的::探讨多层螺旋CT对颌骨放射性骨坏死(ORNJ)的诊断价值。方法:回顾性分析27例经手术、病理证实为ORNJ的CT表现。结果:ORNJ在多层螺旋CT上主要表现为局限性骨质破坏和死骨形成。结论:多层螺旋CT能清楚的显示ORNJ病灶的位置、形态、病灶内的死骨形成、有无骨膜反应及软组织肿块形成等,对ORNJ的诊断及鉴别诊断有重要的价值。

  20. 卵巢囊性畸胎瘤B超及多排螺旋CT的诊断价值比较%Comparison of the diagnostic value of ovarian cystic teratoma B ultrasound and multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    樊兆丽; 彭明洋

    2015-01-01

    Objective To investigate the diagnosis of ovarian cystic teratoma of B ultrasound and multi-slice spiral CT. Methods A retrospective analysis of 40 patients with surgically and pathologically confirmed ovarian cystic teratoma B ultrasound and CT image data.Results Multi-slice spiral CT diagnosis is higher than B ultrasound. Conclusion B ultrasound for routine screening, joint multi-slice spiral CT can improve diagnosis of ovarian cystic teratoma.%目的:探讨卵巢囊性畸胎瘤的B超及多排螺旋CT的诊断价值。方法:回顾性分析40例经手术及病理证实的卵巢囊性畸胎瘤的B超及CT影像资料。结果:多排螺旋CT的诊断符合率高于B超。结论:B超检查适用于常规筛选检查,联合多排螺旋CT检查,可提高卵巢囊性畸胎瘤的定性诊断。

  1. Multi-slice abdominal CT in oncological patients. Influence of table feed and detector configuration on image quality and radiation exposure

    International Nuclear Information System (INIS)

    Purpose: To evaluate the image quality and radiation exposure of different spiral CT scanning parameters for routine staging examination of the abdomen in oncologic patients using a multi-slice CT scanner. Methods/Materials: Examination of 40 patients in 4 groups on a multislice CT scanner (Somatom VolumeZoom, Siemens AG, Forchheim). Functional detector width (4x2.5, 4x5 mm) and pitch (table feed in relation to collimated slice width) were varied (3 and 5). Tube voltage (120 kV), effective tube current (160 mAs), slice-thickness (6 mm), increment (4 mm), kernel (B 30), and contrast injection parameters were dept constant. Axial images were assessed by three radiologists regarding delineation of anatomic structures, artifacts, and overall image quality. Results: Significantly reduced image quality especially due to artifacts was observed using a 5 mm detector configuration with a pitch of 5 (scan time 9 sec). Image quality was rated best for a 2.5 mm detector configuration with a pitch of 3 and a scan time of 28 sec. The effective dose was independent of the pitch. However, the mean effective dose was 9% higher using the smaller detector configuration (9.9 mSv vs 10.9 mSv). Conclusions: For routine staging CT of the abdomen use of a 4x2.5 mm detector configuration with a pitch between 3 and 5 is recommended. A 4x5 mm detector configuration using overlapping data acquisition can also be recommended, but additional thin slice reformations are not possible. (orig.)

  2. Accelerated magnetic resonance diffusion tensor imaging of the median nerve using simultaneous multi-slice echo planar imaging with blipped CAIPIRINHA

    Energy Technology Data Exchange (ETDEWEB)

    Filli, Lukas; Kenkel, David; Boss, Andreas; Manoliu, Andrei; Andreisek, Gustav; Runge, Val M.; Guggenberger, Roman [University Hospital of Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Piccirelli, Marco [University Hospital of Zurich, Department of Neuroradiology, Zurich (Switzerland); Bhat, Himanshu [Siemens Medical Solutions USA Inc, Charlestown, MA (United States)

    2016-06-15

    To investigate the feasibility of MR diffusion tensor imaging (DTI) of the median nerve using simultaneous multi-slice echo planar imaging (EPI) with blipped CAIPIRINHA. After federal ethics board approval, MR imaging of the median nerves of eight healthy volunteers (mean age, 29.4 years; range, 25-32) was performed at 3 T using a 16-channel hand/wrist coil. An EPI sequence (b-value, 1,000 s/mm{sup 2}; 20 gradient directions) was acquired without acceleration as well as with twofold and threefold slice acceleration. Fractional anisotropy (FA), mean diffusivity (MD) and quality of nerve tractography (number of tracks, average track length, track homogeneity, anatomical accuracy) were compared between the acquisitions using multivariate ANOVA and the Kruskal-Wallis test. Acquisition time was 6:08 min for standard DTI, 3:38 min for twofold and 2:31 min for threefold acceleration. No differences were found regarding FA (standard DTI: 0.620 ± 0.058; twofold acceleration: 0.642 ± 0.058; threefold acceleration: 0.644 ± 0.061; p ≥ 0.217) and MD (standard DTI: 1.076 ± 0.080 mm{sup 2}/s; twofold acceleration: 1.016 ± 0.123 mm{sup 2}/s; threefold acceleration: 0.979 ± 0.153 mm{sup 2}/s; p ≥ 0.074). Twofold acceleration yielded similar tractography quality compared to standard DTI (p > 0.05). With threefold acceleration, however, average track length and track homogeneity decreased (p = 0.004-0.021). Accelerated DTI of the median nerve is feasible. Twofold acceleration yields similar results to standard DTI. (orig.)

  3. 多层螺旋CT在先天性心脏病的应用现状%Application of multi-slice computed tomography in congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    陈险峰; 马小静; 江帆; 李林

    2014-01-01

    Congenital heart disease belongs to abnormal embryonic development of cardiovascular malformation. It has a lot of changes in pathology. So, it is very important to have a preoperative diagnosis before the operation. Multi-slice computed tomography (MSCT) can analyze illness comprehensive and provide significant proof for clinic. This article expounded the value and situation of it from the historical process of congenital heart disease, the way of check, the characteristic of diagnostic imaging and radiation dose. Clinical practice shows that the imaging advantage of MSCT apply to diagnose complex congenital heart disease. Meanwhile, we should use all kinds of technology to optimize scanning parameters, plan characteristic medical treatments and maximum lower the subjects' radiation dosage.%先天性心脏病属于胚胎发育异常的心血管畸形,其病理改变千差万别,术前诊断对手术治疗尤为重要;多层螺旋 CT 检查能全面分析疾病,为临床提供重要诊断依据。本文从多层螺旋CT检查复杂CHD的历史进程、检查方法、影像诊断特点、辐射剂量的控制四个方面阐述其应用现状。临床实践表明多层螺旋CT的成像优势适用于复杂CHD的诊断,同时应使用各种技术优化扫描参数,制订个性化检查方案,最大限度地降低受检者的辐射剂量。

  4. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Lei Zhen, E-mail: leizhen2004@163.com [Department of Anatomy, Chinese Medical University, No. 92, Beiermalu Road, Heping District, Shenyang, 110001 (China) and Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Ma Heji, E-mail: maheji9831@sina.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xu Na, E-mail: xuna821230@sohu.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xi Huanjiu, E-mail: xihuanjiu2004@yahoo.cn [Anthropology Institute, Liaoning Medical College, No. 40, Sanduan, Songpo Rd, Jinzhou, 121001 (China)

    2011-05-15

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  5. A comparative study for spatial resolution and subjective image characteristics of a multi-slice CT and a cone-beam CT for dental use

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroshi, E-mail: hiro.orad@tmd.ac.jp [Oral and Maxillofacial Radiology, Division of Oral Restitution, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 1138549 (Japan); Honda, Eiichi [Oral and Maxillofacial Radiology, Division of Oral Health Sciences, The University of Tokushima Graduate School (Japan); Tetsumura, Akemi; Kurabayashi, Tohru [Oral and Maxillofacial Radiology, Division of Oral Restitution, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 1138549 (Japan)

    2011-03-15

    Purpose: Multi-slice CT (MSCT) and cone-beam CT (CBCT) are widely used in dental practice. This study compared the spatial resolution of these CT systems to elucidate which CT modalities should be selected for various clinical cases. Materials and methods: As MSCT and CBCT apparatuses, Somatom Sensation 64 and 3D Accuitomo instruments, respectively, were used. As an objective evaluation of spatial resolution of these CT systems, modulation transfer function (MTF) analysis was performed employing an over-sampling method. The results of MTF analysis were confirmed with a line-pair test using CATPHAN. As a subjective evaluation, a microstructure visualization ability study was performed using a Jcl:SD rat and a head CT phantom. Results: MTF analysis showed that for the in-plane direction, the z-axis ultrahigh resolution mode (zUHR) of the Sensation 64 and 3D Accuitomo instruments had higher spatial resolutions than the conventional mode (64x) of the Sensation 64, but for the longitudinal direction, the 3D Accuitomo had clearly higher spatial resolution than either mode of the Sensation 64. A line-pair test study and microstructure visualization ability studies confirmed the results for MTF analysis. However, images of the rat and the CT phantom revealed that the 3D Accuitomo demonstrated the failure to visualize the soft tissues along with aliasing and beam-hardening artifacts, which were not observed in the Sensation 64. Conclusions: This study successfully applied spatial resolution analysis using MSCT and CBCT systems in a comparative manner. These findings could help in deciding which CT modality should be selected for various clinical cases.

  6. MUSIC. a fast T2* - sensitive MRI technique with enhanced volume coverage

    International Nuclear Information System (INIS)

    A fast imaging method based on gradient-recalled echoes and echo time inter-leaved multi-slice excitation is presented. This method maintains the sensitivity of T2* by using a long echo time of at least 35 milliseconds. Bipolar gradients are used to shift the gradient echoes in order to ensure constant TE for each slab and prevent ghost-artefacts within the images caused by spin- or stimulated echoes. This method enhances the total imaging time of a conventional multi-slice gradient echo technique, while maintaining the high volume coverage. Thus, stimulated human cortical activation maps can be detected on standard clinical MR instruments at several planes within measuring times of a few seconds. The efficiency of the technique is demonstrated in the detection of temporary changes in T2* in functional MRI experiments of the human visual cortex at a magnetic field strength of 2 tesla. (author). 18 refs., 6 figs

  7. 多层螺旋CT核磁共振成像诊断腕关节损伤的临床应用研究%Clinical Analysis of Multi Slice Spiral CT Magnetic Resonance Imaging in Diagnosis of Wrist Joint Injury

    Institute of Scientific and Technical Information of China (English)

    全宏卫

    2015-01-01

    目的:探讨多层螺旋CT(MSCT)与核磁共振成像(MRI)诊断腕关节损伤的价值。方法收集腕关节损伤患者112例,分别应用MSCT、MRI和联合诊断,比较三种诊断方法的诊断效能。结果骨折组中MRI对软骨损伤、骨挫伤和隐匿性骨折的检出率显著高于MSCT,而移位碎骨折片、关节脱位以及关节骨折的检出率显著低于MSCT(P<0.05);无骨折组中MRI检出隐匿性骨折、软骨损伤以及骨挫伤均显著高于MSCT,而关节脱位检出率显著低于MSCT(P<0.05)。结论 MSCT联合MRI诊断腕关节损伤具有较高的检出率以及诊断效能,值得推广应用。%Objective To evaluate multi-slice spiral CT (MSCT) and magnetic resonance imaging (MRI) of wrist injury diagnosis. Methods 112 cases of wrist injury, respectively by MSCT, MRI and combined diagnosis, diagnostic ef iciency comparison of three diagnostic methods. Results In the group of MRI fracture detection rate of cartilage, bone contusions and occult fractures were significantly higher than that of MSCT, and shift broken fracture and joint dislocation and the fracture of the joint detection rate was significantly lower than that of MSCT ( <0.05);without fracture in the group of MRI detected occult fracture, cartilage damage and bone contusion were significantly higher than MSCT, while the dislocation rate was significantly lower than that of MSCT ( <0.05). Conclusion MSCT combined with MRI in diagnosis of wrist joint injury detection rate and diagnosis ef iciency is high, it is worthy of popularization and application.

  8. Comparison of two single-breath-held 3-D acquisitions with multi-breath-held 2-D cine steady-state free precession MRI acquisition in children with single ventricles

    Energy Technology Data Exchange (ETDEWEB)

    Atweh, Lamya A.; Dodd, Nicholas A.; Krishnamurthy, Ramkumar; Chu, Zili D. [Texas Children' s Hospital, EB Singleton Department of Pediatric Radiology, Cardiovascular Imaging, Houston, TX (United States); Pednekar, Amol [Philips Healthcare, Houston, TX (United States); Krishnamurthy, Rajesh [Texas Children' s Hospital, EB Singleton Department of Pediatric Radiology, Cardiovascular Imaging, Houston, TX (United States); Baylor College of Medicine, Department of Radiology, Houston, TX (United States); Baylor College of Medicine, Department of Pediatrics, Houston, TX (United States)

    2016-05-15

    Breath-held two-dimensional balanced steady-state free precession cine acquisition (2-D breath-held SSFP), accelerated with parallel imaging, is the method of choice for evaluating ventricular function due to its superior blood-to-myocardial contrast, edge definition and high intrinsic signal-to-noise ratio throughout the cardiac cycle. The purpose of this study is to qualitatively and quantitatively compare the two different single-breath-hold 3-D cine SSFP acquisitions using 1) multidirectional sensitivity encoding (SENSE) acceleration factors (3-D multiple SENSE SSFP), and 2) k-t broad-use linear acceleration speed-up technique (3-D k-t SSFP) with the conventional 2-D breath-held SSFP in non-sedated asymptomatic volunteers and children with single ventricle congenital heart disease. Our prospective study was performed on 30 non-sedated subjects (9 healthy volunteers and 21 functional single ventricle patients), ages 12.5 +/- 2.8 years. Two-dimensional breath-held SSFP with SENSE acceleration factor of 2, eight-fold accelerated 3-D k-t SSFP, and 3-D multiple SENSE SSFP with total parallel imaging factor of 4 were performed to evaluate ventricular volumes and mass in the short-axis orientation. Image quality scores (blood myocardial contrast, edge definition and interslice alignment) and volumetric analysis (end systolic volume, end diastolic volume and ejection fraction) were performed on the data sets by experienced users. Paired t-test was performed to compare each of the 3-D k-t SSFP and 3-D multiple SENSE SSFP clinical scores against 2-D breath-held SSFP. Bland-Altman analysis was performed on left ventricle (LV) and single ventricle volumetry. Interobserver and intraobserver variability in volumetric measurements were determined using intraclass coefficients. The clinical scores were highest for the 2-D breath-held SSFP images. Between the two 3-D sequences, 3-D multiple SENSE SSFP performed better than 3-D k-t SSFP. Bland-Altman analysis for volumes

  9. Multi-slice spiral CT reconstruction in the diagnosis tracheal bronchus%多排螺旋CT重建技术诊断气管性支气管

    Institute of Scientific and Technical Information of China (English)

    童三龙; 邓宏亮; 张凯; 王新正

    2014-01-01

    目的:探讨多排螺旋CT(MSCT)对气管性支气管的诊断及应用价值,认识先天性气管性支气管的临床意义。方法分析5例气管性支气管(TB)患者的MSCT薄层图像及多平面重组(MPR)、最小密度投影(MinIP)、容积再现(VR)及支气管虚拟内镜(VB)等多种后处理图像。结果5例气管性支气管均为右肺上叶尖段支气管发生在气管及右主支气管的右侧壁或右后壁,经多种后处理,均能清晰地显示气管性支气管的起源部位,有无狭窄及其他合并症情况。结论 MSCT无创、操作简单,可作为气管性支气管诊断的首选检查方法。%Objective To investigate the value of diagnosis and application in multi-slice spiral CT (MSCT) for diagnosing tracheal bronchus (TB), and recognize the clinical significance of tracheal bronchus(TB). Methods Ana-lyze the original and reconstructed MSCT images of 5 patients with TB, the reconstruction techniques included multi-planar reconstruction (MPR), minimum intensity projection (MinIP), volume rendering (VR), virtual bronchoscopy (VB). Results Five cases of tracheal bronchus occurred in the trachea or right main bronchus of the right side wall or the right posterior wall. Initiation site, stenosis, other complications of TB can be clearly displayed by various 3D recon-struction technology. Conclusion As a noninvasive and simple examination methods, MSCT should be the first choice in diagnosing TB.

  10. Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography

    Science.gov (United States)

    Kazuno, Yoshio; Maeno, Yoshio; Kawamori, Hiroyuki; Takahashi, Nobuyuki; Abramowitz, Yigal; Babak, Hariri; Kashif, Mohammad; Chakravarty, Tarun; Nakamura, Mamoo; Cheng, Wen; Friedman, John; Berman, Daniel; Makkar, Raj R.; Jilaihawi, Hasan

    2016-01-01

    Aims Stent-frame morphology of the newer-generation, balloon-expandable transcatheter heart valve (THV), the SAPIEN 3 (S3), after transcatheter aortic valve implantation (TAVI) is unknown. We evaluated the THV stent-frame morphology post TAVI of the S3 using multi-slice computed tomography (MSCT) compared with the prior-generation THV, SAPIEN XT (S-XT). Methods and results A total of 94 consecutive participants of RESOLVE registry (NCT02318342) had MSCT after balloon-expandable TAVI (S3 = 39 and S-XT = 55). The morphology of the THV stent-frame was evaluated for expansion area and eccentricity at the THV-inflow, native annulus, mid-THV and THV-outflow levels. Mean %-expansion area for the S3 and the S-XT was 100.9 ± 5.7 and 96.1 ± 5.5%, respectively (P < 0.001). In the S3 group, the THV-inflow level had the largest value of %-expansion area, which decreased from THV-inflow to mid-THV level (105.2 ± 6.4 to 96.5 ± 5.9%, P < 0.001). However, in the S-XT group, %-expansion area increased from THV-inflow level to mid-THV level (93.2 ± 6.2 to 95.1 ± 6.1%, P = 0.0058). On nominal delivery balloon volume, the S3 in 88.5% of cases had overexpansion at the THV-inflow level. The observed degree of THV oversizing of the S3 was significantly lower than the S-XT (6.3 ± 8.6 vs. 11.8 ± 8.5%, P = 0.0027). Nonetheless, the incidence of post-procedural paravalvular aortic regurgitation (PVR) ≥ mild following the S3 TAVI was also significantly lower than the S-XT TAVI (17.9 vs. 43.6%, P = 0.014). Conclusion The newer-generation, balloon-expandable device, the S3, has a flared inflow morphology, whereas the prior-generation device, the S-XT, has relatively constrained inflow morphology post TAVI. This may contribute to a lesser degree of PVR with the S3. PMID:27002141

  11. Assessment of volumetric bone mineral density of the femoral neck in postmenopausal women with and without vertebral fractures using quantitative multi-slice CT

    Institute of Scientific and Technical Information of China (English)

    Sheng-yong WU; Hui-hui JIA; Didier HANS; Jing LAN; Li-ying WANG; Jing-xue LI; Yue-zeng CAI

    2009-01-01

    Objective: To demonstrate the validity and reliability of volumetric quantitative computed tomography (vQCT) with multi-slice computed tomography (MSCT) and dual energy X-ray absorptiometry (DXA) for hip bone mineral density (BMD) measurements, and to compare the differences between the two techniques in discriminating postmenopausal women with osteoporosis-related vertebral fractures from those without. Methods: Ninety subjects were enrolled and divided into three groups based on the BMD values of the lumbar spine and/or the femoral neck by DXA. Groups 1 and 2 consisted of postmenopausal women with BMD changes <-2SD, with and without radiographically confirmed vertebral fracture (n=11 and 33, respectively).Group 3 comprised normal controls with BMD changes ≥-1SD (n=46). Post-MSCT (GE, LightSpeed16) scan reconstructed images of the abdominal-pelvic region, 1.25 mm thick per slice, were processed by OsteoCAD software to calculate the following parameters: volumetric BMD values of trabecular bone (TRAB), cortical bone (CORT), and integral bone (INTGL) of the left femoral neck, femoral neck axis length (NAL), and minimum cross-section area (mCSA). DXA BMD measurements of the lumbar spine (AP-SPINE) and the left femoral neck (NECK) also were performed for each subject. Results: The values of all seven parameters were significantly lower in subjects of Groups 1 and 2 than in normal postmenopausal women (P<0.05, respectively).Comparing Groups 1 and 2, 3D-TRAB and 3D-INTGL were significantly lower in postmenopausal women with vertebral fracture(s) [(109.8±9.61) and (243.3±33.0) mg/cm3, respectively] than in those without [(148.9±7.47) and (285.4±17.8) mg/cm3,respectively] (P<0.05, respectively), but no significant differences were evident in AP-SPINE or NECK BMD. Conclusion: the femoral neck-derived volumetric BMD parameters using vQCT appeared better than the DXA-derived ones in discriminating osteoporotic postmenopausal women with vertebral fractures from

  12. MSCT重组技术对气管破裂的诊断价值%Multi-slice CT and advanced reconstruction techniques in the diagnosis of tracheal rupture

    Institute of Scientific and Technical Information of China (English)

    杨鸿; 杨文; 蒋洪春; 彭湘晖; 曹林德

    2012-01-01

    Objective:To assess the value of multi slice CT (MSCT) with reconstruction techniques in the diagnosis of tracheal rupture. Methods: 128 slice spiral CT (MSCT) scanning was performed in 7 patients with tracheal rupture caused by severe trauma to the neck and thorax,iatrogenic injury and spontaneous tracheal rupture. The images of multipla nar reconstruction (MPR) ,CT virtual endoscopy (CTVE) were obtained on a postprocessing workstation. Results: CT ap pearances of tracheal rupture included defect in trachea with deep cervical air or air tracking into the mediastinum. MPR clearly displayed the shape and size of tracheal defect,the distances between the tracheal defect to some important anatomic landmarks such as tracheal carina, epiglottis and superior border of the manubrium. CTVE showed the tracheal defects in the 5 patients with trauma to the neck and thorax and spontaneous tracheal ruptures. However,the image of CTVE was a little blurred than MPR. Color coded volume rendered images provided realistic 3D views of air leak distribution of the tra cheal rupture. Conclusion: MSCT with reconstruction techniques play an important role in the diagnosis and treatment of tra cheal rupture.%目的:探讨MSCT重组技术对气管破裂的诊断及临床应用价值.方法:回顾性分析7例气管破裂患者的CT资料,病因分别为颈胸部严重外伤、医源性损伤、自发性因素.采用128层螺旋CT对7例患者行颈胸部平扫,原始数据行减薄重组,将减薄重组后的图像传输到工作站进行多平面重组及CT仿真内窥镜(CTVE)观察.结果:气管破口以及溢出的气体均表现为低密度影,气管壁连续性中断,MPR重组可以完整显示破裂口形态和大小、距气管隆突、会厌或胸骨柄上缘等重要解剖标志的距离;2例严重患者在双侧颜面部、颈部、颞下窝、咽旁组织间隙、前后胸壁皮下、纵隔内均有广泛分布的低密度气影;最轻的1例仅见裂口附近的后纵隔内

  13. Multi-slice Spiral CT Manifestation of Parotid Tumors%腮腺肿瘤的多层螺旋CT表现

    Institute of Scientific and Technical Information of China (English)

    侯学文; 张利中

    2016-01-01

    Objective To investigate the multi-slice spiral CT (MSCT) features of parotid tumors to provide clinical references. Methods Retrospective analysis was conducted on the MSCT manifestation of 23 patients whose diagnosis of parotid tumors were confirmed surgically and pathologically (including 3 cases of mucoepidermoid carcinoma, 11 cases of pleomorphic adenoma, 4 cases of adenolymphoma, 2 cases of lipoma, 2 cases of eosinophilic lymphocytes in the granuloma, 1 case of benign myoepithelial tumor). Through the CT manifestation tumor distribution, form, density, edge, cystic degeneration or necrosis, degree of enhancement, cervical lymph node enlargement of 23 cases were studied. Results Most pathological changes of the parotid gland were unilateral, of which 15 were left and 8 were right. Benign tumors usually located at the junction of the superficial lobe of parotid glands and the deep lobe of parotid glands. The shape of benign tumors was round or mass. The boundary was clear, and the density was uniform and higher than the normal parotid gland tissue. As shown by enhancing scanning, the calcification was found in the multiple adenomas and the cystic changes were found in the pleomorphic adenoma. Malignant tumors were usually located in deep lobes and were lobulated. The boundary was less clear. The density was uneven and more dense than normal parotid gland. Enhanced scan revealed inhomogeneous enhancement. Malignant parotid tumors were often accompanied by cervical lymph node enlargement. Conclusion Parotid gland tumors have certain imaging features. MSCT is helpful in the diagnosis and differential diagnosis and has important clinical diagnostic value.%目的:探讨腮腺肿瘤的多层螺旋CT表现,为临床提供参考。方法回顾性分析23例经手术病理证实的腮腺肿瘤患者(粘液表皮样癌3例,多形性腺瘤11例,腺淋巴瘤4例,脂肪瘤2例,嗜酸性淋巴细胞肉芽肿2例,肌上皮良性病变1例)的多层螺旋CT

  14. Multi-slice spiral computed tomography assessment of cardiac diverticula%多层螺旋CT对心脏憩室的诊断价值

    Institute of Scientific and Technical Information of China (English)

    周碧; 赵静; 朱洪章; 杨有优

    2015-01-01

    目的:探讨多层螺旋CT(MSCT)在心脏憩室诊断中的临床价值。方法回顾性分析11例心脏憩室患者的临床及MSCT资料,行多种后处理技术分析心脏憩室形态表现及其他并发异常。结果11例患者心脏憩室均为单发,分别位于左心室(4例)、右心房(3例)、左心房(2例)、右心室(2例)。10例憩室呈囊袋状,1例憩室呈不规则管状,以窄颈与心腔相通,最大径2.5~8.8 cm。本组3例纤维型心室憩室壁薄、伴钙化,2例肌肉型心室憩室壁较厚。3例右心房憩室合并房间隔缺损,1例左心室憩室合并复杂心内外畸形。结论 MSCT能清楚显示心脏憩室位置、形态及大小,可为心室憩室类型判断提供依据,并能提示合并的心内外异常,是较为理想的心脏憩室非侵入性检查手段。%Objective To assess the value of multi-slice spiral computed tomography (MSCT) in the diagnosis of cardiac diverticula. Methods Cardiac MSCT of 11 patients with surgically or pathologically confirmed cardiac diverticula were retrospectively analyzed. Results The cardiac diverticula were isolated and located in the left ventricle (4), right atrium (3), left atrium (2) and right ventricle(2). The diverticula were protruding sac-like(10) or irregular tube-like(1) in shape with longitudinal diameters of 2.5-8.8 cm and were connected to the cardiac cavity by a narrow neck. The diverticular walls were unevenly thin and calcified in 3 fibrous ventricular diverticula and thick in 2 muscular diverticula..Three right atrial diverticula were associated with atrial septal defect and 1 left ventricular diverticulum was accompanied with complex malformations. Conclusion MSCT can clearly depict the location, morphology, size and type of cardiac diverticula and the associated cardiac malformation.

  15. Portal Venous Blood Flow Quantitative Study with Breath-holding 2D PC and Cine PC MRI in Controls and Cirrhotics%电影相位对比与屏气二维相位对比MRI对肝硬化门静脉血流的对照研究

    Institute of Scientific and Technical Information of China (English)

    李彩英; 田建明; 刘怀军; 崔彩霞; 黄勃源; 孟令惠

    2007-01-01

    目的 探讨MRI电影法相位对比(Cine PC)与屏气二维相位对比(2D PC)在肝硬化患者和正常志愿者门静脉血流测量中的诊断价值. 资料与方法 对照组为82名志愿者,男45名,女37名,平均年龄26.65岁;肝硬化组24例,男14例,女10例,平均年龄42.00岁.空腹状态下采用Cine PC技术对门静脉血流定量测量,同期采用2D PC技术3种不同屏气状态(正常吸气屏气,呼气屏气,平静呼吸屏气)与其进行比较. 结果 肝硬化患者门静脉血流速度较对照组略减低,除2D PC平静呼吸法,余方法两组差异均无统计学意义,肝硬化组门静脉血流量与对照组比较明显增大(P<0.01),但2D PC吸气屏气技术两者差异无统计学意义.采用相关性分析对屏气2D PC(不同呼吸状态)与Cine PC MRI方法定量门静脉血流速度、血流量,显示两种技术相关性很好(r>0.8;P<0.01),但在对照组行相关性分析,仅呼气后屏气2D PC与Cine PC显示中度相关(r>0.5;P<0.01),吸气后屏气与Cine PC相关性较差(r<0.4). 结论 MRI Cine PC在正常呼吸情况下对门静脉血流行定量测量,接近人体生理状态,适合门静脉血流测量;正常呼吸状态屏气对肝硬化患者门静脉血流影响较正常人小,在肝硬化血流测量中,MRI Cine PC与屏气2D PC MRI法显示很好相关性.屏气2D PC MRI技术提供了一种简便、实用、相对准确的肝硬化门静脉血流测量方法.

  16. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.

    1999-01-01

    The Activated Sludge Model No. 2d (ASM2d) presents a model for biological phosphorus removal with simultaneous nitrification-denitrification in activated sludge systems. ASM2d is based on ASM2 and is expanded to include the denitrifying activity of the phosphorus accumulating organisms (PAOs...

  17. 多层螺旋CT与核磁共振成像联合诊断腕关节损伤的探析%Multi-slice spiral CT combined with magnetic resonance imaging in diagnose of wrist joint injury

    Institute of Scientific and Technical Information of China (English)

    郭侨阁; 王顺利; 牛军杰; 刘彦; 唐楠; 周龙

    2015-01-01

    Objective To explore significance of multi-slice spiral CT combined with magnetic resonance imaging in the diagnose of wrist joint injury.Methods 168 patients with wrist joint injury admitted into our hospital from January,2012 to September,2014 were investigated.Their clinical data were analyzed.According the different examination methods,the patients were randomly divided into three groups,56 cases for each group.These 3 groups were given multi-slice spiral CT examination,magnetic resonance imaging examination,and multi-slice spiral CT combined with magnetic resonance imaging examination,respectively.The diagnosis situations and the advantages of different examination methods of the three groups were analyzed.Results The detection rate of multi-slice spiral CT was 73.21%,that of magnetic resonance imaging 75.00%,and that of the combination group 96.43%.The statistical analysis showed that there were no significant differences (P> 0.05).However,the detection rate of the combination group was significantly higher than those multi-slice spiral CT and magnetic resonance imaging (P <0.05);The detection rate of the combination of multi-slice spiral CT and magnetic resonance imaging was significantly higher than that of just one of these two examination methods(P <0.05).Conclusions Multi-slice spiral CT combined with magnetic resonance imaging in the diagnosis of wrist joint injury is most effective.It synthesizes the advantages of the two examination methods,improves the detection rate,and makes the specific injury situation clear.It's worth being clinically generalized.%目的 探究采用多层螺旋CT与核磁共振成像联合诊断腕关节损伤的情况.方法 调查研究我院在2012年1月至2014年9月间收治的168例腕关节损伤患者,分析其临床资料,根据检查方法的不同,将本组患者随机分成三组,各56例,分别给予多层螺旋CT检查、核磁共振成像检查和多层螺旋CT联合核磁共振成像检查.分析

  18. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  19. Diagnostic value of multi-slice spiral CT in occult fractures of proximal tibia%多层螺旋CT对胫骨近端隐匿性骨折的诊断价值

    Institute of Scientific and Technical Information of China (English)

    周俊; 陈庆; 许文渊; 姚雯雯

    2012-01-01

    目的 探讨多层螺旋CT对胫骨近端隐匿性骨折的诊断价值.方法 回顾性分析23例数字放射摄影诊断可疑胫骨近端骨折病例的16层螺旋CT的横轴位、多平面重建、容积再现、最大密度投影,观察多层螺旋CT对胫骨近端隐匿性骨折的诊断率.结果 所选病例数字放射摄影均未显示明确骨折线,16层螺旋CT诊断胫骨近端骨折17例,其中胫骨平台骨折13例、胫骨髁间棘骨折4例;排除骨折6例,阳性率达73.9%.结论 多层螺旋CT对临床怀疑胫骨近端骨折而数字放射摄影不能确诊为骨折的病例能准确地作出诊断,对治疗方案的选择及预后的估计有重要价值.%Objective To discuss the diagnostic value of multi-slice spiral CT for the occult fracture of proximal tibia. Methods 23 patients with suspected fracture of proximal tibia by digital radiography were studied, and their images of transverse, multiplanar reconstruction, and volume rendering and maximum intensity projection of 16-slice spiral CT were analyzed. The diagnostic rate for occult fracture of proximal tibia with multi-slice spiral CT was observed. Results Digital radiography showed no definite fracture signs in all patients. 16-slice spiral CT showed fractures in 17 cases, including fractures of tibia plateau in 13 cases and tibia eminence in 4 cases. The other 6 patients showed negative on 16-slice spiral CT images. Conclusion Multi-slice spiral CT can be used to diagnose definitely occult fractures of proximal tibia and plays an important role in selecting therapy project and evaluating prognosis of occult fractures.

  20. Genetic association of glutathione peroxidase-1 with coronary artery calcification in type 2 diabetes: a case control study with multi-slice computed tomography

    OpenAIRE

    Fujimoto Kei; Nishioka Makiko; Miyashita Yumi; Hiki Yoshito; Sasaki Takashi; Nishimura Rimei; Nemoto Masami; Sakuma Toru; Ohashi Toya; Fukuda Kunihiko; Eto Yoshikatsu; Tajima Naoko

    2007-01-01

    Abstract Background Although oxidative stress by accumulation of reactive oxygen species (ROS) in diabetes has become evident, it remains unclear what genes, involved in redox balance, would determine susceptibility for development of atherosclerosis in diabetes. This study evaluated the effect of genetic polymorphism of enzymes producing or responsible for reducing ROS on coronary artery calcification in type 2 diabetes (T2D). Methods An index for coronary-arteriosclerosis, coronary artery c...

  1. Clinical application of multi-slice helical CT in the diagnosis of costal cartilage fracture%MSCT在肋软骨骨折诊断中的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    何永新; 袁新

    2011-01-01

    目的:探讨多层螺旋CT(MSCT)在肋软骨骨折诊断中的应用价值,提高诊断水平.方法:回顾性分析21例共35处肋软骨骨折的多层螺旋CT表现和临床资料.结果:本组21例共35处肋软骨骨折,CT表现特征为肋软骨钙化中断伴明显错位、肋软骨条状高密度影不连续伴明显错位或错位不明显.结论:多层螺旋CT能清晰显示肋软骨骨折的部位、数目、形态及移位情况,对肋软骨骨折的诊断具有重要价值.%Objective: To evaluate the value of multi-slice helical CT in diagnosing costal cartilage fracture so as to improve the level of imaging diagnosis. Methods:The imaging data of CT and clinical information of 35 costal cartilage fracture in 21 cases were analyzed. Results:35 costal cartilage fracture in 21 cases were found, CT findings included interruption of calcified costal cartilage with obvious malposition and discontinuous focal high-density of costal cartilage with obvious or obscure malposition. Conclusion:Multi-slice spiral CT can display the position, number, pattern and displacement of costal cartilage fracture clearly. It has qrcat value in the diagnosis of costat cartilage fracture.

  2. 多层螺旋CT后处理技术在膝关节交叉韧带MR扫描方式中的应用%Application of multi-slice spiral CT images post-processing in MR scanning mode for the cruciate ligament of knee joint

    Institute of Scientific and Technical Information of China (English)

    严由伦; 李荣; 董燕; 余建国

    2013-01-01

    locating line was parallel with the inner side of the lateral condyle, or incline inward 10 degree with sagittal plane. On the coronal plane, the locating line was parallel with the line which was connected by the intcrcon-dylar eminence and intcrcondylar fossa, or inclines outward 15 degree with lower limb long axis) and the oblique coronal planc( using transverse and sagittal plane as a locating line. On the transverse plane, the locating line was parallel with the line which was connected by the posterior margin between inner condyle and lateral condyle. On the sagittal plane, the locating line was parallel with the direction of anterior cruciate ligament, or incline 35 - 40 degree with conronal) were reconstructed by anatomy course of the knee joint cruciate ligament. Finally, the cruciate ligament images of knee joint was estimated, and the locating method for oblique sagittal plane and the oblique coronal plane were used in MR scanning. Results The cruciate ligament images of knee joint for multi-slice spiral CT and magnetic resonance image had same result statistically. There was no difference between MSCT and MRI. The display rate of the anterior cruciate ligament on the oblique coronal plane were 100%, and on the oblique sagittal plane 98% , the display rates of the posterior cruciate ligament on the sagittal plane was 100% on MR imaging. Conclusion The multi-slice spiral CT had given instructions to assist optimal orientation of MR imaging the cruciate ligament of knee joint, which is simple and easy operation.

  3. Lectures on 2D gravity and 2D string theory

    International Nuclear Information System (INIS)

    This report the following topics: loops and states in conformal field theory; brief review of the Liouville theory; 2D Euclidean quantum gravity I: path integral approach; 2D Euclidean quantum gravity II: canonical approach; states in 2D string theory; matrix model technology I: method of orthogonal polynomials; matrix model technology II: loops on the lattice; matrix model technology III: free fermions from the lattice; loops and states in matrix model quantum gravity; loops and states in the C=1 matrix model; 6V model fermi sea dynamics and collective field theory; and string scattering in two spacetime dimensions

  4. 2D-hahmoanimaation toteuttamistekniikat

    OpenAIRE

    Smolander, Aku

    2009-01-01

    Opinnäytetyössä tutkitaan erilaisia 2D-hahmoanimaation toteuttamistekniikoita. Aluksi luodaan yleiskatsaus animoinnin historiaan ja tekniikoihin piirtämisestä mallintamiseen. Alkukatsauksen jälkeen tutkitaan 2D-hahmon suunnittelua ja liikkeitä koskevia sääntöjä. Hahmoanimaation liikkeissä huomionarvoisia asioita ovat muun muassa ajastus, liioittelu, ennakointi ja painovoima. Seuraavaksi perehdytään itse 2D-hahmoanimaation toteuttamistekniikoihin. Tavoitteena on selvittää, tutkia ja vertailla ...

  5. Value of multi-slice spiral CT in the diagnosis of small hepatocellular carcinoma%多排螺旋CT灌注成像对小肝癌诊断价值

    Institute of Scientific and Technical Information of China (English)

    王恩峰; 陈文军; 苏保民; 程明; 赵新宇; 张立彬; 王丽梅

    2012-01-01

    Objective To study the diagnostic value of multi-slice spiral CT (MSCT) dynamic contrast-enhanced perfusion imaging in small hepatocellular carcinoma (SHCC) and improve the diagnostic accuracy of SHCC. Methods Multi-slice spiral CT dynamic contrast-enhanced perfusion imaging was used in 23 patients with SHCC, and the time-density curve(T-DC) were gotten. Blood flow( BF) , blood volume ( BV ) , hepatic arterial fraction ( HAF) , mean transit time(MTT) , permeability surface (PS) and time of arrival of SHCC and liver parenchyma were measured, and the colored perfusion maps for each of the above-mentioned parameters were acquired. Also the receiver operating characteristic curves ( ROC) were analyzed. Results SHCC showed BF,BV and HAF higher than those of the liver parenchyma(P 0. 05). T-DC of SHCC was fast rise, and its peak was significantly earlier than the liver parenchyma. Especially in hepatic arterial fraction determination, when ROC critical value was set to 0. 31, the sensitivity and specificity can be achieved respectively 100% and 90%. Conclusion Hepatic CT perfusion imaging is important for the diagnosis of small hepatocellular carcinoma.%目的 研究多排螺旋CT(multi-slice spiral CT,MSCT)动态增强灌注成像对小肝癌(small hepatocellular carcinoma,SHCC)的诊断价值,提高SHCC的诊断准确率.方法 使用多排螺旋CT对23例小肝癌患者行动态增强灌注成像,生成时间-密度曲线(time-density curve,T-DC),测量肝癌病灶及肝实质的CT灌注值包括血流量(blood flow,BF)、血容量(blood volume,BV)、肝动脉分数(hepatic arterial fractin,HAF),平均通过时间(mean transit time,MTT)、血管表面通透性(permeability suface,PS)和对比剂到达时间,并获得相应的灌注伪彩图.分析接受者工作特征曲线(receiver operating characterisic curves,ROC).结果 小肝癌血流量、血容量及肝动脉分数值均明显高于肝实质(P<0.05),其它的灌注值在两者

  6. Post-processing techniques of multi-slice spiral CT in normal orbital related structures%MSCT后处理技术在眶骨正常解剖中的应用

    Institute of Scientific and Technical Information of China (English)

    李晓; 李春卫; 张峰峰; 徐卓东

    2011-01-01

    Objective: To explore the value of post-processing techniques of multi-slice spiral CT(MSCT) in normal orbiral related structures. Methods: 207cases with the source images of normal orbit were retrospectively reviewed and processed using multiple planar reformation ( MPR) , curved planar reformation (CPR ) , volume rendering rechnique ( VRT).The show results of conventional and reconstructed sections were statistically analysed. Results : The orbital related structures can be display symmetrically by the standard section. The display rate of sutura nygomaticofrontalis. the canal of temporal bone , infraorbital canal, supraorbital notch and optic canal in the standard section was significantly higher than in conventional images ( P <0.05). There was no difference in the display rate of the sutura zygomaticosphenoidalis ( P >0. 05), Conclusion:① The post-processing of multi-slice CT isotropic scanning can reduce the radiation dose and avoid the difficulty in positioning patient;② The orbital related structures can be display very well after post processing with multislice CT isotropic scanning by using the post-processing rechniques.%目的:探讨多层螺旋CT后处理技术在眶骨正常相关结构中的应用价值.方法:收集207例正常眶骨被检者的多层螺旋CT图像,对所得图像进行MPR,CPR,VRT后处理,对某些结构常规显示断面和标准化断面的显示结果进行统计学分析.结果:重组后的标准化图像能清晰显示眶骨相关结构的左右对称情况.标准化图像对颧额缝、颧骨管、眶下管、眶上切迹及视神经管的对称性显示明显优于常规扫描图像(P<0.01):而对颧蝶缝的显示无明显差异(P>0.05).结论:①利用多层螺旋CT各向同性扫描进行后处理在避免摆位困难的同时,减少了患者的辐射剂量;②多层螺旋CT各向同性扫描结合多种后处理技术能够很好地对称显示眼眶相关结构.

  7. Multi- slice CT imaging of costal cartilaginous and anatomic shape of adult%多层螺旋CT肋软骨成像及成人肋软骨形态学研究

    Institute of Scientific and Technical Information of China (English)

    向子云; 周伟生; 罗良平; 肖树恺; 韦日宇

    2004-01-01

    目的探讨多层螺旋CT肋软骨成像方法及成人肋软骨的形态学表现.方法对100例无肋软骨病症者行多层螺旋CT容积扫描,扫描完后将图像导入CT 3D工作站,用软件MPR、MIP、SSD及VRT进行图像后处理,由两位有经验的影像科医生一起对图像进行分析和评价.结果100例受检者的CT扫描图像经过MPR、MIP、SSD及VRT进行后处理后均能显示出肋软骨,其中以MIP、VRT及SSD的效果较好.结论多层螺旋CT能很好地显示肋软骨,为在活体上研究肋软骨形态学开创了一条全新途径,是一种无创伤性研究肋软骨疾病的最佳影像学方法.%Objective: To Study the method of multi-slice CT in costal cartilaginous resemble and the anatomic shape of adult costal cartilaginous. Methods: MSCT examination was made in 100 cases that have no the costal cartilaginous disease, then the row date was trans mitted to the CT 3 D work station, source images were processed using post-processing software - the MPR, MIP, SSD and VRT ,All of images were analysed and evaluated by two radiologists. Results: 100 cases multi - slice CT imaging can all display the costal cartilaginous, among them the images with MIP, VRT and SSD are the best. Conclusions:MSCT can nicely show the costal cartilaginous imaing, for on the live research costal cartilaginous anatomic shape to found a new pathed, is the best research method and have no wound in diagnosis costal cartilaginous disease.

  8. 多层螺旋CT尿路成像在上尿路疾病中的应用%Application of Multi-slice Spiral CT Urography in Diagnosis of Upper Ureteric Diseases

    Institute of Scientific and Technical Information of China (English)

    李建勇; 程树林; 陈双全; 朱平宇; 廖波

    2013-01-01

    目的探讨多层螺旋CT尿路成像(CTU)在上尿路疾病中的临床应用价值。方法对41例经B超或IVP检查显示上尿路疾病患者行螺旋 CT扫描,并行三维重建,将诊断与手术结果进行对照。结果41例中输尿管狭窄20例,肾盂及输尿管肿瘤10例,输尿管结石8例,结核3例。CTU均立体直观地显示病变形态及其与周围组织的关系,诊断与最终手术结果均相符。结论 CTU是一种安全有效的非侵袭性的影像学检查方法,对上尿路疾病的诊断具有极高价值。%Objective To assess the diagnostic value of multi slice spiral CT urography (CTU) in patients with upper urinary tract diseases. Methods 41 patients with upper urinary tract diseases confirmed by B-ultrasound or IVP performed multi slice spiral CT urography (CTU) scan and the three dimensional reconstructions. The imaging findings were checked with post operative pathological findings. Results In the 41 cases , congenital stricture in ureteropelvic junction or ureterovesical orifice were found in 20 cases ,21 patients were diagnosed as pyeloureter neoplasm (10 cases) , ureter negative stone (8 cases),tuberculosis of ureter (3 cases).CTU provided high resolution images of the pelvis and ureter tract in al patients. All the cases were confirmed by operation.Conclusion CTU is a safe, highly efficient and noninvasive method, it plays important role in the diagnosis of urinary diseases.

  9. 多层螺旋CT在结肠癌诊断中的临床应用研究%Multi slice spiral CT in diagnosis of colon cancer clinical application study

    Institute of Scientific and Technical Information of China (English)

    王日武

    2012-01-01

    OBJECTIVE To study the multi-slice spiral CT in diagnosis of colon cancer and clinical application value. METHODS A retrospective study included 106 patients with colon cancer, and they were divided into regular CT examination as observation group and not receiving CT examination as the control group. We observed tumor staging and grading, intraopera-tive and postoperative parameters. RESULTS The patients in the observation group tumor TNM stage and histological grade were better than the control group; The operation time, intraoperative bleeding, blood transfusion, postoperative drainage volume, exhaust time, recovery time, postoperative hospital stay, HAMA score, VAS score were significantly lower than that in the control group. MUNSH score and QOLS score was significantly higher than that of control group. CONCLUSION Multi slice spiral CT in favor of colon cancer early detection and treatment for colon cancer, and the diagnosis process has positive significance.%目的 研究多层螺旋CT在结肠癌诊断中的临床应用价值.方法 回顾性研究106名结肠癌患者,分为定期接受CT检查的观察组和未接受CT检查的对照组,观察肿瘤的分期和分级、术中和术后各项指标.结果 观察组患者肿瘤TNM分期及病理分级情况均好于对照组;手术时间、术中出血量、输血例数、术后引流量、排气时间、下床时间、术后住院时间、HAMA评分、VAS评分明显低于对照组,MUNSH评分、QOLS评分明显高于对照组.结论 多层螺旋CT有利于结肠癌的早期发现和治疗,对于结肠癌的诊治过程具有积极意义.

  10. Clinical Application of Multi-slice Spiral CT Scanning with Dental Planning in Extraction of Impacted Teeth%MSCT全景齿科重组在埋伏牙拔除中的临床价值

    Institute of Scientific and Technical Information of China (English)

    王振平; 罗是是; 李国; 李建军; 余宁; 陈井鑫

    2014-01-01

    目的 探讨MSCT齿科重组在颌骨埋伏牙诊断和治疗中的临床价值.方法 对20例埋伏牙病例进行256层螺旋CT扫描,并通过Dental planning软件进行齿科全景重组后处理,对埋伏牙进行定位诊断.结果 20例患者共27颗埋伏牙均被精确定位,埋伏牙的牙体形态、位置以及与邻牙的关系均清晰显示,并根据Dental planning 软件分析最佳手术入路后均顺利拔除埋伏牙.结论 MSCT全景齿科重组是一种高效准确的定位诊断埋伏牙的方法,在埋伏牙拔除的方案制定中有重要的指导价值.%Objective To investigate the clinical application of multi-slice CT scanning with dental planning software in diagnosing and treating the impacted teeth.Methods 256-slice spiral CT scanning was performed in 20 cases with impacted teeth in jaw bone.By using dental planning software the reconstruction of panoramic structures was conducted,and the exact localization of the impacted teeth in jaw bone was determined.Results A total of 27 impacted teeth were detected in 20 patients.The tooth shape,location and its relationship with the neighboring teeth,including the morphology of tooth crown and root,the direction of impacted teeth eruption and the neighboring anatomy,were clearly displayed in all patients.According to dental planning software analysis,the optimal surgical access was worked out.Successful extraction of impacted teeth was accomplished in all patients.Conclusion Multi-slice spiral CT scanning with dental planning is an effective and accurate method for precise localization of impacted teeth.It has an important value in guiding the extraction of impacted teeth.

  11. Accretion Disks Phase Transitions 2-D or not 2-D?

    CERN Document Server

    Abramowicz, M A; Igumenshchev, I V; Abramowicz, Marek Artur; Bjornsson, Gunnlaugur; Igumenshchev, Igor V.

    2000-01-01

    We argue that the proper way to treat thin-thick accretion-disk transitions should take into account the 2-D nature of the problem. We illustrate the physical inconsistency of the 1-D vertically integrated approach by discussing a particular example of the convective transport of energy.

  12. The Clinical Value of Multi-slice CT Perfusion in the Differentiation of Lung Lesions%多层CT灌注技术在鉴别肺占位病变的临床价值

    Institute of Scientific and Technical Information of China (English)

    何建平; 白毓

    2015-01-01

    目的:探讨多层CT灌注技术在鉴别肺占位病变中的应用价值。方法前瞻性分析我院自2013年2月-2015年2月收治的92例肺部占位病变患者,其中肺癌58例,病灶直径2-7cm,34例为良性,其中肺结核14例,肺脓肿6例,炎性假瘤2例,非特异性炎症6例,错构瘤4例,曲菌球2例,病灶直径2-5cm,所有病例均行多层CT灌注扫描,图像传输至工作站,应用肿瘤软件包分析,记录病变BV(血容积)、BF(血流量)、PS(表面渗透性)、MTT(平均通过时间),分析多层CT灌注成像在鉴别肺肿瘤病变中的应用价值。结果本组92例肺部占位患者,恶性病变患者灌注参数BF、BV、MTT、PS参数均较良性组高,两组间BV、MTT及PS参数差异有统计学意义(P<0.05),以BV值≥6mg/100g作为恶性病变阈值,则多层CT灌注成像诊断良性组符合率为64.71%,恶性组符合率则达100.00%。若以PS值≥30ml/min·100g作为恶性病变阈值,34例良性肺病变中,30例确诊,符合率为88.24%,4例误诊(肺结核2例,肺脓肿2例),58例恶性病变中,50例确诊,8例误诊,符合率为86.21%。结论恶性肺肿瘤CT灌注参数BV、PS值均高于良性组。多层螺旋CT灌注成像检查,可反映不同性质肺肿瘤病变微血管特征,有利于良恶性肿瘤的鉴别。%Objective To investigate the application value of multi-slice CT perfusion in the differentiation of lung lesions.Methods A total of 92 cases lung lesions patients which admitted into the hospital during February 2013 to February 2015 were prospectively analyzed. Among the objects, 58 cases were lung cancer with the diameter of 2-7cm,34 cases were benign lesions, including pulmonary tuberculosis (14 cases), lung abscess (6 cases), inflammatory pseudotumor in (2 cases), nonspecific inflammation(6 cases), hamartoma in (4 cases), and Aspergillus in (2 cases). The diameters of the lesions were 2 to 5cm. All cases underwent multi-slice

  13. Application of Multi-slice Spiral Computed Tomography To Diagnose Hyoid Fracture%多层螺旋CT对舌骨骨折的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    周建中; 石士奎; 季立平

    2008-01-01

    目的 探讨多层螺旋CT(multi-slice spiral computed tomography,MSCT)对舌骨骨折的诊断价值,提高对舌骨骨折临床重要性的认识.方法 回顾性分析6例舌骨骨折的MSCT及临床表现特点.结果 本组6例舌骨骨折中,舌骨大角骨折1例,舌骨体部骨折1例,舌骨大角与体部连接处骨折4例,其中舌骨大角与体部连接处骨折MSCT仅表现为连接处间隙增宽、错位,未见明确骨皮质连续性中断征象.结论 MSCT对舌骨骨折具有重要的诊断价值,对可疑舌骨骨折患者应行MSCT检查.

  14. 多层螺旋CT对肝外梗阻性黄疸的诊断价值%Diagnostic value of multi-slice spiral CT in extrahepatic obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    王小仁; 张云; 蔡顺达

    2015-01-01

    Objective To explore the diagnostic value of multi-slice spiral CT in extrahepatic obstructive jaundice.Methods MSCT findings in 12 cases ofextrahepatic obstructive jaundice confirmed by the surgery and clinic were retrospectively analyzed.Results Among 12 cases,10 cases were subjected to anhanced scanning;Among all cases,6 cases of bile duct carcinoma,3 cases of carcinoma of head of pancreas, 3 cases of bile duct stones.Conclusion CT scan can clearly without obstruction, determining the site of obstruction,further qualitative diagnosis.%目的:探讨多层螺旋CT对梗阻性黄疸的诊断价值。方法:回顾性分析由手术和临床证实的12例患者的CT资料。结果:12例患者中,10例行CT平扫加增强扫描;12例患者中胆管癌6例,胰头癌3例,胆管结石3例。结论:CT检查可明确有无梗阻的存在,确定梗阻部位,进一步行定性诊断。

  15. SES2D user's manual

    International Nuclear Information System (INIS)

    SES2D is an interactive graphics code designed to generate plots of equation of state data from the Los Alamos National Laboratory Group T-4 computer libraries. This manual discusses the capabilities of the code. It describes the prompts and commands and illustrates their use with a sample run

  16. Computational 2D Materials Database

    DEFF Research Database (Denmark)

    Rasmussen, Filip Anselm; Thygesen, Kristian Sommer

    2015-01-01

    , and comparison is made with different density functional theory descriptions. Pitfalls related to the convergence of GW calculations for two-dimensional (2D) materials are discussed together with possible solutions. The monolayer band edge positions relative to vacuum are used to estimate the band alignment...

  17. Aero Fighter - 2D Gaming

    CERN Document Server

    Ahmed, Zeeshan

    2010-01-01

    Designing and developing quality based computer game is always a challenging task for developers. In this paper I briefly discuss aero fighting war game based on simple 2D gaming concepts and developed in C & C++ programming languages, using old bitmapping concepts. Going into the details of the game development, I discuss the designed strategies, flow of game and implemented prototype version of game, especially for beginners of game programming.

  18. Comparative study on the clinical value between multi slice spiral CT urography and intravenous pyelography%多层螺旋CT尿路成像与静脉肾盂造影的临床价值对比研究

    Institute of Scientific and Technical Information of China (English)

    傅其添; 林忠伟; 陈恩明

    2014-01-01

    目的:通过对比多层螺旋 CT 尿路成像(MDCTU)和静脉肾盂造影(IVP)对泌尿系统疾病检出和诊断准确率,探讨MDCTU检查对泌尿系统疾病的临床应用价值和对IVP的优良替代性。方法:2011-2013年收治泌尿系疾病患者75例,均接受MDCTU和IVP检查。比较两种检查方法对泌尿系统疾病的检出及诊断差异,并与手术病理或临床随访结果对照。结果:经手术病理或临床随访证实,共发现结石39例,肿瘤14例,炎症8例,肾囊肿8例,创伤3例,先天性畸形3例。75例患者中MDCTU和IVP检查诊断检出率分别为96%(72/75)、52%(42/75),两者差异有统计学意义(P<0.05)。结论:CTU能够提供IVP所无法具备的丰富的诊断信息,对泌尿系统疾病检出、定性、周边侵犯等方面诊断明显优于IVP,完全可代替IVP而成为临床常规检查。%Objective:By comparing the detection rate and the accurate rate of diagnosis of multi slice spiral CT urography(MDCTU) and multi-slice spiral CT imaging and urinary detection(MDCTU) and intravenous pyelography(IVP) in urinary system diseases,to explore the clinical application value and excellent alternative to IVP of MDCTU examination in urinary system disease.Results:75 cases with urinary tract diseases were selected from 2011 to 2013.They were given MDCTU and IVP examination.We compared the detection rate and the accurate rate of the two check modes,and compared it with operation and pathology or clinical follow-up results.Results:Proved by operation and pathology or clinical follow-up,39 cases were calculi;14 cases were tumor;8 cases were inflammation;8 cases were renal cysts;3 cases were trauma;3 cases were congenital malformation.In 75 cases,the detection rate of MDCTU and IVP were 96% (72/75) and 52% (42/75),and the difference was statistically significant(P<0.05).Conclusion:CTU can provide abundant diagnostic information which IVP cannot be made.The diagnosis of urinary

  19. Evaluation of multi-slice spiral CT perfusion on blood supply of rabbits model bearing VX2 hepatic carcinoma%多排螺旋CT灌注成像对兔VX2肝癌血供的评价

    Institute of Scientific and Technical Information of China (English)

    周悦; 高剑波; 杨学华; 张永高; 岳松伟; 曲艳红

    2011-01-01

    Aim:To assess the diagnostic value of Muhi-slice CT perfusion for blood supply evaluation of the rabbits VX2 hepatic tumors. Methods: VX2 hepatic carcinoma mass were implanted into the left lobe of liver of 30 rabbits via laparotomic route. Multi-slice CT enhancement and perfusion were performed in these rabbits at twenty-one day after implantation. The CT imaging features of the tumors were observed and the perfusion parameters were measured in the rim of the tumor, non-tumorous regions nearby the tumor and the normal liver tissues. Results: Twenty-five (83%) rabbits were sucessfully implanted with the tumor. The tumors which has smooth border were demostrated itself as the round-shaped tumors with hypodensity on plain CT scan,significantly tinge-enhancement on arterial phase, relatively hypodensity on portal phase and no enhanced in the zone of necrosis. Blood flow, blood volume, permeability surface, hepatic arterial fraction, hepatic arterial perfusion increased and mean transit time decreased in the rim of the tumor compared with those of the non-normorous regions nearby the tumor and the normal liver ( P < 0.05). Conclusion: Multi-slice CT perfusion could evaluate the blood supply station of hepatic tumors in vivo by perfusion parameters.%目的:探讨多排螺旋CT灌注成像对兔VX2肝癌血供的评价价值.方法:采用开腹瘤组织块直接包埋法将VX2肝癌移植瘤植入30只新西兰大白兔肝左叶,并于种植后第21天行多排螺旋CT增强及灌注扫描,观察其CT征象,并对比肿瘤边缘区、瘤旁肝组织以及对照肝组织的CT灌注参数(血流量、血容量、平均通过时间、表面通透性、肝动脉分数以及肝动脉灌注量).结果:25只(83%)大白兔种植成功.CT平扫肿瘤为类圆形低密度灶;增强动脉期病灶表现为边缘环状强化;门脉期呈相对低密度,中心见低密度坏死区,与周围组织界限较清.CT灌注成像结果:肿瘤边缘区、瘤旁肝组织及对照肝

  20. 中央型小细胞肺癌和鳞癌的多层螺旋CT表现分析%Analysis of Multi Slice Spiral CT in Central Type Small Cell Lung Cancer and Squamous Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    陈亮

    2016-01-01

    目的:对中央型小细胞肺癌和鳞癌的多层螺旋 CT 表现进行分析探讨,为今后的临床诊断工作,提供有价值的参考信息。方法选择2014年8月~2015年5月我院收治的获得明确诊断的,中央型小细胞肺癌与鳞癌患者共计48例作为研究对象,对其展开多层螺旋 CT 检查,并对检查资料展开回顾性分析。结果观察发现,中央型小细胞肺癌患者的胸膜腔存在积液、远处有转移、支气管狭窄无阻塞、心脏大血管受到侵害、肺叶发生实变、纵隔肺门淋巴结肿大、淋巴结融合发生率较鳞癌患者高(P <0.05);对比发现,两组患者心包腔积液、胸膜结节、支气管不全性阻塞、肺不张发生率比较,差异无统计学意义(P >0.05)。鳞癌患者肿瘤不均匀强化、坏死、支气管闭塞发生率较中央型小细胞肺癌高(P <0.05)。结论中央型小细胞肺癌、鳞癌患者的多层螺旋 CT 表现存在一定差异,综合分析,可做出准确鉴别。%Objective Purpose of center type smal cel lung cancer and squamous cel carcinoma of the multislice spiral CT findings were analyzed for future clinical work,providing valuable reference information. Methods From August 2014 to May 2015,our hospital access to diagnosis,central smal cel lung cancer in patients with squamous cel carcinoma of 48 cases studied,the multi-slice spiral CT examination and check the information retrospectively. Results Observed that patients with central type smal cel lung cancer pleural cavity effusion,distant have transfer,bronchial stenosis,non blocking, heart and great vessels have been infringed,lobar occur consolidation,mediastinal and hilar lymph nodes,lymph node fusion rate is high in patients with squamous cel carcinoma(P 0.05)in two groups of patients with pericardial effusion, pleural nodules,bronchial obstruction,and the incidence of lung failure. The incidence of non homogeneous enhancement

  1. 多排螺旋CT与CR在肋骨骨折诊断中的比较%Comparison of Multi-slice Spiral CT and CR in Rib Fracture

    Institute of Scientific and Technical Information of China (English)

    高雷

    2016-01-01

    Objective Evaluation of row Multi-slice Spiral CT and CR use value in the diagnosis of rib fracture, and to discuss the advantages of two different methods in the diagnosis of rib fracture, so look for ways to improve the accuracy of diagnosis. Methods Retrospective analysis of 60 patients who check rib fracture from 2014 to 2015 in our hospital because of chest trauma. The patients were randomly divided into CT inspection group and CR inspection group, and each group of 30 cases. Among them CT inspection group: male 19, female 11; CR inspection group: male 17, female 13. Two radiologists doctor diagnosis with double-blind method. Results 1 ~ 3 ribs: The diagnostic accuracy of CT was 46.3% (25/54), and the diagnostic accuracy of CR was 74.4% (32/43);4~8 ribs:The diagnostic accuracy of CT was 88.5% (119/135), and the diagnostic accuracy of CR was 55.1% (81/147); 9~12 ribs: The diagnostic accuracy of CT was 91.7% (55/60), and the diagnostic accuracy of CR was 53.2% (33/62). False positive misdiagnosis rate of CT was 15.1% (71/471), and false positive misdiagnosis rate of CR was 7.1% (33/468). Conclusion Multi-slice spiral CT and CR each other and cooperate with the inspection can effectively improve the accuracy of diagnosis of rib fracture, meanwhile reduce missed diagnosis and misdiagnosis rate.%目的:评价多排螺旋CT与CR在肋骨骨折诊断中的运用价值,探讨两种检查方法各自诊断肋骨骨折的优势,寻找提高诊断准确性的检查方法。方法回顾性分析2014~2015年60例因胸部外伤后来我院行影像学检查诊断有无肋骨骨折的患者。将患者随机分为CT检查组和CR检查组,每组30例。其中CT检查组:男19例,女11例;CR检查组:男17例,女13例。由放射科两名主治医师采用双盲法进行诊断。结果第1~3肋骨:CT诊断准确率为46.3%(25/54),CR诊断准确率为74.4%(32/43);第4~8肋骨:CT诊断准确率为88.5%(119/135),CR诊断准确率为55.1%(81/147);第9~12

  2. Clinical value of multi-slice helical CT angiography in diagnosis of cerebral vascular diseases%MSCTA在脑血管性疾病诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    宁殿秀; 李智勇; 王克礼

    2006-01-01

    Objective: To evaluate the clinical value of multi-slice helical CT angiography (MSCTA) in diagnosis of cerebral vascular diseases.Methods: 52 patients with cerebral vascular diseases were examined with GE Light Speed 4-slice and 16-slice helical CT.Pitch: 0.5-3,slice thickness: 0.625-1.25 mm,adult injection dosage: 90-100 mL,children injection dosage: 2 mL/kg,injection rate: 2.5-4.0 mL/s,delay time: 15-22 s.Intelligent track scan (Smart prep Rx) were adopted in parts of these cases.Three-dimensional cerebral vascular images were processed at ADW 3.1 and ADW 4.2 workstation.Results:MSCTA could clearly display spacious anatomic details of cerebral aneurysm,including its origin,size,neck width,and trend etc.MSCTA results of 19 cases were consistent with those of operations.The diameter of the smallest cerebral aneurysm shown in our research was about 3 mm.As a non-invasive examination,MSCTA could also be applied in post-operational evaluation of cerebral aneurysm by observing the location of silver clip and the distant vessels.Besides,MSCTA could be used to diagnose arteriovenous malformation and moyamoya disease.Of all the three-dimentional imaging methods,volume rendering (VR)is the best means to display the cerebral vascular diseases.Conclusion: As a non-invasive examination,MSCTA plays an important role in detection,pre-operational and post-operational evaluation of cerebral vascular diseases.

  3. The Effects Analysis of Multi-slice Spiral CT Perfusion Imaging of Different Parts of Normal Pancreas%正常胰腺不同部位的多层螺旋CT灌注成像效果分析

    Institute of Scientific and Technical Information of China (English)

    黄英荷; 杜绪仓

    2013-01-01

    目的:对正常胰腺不同部位的多层螺旋CT灌注成像效果进行分析。方法:抽取行中上腹部CT增强检查而胰腺正常的病例20例作为研究对象,对其胰腺头部、体部以及尾部感兴趣区层面进行CT灌注扫描,对采集的影像数据使用相关灌注软件进行计算,并对灌注参数进行统计学分析。结果:患者正常胰腺的头部、体部以及尾部的灌注参数均无统计学意义,P>0.05。结论:正常胰腺的头部、体部以及尾部的CT灌注参数基本一致。%Objective:To analyze the multi-slice spiral CT perfusion imaging effects of different parts of the normal pancreas Methods:20 patients with normal pancreas were included in this study from January 2010 to December 2011. All Cases underwent contrast-enhanced CT scan and perfusion imaging with pancreatic head,body and tail which included the region of interest (ROI). The perfusion parameters were calculated and statistically analyzed by using the correlational perfusion software. Results:There were not significantly perfusion parameters difference among the head, body and tail of pancreas, P>0.05.Conclusion:The perfusion parameters of normal pancreatici are even consistent.

  4. Chest MRI

    Science.gov (United States)

    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  5. 2D-animaatiotuotannon optimointi

    OpenAIRE

    Saturo, Reetta

    2015-01-01

    Tämän opinnäytetyön tavoitteena on tutkia 2D-animaatiotuotannon optimoinnin mahdollisuuksia tiukan tuotantoaikataulun vaatimuksissa. Tutkielmassa tarkastellaan kahta asiakasprojektia, jotka on toteutettu pienellä tuotantotiimillä. Työkaluna animaatioissa on käytetty pääosin Adoben After Effects -ohjelmistoa. Tutkielman alussa esitellään animaatiotuotannot, joiden tuloksena syntyi kaksi lyhyttä mainoselokuvaa. Sen jälkeen käydään läpi animaatioelokuvan tuotantoprosessia vaiheittain ja tark...

  6. Head First 2D Geometry

    CERN Document Server

    Fallow), Stray

    2009-01-01

    Having trouble with geometry? Do Pi, The Pythagorean Theorem, and angle calculations just make your head spin? Relax. With Head First 2D Geometry, you'll master everything from triangles, quads and polygons to the time-saving secrets of similar and congruent angles -- and it'll be quick, painless, and fun. Through entertaining stories and practical examples from the world around you, this book takes you beyond boring problems. You'll actually use what you learn to make real-life decisions, like using angles and parallel lines to crack a mysterious CSI case. Put geometry to work for you, and

  7. MRI and low back pain

    Science.gov (United States)

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  8. 2D SIMPLIFIED SERVO VALVE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel pilot stage valve called simplified 2D valve, which utilizes both rotary and linear motions of a single spool, is presented.The rotary motion of the spool incorporating hydraulic resistance bridge, formed by a damper groove and a crescent overlap opening, is utilized as pilot to actuate linear motion of the spool.A criterion for stability is derived from the linear analysis of the valve.Special experiments are designed to acquire the mechanical stiffness, the pilot leakage and the step response.It is shown that the sectional size of the spiral groove affects the dynamic response and the stiffness contradictorily and is also very sensitive to the pilot leakage.Therefore, it is necessary to establish a balance between the static and dynamic characteristics in deciding the structural parameters.Nevertheless, it is possible to sustain the dynamic response at a fairly high level, while keeping the leakage of the pilot stage at an acceptable level.

  9. Personalized 2D color maps

    KAUST Repository

    Waldin, Nicholas

    2016-06-24

    2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. In this paper we present a novel method to measure a user\\'s ability to distinguish colors of a two-dimensional color map on a given monitor. We show how to adapt the color map to the user and display to optimally compensate for the measured deficiencies. Furthermore, we improve user acceptance of the calibration procedure by transforming the calibration into a game. The user has to sort colors along a line in a 3D color space in a competitive fashion. The errors the user makes in sorting these lines are used to adapt the color map to his perceptual capabilities.

  10. 多层螺旋CT(MSCT)在异位阑尾炎诊断中的临床价值%Value of Multi-slice Spiral CT in the Diagnosis of Heterotopia Appendicitis

    Institute of Scientific and Technical Information of China (English)

    裴守科

    2015-01-01

    目的探讨MSCT (多层螺旋CT)超薄层扫描和后处理技术在异位阑尾炎诊断中的临床价值。方法18例异位阑尾炎患者行MSCT,并经计算机后处理工作站行多平面重组(Multiplanar reconstruction,MPR)、曲面重组(Curved planar reformation,CPR),回顾性分析其类型,对异位阑尾炎CT表现进行分析、总结,并与手术及病理结果对照。结果18例患者中高位肝下阑尾5例,低位阑尾7例,盲肠后腹膜外阑尾(腰部阑尾)2例,左下腹位阑尾4例。结论 MSCT超薄层扫描及后处理技术可以多方位显示异位阑尾解剖关系及病变周边情况,提高对异位阑尾炎术前诊断准确率。%Objective To evaluate the clinical value of Multi-slice spiral CT (MSCT) in the diagnosis of Heterotopia Appendicitis. Methods 18 patients with Heterotopia Appendicitis underwent preoperative contrast-enhanced MSCT.Images were transfer ed to the workstation and then processed with multiplanar reconstruction (MPR),curved planar reformation (CPR).CT manifestations were analysed and compared with surgical and pathological findings. Results 18 patients with Heterotopia Appendicitis , 5 have under liver high Appendix ,and 7 have low Appendix, 2 for waist Appendix, and 4 for the bot om left of abdomen Appendix. Conclusion MSCT and MPR/CPR can provide an advantage of showing the appendix multi-directional y that can improve the diagnosis accuracy of Heterotopia Appendicitis .

  11. Clinical Significance of Multi - slice CT in Diagnosis of Thyroid Nodules with Calcification%多层螺旋CT诊断钙化性甲状腺结节的临床意义

    Institute of Scientific and Technical Information of China (English)

    于军

    2012-01-01

    Objective To investigate the clinical significance of features of thyroid nodule with calcification in diagnosis and differential diagnosis of benign and malignant thyroid nodules. Methods We retrospectively analyzed the pathologic results and multi - slice CT (MSCT) signs of 77 cases of thyroid nodules. Results The detection rate of thyroid nodules with calcification in MSCT imaging was 21.60% (35/162), the detection rate of benign nodules was 15.45% (19/123) which was significantly lower than 41.03% (16/39) of malignant nodules. The thyroid calcification ratio of bulky- calcification in benign nodules was higher than that of malignant nodules, while micro - calcification in malignant nodules was higher than that in benign nodules (P<0.05). But there was no significant correlation between the number of calcification and malignant nodules. Conclusions Thyroid nodules with calcification especially micro- calcification is considered to be the important sign of thyroid carcinoma.%目的 探讨甲状腺结节的钙化特点对其良恶性诊断与鉴别诊断中的临床意义.方法 对137例经病理和多层螺旋CT(MSCT)检查证实的甲状腺结节的临床资料进行回顾性分析.结果 甲状腺结节MSCT的钙化检出率为21.60% (35/162),良性结节为15.45%(19/123),显著低于癌性结节的41.03% (16/39);良性钙化粗大钙化的发生率显著高于恶性结节,而良性结节微小钙化的发生率显著低于恶性结节(P<0.05),但钙化灶数目与甲状腺恶性结节无显著性关系.结论 甲状腺结节伴有钙化尤其是微小钙化灶是诊断甲状腺癌的重要征象.

  12. Analysis about Inlfuencing Factors of Image Quality of Coronary Angiography with Multi-Slice CT%MSCT冠状动脉成像质量的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    赵坤; 邵广瑞; 王勇; 侯代伦

    2014-01-01

    目的:分析64层螺旋CT冠状动脉扫描中影响成像质量的各种因素。方法对89例怀疑冠心病或冠心病复查患者进行64层螺旋CT冠状动脉检查,回顾性分析成像质量,探讨心率及心率波动对冠脉成像质量的影响,pitch值与心率的关系,替代(override)功能的应用价值,从而优化扫描参数。结果心率及心率波动与冠脉成像质量成负相关;心率与扫描/重建方式及pitch值存在相互对应关系;心率替代功能的合理使用可以提高CT冠状动脉的成像质量。结论通过控制心率及心率波动,选择心率替代功能,采取适当的扇区扫描/重建模式可以提高图像质量和冠状动脉诊断的可靠性。%Objective To analyze the inlfuencing factors of image quality of coronary angiography with 64-slice CT.Methods Eighty-nine patients with known or suspected CAD underwent CT coronary angiography using 64 multi-slice CT. The image quality in those cases was analyzed retrospectively to evaluate the influence of heart rate, fluctuation of heart rate during the scanning. The relationship between heart rate and the value of pitch was analyzed, and the application value of the override function was discussed.Results① The patient’s heart rate and lfuctuation were negatively related to the coronary image quality.② There was corresponding relationship between the value of pitch and segment scan/reconstruction mode according to the heart rate.③ Correct use of override function could improve the image quality of coronary.Conclusion The appropriate control of heart rate and lfuctuation, the correct use of override function, and the corresponding selection of segment scan/reconstruction mode according to the heart rate could improve the image quality and reliability of coronary angiography.

  13. Brain Extraction and Fuzzy Tissue Segmentation in Cerebral 2D T1-Weigthed Magnetic Resonance Images

    OpenAIRE

    Bouchaib Cherradi; Omar Bouattane; Mohamed Youssfi; Abdelhadi Raihani

    2011-01-01

    In medical imaging, accurate segmentation of brain MR images is of interest for many brain manipulations. In this paper, we present a method for brain Extraction and tissues classification. An application of this method to the segmentation of simulated MRI cerebral images in three clusters will be made. The studied method is composed with different stages, first Brain Extraction from T1-weighted 2D MRI slices (TMBE) is performed as pre-processing procedure, then Histogram based centroids init...

  14. 不同影像学方法对胰腺癌T、N、M分期及可切除性的评估%Prospective evaluation of ultrasonography, multi-slice spiral CT, endoscopic ultrasonography, and magnetic resonance imaging in assessment of TNM staging and assessment of resectibility in pancreatic carcinoma

    Institute of Scientific and Technical Information of China (English)

    田艳涛; 曲辉; 赵平; 王成锋; 单毅; 赵东兵; 王贵齐; 赵心明; 欧阳汉; 郝玉芝; 孙跃民

    2008-01-01

    目的 前瞻性评估超声(US)、多层螺旋CT(MSCT)、内镜超声(EUS)和核磁共振(MRI)在胰腺癌T、N、M分期及可切除性的预测价值.方法 对68例胰腺癌分别进行超声(US)、螺旋CT(MSCT)、核磁共振(MRI)、超声内镜(EUS)检查,评估其在T、N、M分期和可切除性与手术病理结果比较及临床意义.结果 EUS对肿瘤大小的独立预测效果最好,最大径回归系数和最小径回归系数分别为1.025(P=0.043)和0.987(P<0.0001);在对淋巴结转移的评估中,EUS具有最高的敏感性(75.0%)、准确性(87.5%)和阴性预测价值(91.7%),单元Logistic回归显示与外科发现有显著相关性(OR值:33.00,95%CI:7.18~151.77 P<0.0001),且多元Logistic回归分析证实EUS具独立预测价值(OR值:34.50,95%CI:6.54~182.09,P<0.0001).MSCT评估远处转移具最高敏感性88.9%,其对胰腺癌术前TNM分期准确率最高,为61.8%.4种方法对胰腺癌可切除性的判断均与手术结果具有相关性,但多元回归分析尚无一种影像学检查具有独立预测价值.结论 MSCT对胰腺癌的TNM分期准确性最高,EUS评估肿瘤大小和淋巴结转移效果最好,对胰腺癌的术前评估尚需要两种以上的方法联合应用.%Objective To evaluate prospectively the efficacy and clinical significance of ultrasonography(US), multi-slice spiral CT (MSCT) , magnetic resonance imaging (MRI) , and endoscopic ultrasonography (EUS) in assessment of the TNM staging and resectibility of pancreatic carcinoma. Methods Consecutive 68 patients with pancreatic carcinoma underwent US, MSCT, MRI, and EUS to assess their efficacies in assessment of the size of carcinoma, lymph node metastasis, and distant metastasis. The results of theses imaging techniques were compared with the surgical and pathological findings. Results EUS was the most precise technique in evaluating the T staging of pancreatic carcinoma with the coefficients of regression of maximum and minimum radiuses of 1. 025 (P=0

  15. Learn Unity for 2D game development

    CERN Document Server

    Thorn, Alan

    2013-01-01

    The only Unity book specifically covering 2D game development Written by Alan Thorn, experience game developer and author of seven books on game programming Hands-on examples of all major aspects of 2D game development using Unity

  16. The clinical value of multi-slice spiral CT perfusion imaging in diagnosis of thyroid diseases%多层螺旋CT灌注成像在甲状腺疾病诊断中的临床价值

    Institute of Scientific and Technical Information of China (English)

    龚礼春

    2015-01-01

    ObjectiveTo investigate the clinical application value of multi-slice spiral CT perfusion imaging in diagnosis of thyroid diseases.Methods 112 patients with thyroid diseases in our hospital from January 2011 to December 2014 were selected as the research object. All patients with thyroid disease preoperatively received thyroid spiral CT scan, perfusion imaging and color Doppler ultrasonography, diagnosis and comparison of CT and ultrasound results and comparison of application effect in the differential diagnosis of benign and malignant thyroid lesions and imaging characteristics of spiral CT perfusion imaging.ResultsThe operation findings and pathology results was the gold standard, CT group detected thyroid benign lesions in 58 cases, 49 cases of malignant lesions, diagnosis rate was 95.54%, the diagnosis rate was significantly higher than the ultrasound group, and no significant difference compared with pathology results(P>0.05), has no statistical significance; Comparison of benign and malignant thyroid lesions of CT perfusion parameters known, benign and malignant lesions of blood volume (BV) and blood flow (BF) showed no significant difference, but the perfusion time to peak (TTP) and capillary permeability surface (PS) index comparison had the remarkable difference(P<0.05), was statistically significant.Conclusion The sensitivity and specificity for the diagnosis of thyroid diseases with high multi-slice spiral CT perfusion imaging and blood vessels, according to the pathological perfusion parameters and image difference can be accurately distinguish benign and malignant thyroid disease form, has the clinical value of application and popularization.%目的:探讨多层螺旋CT灌注成像在甲状腺疾病诊断中的临床应用价值。方法选取2011年1月~2014年12月我院收治的甲状腺疾病患者112例,作为研究对象。所有患者均以甲状腺疾病拟手术治疗术前进行甲状腺螺旋CT平扫、血管灌注成像及彩色多

  17. MRI Scans

    Science.gov (United States)

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  18. Multi-slice spiral CT perfusion imaging of chronic obstructive pulmonary disease%多层螺旋CT灌注成像对慢性阻塞性肺疾病的诊断价值

    Institute of Scientific and Technical Information of China (English)

    邵燕惠; 钱农; 薛跃君; 戴伊红

    2008-01-01

    目的 研究CT灌注成像对慢性阻塞性肺疾病(COPD)的诊断价值.方法 20例COPD患者和20例志愿者行8层螺旋CT灌注成像,采用电影扫描(cine)方式,层厚5 mm,扫描时间0.5 s/层,注射对比剂后延时5 s,总扫描时间为45 s,测量感兴趣区血流量、血容量、平均通过时间及表面通透性和时间-密度曲线.结果 COPD患者的时间-密度曲线较志愿者曲线平坦,峰值明显降低.COPD患者血流量[(24.77±11.49)ml·min-1·100 g-1]、血容量[(2.48±1.02)ml/100 g]及表面通透性[(2.75±1.13)ml·min-1·100 g-1]明显低于志愿者[血流量(290.14±107.59)ml·min-1·100 g-1、血容量(16.51±5.98)ml/100 g、表面通透性(8.80±3.03)ml·min-1·100 g-1];平均通过时间[(10.58±4.85)s]高于志愿者[(4.50±1.71)s],差异均具有统计学意义(P<0.01).结论 多层螺旋CT肺灌注扫描对COPD的诊断有一定的辅助作用.%Objective To evaluate the diagnostic value of multi-slice spiral CT(MSCT)perfusion imaging in chronic obstructive pulmonary disease(COPD).Methods Twenty COPD patients and20 volunteers underwent 8-row detector spiral CT(MSCT)perfusion imaging using cine scan mode with5 mm slice thickness.0.5 s rotation time and a total scan time of 45 s with 5 s intervals.60 ml contrast agent(300 mg I/ml)were administered at a rate of 4 ml/s from the forearm superficial vein.The imaging data were transferred to a workstation.A time-density curve and pseudo-color map were generated automatically with GE CT perfusion 3 software,the blood flow(BF),blood volume(BV),mean transit time(MTr)and permeability surface(PS)were measured.Results Time-density curve was flatter and the peak of the curve was obviously lower in COPD patients than the volunteers.The BF.BV.PS in COPD volunteers was(10.58 ±4.85)s and(4.50 ±1.71)s respectively.The BF,BV and PS in COPD patients Was lower than the volunteers,the MTY was higher(P<0.01).Conclusion MSCT perfusion imaging is helpful for the diagnosis of COPD.

  19. Study on Blood Perfusion of Normal Femur Heads Epiphyses in Piglets by Multi-Slice CT Perfusion%正常乳猪股骨头骨骺的MSCT灌注研究

    Institute of Scientific and Technical Information of China (English)

    黄春元; 罗帝林; 赵志清; 许朝璇; 梁焕莲; 吴冬; 冯登殿

    2011-01-01

    Objective To evaluate the blood perfusion of epiphyses, physis and metaphysis in normal femur heads of piglets by using multi-slice CT perfusion techniques. Methods Fifty five piglets(2 weeks old) were scanned by MSCT perfusion. The data of creating dynamic picture were analyzed, and the dynamic pictures of 26 femur heads were obtained completely. Every parameters including blood flow(BF) ,blood volume(BV) ,mean transit time(MTT) and time to peak(TTP) were analyzed,and compared with the histological findings. Results The BF of physis was higher than that of epiphysis( P <0.05 ). The BV of metaphysis was the highest in all anatomic regions( P <0.05). The MTT of epiphysis was the longest( P <0.05). There was no significant difference in MTT between physis and metaphysis( P >0.05 ). The TTP of physis was the shortest( P <0.05 ) ,and the other two were the same. CT perfusion imaging coincided with the histological results of the locations and concentrations of blood vessels in epiphyses,physis and metaphysis. Conclusion MSCT perfusion images can demonstrate the perfusion features in the various anatomic regions of femur heads.%目的 运用多层螺旋CT灌注技术评价正常乳猪股骨头骨骺、骺板软骨、干骺端等不同解剖区域的血液供应特征.方法 对15只2周龄的健康乳猪进行多层螺旋CT电影模式灌注扫描,对生成的动态图像数据进行测量分析,共获得26个股骨头的完整图像资料,统计并比较血流量(BF)、血容量(BV)、平均通过时间(MTT)、对比剂到达峰值时间(TTP),并与相应组织学表现进行时照.结果 骺板软骨的BF比骨骺的BF有明显增高(P0.05).各解剖区域中骺板软骨的TTP最短(P<0.05),骨骺与干骺端的TTP基本相同.组织学发现骨骺、骺板软骨、干骺端的血管密度分布特征与相应部位的CT增强率所提示的血供状态基本吻合.结论 多层螺旋CT灌注能够显示股骨头不同解剖区域的血液灌注特征.

  20. 多层螺旋CT在胃肠间质瘤定位和定性诊断中的价值%Values of multi-slice CT in differential diagnosis of gastrointestinal stromal tumors

    Institute of Scientific and Technical Information of China (English)

    卢文彬

    2014-01-01

    目的:探讨多层螺旋CT在胃肠道间质瘤( GIST)定位和定性中的诊断价值。方法:对本院30例手术病理证实为胃肠间质瘤的患者的CT影像特点进行回顾性分析。均行16层螺旋CT平扫和增强扫描,探讨病灶位置、大小及有无坏死等情况。结果:胃肠道间质瘤单发患者21例、多发9例;其中17例肿瘤部位在胃部、8例位于小肠、5例位于直肠。19例向腔内外同时生长、8例向腔外生长、3例向腔内生长。恶性GIST 强化不均匀,可有邻近脏器侵犯。16层螺旋CT定性准确率为83.3%(25/30)、定位准确率90.0%(27/30)。结论:CT 增强扫描有利于GIST的定位诊断及对肿瘤良恶性质的判断,能准确显示肿瘤的部位、形态、大小,是目前检查GIST的重要方法之一。%Objective:To investigate the diagnosis values of multi-slice CT ( MSCT ) on diagnosis of gastrointestinal stromal tumors ( GIST) . Methods:The CT characteristics of 30 tumors of pathological confirmed GIST in our hospital were retrospectively analyzed. All patients were scanned with unenhanced and enhanced 16-slice CT, and then the location, size and necrosis of lesions were analyzed. Results:Among all 30 cases, single lesions of GIST were 21 cases, and motile lesions of GIST were 9 cases. And 17 cases located at stomach, 8 cases at small intestine, and 5 cases at rectum. There were 19 cases simultaneously inside and outside the chamber, 8 cases of external cavity growth, and 3 cases of intracavity growth. The malignant GIST exhibited inhomogeneous enhancement and invasion to adjacent organs. Accuracy of 16-slice CT diagnosis for qualitative analysis was 83. 3% ( 25/30 ) and for location was 90. 0% ( 27/30 ) of GISTs. Conclusion: CT enhanced scan benefits the localization diagnosis of GIST and the determination of benign or malignant tumors. It could accurately show the location, form and size of tumors, which is one of the significant methods to examine

  1. The Diagnostic Value and Type of Multi-slice Spiral CT Reconstruction in Small Renal Carcinomas%多层螺旋CT三维重建对小肾癌的诊断及分型

    Institute of Scientific and Technical Information of China (English)

    宋强; 汪秀玲; 胡春峰

    2011-01-01

    Objective:According to the CT scan image and the performance of three-dimensional reconstruction,to study the diagnostic value and type of MSCT reconstruction in small renal carcinomas.Materials and Methods:A retrospective analysis was done for 43 cases of small renal carcinomas which received MSCT examination and confirmed by pathology in our hospital,analysis and type them with their performance in the CT examination.Results:There are 16 cases of small renal carcinoma of protruding type,their performance of CT examination are the tumors convex to the outline of the kidney or convex to the renal pelvis or calyx,when in enhancement CT scan,the contrast agent in the tumor are fast flowing in and fast flowing out which are the performance of malignant tumor;There are 6 cases of small renal carcinoma of inside renal parenchyma type,their performance of CT examination are the tumors limited in the renal parenchyma,when in enhancement CT scan,the performance of the tumor are f the typical performance of malignant tumor;There are 9 cases of small renal carcinoma of cystic type,their performance of CT examination are that when in enhancement CT scan,there are multiple enhanced uneven thickness stripes or small pitchy enhancement in the tumor;There are 5 cases of small renal carcinoma of multiple type,their performance of CT examination are that there are multiple small renal carcinomas in one kidney.Conclusion:Multi-slice spiral CT scan with 3D reconstruction image post-processing techniques can accurately and effectively diagnose various types of small renal carcinoma.%目的:根据CT扫描图像及三维重建表现,探讨多层螺旋CT扫描对小肾癌的诊断及鉴别诊断的价值,并对小肾癌进行分型。资料与方法:收集行多层螺旋CT扫描并经临床病理证实的43例小肾癌病例资料,就其CT表现进行分析并进行分型。结果:凸出型小肾癌23例,CT表现为肿瘤凸向肾轮廓之外或凸向肾盂、肾盏,增强

  2. The Analysis of 8 Missed Diagnosis of Rib Fracture by Multi-slice CT%多层螺旋CT诊断肋骨骨折8例漏诊分析

    Institute of Scientific and Technical Information of China (English)

    冯莹印; 王浩; 纪盛章

    2012-01-01

    目的 通过回顾性分析2007年以来8例肋骨CT检查漏诊病例,探讨多层螺旋CT诊断肋骨骨折的限度.资料和方法 2007年1月至2011年9月127例行肋骨CT检查患者,男83例,女44例,年龄18-88岁,平均51.83岁.应用TOSHIBA AQUILION 16层螺旋CT或GE Lightspeed 64层VCT行肋骨CT扫描,扫描数据传至工作站,应用多平面重组(multiplanar reconstruction,MPR)、曲面重组(curved planar reformation,CPR)、容积再现(volumerendering,VR)、电影显示等方法观察骨折情况.结果 127例患者中,共检出骨折患者115例,骨折5 65处.1 4例复查患者中,6例骨折情况无变化.另有8例可见原未显示的新骨折,共检出14处.结论 虽然MSCT作为诊断肋骨骨折的必要检查手段有重要意义,但是它存在一定的局限性.因此,我们对可能发生的“隐匿性骨折”病例应提示必要复查,避免医疗纠纷发生.%Objective To investigate the limitation of diagnosing rib fracture by multi-slice CT(MSCT)through retrospective analysis of 8 missed diagnosis of rib fracture since 2007. Methods 127 patients from Jan.2007 to Sep.2011,83 male and 44 female, the scope of age from 18 to 88,the average age was 51.83 years old.Applied TOSHIBA AQUILION 16-Slice Spiral CT or GE Lightspeed 64-Slice VCT for scanning .scanning data transferred to workstation. Observed ribs by MPR, CPR, VR and film visualizing method. Results Of the 127 patients, 115 patients were found 565 fractures.Among the 14 patients of reexamination, 6 patients had no discrepancy and 8 patients had total 14 new fractures which were not found in the first diagnosis. Conclusion MSCT examination is a important method for diagnosing rib fracture, but it have some limitations. So, patients who maybe have occult fracture should be known that reexamination is necessary,in order to avoid medical disputes.

  3. Spontaneous isolated dissection of the superior mesenteric artery:multi-slice computed tomographic angiography findings in seven cases%MSCT血管成像对孤立性肠系膜上动脉夹层的诊断价值

    Institute of Scientific and Technical Information of China (English)

    陈则君; 谢旭纲; 孟宪平; 朱建新; 王伯元

    2011-01-01

    目的:探讨MSCT血管成像诊断孤立性肠系膜上动脉夹层(SISAMD)的临床应用价值.方法:对7例急性肠缺血患者行MSCT血管成像,采用容积再现(VR)、多平面重组(MPR)、曲面重组(CPR)及最大密度投影(MIP)重组图像,由两位经验丰富的心血管影像医师评估夹层的部位和范围.结果:SISAMD与主动脉夹层CT血管成像(CTA)表现相同,CTA清晰显示撕裂内膜5例,破裂口均位于肠系膜上动脉(SMA)近心端.根据Yun分型:Ⅰ型1例,Ⅱa型3例,Ⅱb型2例,Ⅲ型1例.SMA直径增粗2例,SMA周围脂肪间隙模糊2例,局部回肠壁增厚、水肿2例,升结肠扩张、积液1例,腹腔及盆腔内少量积液2例.结论:MSCTA能清晰显示病变特征和累及范围,是孤立性肠系膜上动脉夹层首选的检查方法.%Objective : To asscss the value of multi-slice computed tomographic angiography (MSCTA) in the diagno sis of spontancous isolated dissection of superior mesenteric artery (SMA). Methods:7 patients with clinically suspected a cute mesenteric ischemia underwent MSCTA. Multiplanar and three-dimensional images were obtained by imaging postpro cessing techniques including volume rendering technique (VRT) , multiplanar reconstruction (MPR) , curved planar reforma tion (CPR) and maximum intensity projection (MIP) on a workstation. Image reading was performed in consensus by two experienced cardiovascular radiologists. Results: According to Yun's classification,there were one case of type Ⅰ , three type Ⅱ a,two type Ⅱ b and one type Ⅲ . Spontaneous isolated dissection of SMA displays the same MSCTA features as aortic dis section. Intimal flaps were seen in five patients,with intimal tears at the proximal SMA. Other MSCTA findings associated with spontaneous isolated dissection of SMA were enlarged diameter of the SMA (n=2) ,increased attenuation of the fat a round the SMA (n=2) ,local ileum wall thickening due to edema (n=2) , dilated ascending colon (n=1) and hemorrhagic

  4. 不同侵袭危险度小肠间质瘤的MSCT表现%Multi-slice spiral CT manifestations of small intestinal stromal tumor with different aggressive risk

    Institute of Scientific and Technical Information of China (English)

    顾艳; 周胜利; 苗重昌

    2012-01-01

    Objective:To analyze the value of the multi slice spiral CT (MSCT) in the diagnosis and evaluation of ag gressiveness of risk in small intestinal stromal tumor (SIST). Methods:The clinical and MSCT materials of 32 cases with SIST confirmed by surgery, pathology and immuno his to pathology were analyzed retrospectively. According to histopatholo gy,the risk aggressiveness of these 32 cases were classified to low and very low,medium and high risk groups. Analysis of the MSCT features included location,size,shape,density,margin and enhancement pattern of the tumor and the MSCT find ings were compared with the risk aggressiveness using chi square test. Results: Among the 32 cases, there were low and very low risk (14 cases) ,medium (8 cases) and high risk (10 cases). 23 cases had the tumor originated from the jejunum,6 cases from ileum and 3 cases from duodenum. Significant statistical differences were showed in shape,density,margin and vessel like enhancement between different risk groups of SIST (P<0. 05) ,The enhancement of lesion was mostly markedly inho mogeneous, and enhancement in venous phase was more intense than that in arterial phase.But no statistical difference was existed in the peak of enhancement and the location of tumor (P>0. 05). Conclusion:Certain MSCT characteristics of SIST were assessed,and MSCT features showed significant differences between different groups with risk aggressiveness. Length of tumor >5 cm, inhomogeneous density, irregular shape, ill defined margin and vessel like enhancement were showed in groups with medium and high risk,which is helpful in diagnosing and evaluating the risk aggressiveness of SIST before sur gery.%目的:探讨MSCT对小肠间质瘤(SIST)诊断和侵袭危险度的评估价值.方法:回顾性分析经手术病理和免疫组织化学证实的32例SIST患者的临床和影像学资料,依据病理组织学将其分为极低和低危、中危、高危3组.MSCT图像分析包括肿瘤的部位、大小、

  5. 多排CT对肾结石并肾盂恶性肿瘤的诊断价值%Value of Multi-slice CT for the Diagnosis of Kidney Calculi with Renal Pelvis Malignant Tumor

    Institute of Scientific and Technical Information of China (English)

    易志军; 刘建滨; 范立新; 谢安; 郑海军; 王诗斌; 彭国洪

    2012-01-01

    [Objective] To explore the CT diagnosis and the reason of missed diagnosis of kidney calculi with renal pelvis malignant tumor. [Methods] The CT data of 9 cases of kidney calculi with renal pelvis malignant tumor confirmed by pathology were analyzed retrospectively. The site of pathogenesis, histological type, metastasis, complication and the relation with the surrounding tissue were observed. [Results] Among 9 cases of kidney calculi with renal pelvis malignant tumor, 5 cases were transitional cell carcinoma, 3 cases were squamous cell carcinoma and 1 case was adenocarcinoma. Retroperitoneal lymph node metastasis was found in 5 cases including one case of adenocarcinoma and one case of transitional cell carcinoma involving the metastasis of renal capsule and adjacent adipose tissue, liver and adrenal gland. Seven cases were combined with the inflammation of renal pelvis and ureter or pyonephrosis. Three cases were combined with inflammatory granulation of renal pelvis. Two cases of transitional cell carcinoma and one case of cases of squamous cell carcinoma were misdiagnosed as kidney calculi with hydronephrosis infection. The definite diagnosis rate was 66. 7% (6/9) and the misdiagnosis rate was 33. 3% (3/9). [Conclusion] Multi-slice CT for kidney calculi with renal pelvis malignant tumor has higher diagnostic value. However, kidney calculi with renal pelvis accompanied by other lesions are easy to be misdiagnosed.%[目的]探讨肾结石并肾盂恶性肿瘤的CT诊断和漏诊原因.[方法]回顾性分析经手术病理证实的9例肾结石并肾盂恶性肿瘤的CT资料,重点观察肾结石并肾盂恶性肿瘤的发生部位、病理类型、有无转移、合并症及与周围组织关系.[结果]9例肾结石并肾盂恶性肿瘤患者5例为肾盂移行细胞癌,3例为肾盂鳞癌,1例腺癌;5例有腹膜后淋巴结转移,鳞癌、移行细胞癌各1例,累及肾被膜及邻近脂肪组织及肝、肾上腺等多处转移;7例合并肾盂、

  6. MSCT尿路成像技术在泌尿系统疾病诊断中的价值%The value of multi-slice CT urography in diagnosis of urinary tract diseases

    Institute of Scientific and Technical Information of China (English)

    沈纪芳; 朱玉春; 王建良

    2012-01-01

    目的 探讨多层螺旋CT(MSCT)尿路成像技术在泌尿系统疾病诊断中的价值.方法 对80例泌尿系统疾病患者行CT尿路成像检查,通过常规平扫、动脉期、静脉期、延迟期图像数据进行多平面重组法(MPR)、曲面重组法(CPR)、最大密度投影法(MIP)和容积成像法(VR)进行三维重组,对影像图像进行分析.结果 CT尿路成像技术能够清晰显示泌尿系统的整体结构和输尿管走行和周围组织的关系.80例中,泌尿系统结石46例,输尿管癌4例,肾盂癌1例,先天性发育畸形5例,输尿管炎性狭窄9例,输尿管瘘1例,输尿管息肉1例,盆腔内恶性肿瘤累及或术后侵犯7例,正常6例.MSCT尿路成像诊断特异性为i00%(80/80),诊断准确率为95%(76/80);1例输尿管息肉和3例炎性狭窄误诊为输尿管癌,误诊率为5%(4/80).结论 MSCT尿路成像图像清晰直观,可以作为早期确诊泌尿系统疾病的有效影像检查方法.%Objective To investigate the diagnostic value of multi-slice CT(MSCT) urography in urinary tract diseases. Methods CT urography was performed in 80 cases with urinary tract diseases. The multiplanar reconstruction (MPR), maximum intensity recontruction (MIP), cured planar reformation(CPR) and volume rendering(VR) were reconstructed based on the data extracted by conventional plain scan,arteral phase, venous phase and lag period scaa Results MSCT urography provided clear three dimensional images of the whole kidney, ureter and urinary bladder, the entire and partial structure,shape and relation with the tissues surrounding them. Of 80 cases, the diagnosis of urinary calculus was confermed in 46 cases, ureteral carcinoma in 4 cases, renal pelvic carcinoma in 1 case,urinary congenital malformation in 5 cases, urinary inflammation in 9 cases, ureteral fistula in 1 case,ureteral polyp in 1 case, ureter invaded by palvic magligant mass in 7 cases, and normal in 6 cases. In the diagnosis of urinary tract diseases, the

  7. 多层螺旋CT对健康成人肾周间隙及肾筋膜的测量%Anatomy of the perirenal space and renal fascia:a multi-slice spiral CT observation

    Institute of Scientific and Technical Information of China (English)

    王娜; 刘荣波; 孔维芳

    2011-01-01

    Objective: To measure the renal fascia and evaluate the anatomy of perirenal space and its communications sand boundarics with multi-slice spiral CT (MSCT). Methods : MSCT scanning was performed in 97 normal subjects , and the multiplanar reconstruction (MPR) images of perirenal space and its anatomical communications were obtained on a postprocessing workstation. The shapc, size and anatomical communications of the perirenal space were observed and measured.Results : Between the upper and lower pole of kidney,the detection rate of renal fascia was 100%. It was easier to visualize the renal fascia on MPR images than those on transverse CT images. The thickness of the left and right renal fascia was (0.13+0. 02)cm and (0. 12+0. 02)cm, respectively. No significant difference in renal fascia thickness was found between different gender and age groups (all P>0.05). Different types of adhesion and anatomical communication of renal fascia were distinctly visualized on MSCT images. Conclusions : MSCT and MPR images could clearly visualize the morphologic features and anatomical communication of the perirenal space, which may be helpful in making diagnostic decisions.%目的:通过多层螺旋CT对正常成人肾筋膜和肾周闯隙的观察和测量.探讨多层螺旋CT显示肾筋膜的附着及通连情况.方法:搜集在我院接受腹部CT增强扫描检查的健康成人资料97例,采用多层螺旋CT扫描对肾周间隙行多平面三维重组,测定肾筋膜的厚度,并观察肾筋膜的显示率以及肾筋膜向上和向下的通连情况.结果:肾筋膜在肾脏上、下极之间的显示率为100%,且双侧肾筋膜在MPR图像上的显示率大于轴面图像.左、右侧肾筋膜厚度分别为(0.13±0.02)cm和(0.12±0.02)cm,不同性别及年龄组别间筋膜厚度差异无统计学意义(P>0.05).多层螺旋CT发现肾筋膜的附着及肾周间隙的通连情况具有不同类型:①双侧肾前、后筋膜向下融合,融

  8. 鼻咽癌多层螺旋CT灌注输入动脉的选择%Selection of reference arteries with multi-slice spiral CT perfusion imaging in diagnosis of nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    丁玲; 苏丹柯; 刘丽东; 金观桥; 赵梦鸥

    2011-01-01

    目的 分析不同输入动脉所得鼻咽癌(NPC)多层螺旋CT灌注参数值的差异.方法 对38例经病理确诊的初发NPC患者进行CT灌注扫描,每例患者均分别选择肿瘤同侧的颈内动脉(ICA组)和颈外动脉(ECA组)作为输入动脉、颈内静脉作为输出静脉进行灌注成像后处理,获得两组灌注参数.采用配对t检验分析两组灌注参数值的差异,并对两组数据进行直线相关分析.结果 两组不同血管所得灌注参数值差异均无统计学意义(P>0.05),两组数据血流量、血容量、平均通过时间和表面通透性的相关系数分别为0.879、0.630、0.525、0.695(P均<0.001),两组血管所得数据均成正相关.结论 在对NPC患者进行CT灌注成像后处理时,可根据患者血管的显示情况选择颈内动脉和(或)颈外动脉作为输入动脉.%Objective To observe the difference of multi-slice spiral CT perfusion parameters in different reference arteries in diagnosis of nasopharyngeal carcinoma (NPC). Methods Thirty-eight patients with NPC underwent CT perfusion imaging, internal carotid artery (ICA group) and external carotid artery (ECA group) were selected respectively as reference artery with CT perfusion imaging post-processing in each patient. The differences of perfusion parameters between the two groups were analyzed with paired-samples t test and linear correlation. Results Parameters derived from ICA and ECA as reference artery were not statistically different (all P>0. 05). There were positive correlation of all parameters between both groups, the correlation coefficients was 0. 879 for blood flow, 0. 630 for blood volume, 0. 525 for mean transit time and 0. 695 for permeability surface (all P<0. 001). Conclusion On the post-processing of CT perfusion imaging for NPC,internal carotid artery and external carotid arteries can both be selected as the reference artery according to their displaying.

  9. Correlative Study between Multi-slice CT Perfusion Imaging and Molecular Pathology in Renal Cell Carcinoma%肾细胞癌MSCT灌注成像与分子病理学的相关性研究

    Institute of Scientific and Technical Information of China (English)

    相成; 丰长申; 徐锐; 朱甲峰

    2010-01-01

    目的 运用多层螺旋CT(MSCT)获取肾癌灌注图像,并与其分子病理学特征相对照,探讨MSCT灌注成像在肾癌诊断和鉴别诊断中的临床应用价值.方法 对42例疑有肾肿瘤的患者行MSC灌注扫描,获得伪彩色的血流灌注参数图,包括血流量(BF)、血容量(BV)、表面通透性(PS)及平均通过时间(MTT)图.在瘤体及瘤旁正常肾皮质选取感兴趣区并记录相应的各项参数值.所有患者均经手术病理证实.采用免疫组化方法(SP法)检测肾肿瘤中血管内皮生长因子(VEGF)的表达及微血管密度(MVD).结果 肾细胞癌的BF、BV和PS值均明显低于正常肾皮质,且Ⅲ级肾癌与Ⅰ、Ⅱ级相比,其BF、BV和PS值明显增高.肾癌的BF、BV、PS值与其VEGF平均光密度值呈正相关(P<0.05),MTT值与VEGF平均光密度值呈负相关(P<0.05).肾癌的MVD值与VEGF值呈正相关(P<0.05).结论 MSCT灌注成像能定量评价肿瘤血管生成、血流灌注及血管通透性改变,有助于肾细胞癌的术前分级,并在肾癌的定性诊断和鉴别诊断方面有一定临床应用价值.%Objective To study the correlation of the perfusion CT parameters and the molecular pathology characteristics of the renal cell carcinoma( RCC ),and to discuss the value of multi-slice CT(MSCT) perfusion imaging in the diagnosis and differential diagnosis of RCC.Methods 42 patients with clinically suspected renal tumors underwent MSCT perfusion imaging.The maps of renal blood volume (BV),blood flow (BF),permeability surface (PS)and mean transit time (MTT)were obtained.Regions of interest (ROI)were drawn within the tumor and the region of normal area adjacent to the tumor.All of the tumors were proved by surgery and pathology withRCC ( n = 42 ).Vascular endothelial growth factor (VEGF) expression and micro-vascular density (MVD) were measured with immuno-histology chemistry technique( SP technique).Results Of the 42RCC,the mean BF,BV and PS value were obviously lower

  10. 肺磨玻璃病变的CT特征分析%The diagnosis and differential diagnosis of pulmonary ground-glass opacities with multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    高前宁

    2012-01-01

    目的 探讨多层螺旋CT对肺部磨玻璃影的诊断及鉴别诊断价值.方法 回顾分析46例肺部CT表现为磨玻璃影的分布特征及伴随征象.结果 本组46例中,16例经肺部穿刺确诊,19例经支气管镜及实验室检查确诊,11例患者经临床确诊.其中,24例间质性肺部疾病患者,磨玻璃影主要表现为外周性、局限性,多边界模糊.肺实质病变11例,磨玻璃影主要表现为中央型、局限性,但边缘多清晰.11例患者诊断为阻塞性通气功能障碍,磨玻璃影外周型与中央型均较常见,多伴随病灶区蜂窝状细网及小血管增粗表现.结论 肺部磨玻璃影可见于肺间质病变、实质病变及阻塞性肺疾病等,不同疾病的肺部磨玻璃影仍有不同的形体分布及伴随征象,有利于临床缩小诊断范围.%Objective To analyze data of 46 cases of patients with ground - glass shadow and to explore the value of multi - slice spiral CT in the diagnosis and differential diagnosis of pulmonary ground - glass opacities. Methods Data of patients in our hospital of which lung CT showed ground - glass opacities were analyzed, the distribution of ground glass, combined signs, and ultimately clinical findings were studied, and different diseases pulmonary ground - glass features were explored. Results In the 46 patients with pulmonary disease, 16 patients were definitely diagnosed with lung puncture, 19 patients with bronchoscopy and laboratory, and 11 patients by clinic. Of these, there were 24 cases of interstitial lung disease, in which ground - glass opacities was mainly peripheral, limited, and the boundary was fuzzy. Pul-monary parenchymal disease was found in 11 cases, in which ground -glass opacities was central, limited , but the edge was clear. 11 patients were diagnosed with obstructive ventilatory dysfunction, in which ground -glass opacities were peripheral and central in common, and more with fine mesh honeycomb lesions and small vessel thickening

  11. 2D-3D image registration in diagnostic and interventional X-Ray imaging

    NARCIS (Netherlands)

    Bom, I.M.J. van der

    2010-01-01

    Clinical procedures that are conventionally guided by 2D x-ray imaging, may benefit from the additional spatial information provided by 3D image data. For instance, guidance of minimally invasive procedures with CT or MRI data provides 3D spatial information and visualization of structures that are

  12. Cortical language activation in aphasia:a functional MRI study

    Institute of Scientific and Technical Information of China (English)

    徐晓俊; 张敏鸣; 商德胜; 汪启东; 罗本燕; 翁旭初

    2004-01-01

    Background Functional neuroimaging has been used in neurolinguistic research on normal subjects and on patients with brain damage. This study was designed to investigate the differences of the neural basis underlying language processing between normal subjects and aphasics.Methods Functional magnetic resonance imaging (fMRI) was used to map the language network in 6 normal subjects and 3 patients with aphasia who were in the stage of recovery from acute stroke. The participants performed a word generation task during multi-slice functional scanning for the measurement of signal change associated with regional neural activity induced by the task. Results In normal subjects, a distributed language network was activated. Activations were present in the frontal, temporal, parietal and occipital regions. In the patient group, however, no activation was detected in the left inferior frontal gyrus whether the patient had a lesion in the left frontal lobe or not. Two patients showed activations in some right hemisphere regions where no activation appeared in normal subjects. Conclusions fMRI with word generation task is feasible for evaluating language function in aphasic patients. Remote effect of focal lesion and functional redistribution or reorganisation can be found in aphasic patients.

  13. Perspectives for spintronics in 2D materials

    Directory of Open Access Journals (Sweden)

    Wei Han

    2016-03-01

    Full Text Available The past decade has been especially creative for spintronics since the (rediscovery of various two dimensional (2D materials. Due to the unusual physical characteristics, 2D materials have provided new platforms to probe the spin interaction with other degrees of freedom for electrons, as well as to be used for novel spintronics applications. This review briefly presents the most important recent and ongoing research for spintronics in 2D materials.

  14. Surface modelling for 2D imagery

    OpenAIRE

    Lieng, Henrik

    2014-01-01

    Vector graphics provides powerful tools for drawing scalable 2D imagery. With the rise of mobile computers, of different types of displays and image resolutions, vector graphics is receiving an increasing amount of attention. However, vector graphics is not the leading framework for creating and manipulating 2D imagery. The reason for this reluctance of employing vector graphical frameworks is that it is difficult to handle complex behaviour of colour across the 2D domain. ...

  15. Perspectives for Spintronics in 2D Materials

    OpenAIRE

    Wei Han

    2016-01-01

    The past decade has been especially creative for spintronics since the (re)discovery of various two dimensional (2D) materials. Due to the unusual physical characteristics, 2D materials have provided new platforms to probe the spin interaction with other degrees of freedom for electrons, as well as to be used for novel spintronics applications. This review briefly presents the most important recent and ongoing research for spintronics in 2D materials.

  16. Experimental research and its clinical significance of precise postural adjustment and mean measurement by multi-slice spiral CT reconstruction of acetabular abduction angle%测量髋臼外展角度的实验研究及其临床意义MSCT三维重建精确体位调整均值法

    Institute of Scientific and Technical Information of China (English)

    范新成; 马振波; 于春丽; 朱海涛; 赵伟; 彭国庆; 张伟; 魏开斌; 刘峰

    2016-01-01

    Objective:To investigate the application of multi-slice spiral CT reconstruction accurate measurement of ace-tabular abduction angle,and to provide a scientific basis for guidance of total hip replacement acetabular prosthesis individu-alized accurate placement and postoperative evaluation. Methods:The research objects were 60 acetabulars of 30 pelvic spec-imens,and with anterior plane of pelvis as a reference plane,acetabular abduction angles were measured respectively by digital goniometer and multi-slice CT reconstruction with precise postural adjustment. Results:The acetabular abduction an-gle means of 30 pelvic specimens by digital goniometer and multi-slice CT reconstruction with precise postural adjustment were(48. 73 ± 3. 19)°and(48. 65 ± 2. 47)° respectively,and they had no significant difference(P > 0. 05). These data showed that the measurement of acetabular abduction angle by multi-slice CT reconstruction with precise postural ad-justment was accurate,which had no significant difference from the actual measurement. Conclusion:Multi-slice CT recon-struction with precise postural adjustment,with the anterior plane of the pelvis as a reference plane,is a new method of a preoperative acetabular abduction angle measurement for total hip arthroplasty,which can reduce human error in operation and achieve standardized measurement and evaluation of hip acetabular abduction angle.%目的:探讨应用 MSCT 三维重建精确测量髋臼外展角度的新方法,为指导全髋关节置换髋臼假体个体化准确置入及术后评估提供科学依据。方法选取30具骨盆标本共60个髋臼为研究对象,以骨盆前平面为参照平面,分别应用数显角度仪及 MSCT 三维重建精确体位调整均值法对髋臼外展角度数值进行测量,对两种方法的测量结果进行比较。结果应用数显角度仪及 MSCT 三维重建精确体位调整均值法测量髋臼外展角度分别为(48.73±3.19)°和(48.65±2.47)°

  17. UNITS IN $F_2D_{2p}$

    OpenAIRE

    Kaur, Kuldeep; Khan, Manju

    2012-01-01

    Let $p$ be an odd prime, $D_{2p}$ be the dihedral group of order 2p, and $F_{2}$ be the finite field with two elements. If * denotes the canonical involution of the group algebra $F_2D_{2p}$, then bicyclic units are unitary units. In this note, we investigate the structure of the group $\\mathcal{B}(F_2D_{2p})$, generated by the bicyclic units of the group algebra $F_2D_{2p}$. Further, we obtain the structure of the unit group $\\mathcal{U}(F_2D_{2p})$ and the unitary subgroup $\\mathcal{U}_*(F_...

  18. 2D Barcode for DNA Encoding

    CERN Document Server

    Purcaru, Elena

    2012-01-01

    The paper presents a solution for endcoding/decoding DNA information in 2D barcodes. First part focuses on the existing techniques and symbologies in 2D barcodes field. The 2D barcode PDF417 is presented as starting point. The adaptations and optimizations on PDF417 and on DataMatrix lead to the solution - DNA2DBC - DeoxyriboNucleic Acid Two Dimensional Barcode. The second part shows the DNA2DBC encoding/decoding process step by step. In conclusions are enumerated the most important features of 2D barcode implementation for DNA.

  19. 2D Barcode for DNA Encoding

    Directory of Open Access Journals (Sweden)

    Elena Purcaru

    2011-09-01

    Full Text Available The paper presents a solution for endcoding/decoding DNA information in 2D barcodes. First part focuses on the existing techniques and symbologies in 2D barcodes field. The 2D barcode PDF417 is presented as starting point. The adaptations and optimizations on PDF417 and on DataMatrix lead to the solution – DNA2DBC – DeoxyriboNucleic Acid Two Dimensional Barcode. The second part shows the DNA2DBC encoding/decoding process step by step. In conclusions are enumerated the most important features of 2D barcode implementation for DNA.

  20. The MRI diagnosis of triangular fibrocartilage complex injures in the wrist%腕三角纤维软骨复合体损伤的MRI诊断

    Institute of Scientific and Technical Information of China (English)

    万梦楠; 周胜法; 林锋; 陈久尊; 何家维; 郑显秋

    2016-01-01

    目的:探讨3.0T MRI在腕关节三角纤维软骨复合体(TFCC)损伤中的价值。方法回顾性分析26例TFCC损伤的MRI及X线平片、CT表现。结果26例X线检查13例阴性,5例茎突骨折,2例桡骨远端骨折,2例月骨坏死,6例尺骨径突阳性征。5例多层螺旋CT扫描,发现骨折或/和骨坏死2例。26例MRI检查中,21例诊断TFCC损伤,其中包括TFCC撕裂或穿孔8例,主要表现为在MRI脂肪抑制序列( STIR)、2D MERGE及T2 WI上点状、条片状高信号,在T1 WI序列上呈等信号;9例腕部骨折(包括尺骨茎突5例,桡骨2例,腕骨2例);3例三角骨或月骨坏死;8例尺桡骨或腕骨挫伤;10例腕关节腔积液。结论 TFCC形态细小而不规则,损伤时X线平片和CT检查价值有限,MRI多序列多方位薄层图像对显示其损伤及邻近骨质病变有重要价值。%Objective To investigate the value of 3.0 T MRI in triangular fibrocartilage complex (TFCC) injures in the wrist. Methods The MRI, X-ray and CT characteristics of 26 cases of TFCC injuries were analyzed retrospectively .Results Of the 26 cases with X-ray examination , 13 were negative cases , 5 ulnar styloid fracture , 2 distal radial fracture , 2 lunate necrosis and 6 positive ulnar styloid.5 cases underwent multi-slice CT scan, of which 2 cases had fracture or/and necrosis, others hadn’t ab-normal sign.Of the 26 patients underwent MRI examination , 21 cases were diagnosed as TFCC injuries including 8 cases with TF-CC tear or perforation which were mainly spotty and stripped hyperintense on MRI short time inverse recovery ( STIR ) , 2DMERGE and T2 WI and isointense on T 1 WI;9 were wrist fracture (5 ulnar styloid, 2 radius and 2 wrists);3 were triangular bone or lunate necrosis;8 were radius and ulna or wrist contusion and 10 wrist joints effusion.Bone contusion was long T 1 and long T2 , including bone fracture with bone trabecular or bone cortex breaking .Conclusion The

  1. Annotated Bibliography of EDGE2D Use

    International Nuclear Information System (INIS)

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables

  2. Port Adriano, 2D-Model Tests

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke; Jensen, Palle Meinert

    This report present the results of 2D physical model tests (length scale 1:50) carried out in a waveflume at Dept. of Civil Engineering, Aalborg University (AAU).......This report present the results of 2D physical model tests (length scale 1:50) carried out in a waveflume at Dept. of Civil Engineering, Aalborg University (AAU)....

  3. Annotated Bibliography of EDGE2D Use

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Strachan and G. Corrigan

    2005-06-24

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables.

  4. The clinical value of multi-slice spiral CT angiography in the diagnosis of aortic coarctation%MSCT血管成像技术在主动脉缩窄诊断中的临床价值

    Institute of Scientific and Technical Information of China (English)

    姚凤明; 戴闽晔; 任峰; 付峰; 李晖

    2012-01-01

    Objective: To evaluate the clinical value of multi-slice spiral CT angiography (MSCTA) in the diagnosis of cardiac malformation associated with aortic coarctation (CoA). Methods: 11 cases of Co A underwent pre-and post-contrast enhanced MSCT.and the original data were post-processed with multi-planar reformation (MPR) .maximum intensity projection (MIP) .volume rendering (VR) and virtual endoscopy (VE) techniques. All of the patients were examined by echo-cardiography before surgery. The results of MSCTA were correlated with that of surgery and echocardiography.and the advantages and disadvantages of MSCTA in the diagnosis of CoA associated with cardiac malformation were analyzed. Results: Totally 35 extra-/intra-cardiac malformations were detected in those 11 patients. 26 lesions were diagnosed by MSCTA with the accuracy rate as 74. 3% .including 19 extra-cardiac malformations (accuracy rate,95%) ,however,1 case of patent duc-tus arteriosus was missed;7 intra-cardiac malformations were diagnosed (accuracy rate,46. 7%) .and 8 malformations were missed,with 2 cases of atrial septal defect and 6 valvular lesions. 29 malformations were diagnosed by echocardiography with the accuracy rate as 82. 9% .including 14 extra-cardiac malformations (accuracy,70%) ,6 malformations were missed, in which 5 cases of CoA and 1 case of pulmonary venous ectasia,however, all intra-cardiac malformations were diagnosed with the accuracy rate as 100%. Conclusion:The specific features of CoA could be directly displayed by MSCTA,the position, type and the status of collateral vessels could be clearly identified. MSCTA provides significant clinical values in the diagnosis, selection of treatment,observing of curative effect after-surgery and follow-up. MSCTA in combination with echocardiography is the best approach in the diagnosis of the complicated intra- and extra-cardiac malformations.%目的:评价MSCT血管成像(MSCTA)技术在主动脉缩窄伴心脏畸形

  5. 痉挛性斜颈术前多层螺旋CT的诊断价值%Diagnostic value of multi-slice CT in the spasmodic torticollis before operation

    Institute of Scientific and Technical Information of China (English)

    李良才; 唐秉航; 陈信康; 何亚奇; 黄德成; 吴任国

    2009-01-01

    Objective To explore the method and its clinical value of Multi-slice CT (MSCT) in spasmodic torticollis (ST). Methods Thirty-three cases of spasmodic torticollis, including rotational type (18 cases, 55%), laterocollis(10 cases, 30%), bilateral retrocollis(5 cases, 15%), and the other 42 cases of normal persons as controls were studied using MSCT. The thickness of each paired cervical muscles in images were measured and compared. If hypertrophied muscles were found in different types of ST, the incrassated values on CT images and amplitude with EMG examination were measured and analyzed using Pearson's correlation test. Results (1) CT features of all 33 cases of ST correlated with its clinical types. The hypertrophied muscles in rotational type were distributed in the 1/4 postero-lateral region of rotational side and the 1/4 antero-lateral region of opposite side. The hypertrophied muscles in laterocollis were mainly distributed in the postero-lateral and antero-lateral region of same side. And the hypertrophied musles in laterocollis were distributed in the 1/4 postero-lateral region of both sides. (2) The thickness of cervical muscles could be measured correctly on axial CT images. The means of thickness of each paired cervical muscles in rotanional type and laterocollis showed significant differences(t = 2. 482~6. 540, P < 0. 05)The means of thickness of obliquns inferior, splenius capitis and semispinalis capitis in bilateral retrocollis showed significant differences with that of the normal group(F =4. 947~15.713, P <0.01)The increasing values of thickness of hypertrophied muscles on CT images and its amplitude with EMG examination showed positive correlation (r=0.713~0.963, P<0.01) (3) The results of MSCT and EMG examination could provide a basis of strategy for surgical treatment and improve the curative effect. Conclusions MSCT can clearly and definitely show the morphological change of cervical muscles in ST, and show the hypertrophied muscles

  6. 多层螺旋CT在肠系膜上动脉栓塞诊断中的应用价值%Application of Multi-slice CT in the Diagnosis of Superior Mesenteric Artery Embolization

    Institute of Scientific and Technical Information of China (English)

    张银; 吴智玲; 周立强; 杨建平; 徐开鹏; 陈士花; 宋淮

    2013-01-01

    Objective To investigate the value of multi - slice CT ( MSCT ) in diagnosis of superior mesenteric artery embolization ( SMAE ) . Methods Clinical and imaging data of 18 SMAE patients admitted to our hospital from April 2006 to November 2011 were retrospectively analyzed to summarize the MSCT imaging characteristics of SMAE. Results All the 18 patients were given MSCT three - phase scan, and 11 patients were also given DSA test. The accuracy of MSCT in predicting trunk embolism of SMA was 100. 0% ( 13/13 ), while the accuracy of MSCT in predicting branch embolism was 60% ( 3/5 ), and 2 cases were suspected of SMAE and then confirmed by DSA. MSCT plain scan showed that the embolus was low density and could not be easily differentiated from normal SMA. 4 cases were combined with gut cavity expansion, but without seroperitoneum or intestinal obstruction. Enhancement scan showed that 13 cases had filling defects of SMA trunk, and dotted or oval enhanced shadow were seen in 6 incomplete SMA trunk embolism cases and filling defect shadow were seen in 5 complete branch embolism cases. Data post -processing and image reconstruction showed that volume rendering ( VR ) of the 13 SMA trunk embolism cases could well demonstrate space relationship and could well demonstrate the shape of blood vessels and their relationship with surroundings. MIP of the 3 cases showed the formation of plaque on blood vessel wall. Multi - planar reconstruction ( MPR ) and curve planar reformation ( CPR ) could demonstrate vessel lumen more directly. Conclusion MSCT and post - processing technology is non - invasive, and can diagnose SMAE rapidly and accurately, providing reliable information for assessing the condition of SMAE.%目的 探讨多层螺旋CT(MSCT)在肠系膜上动脉栓塞(SMAE)诊断中的应用价值.方法 回顾性分析我院2006年4月-2011年11月收治的18例SMAE患者的临床及影像学资料,总结SMAE的MSCT影像学特征.结果 18例

  7. 腹主动脉瘤术前CT血管造影重建方法的选择%The choice of multi slice computer tomography angiography reconstruction methods in the pre-operative abdominal aortic aneurysms

    Institute of Scientific and Technical Information of China (English)

    黄小勇; 黄连军; 濮欣; 窦瑞雨; 董继伟; 李杰; 薛玉国

    2011-01-01

    Objective To assess the clinical value of integrated applications of multi slice computer tomography angiography(MSCTA) and multiple reconstruction methods in pre-operative abdominal aortic aneurysms.Methods The MSCTA data of 100 abdominal aortic aneurysms(AAA) from June 2009 to March 2011 were analyzed retrospectively.And the parameters that endovascular aortic repair(EVAR) required were measured by volume rendering techique( VRT),mulit-planar reformation( MPR),maximum intensity projection(MIR) and curved planar reformation(CPR) reconstruction seperately in 83 cases which had underwent EVAR successfully.Compared with single axis view of measurements,the differences between MSCTA different reconstruction methods were assessed.Results Traditional surgeries were performed in 15 cases,clinical follow up were performed in 2 cases,and EVAR were performed in 83 cases.In 83 cases which underwent EVAR,2 cases were type Ⅰ (2/83,2.4% ),66 cases were type Ⅱ ( 66/83,79.5 % ),in which 35 cases were type Ⅱ a,18 cases were type Ⅱ b,13 cases were type Ⅱ c,and 15 cases were type Ⅲ ( 15/83,18.1% ).The parameters including the length and diameter of proximal and distal neck,the bilateral common iliac arteries,the diameter of bilateral external iliac arteries,the length of aneurysm,and the angles were measured in MSCTA.Compared with the single axis view of measurements,there was significance differences.Conclusions The abdominal aortic aneurysm measured by single axis view can lead to an error measurements of length.The integrated applications of MSCTA and multiple reconstruction methods can describe the details of AAA.%目的 探讨综合应用CT血管造影(CTA)多种重建方法对腹主动脉瘤(AAA)腔内隔绝术术前影像学评估的价值.方法 回顾分析2009年6月至2011年3月共100例AAA多排螺旋CT血管造影(MSCTA)资料,并分析其中83例成功实施主动脉腔内修复术(EVAR)患者的MSCTA影像学资料,应用容积再现(VRT)、多平

  8. 腹主动脉瘤术前CT血管造影重建方法的选择%The choice of multi slice computer tomography angiography reconstruction methods in the pre-operative abdominal aortic aneurysms

    Institute of Scientific and Technical Information of China (English)

    黄小勇; 黄连军; 濮欣; 窦瑞雨; 李杰; 薛玉国

    2011-01-01

    Objective To assess the clinical value of integrated applications of multi slice computer tomography angiography (MSCTA) and multiple reconstruction methods in pre-operative abdominal aortic aneurysms.Methods The MSCTA data of 100 abdominal aortic aneurysms(AAA) from June 2009 to March 2011 were analyzed retrospectively.And the parameters that endovascular aortic repair(EVAR) required were measured by volume rendering techique,mulit-planar reformation,maximum intensity projection and curved planar reformation reconstruction seperately in 83 cases which had underwent EVAR successfully.Compared with single axis view of measurements,the differences between MSCTA different reconstruction methods were assessed.Results Traditional surgeries were performed in 15 cases,clinical follow up were performed in 2 cases,and EVAR were performed in 83 cases.In 83 cases which underwent EVAR,2 cases were type Ⅰ (2.4%),66 cases were type Ⅱ (79.5%),in which 35 cases were type Ⅱ a,18 cases were type Ⅱ b,13 cases were type Ⅱ c,and 15 cases were type Ⅲ ( 18.1% ).The parameters including the length and diameter of proximal and distal neck,the bilateral common iliac arteries,the diameter of bilateral external iliac arteries,the length of aneurysm,and the angles were measured in MSCTA.Compared with the single axis view of measurements,there was significance differences.Conclusions The abdominal aortic aneurysm measured by single axis view can lead to an error measurements of length.The integrated applications of MSCTA and multiple reconstruction methods can describe the details of AAA.%目的 探讨综合应用CT血管造影(CTA)多种重建方法对腹主动脉瘤(AAA)腔内隔绝术术前腹主动脉瘤测量影像学评估的价值.方法 回顾分析2009年6月至2011年3月共100例AAA多排螺旋CT血管造影(MSCTA)资料,并分析其中83例成功实施主动脉腔内修复术(EVAR)患者的MSCTA影像学资料,应用容积再现、多平面重建、最大

  9. The role of multi-slice spiral CT in diagnosis and treatment of lumbar hernia%多层螺旋 CT 在腰疝诊治中的意义

    Institute of Scientific and Technical Information of China (English)

    吴茂铸; 汪官富; 倪淑红; 赵年家; 王芬; 韩子华

    2015-01-01

    Objective To explore the imaging appearances and the value of multi-slice CT (MSCT)with post-processing tech-niques in diagnosis and treatment of lumbar hernia (LH).Methods The imaging and clinical data of 1 6 patients with LH which were confirmed by surgery were analyzed retrospectively.Results In 1 6 patients,1 7 lesions of LH were revealed by MSCT.There were superior lumbar hernias in 13 (76.5%),inferior lumbar hernias in 3 (1 7.6%)and diffuse lumbar hernia in 1 (5.9%).Hernia ring in diameter ranged from 1.5 to 9.3 cm,and the hernia sac size ranged from 1.8 cm×2.4 cm to 1 1.3 cm× 6.2 cm.MSCT showed oval or flask shaped mass of extraperitioneal fat with or without peritoneum and visceral contents protruded through the de-fecting fascia floor into lumbar triangle.Superior lumbar hernia was bounded by the 12th rib superiorly,the erector spine muscle medially and the internal oblique muscle laterally.Inferior lumbar hernia was bounded by latissimus dorsi muscle medially,the ex-ternal oblique muscle laterally and the iliac crest inferiorly.Hernia contents included colon in 3 patients and small bowel in 2 with in-carcerated hernia with small bowel obstruction in 1,and adipose tissue and mesentery in other 12.All patients received surgery treatment,and the appropriate surgical methods were selected according to the MSCT findings.The surgical findings were consistent with MSCT results.No recurrence was found during follow-up.Conclusion LH has characteristic CT manifestations.MSCT volu-metric scanning with post-processing techniques can clearly display the type of LH,the size of abdominal wall defect,hernia contents and their complications.It is helpful for diagnosis of the LH and differentiation from other diseases,which may provide important information for clinical surgery.%目的:探讨腰疝(LH)的多层螺旋 CT(MSCT)表现特征及后处理重建技术在 LH 诊治中的临床价值。方法收集经手术病理证实的 LH 16例,回顾性分析其临

  10. 正常胰腺不同部位的多层螺旋CT灌注成像研究%A study on multi-slice spiral CT perfusion imaging in different parts of normal pancreas

    Institute of Scientific and Technical Information of China (English)

    张喜荣; 黄小华; 董国礼; 张小明; 敬宗林; 郭静

    2012-01-01

    目的 应用多层螺旋CT灌注成像技术,探讨正常胰腺头、体和尾部的血流灌注特点.方法 选择临床行中上腹增强CT检查并符合正常胰腺纳入标准的患者35例,采用Toshiba Aquilion 16层螺旋CT先行平扫,在胰腺头、体和尾部显示完整的中心层面进行胰腺同层动态增强扫描,将扫描后所得影像数据传输到Vitrea 2.0后处理工作站,采用Toshiba体部灌注软件对正常胰腺各部位灌注参数做三点测量,其每部三点测量的平均值视为各部灌注参数最后值,并对各部灌注参数行统计学分析.结果 正常胰腺头部、体部和尾部的血流量(BF)、血容量(BV)、表面通透性(PS)和平均通过时间(MTT)的测量值分别为:头部(128.34±29.23) mL·100 g-1·min-1,(43.19±13.77) mL/100 g,(218.39±99.21) mL·100 g-1·min-1,(299.26±81.99)0.1 s;体部 (136.20±23.00) mL·100 g-1·min-1,(44.63±13.74) mL/100 g,(223.20±73.82) mL·100 g-1·min-1,(310.99±59.00) 0.1 s;尾部(128.04±27.67) mL·100 g-1·min-1,(46.04±20.14) mL/100 g,(232.24±76.65) mL·100 g-1·min-1,(299.96±71.45) 0.1 s.3组参数间均无统计学意义(P>0.05).结论 正常胰腺头部、体部和尾部供血动脉有所差异,但各部组织血流灌注基本一致.%Objective To explore the blood flow perfusion characteristics of different parts of normal pancreas by means of multi-slices spiral CT perfusion imaging. Methods Thirty-five patients without pancreatic disease,received contrast-enhanced CT exami-nation for the venter superior abdomen by 16-slice spiral CT. The completely displayed center level in the head,body and tail of nor-mal pancreas were examined by dynamic enhancement scanning. These data were processed on a Start Vitrea 2. 0 workstation by using Toshiba body software package. The three-point measurement approach was used to examin the parameters of blood flow (BF) ,blood volume (BV) ,permeability surface (PS) and mean transit time (MTT) of pancreatic tissues in

  11. A differentiated approach to the diagnosis of pulmonary embolism and deep venous thrombosis using multi-slice CT; Abklaerung von Lungenembolie und venoeser Thromboembolie mittels Mehrschicht-Spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, J.E.; Mahnken, A.H.; Stargardt, A.; Haage, P.; Guenther, R.W. [Klinik fuer Radiologische Diagnostik (Germany); Sinha, A.M. [Medizinische Klinik 1, Universitaetsklinikum der RWTH Aachen (Germany); Schaller, S. [Siemens Medical Solutions, Computertomographie, Forchheim (Germany)

    2002-03-01

    Purpose: To establish a differentiated protocol for multi-slice CT (MSCT) examinations in cases of clinically suspected pulmonary embolism (PE) using pulmonary CT-angiography (CTA) and indirect CT-phlebography (CTP). Materials and Methods: 161 patients with suspected PE were examined using an MSCT (SOMATOM Volume Zoom; Siemens, Forchheim, Germany). After intravenous administration of 120 ml of contrast material, a thin collimation chest-CT scan was performed (120 kV, 100 mAs, collimation: 4 x 1 mm). If PE was present, or previous examinations and clinical signs suggested deep venous thrombosis (DVT), a CTP was subsequently completed. CTPs were performed using a 4 x 5 mm protocol (120 kV, 170 mAs). Venous phase scanning, starting from the pelvic crest, was completed in the popliteal fossa three minutes after contrast material injection. In 73 extremities, CTP were compared to the results of ultrasound, phlebography and autopsy. Scan ranges were documented in all patients. Cumulative doses were calculated for male and female subgroups. Results: 62 patients in our series suffered from PE and in 47 of these patients deep venous thrombosis was seen additionally. Of the 99 patients without PE, 47 also received indirect CTP. CTP confirmed the suspicion and extent of DVT in 8 patients. Only in 2 of 39 patients (5.1%) was previously unknown DVT found, despite the exclusion of PE. Regarding DVT, sensitivity was 94.3% and specificity was 92.1% for indirect CTP. Cumulative chest CT doses averaged 3.3 mSv for males and 4.2 mSv for females, the calculated CTP dosage was 9.3 mSv (according to ICRP 60). Conclusions: the examination protocol presented its suitable for clinical usage in patients with suspected PE. If PE is confirmed, indirect CTP is justified, so that detailed information of the venous system can be obtained. However, the relatively high radiation dosage of an additional CTP requires a strict indication regiment in patients with a negative CTA. (orig.) [German

  12. 2D materials for nanophotonic devices

    Science.gov (United States)

    Xu, Renjing; Yang, Jiong; Zhang, Shuang; Pei, Jiajie; Lu, Yuerui

    2015-12-01

    Two-dimensional (2D) materials have become very important building blocks for electronic, photonic, and phononic devices. The 2D material family has four key members, including the metallic graphene, transition metal dichalcogenide (TMD) layered semiconductors, semiconducting black phosphorous, and the insulating h-BN. Owing to the strong quantum confinements and defect-free surfaces, these atomically thin layers have offered us perfect platforms to investigate the interactions among photons, electrons and phonons. The unique interactions in these 2D materials are very important for both scientific research and application engineering. In this talk, I would like to briefly summarize and highlight the key findings, opportunities and challenges in this field. Next, I will introduce/highlight our recent achievements. We demonstrated atomically thin micro-lens and gratings using 2D MoS2, which is the thinnest optical component around the world. These devices are based on our discovery that the elastic light-matter interactions in highindex 2D materials is very strong. Also, I would like to introduce a new two-dimensional material phosphorene. Phosphorene has strongly anisotropic optical response, which creates 1D excitons in a 2D system. The strong confinement in phosphorene also enables the ultra-high trion (charged exciton) binding energies, which have been successfully measured in our experiments. Finally, I will briefly talk about the potential applications of 2D materials in energy harvesting.

  13. Internal Photoemission Spectroscopy of 2-D Materials

    Science.gov (United States)

    Nguyen, Nhan; Li, Mingda; Vishwanath, Suresh; Yan, Rusen; Xiao, Shudong; Xing, Huili; Cheng, Guangjun; Hight Walker, Angela; Zhang, Qin

    Recent research has shown the great benefits of using 2-D materials in the tunnel field-effect transistor (TFET), which is considered a promising candidate for the beyond-CMOS technology. The on-state current of TFET can be enhanced by engineering the band alignment of different 2D-2D or 2D-3D heterostructures. Here we present the internal photoemission spectroscopy (IPE) approach to determine the band alignments of various 2-D materials, in particular SnSe2 and WSe2, which have been proposed for new TFET designs. The metal-oxide-2-D semiconductor test structures are fabricated and characterized by IPE, where the band offsets from the 2-D semiconductor to the oxide conduction band minimum are determined by the threshold of the cube root of IPE yields as a function of photon energy. In particular, we find that SnSe2 has a larger electron affinity than most semiconductors and can be combined with other semiconductors to form near broken-gap heterojunctions with low barrier heights which can produce a higher on-state current. The details of data analysis of IPE and the results from Raman spectroscopy and spectroscopic ellipsometry measurements will also be presented and discussed.

  14. 2D supergravity in p+1 dimensions

    OpenAIRE

    Gustafsson, H.; Lindstrom, U.

    1998-01-01

    We describe new $N$-extended 2D supergravities on a $(p+1)$-dimensional (bosonic) space. The fundamental objects are moving frame densities that equip each $(p+1)$-dimensional point with a 2D ``tangent space''. The theory is presented in a $[p+1, 2]$ superspace. For the special case of $p=1$ we recover the 2D supergravities in an unusual form. The formalism has been developed with applications to the string-parton picture of $D$-branes at strong coupling in mind.

  15. 2D Barcode for DNA Encoding

    OpenAIRE

    Elena Purcaru; Cristian Toma

    2012-01-01

    The paper presents a solution for endcoding/decoding DNA information in 2D barcodes. First part focuses on the existing techniques and symbologies in 2D barcodes field. The 2D barcode PDF417 is presented as starting point. The adaptations and optimizations on PDF417 and on DataMatrix lead to the solution – DNA2DBC – DeoxyriboNucleic Acid Two Dimensional Barcode. The second part shows the DNA2DBC encoding/decoding process step by step. In conclusions are enumerated the most important features ...

  16. 2D Saturable Absorbers for Fibre Lasers

    Directory of Open Access Journals (Sweden)

    Robert I. Woodward

    2015-11-01

    Full Text Available Two-dimensional (2D nanomaterials are an emergent and promising platform for future photonic and optoelectronic applications. Here, we review recent progress demonstrating the application of 2D nanomaterials as versatile, wideband saturable absorbers for Q-switching and mode-locking fibre lasers. We focus specifically on the family of few-layer transition metal dichalcogenides, including MoS2, MoSe2 and WS2.

  17. Beltrami States in 2D Electron Magnetohydrodynamics

    OpenAIRE

    Shivamoggi, B. K.

    2015-01-01

    In this paper, the Hamiltonian formulations along with the Poisson brackets for two-dimensional (2D) electron magnetohydrodynamics (EMHD) flows are developed. These formulations are used to deduce the Beltrami states for 2D EMHD flows. In the massless electron limit, the EMHD Beltrami states reduce to the force-free states, though there is no force-free Beltrami state in the general EMHD case.

  18. Glitter in a 2D monolayer.

    Science.gov (United States)

    Yang, Li-Ming; Dornfeld, Matthew; Frauenheim, Thomas; Ganz, Eric

    2015-10-21

    We predict a highly stable and robust atomically thin gold monolayer with a hexagonal close packed lattice stabilized by metallic bonding with contributions from strong relativistic effects and aurophilic interactions. We have shown that the framework of the Au monolayer can survive 10 ps MD annealing simulations up to 1400 K. The framework is also able to survive large motions out of the plane. Due to the smaller number of bonds per atom in the 2D layer compared to the 3D bulk we observe significantly enhanced energy per bond (0.94 vs. 0.52 eV per bond). This is similar to the increase in bond strength going from 3D diamond to 2D graphene. It is a non-magnetic metal, and was found to be the global minima in the 2D space. Phonon dispersion calculations demonstrate high kinetic stability with no negative modes. This 2D gold monolayer corresponds to the top monolayer of the bulk Au(111) face-centered cubic lattice. The close-packed lattice maximizes the aurophilic interactions. We find that the electrons are completely delocalized in the plane and behave as 2D nearly free electron gas. We hope that the present work can inspire the experimental fabrication of novel free standing 2D metal systems.

  19. 2d index and surface operators

    Science.gov (United States)

    Gadde, Abhijit; Gukov, Sergei

    2014-03-01

    In this paper we compute the superconformal index of 2d (2, 2) supersymmetric gauge theories. The 2d superconformal index, a.k.a. flavored elliptic genus, is computed by a unitary matrix integral much like the matrix integral that computes the 4d superconformal index. We compute the 2d index explicitly for a number of examples. In the case of abelian gauge theories we see that the index is invariant under flop transition and under CY-LG correspondence. The index also provides a powerful check of the Seiberg-type duality for non-abelian gauge theories discovered by Hori and Tong. In the later half of the paper, we study half-BPS surface operators in = 2 super-conformal gauge theories. They are engineered by coupling the 2d (2, 2) supersymmetric gauge theory living on the support of the surface operator to the 4d = 2 theory, so that different realizations of the same surface operator with a given Levi type are related by a 2d analogue of the Seiberg duality. The index of this coupled system is computed by using the tools developed in the first half of the paper. The superconformal index in the presence of surface defect is expected to be invariant under generalized S-duality. We demonstrate that it is indeed the case. In doing so the Seiberg-type duality of the 2d theory plays an important role.

  20. Selection and application of multi-slice CT 3D reconstruction techniques in assisting mini-implant ahchorage implant surgery%多层螺旋CT三维重建技术在辅助微螺钉种植支抗植入中的选择应用

    Institute of Scientific and Technical Information of China (English)

    陈京奕; 吴晓伟; 张洪刚; 焦建军; 张学强; 姚传臣

    2011-01-01

    背景:提高正畸支抗系统微螺钉种植体稳定性的关键在于种植前对局部骨质、骨量进行精确评估,但常规二维影像学检查,如根尖片、曲面断层摄影片、侧位头影测量片等均存在不同程度的局限性.目的:分析总结多层螺旋CT多种图像重建技术在辅助微螺钉种植支抗植入中的不同特点及优势,以便精确指导微螺钉的种植,提高其稳定性.方法:种植前以多层螺旋CT对猪颅骨进行定位扫描及多种图像重建,通过多种图像联合应用初步观测种植区骨质骨量及解剖情况,然后利用计算机在影像上精确设计三维种植角度,根据影像信息制作隧道式手术模板指导种植32枚微螺钉支抗,种植后多层螺旋CT再次扫描重建,将种植前后多层螺旋CT设计及测量角度与术后解剖组织块实物测量角度作对比分析.结果与结论:32枚微螺钉种植情况满意,无伤及邻近牙根及周围重要组织结构的情况.种植前设计与种植后多层螺旋CT测量角度比较,以及种植后多层螺旋CT测量与实物测量角度比较,在轴位面及侧断面上其差异均无显著性意义(P > 0.05),且一致性极好.说明多层螺旋CT能够提供精确而丰富的影像信息,恰当选择合理应用能充分实现微螺钉种植影像学检查目的,从而为提高种植的成功率提供可靠保障.%BACKGROUND: The key method to improve the stability of miniscrew orthodontic anchorage system is accurate preoperative bone mass evaluation in the implant region. Routine 2D image examinations such as periapical radiography and panoramic tomography and lateral cephalometric radiography have limitations.OBJECTIVE: To analyze the traits and advantages of various multi-slice CT (MSCT) reconstruction images in assisting miniscrew anchorage surgery to improve the stability of miniscrew.METHODS: Preplant MSCT scanning and various images reconstruction were made and helped to exam the peri-implant bone

  1. 2-D DOA Estimation Based on 2D-MUSIC%基于2D-MUSIC算法的DOA估计

    Institute of Scientific and Technical Information of China (English)

    康亚芳; 王静; 张清泉; 行小帅

    2014-01-01

    This paper discussed the performance of classical two-dimensional DOA estimation with 2D-MUSIC, based on the mathematical model of planar array and 2D-MUSIC DOA estimation, Taking uniform planar array for example, comput-er simulation experiment was carried for the effect of three kinds of different parameters on 2-D DOA estimation, and the simulation results were analyzed. And also verification test about the corresponding algorithm performance under the differ-ent parameters was discussed.%利用经典的2D-MUSIC算法对二维阵列的DOA估计进行了研究,在平面阵列数学模型以及2D-MUSIC算法的DOA估计模型基础上,以均匀平面阵列为例,对3种不同参数的DOA估计进行了计算机仿真,分析了仿真结果。得出了在不同参数变化趋势下DOA估计的相应变化情况。

  2. 2d Index and Surface operators

    CERN Document Server

    Gadde, Abhijit

    2013-01-01

    In this paper we compute the superconformal index of 2d (2,2) supersymmetric gauge theories. The 2d superconformal index, a.k.a. flavored elliptic genus, is computed by a unitary matrix integral much like the matrix integral that computes 4d superconformal index. We compute the 2d index explicitly for a number of examples. In the case of abelian gauge theories we see that the index is invariant under flop transition and CY-LG correspondence. The index also provides a powerful check of the Seiberg-type duality for non-abelian gauge theories discovered by Hori and Tong. In the later half of the paper, we study half-BPS surface operators in N=2 superconformal gauge theories. They are engineered by coupling the 2d (2,2) supersymmetric gauge theory living on the support of the surface operator to the 4d N=2 theory, so that different realizations of the same surface operator with a given Levi type are related by a 2d analogue of the Seiberg duality. The index of this coupled system is computed by using the tools de...

  3. Pediatric MRI

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Study of Normal Brain Development is a longitudinal study using anatomical MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS) to map pediatric...

  4. 下腔静脉病变的 CT 与 MRI 诊断价值%Study on the significance of CT scanning and MRI in diagnosis of lesions in inferior vena cava

    Institute of Scientific and Technical Information of China (English)

    王文生; 丁长青; 孙迎迎; 罗慧; 代兰兰; 丁爱兰

    2014-01-01

    Objective To explore the significance of multi - slice spiral CT scanning and MRI in diagnosis of lesions in inferior vena cava (IVC). Methods The data of 16 - slice spiral CT scanning and 0. 35T MRI imaging of 80 patients with clinically confirmed IVC lesions were retrospectively analyzed. The CT scanning was given with multi - phase contrast - enhanced examination,MRI was mainly by plain scanning. These examinations were focused on analyzing the scope and nature of inferior vena cava. Results Among these 80 cases,9 cases were congenital malformation of IVC(5 cases were diagnosed by CT scanning,and 4 cases by MRI),formation of emboli in 36 cases(including 5 with thrombo-sis,31 with cancer embolus;32 cases were diagnosed by CT,and 4 cases by MRI ),16 cases of Budd Chiari syndrome(diagnosed by CT scan-ning in 15 cases,MRI in 1 case),stenosis caused by external pressure in 12 cases(diagnosed by CT scanning in 8 cases,and by MRI in 4 ca-ses),placement of stent in 3 cases(diagnosed by CT scanning). Conclusion Multi - slice spiral CT scanning and MRI can rapidly,accurately and non - invasively demonstrate IVC and its lesions,hence they are worthy to be applied for clinical diagnosis.%目的:探讨多层螺旋 CT 及 MRI 在下腔静脉病变中的诊断价值。方法回顾性分析临床证实的80例下腔静脉病变的16层螺旋 CT 及0.35T MRI 资料,CT 以多期增强检查为主,MRI 以平扫为主。重点分析下腔静脉病变部位、范围及性质。结果检出下腔静脉先天畸形9例(其中 CT 诊断5例,MRI 诊断4例),下腔静脉栓子形成36例(其中血栓5例,癌栓31例;CT 诊断32例,MRI 诊断4例),布加综合征16例(其中 CT 诊断15例,MRI 诊断1例),外压性狭窄12例(其中 CT 诊断8例,MRI 诊断4例),支架置入3例(均为 CT 诊断)。结论多层螺旋 CT 及 MRI 能够快速、无创较为准确显示下腔静脉及其病变,值得临床应用。

  5. Uncertainty estimations for quantitative in vivo MRI T1 mapping

    Science.gov (United States)

    Polders, Daniel L.; Leemans, Alexander; Luijten, Peter R.; Hoogduin, Hans

    2012-11-01

    Mapping the longitudinal relaxation time (T1) of brain tissue is of great interest for both clinical research and MRI sequence development. For an unambiguous interpretation of in vivo variations in T1 images, it is important to understand the degree of variability that is associated with the quantitative T1 parameter. This paper presents a general framework for estimating the uncertainty in quantitative T1 mapping by combining a slice-shifted multi-slice inversion recovery EPI technique with the statistical wild-bootstrap approach. Both simulations and experimental analyses were performed to validate this novel approach and to evaluate the estimated T1 uncertainty in several brain regions across four healthy volunteers. By estimating the T1 uncertainty, it is shown that the variation in T1 within anatomic regions for similar tissue types is larger than the uncertainty in the measurement. This indicates that heterogeneity of the inspected tissue and/or partial volume effects can be the main determinants for the observed variability in the estimated T1 values. The proposed approach to estimate T1 and its uncertainty without the need for repeated measurements may also prove to be useful for calculating effect sizes that are deemed significant when comparing group differences.

  6. Optical modulators with 2D layered materials

    Science.gov (United States)

    Sun, Zhipei; Martinez, Amos; Wang, Feng

    2016-04-01

    Light modulation is an essential operation in photonics and optoelectronics. With existing and emerging technologies increasingly demanding compact, efficient, fast and broadband optical modulators, high-performance light modulation solutions are becoming indispensable. The recent realization that 2D layered materials could modulate light with superior performance has prompted intense research and significant advances, paving the way for realistic applications. In this Review, we cover the state of the art of optical modulators based on 2D materials, including graphene, transition metal dichalcogenides and black phosphorus. We discuss recent advances employing hybrid structures, such as 2D heterostructures, plasmonic structures, and silicon and fibre integrated structures. We also take a look at the future perspectives and discuss the potential of yet relatively unexplored mechanisms, such as magneto-optic and acousto-optic modulation.

  7. Automatic Contour Extraction from 2D Image

    Directory of Open Access Journals (Sweden)

    Panagiotis GIOANNIS

    2011-03-01

    Full Text Available Aim: To develop a method for automatic contour extraction from a 2D image. Material and Method: The method is divided in two basic parts where the user initially chooses the starting point and the threshold. Finally the method is applied to computed tomography of bone images. Results: An interesting method is developed which can lead to a successful boundary extraction of 2D images. Specifically data extracted from a computed tomography images can be used for 2D bone reconstruction. Conclusions: We believe that such an algorithm or part of it can be applied on several other applications for shape feature extraction in medical image analysis and generally at computer graphics.

  8. 2D microwave imaging reflectometer electronics

    Energy Technology Data Exchange (ETDEWEB)

    Spear, A. G.; Domier, C. W., E-mail: cwdomier@ucdavis.edu; Hu, X.; Muscatello, C. M.; Ren, X.; Luhmann, N. C. [Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-11-15

    A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

  9. Towards quantification of blood-flow changes during cognitive task activation using perfusion-based fMRI.

    Science.gov (United States)

    Mildner, Toralf; Zysset, Stefan; Trampel, Robert; Driesel, Wolfgang; Möller, Harald E

    2005-10-01

    Multi-slice perfusion-based functional magnetic resonance imaging (p-fMRI) is demonstrated with a color-word Stroop task as an established cognitive paradigm. Continuous arterial spin labeling (CASL) of the blood in the left common carotid artery was applied for all repetitions of the functional run in a quasi-continuous fashion, i.e., it was interrupted only during image acquisition. For comparison, blood oxygen level dependent (BOLD) contrast was detected using conventional gradient-recalled echo (GE) echo planar imaging (EPI). Positive activations in BOLD imaging appeared in p-fMRI as negative signal changes corresponding to an enhanced transport of inverted water spins into the region of interest, i.e., increased cerebral blood flow (CBF). Regional differences between the localization of activations and the sensitivity of p-fMRI and BOLD-fMRI were observed as, for example, in the inferior frontal sulcus and in the intraparietal sulcus. Quantification of CBF changes during cognitive task activation was performed on a multi-subject basis and yielded CBF increases of the order of 20-30%.

  10. Multidetector CT and MRI in pancreatic diseases

    International Nuclear Information System (INIS)

    Multidetector CT and MRI are the most efficient non invasive techniques in the assessment of pancreatic diseases. As with MRI, multidetector CT has now become an all in one examination using 2 D and 3 D multiplanar reformations with the ability to perform with high accuracy: a) vascular assessment using MIP reconstruction and b) biliary and pancreatic ducts assessment using minIP reconstruction. This review compares and illustrates the respective advantages of MRI and multidetector CT in the assessment of pancreatic diseases. (authors)

  11. Horns Rev II, 2-D Model Tests

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Frigaard, Peter

    This report present the results of 2D physical model tests carried out in the shallow wave flume at Dept. of Civil Engineering, Aalborg University (AAU), on behalf of Energy E2 A/S part of DONG Energy A/S, Denmark. The objective of the tests was: to investigate the combined influence of the pile...

  12. 2D PIM Simulation Based on COMSOL

    DEFF Research Database (Denmark)

    Wang, Xinbo; Cui, Wanzhao; Wang, Jingyu;

    2011-01-01

    Passive intermodulation (PIM) is a problematic type of nonlinear distortion en- countered in many communication systems. To analyze the PIM distortion resulting from ma- terial nonlinearity, a 2D PIM simulation method based on COMSOL is proposed in this paper. As an example, a rectangular waveguide...

  13. Baby universes in 2d quantum gravity

    OpenAIRE

    Ambjorn, J.; S. Jain; G. Thorleifsson

    1993-01-01

    We investigate the fractal structure of $2d$ quantum gravity, both for pure gravity and for gravity coupled to multiple gaussian fields and for gravity coupled to Ising spins. The roughness of the surfaces is described in terms of baby universes and using numerical simulations we measure their distribution which is related to the string susceptibility exponent $\\g_{string}$.

  14. Characteristics and diagnostic value of multi-slice spiral computed tomography examination of gastrointestinal lipoma%胃肠道脂肪瘤的多排螺旋CT检查特征与诊断价值

    Institute of Scientific and Technical Information of China (English)

    郑汉朋; 王晓阳; 藤陈迪; 许崇永; 郑祥武; 邱乾德

    2016-01-01

    Objective To investigate the characteristics and diagnostic value of multi-slice spiral computed tomography (MSCT) examination of gastrointestinal lipoma.Methods The cross-sectional study was adopted.The clinicopathological data of 96 patients with gastrointestinal lipoma including 32 from the Second Hospital Affiliated to Wenzhou Medical University,30 from the First Hospital Affiliated to Wenzhou Medical University,17 from the Ruian People's Hospital of Zhejiang,11 from the Yueqing People's Hospital,3 from the Wenzhou Central Hospital and 3 from the Wenzhou People's Hospital from December 2006 to September 2015 were collected.All patients were fasted for 8 hours prior to the examination,and partial patients underwent enhanced scan after the conventional CT scanning with breathless scanning and no abdominal pressure.Coronal and sagittal images of gastrointestinal tract including the tumor were administrated with multiple planar reconstruction (MPR)techniques of Reformat software.Based on MPR images,the curves along the gastrointestinal tract were drawn,voxel distributed along the curve track were reconstructed,and curved planar reconstruction (CPR) images were obtained.The patients received operation or follow-up according to individual characteristics after examinations.The patients undergoing operation were followed up for detecting tumor recurrence and metastasis by CT examination and patients receiving follow-up were observed by endoscopy for detecting changes of tumor size and morphology up to June 2015.The analysis indexes included tumor location and size,performance of MSCT examination (tumor shape,density,margin,intussusceptions,enhanced MSCT examination),intraoperative findings,results of pathological examination and results of follow-up.Measurement data with normal distribution were presented as i ± s.Results All the 96 patients received MSCT plain scan and the 42 received enhanced MSCT scan.The CPR images in 30 patients were collected.(1) Tumor location

  15. Application of 2D Non-Graphene Materials and 2D Oxide Nanostructures for Biosensing Technology.

    Science.gov (United States)

    Shavanova, Kateryna; Bakakina, Yulia; Burkova, Inna; Shtepliuk, Ivan; Viter, Roman; Ubelis, Arnolds; Beni, Valerio; Starodub, Nickolaj; Yakimova, Rositsa; Khranovskyy, Volodymyr

    2016-02-06

    The discovery of graphene and its unique properties has inspired researchers to try to invent other two-dimensional (2D) materials. After considerable research effort, a distinct "beyond graphene" domain has been established, comprising the library of non-graphene 2D materials. It is significant that some 2D non-graphene materials possess solid advantages over their predecessor, such as having a direct band gap, and therefore are highly promising for a number of applications. These applications are not limited to nano- and opto-electronics, but have a strong potential in biosensing technologies, as one example. However, since most of the 2D non-graphene materials have been newly discovered, most of the research efforts are concentrated on material synthesis and the investigation of the properties of the material. Applications of 2D non-graphene materials are still at the embryonic stage, and the integration of 2D non-graphene materials into devices is scarcely reported. However, in recent years, numerous reports have blossomed about 2D material-based biosensors, evidencing the growing potential of 2D non-graphene materials for biosensing applications. This review highlights the recent progress in research on the potential of using 2D non-graphene materials and similar oxide nanostructures for different types of biosensors (optical and electrochemical). A wide range of biological targets, such as glucose, dopamine, cortisol, DNA, IgG, bisphenol, ascorbic acid, cytochrome and estradiol, has been reported to be successfully detected by biosensors with transducers made of 2D non-graphene materials.

  16. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  17. MRI Artifacts

    Directory of Open Access Journals (Sweden)

    Abed Al Nasser Assi

    2009-12-01

    Full Text Available   "nMagnetic resonance imaging (MRI has become more and more frequently used in medical imaging diagnostic in recent years. Radiologists and technicians working at these systems are relatively often confronted with image artifacts related to the radiowave with strong magnetic in the scanner. Many artifacts may be corrected or modulated through an understanding of their cause. This requires familiarity with scanner design; theory of operation; and image acquisition. The purpose of this review article is to present the most relevant artifacts that arise in MRI scanner, to provide some physical background on the formation of artifacts, and to suggest strategies to reduce or avoid these artifacts. The most frequent artifacts that can occur during MRI scanning are Motion related artifacts; Para-magnetic artifacts; Phase Wrap artifacts; Frequency artifacts; Susceptibility artifacts; Clipping artefact; Chemical Shift artifact and "Zebra" artefact .    "n  

  18. MRI Safety during Pregnancy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z MRI Safety During Pregnancy Magnetic resonance imaging (MRI) Illness ... during the exam? Contrast material MRI during pregnancy Magnetic resonance imaging (MRI) If you are pregnant and your doctor ...

  19. Fetal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D.; Brugger, P.C. [University Hospital of Vienna (Austria). Division of Neuroradiology

    2004-07-01

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  20. Multi slice CT MPR technology and MR of cruciate ligament Comparison of damage diagnosis%多排CT的MPR技术与MR对交叉韧带损伤影诊断的对比

    Institute of Scientific and Technical Information of China (English)

    胡瑞峰; 王琨; 王姝君

    2015-01-01

    Knee ligament damage is very common clinical, MRI is the knee ligament damage check ideal check method, but MRI equipment expensive, a lot of basic-level hospital has not been popular, and MR imaging is the signal imaging, video con-tinuity and 3 d stereoscopic feeling bad, if have metallic implants, are not for MR check, and will influence the MSCT small. At present, multidetector-row CT increasing popularity, multidetector-row CT MPR reconstruction technique in the whole body each system widely used, and the MSCT can also found joint concurrent damage inside and outside, the scanning bilateral knee, in addition, without changes to limb natural postures, reduce pain patients. Will the knee ligament damage is concerned, the do-mestic rarely reported in the literature, through the multidetector-row CT (MSCT) image reconstruction and MPR technology for knee ligament damage across the image diagnosis and an MRI results of the comparison of the science, with the diagnosis rate 97%, and multidetector-row CT of the MPR reconstruction technique for knee ligament damage the diagnostic value of more than MR examination has authenticity, scientific and practical, has the extensive use of the value and popularize value.%膝关节韧带损伤临床上很常见,MRI是目前膝关节韧带损伤检查较理想的检查方法,但MRI设备昂贵,很多基层医院尚未普及,据不完全统计本市的MRI占20%,而且MR影像是信号成像,影像连续性及三维立体感差,如有金属内置物,则不能进行MR检查,而MSCT则影响较小。目前,多排螺旋CT日益普及,多排螺旋CT的MPR重建技术在全身各个系统广泛应用,且MSCT可同时发现关节内外的并发损伤,可同时扫描双侧膝关节,另外,不需改动患肢自然体位,减少患者痛苦。就膝关节韧带损伤而言,国内文献报道很少,通过多排螺旋CT (MSCT)影像三维重建及MPR技术对膝关节交叉韧带损伤的影像诊断与MRI

  1. 2-D geometrical analysis of deformation

    International Nuclear Information System (INIS)

    Engineering structures such as dams, bridges, high rise buildings, etc. are subject to deformation. Deformation survey is therefore necessary to determine the magnitude and direction of such movements for the purpose of safety assessment. In this study, a strategy for two-step analyses for deformation survey rising the two dimensional (2-D) geodetic method has been developed, consisting of independent least squares estimation (LSE) of each epoch followed by deformation detection. Important aspects on LSE include global and local testing. In deformation detection, the following aspects were implemented; datum definition by the user. determination of stable datum points, geometrical analysis of deformation and graphic presentation. The developed strategy has been implemented in three computer programs, COMPUT, DEFORM and STRANS. Tests carried out with simulated and known data show that the developed strategy and programs are applicable for 2-D geometrical detection of deformation. (Author)

  2. 2D photonic-crystal optomechanical nanoresonator.

    Science.gov (United States)

    Makles, K; Antoni, T; Kuhn, A G; Deléglise, S; Briant, T; Cohadon, P-F; Braive, R; Beaudoin, G; Pinard, L; Michel, C; Dolique, V; Flaminio, R; Cagnoli, G; Robert-Philip, I; Heidmann, A

    2015-01-15

    We present the optical optimization of an optomechanical device based on a suspended InP membrane patterned with a 2D near-wavelength grating (NWG) based on a 2D photonic-crystal geometry. We first identify by numerical simulation a set of geometrical parameters providing a reflectivity higher than 99.8% over a 50-nm span. We then study the limitations induced by the finite value of the optical waist and lateral size of the NWG pattern using different numerical approaches. The NWG grating, pierced in a suspended InP 265-nm thick membrane, is used to form a compact microcavity involving the suspended nanomembrane as an end mirror. The resulting cavity has a waist size smaller than 10 μm and a finesse in the 200 range. It is used to probe the Brownian motion of the mechanical modes of the nanomembrane. PMID:25679837

  3. Robust and resistant 2D shape alignment

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Eiriksson, Hrafnkell

    2001-01-01

    We express the alignment of 2D shapes as the minimization of the norm of a linear vector function. The minimization is done in the \\$l\\_1\\$, \\$l\\_2\\$ and the \\$l\\_\\$\\backslash\\$infty\\$ norms using well known standard numerical methods. In particular, the \\$l\\_1\\$ and the \\$l\\_\\$\\backslash\\$infty\\......We express the alignment of 2D shapes as the minimization of the norm of a linear vector function. The minimization is done in the \\$l\\_1\\$, \\$l\\_2\\$ and the \\$l\\_\\$\\backslash\\$infty\\$ norms using well known standard numerical methods. In particular, the \\$l\\_1\\$ and the \\$l......\\_\\$\\backslash\\$infty\\$ norm alignments are formulated as linear programming problems. The linear vector function formulation along with the different norms results in alignment methods that are both resistant from influence from outliers, robust wrt. errors in the annotation and capable of handling missing datapoints...

  4. Experimental research of acetabular abduction angle and anteversion measurement by three-dimensional reconstruction of multi-slice spiral CT%多层螺旋CT三维重建测量髋臼外展角及前倾角的实验研究

    Institute of Scientific and Technical Information of China (English)

    范新成; 葛东; 刘峰; 魏开斌; 马振波; 张伟; 赵伟; 李军; 朱海涛; 初培罡

    2014-01-01

    Objective To investigate a new method of three-dimensional reconstruction of multi-slice spiral CT in measurement of acetabular abduction angle and acetabular anteversion. Methods The research objects were 60 acetabulars of 30 pelvic specimens, acetabular abduction angle and acetabular anteversion were measured respectively by radiological and actual measurements. The first one using digital X-ray photography and three-dimensional reconstruction of multi-slice spiral CT. The second one using a protractor and digital goniometer two methods. Results The acetabular abduction angle and anteversion were (48.61±2.31)° and (15.82±4.62)° respectively, there was no statistically significant difference of these two angles between actual measurement and radiological measurement(P>0.05). There were no significant differences for each angle between radiological and actual measurements(P>0.05). Conclusions The measurement of acetabular abduction angle and anteversion by MSCT three-dimensional reconstruction were accurate, which provide a new and standardized method of measurement of acetabular abduction angle and anteversion. The digital goniometer provide an accurate and convenient new method for specimens’ anatomical measurements.%目的:探讨应用多层螺旋CT(multi-slice spiral CT,MSCT)三维重建精确测量髋臼外展角及前倾角的新方法。方法选用30具成人完整骨盆标本共60个髋臼为研究对象,应用放射学方法及实际测量法分别对其外展角、前倾角进行测量,放射学方法采用数字化 X 线摄影(digital X-ray radiography,DR)及MSCT三维重建两种方法,实际测量采用量角器及数显角度仪两种方法。结果 MSCT重建法测得的髋臼外展角为48.61°±2.31°,前倾角为15.82°±4.62°,与实际测量结果比较,差异均无统计学意义(P>0.05);放射学方法与实际测得的髋臼外展角、前倾角分别比较,差异均无统计学意义(P>0.05

  5. 多层螺旋CT平扫联合尿路重建在急性肾绞痛诊断中的临床应用%Clinical application of multi-slice helical CT plain scan combined with urinary reconstruction in diagnosis of acute renal colic

    Institute of Scientific and Technical Information of China (English)

    陈刚; 吴小候; 尹志康; 何云锋

    2011-01-01

    目的 探讨多层螺旋CT平扫联合尿路重建在急性肾绞痛诊断中的的临床应用价值.方法 将126例急诊肾绞痛患者随机分两组:CT组(67例)和静脉尿路造影(IVU)组(59例),CT组行多层(16层或64层)螺旋CT平扫联合尿路重建,IVU组行相关准备后行腹部X线平片(KUB)联合IVU检查.在明确诊断为输尿管梗阻或输尿管结石后,急诊行输尿管镜碎石术或置管治疗,比较两组患者的术前结石确诊率、肾绞痛缓解时间、住院时间及住院总费用等.结果 所有患者术后肾绞痛均缓解,CT组术前结石确诊率明显高于IVU组(P<0.05),CT组肾绞痛缓解时间和住院时间短于IVU组(P<0.05),CT组住院总费与IVU组比较差异无统计学意义(P>0.05).结论 多层螺旋CT平扫联合尿路重建对于急诊肾绞痛患者的诊治是高效和相对经济的.%Objective To investigate clinical application of multi-slice helical CT plain scan combined with urinary reconstruction in diagnosis of acute renal colic. Methods 126 patients with acute renal colic were randomized divided into two groups. 67 cases were diagnosed by multi-slice helical CT combined with urinary reconstruction and 59 cases were diagnosed by abdominal plain film radiography combined with IVU. All patients were treated by ureteroscope lithotripsy. The stone diagnosis rate was compared as well as the renal colic time , the hospitalization time and the hospitalization cost. Results The stone diagnosis rate in CT group was more than that in IVU group(P<0. 05). However,the renal colic time hospitalization time in CT group was less than that in IVU group as well as hospitalization time(P<0. 05). There was no significantly difference on the hospitalization cost between two groups(P>0. 05). Conclusion Multi-slice helical CT plain scan combined with urinary reconstruction is efficient and economic in diagnosis of acute renal colic.

  6. 多层螺旋CT灌注成像在肾脏良恶性肿瘤鉴别诊断中的临床应用%Clinical Application of Multi - slice Spiral CT Perfusion Imaging in the Differential Diagnosis of Benign and Malignant Renal Tumors

    Institute of Scientific and Technical Information of China (English)

    赵红; 夏文平; 李培

    2012-01-01

    Objective To discuss the clinical practice value of multi - slice spiral CT perfusion imaging in the differential diagnosis of benign and malignant renal tumors. Methods Using multi - slice spiral CT machine, we detected the CT perfusion parameters of 20 cases of normal healthy volunteers(the control group) ,22 cases of renal clear cell carcinoma proved by operation (the renal carcinoma group) and 18 cases of renal hamarloma( the renal hamartoma group). Perfusion (perfusion) , relative blood volume (rBV) , time to peak (TTP) and peak enhancementimage (PEI) were obtained and calaculated. Results ①The perfusion,PEI of the renal carcinoma group Were significantly lower than thnse of the coutrol group, while the rBV.TTP were significantly higher than those of the control group; ② The perfusion, PEI of the renal hamarlunia group were significantly lower than those of the control group, while the rBV ,TTP of the renal hamanoma group were significantly higher than those of the control group; ③The perfusion .PEI of ihe renal carcinoma group were significantly higher than those of the renal hamartoma group, while the rBV,TTP of the renal carcinoma group were significantly lower lhan those of renal hamartoma group. The differences were significant statistically significant. Conclusion Multi - slice spiral CT perfusinn imaging can quantitatively assess hemortynamics variation of the normal kidney,benign and malignant renal tumors. It can provide a reliable hasis for differential diagnosis,which has important clinical application value.%目的 探讨多层螺旋CT(MSCTPI)灌注成像在肾脏良恶性肿瘤鉴别诊断中的应用价值.方法 采用多层螺旋CT机对正常健康志愿者20例(对照组)及经手术病理证实的肾透明细胞癌患者22例(肾癌组)、肾错构瘤患者18例(肾错构瘤组)的肾皮质CT灌注参数进行检测,分别计算:灌注(perfusion);相对组织血容量(rBV);峰值时间(TTP);峰值增强影像(PEI).结果 ①肾

  7. 2D-Tasks for Cognitive Rehabilitation

    OpenAIRE

    Caballero Hernandez, Ruth; Martinez Moreno, Jose Maria; García Molina, A.; Ferrer Celma, S.; Solana Sánchez, Javier; Sanchez Carrion, R.; Fernandez Casado, E.; Pérez Rodríguez, Rodrigo; Gomez Pulido, A.; Anglès Tafalla, C.; Cáceres Taladriz, César; Ferre Vergada, M.; Roig Rovira, Teresa; Garcia Lopez, P.; Tormos Muñoz, Josep M.

    2011-01-01

    Neuropsychological Rehabilitation is a complex clinic process which tries to restore or compensate cognitive and behavioral disorders in people suffering from a central nervous system injury. Information and Communication Technologies (ICTs) in Biomedical Engineering play an essential role in this field, allowing improvement and expansion of present rehabilitation programs. This paper presents a set of cognitive rehabilitation 2D-Tasks for patients with Acquired Brain Injury (ABI). These t...

  8. Realistic and efficient 2D crack simulation

    Science.gov (United States)

    Yadegar, Jacob; Liu, Xiaoqing; Singh, Abhishek

    2010-04-01

    Although numerical algorithms for 2D crack simulation have been studied in Modeling and Simulation (M&S) and computer graphics for decades, realism and computational efficiency are still major challenges. In this paper, we introduce a high-fidelity, scalable, adaptive and efficient/runtime 2D crack/fracture simulation system by applying the mathematically elegant Peano-Cesaro triangular meshing/remeshing technique to model the generation of shards/fragments. The recursive fractal sweep associated with the Peano-Cesaro triangulation provides efficient local multi-resolution refinement to any level-of-detail. The generated binary decomposition tree also provides efficient neighbor retrieval mechanism used for mesh element splitting and merging with minimal memory requirements essential for realistic 2D fragment formation. Upon load impact/contact/penetration, a number of factors including impact angle, impact energy, and material properties are all taken into account to produce the criteria of crack initialization, propagation, and termination leading to realistic fractal-like rubble/fragments formation. The aforementioned parameters are used as variables of probabilistic models of cracks/shards formation, making the proposed solution highly adaptive by allowing machine learning mechanisms learn the optimal values for the variables/parameters based on prior benchmark data generated by off-line physics based simulation solutions that produce accurate fractures/shards though at highly non-real time paste. Crack/fracture simulation has been conducted on various load impacts with different initial locations at various impulse scales. The simulation results demonstrate that the proposed system has the capability to realistically and efficiently simulate 2D crack phenomena (such as window shattering and shards generation) with diverse potentials in military and civil M&S applications such as training and mission planning.

  9. 2D materials: Graphene and others

    Science.gov (United States)

    Bansal, Suneev Anil; Singh, Amrinder Pal; Kumar, Suresh

    2016-05-01

    Present report reviews the recent advancements in new atomically thick 2D materials. Materials covered in this review are Graphene, Silicene, Germanene, Boron Nitride (BN) and Transition metal chalcogenides (TMC). These materials show extraordinary mechanical, electronic and optical properties which make them suitable candidates for future applications. Apart from unique properties, tune-ability of highly desirable properties of these materials is also an important area to be emphasized on.

  10. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  11. Engineering light outcoupling in 2D materials

    KAUST Repository

    Lien, Derhsien

    2015-02-11

    When light is incident on 2D transition metal dichalcogenides (TMDCs), it engages in multiple reflections within underlying substrates, producing interferences that lead to enhancement or attenuation of the incoming and outgoing strength of light. Here, we report a simple method to engineer the light outcoupling in semiconducting TMDCs by modulating their dielectric surroundings. We show that by modulating the thicknesses of underlying substrates and capping layers, the interference caused by substrate can significantly enhance the light absorption and emission of WSe2, resulting in a ∼11 times increase in Raman signal and a ∼30 times increase in the photoluminescence (PL) intensity of WSe2. On the basis of the interference model, we also propose a strategy to control the photonic and optoelectronic properties of thin-layer WSe2. This work demonstrates the utilization of outcoupling engineering in 2D materials and offers a new route toward the realization of novel optoelectronic devices, such as 2D LEDs and solar cells.

  12. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  13. Fetal MRI

    International Nuclear Information System (INIS)

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  14. In Situ Active Control of Noise in a 4-Tesla MRI Scanner

    Science.gov (United States)

    Li, Mingfeng; Rudd, Brent; Lim, Teik C.; Lee, Jing-Huei

    2011-01-01

    Purpose To evaluate the effectiveness of the proposed active noise control (ANC) system for the reduction of the acoustic noise emission generated by a 4 T MRI scanner during operation and to assess the feasibility of developing an ANC device that can be deployed in situ. Materials and Methods Three typical scanning sequences, namely EPI (echo planar imaging), GEMS (gradient echo multi-slice) and MDEFT (Modified Driven Equilibrium Fourier Transform), were used for evaluating the performance of the ANC system, which was composed of a magnetic compatible headset and a multiple reference feedforward filtered-x least mean square controller. Results The greatest reduction, about 55 dB, was achieved at the harmonic at a frequency of 1.3 kHz in the GEMS case. Approximately 21 dB and 30 dBA overall reduction was achieved for GEMS noise across the entire audible frequency range. For the MDEFT sequence, the control system achieved 14 dB and 14 dBA overall reduction in the audible frequency range, while 13 dB and 14 dBA reduction was obtained for the EPI case. Conclusion The result is highly encouraging because it shows great potential for treating MRI noise with an ANC application during real time scanning. PMID:21751284

  15. Advanced flow MRI: emerging techniques and applications.

    Science.gov (United States)

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented. PMID:26944696

  16. Limit theorems for 2D invasion percolation

    CERN Document Server

    Damron, Michael

    2010-01-01

    We prove limit theorems and variance estimates for quantities related to ponds and outlets for 2D invasion percolation. We first exhibit several properties of a sequence (O(n)) of outlet variables, the n-th of which gives the number of outlets in the box centered at the origin of side length 2^n. The most important of these properties describe the sequence's renewal structure and exponentially fast mixing behavior. We use these to prove a central limit theorem and strong law of large numbers for (O(n)). We then show consequences of these limit theorems for the pond radii and outlet weights.

  17. Interparticle attraction in 2D complex plasmas

    CERN Document Server

    Kompaneets, Roman; Ivlev, Alexei V

    2015-01-01

    Complex (dusty) plasmas allow experimental studies of various physical processes occurring in classical liquids and solids by directly observing individual microparticles. A major problem is that the interaction between microparticles is generally not molecular-like. In this Letter, we propose how to achieve a molecular-like interaction potential in laboratory 2D complex plasmas. We argue that this principal aim can be achieved by using relatively small microparticles and properly adjusting discharge parameters. If experimentally confirmed, this will make it possible to employ complex plasmas as a model system with an interaction potential resembling that of conventional liquids.

  18. Periodically sheared 2D Yukawa systems

    Energy Technology Data Exchange (ETDEWEB)

    Kovács, Anikó Zsuzsa [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege Miklós str. 29-33, H-1121 Budapest (Hungary); Hartmann, Peter [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege Miklós str. 29-33, H-1121 Budapest (Hungary); Center for Astrophysics, Space Physics and Engineering Research (CASPER), One Bear Place 97310, Baylor University, Waco, Texas 76798 (United States); Donkó, Zoltán [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege Miklós str. 29-33, H-1121 Budapest (Hungary); Physics Department, Boston College, Chestnut Hill, Massachusetts 20467 (United States)

    2015-10-15

    We present non-equilibrium molecular dynamics simulation studies on the dynamic (complex) shear viscosity of a 2D Yukawa system. We have identified a non-monotonic frequency dependence of the viscosity at high frequencies and shear rates, an energy absorption maximum (local resonance) at the Einstein frequency of the system at medium shear rates, an enhanced collective wave activity, when the excitation is near the plateau frequency of the longitudinal wave dispersion, and the emergence of significant configurational anisotropy at small frequencies and high shear rates.

  19. Extrinsic curvature induced 2-d gravity

    CERN Document Server

    Viswanathan, K S

    1993-01-01

    Abtract: 2-dimensional fermions are coupled to extrinsic geometry of a conformally immersed surface in ${\\bf R}^3$ through gauge coupling. By integrating out the fermions, we obtain a WZNW action involving extrinsic curvature of the surface. Restricting the resulting effective action to surfaces of $h\\sqrt g=1$, an explicit form of the action invariant under Virasaro symmetry is obtained. This action is a sum of the geometric action for the Virasaro group and the light-cone action of 2-d gravity plus an interaction term. The central charges of the theory in both the left and right sectors are calculated.

  20. 2-d Simulations of Test Methods

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2004-01-01

    using both a Newton and Bingham model for characterisation of the rheological properties of the concrete. From the results, it is expected that both the slump flow and L-box can be simulated quite accurately when the model is extended to 3-d and the concrete is characterised according to the Bingham...... approach is presented by showing initial results from 2-d simulations of the empirical test methods slump flow and L-box. This method assumes a homogeneous material, which is expected to correspond to particle suspensions e.g. concrete, when it remains stable. The simulations have been carried out when...... model....

  1. Instant HTMl5 2D platformer

    CERN Document Server

    Temple, Aidan

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. The step-by-step approach taken by this book will show you how to develop a 2D HTML5 platformer-based game that you will be able to publish to multiple devices.This book is great for anyone who has an interest in HTML5 games development, and who already has a basic to intermediate grasp on both the HTML markup and JavaScript programming languages. Therefore, due to this requirement, the book will not discuss the inner workings of either of these languages but will instead attempt to

  2. Phase Engineering of 2D Tin Sulfides.

    OpenAIRE

    Mutlu, Z; Wu, RJ; Wickramaratne, D.; Shahrezaei, S; Liu, C; Temiz, S; Patalano, A; M Ozkan; Lake, RK; Mkhoyan, KA; Ozkan, CS

    2016-01-01

    Tin sulfides can exist in a variety of phases and polytypes due to the different oxidation states of Sn. A subset of these phases and polytypes take the form of layered 2D structures that give rise to a wide host of electronic and optical properties. Hence, achieving control over the phase, polytype, and thickness of tin sulfides is necessary to utilize this wide range of properties exhibited by the compound. This study reports on phase-selective growth of both hexagonal tin (IV) sulfide SnS2...

  3. Interparticle Attraction in 2D Complex Plasmas

    Science.gov (United States)

    Kompaneets, Roman; Morfill, Gregor E.; Ivlev, Alexei V.

    2016-03-01

    Complex (dusty) plasmas allow experimental studies of various physical processes occurring in classical liquids and solids by directly observing individual microparticles. A major problem is that the interaction between microparticles is generally not molecularlike. In this Letter, we propose how to achieve a molecularlike interaction potential in laboratory 2D complex plasmas. We argue that this principal aim can be achieved by using relatively small microparticles and properly adjusting discharge parameters. If experimentally confirmed, this will make it possible to employ complex plasmas as a model system with an interaction potential resembling that of conventional liquids.

  4. Battlefield MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  5. WFR-2D: an analytical model for PWAS-generated 2D ultrasonic guided wave propagation

    Science.gov (United States)

    Shen, Yanfeng; Giurgiutiu, Victor

    2014-03-01

    This paper presents WaveFormRevealer 2-D (WFR-2D), an analytical predictive tool for the simulation of 2-D ultrasonic guided wave propagation and interaction with damage. The design of structural health monitoring (SHM) systems and self-aware smart structures requires the exploration of a wide range of parameters to achieve best detection and quantification of certain types of damage. Such need for parameter exploration on sensor dimension, location, guided wave characteristics (mode type, frequency, wavelength, etc.) can be best satisfied with analytical models which are fast and efficient. The analytical model was constructed based on the exact 2-D Lamb wave solution using Bessel and Hankel functions. Damage effects were inserted in the model by considering the damage as a secondary wave source with complex-valued directivity scattering coefficients containing both amplitude and phase information from wave-damage interaction. The analytical procedure was coded with MATLAB, and a predictive simulation tool called WaveFormRevealer 2-D was developed. The wave-damage interaction coefficients (WDICs) were extracted from harmonic analysis of local finite element model (FEM) with artificial non-reflective boundaries (NRB). The WFR-2D analytical simulation results were compared and verified with full scale multiphysics finite element models and experiments with scanning laser vibrometer. First, Lamb wave propagation in a pristine aluminum plate was simulated with WFR-2D, compared with finite element results, and verified by experiments. Then, an inhomogeneity was machined into the plate to represent damage. Analytical modeling was carried out, and verified by finite element simulation and experiments. This paper finishes with conclusions and suggestions for future work.

  6. Comments on Thermalization in 2D CFT

    CERN Document Server

    de Boer, Jan

    2016-01-01

    We revisit certain aspects of thermalization in 2D CFT. In particular, we consider similarities and differences between the time dependence of correlation functions in various states in rational and non-rational CFTs. We also consider the distinction between global and local thermalization and explain how states obtained by acting with a diffeomorphism on the ground state can appear locally thermal, and we review why the time-dependent expectation value of the energy-momentum tensor is generally a poor diagnostic of global thermalization. Since all 2D CFTs have an infinite set of commuting conserved charges, generic initial states might be expected to give rise to a generalized Gibbs ensemble rather than a pure thermal ensemble at late times. We construct the holographic dual of the generalized Gibbs ensemble and show that, to leading order, it is still described by a BTZ black hole. The extra conserved charges, while rendering $c < 1$ theories essentially integrable, therefore seem to have little effect o...

  7. Multienzyme Inkjet Printed 2D Arrays.

    Science.gov (United States)

    Gdor, Efrat; Shemesh, Shay; Magdassi, Shlomo; Mandler, Daniel

    2015-08-19

    The use of printing to produce 2D arrays is well established, and should be relatively facile to adapt for the purpose of printing biomaterials; however, very few studies have been published using enzyme solutions as inks. Among the printing technologies, inkjet printing is highly suitable for printing biomaterials and specifically enzymes, as it offers many advantages. Formulation of the inkjet inks is relatively simple and can be adjusted to a variety of biomaterials, while providing nonharmful environment to the enzymes. Here we demonstrate the applicability of inkjet printing for patterning multiple enzymes in a predefined array in a very straightforward, noncontact method. Specifically, various arrays of the enzymes glucose oxidase (GOx), invertase (INV) and horseradish peroxidase (HP) were printed on aminated glass surfaces, followed by immobilization using glutardialdehyde after printing. Scanning electrochemical microscopy (SECM) was used for imaging the printed patterns and to ascertain the enzyme activity. The successful formation of 2D arrays consisting of enzymes was explored as a means of developing the first surface confined enzyme based logic gates. Principally, XOR and AND gates, each consisting of two enzymes as the Boolean operators, were assembled, and their operation was studied by SECM. PMID:26214072

  8. Photocurrent spectroscopy of 2D materials

    Science.gov (United States)

    Cobden, David

    Confocal photocurrent measurements provide a powerful means of studying many aspects of the optoelectronic and electrical properties of a 2D device or material. At a diffraction-limited point they can provide a detailed absorption spectrum, and they can probe local symmetry, ultrafast relaxation rates and processes, electron-electron interaction strengths, and transport coefficients. We illustrate this with several examples, once being the photo-Nernst effect. In gapless 2D materials, such as graphene, in a perpendicular magnetic field a photocurrent antisymmetric in the field is generated near to the free edges, with opposite sign at opposite edges. Its origin is the transverse thermoelectric current associated with the laser-induced electron temperature gradient. This effect provides an unambiguous demonstration of the Shockley-Ramo nature of long-range photocurrent generation in gapless materials. It also provides a means of investigating quasiparticle properties. For example, in the case of graphene on hBN, it can be used to probe the Lifshitz transition that occurs due to the minibands formed by the Moire superlattice. We also observe and discuss photocurrent generated in other semimetallic (WTe2) and semiconducting (WSe2) monolayers. Work supported by DoE BES and NSF EFRI grants.

  9. Locality constraints and 2D quasicrystals

    International Nuclear Information System (INIS)

    The plausible assumption that long-range interactions between atoms are negligible in a quasicrystal leaks to the study of tilings that obey constraints on the local configurations of tiles. The theory of such constraints (called matching rules) for 2D quasicrystal tilings is reviewed here. Different types of matching rules are defined and examples of tilings obeying them are given where known. The role of tile decoration is discussed and is shown to be significant in at least two cases (octagonal and dodecagonal duals of periodic 4-grids and 6-grids). A new result is introduced: a constructive procedure is described for generating weak matching rules for tilings with N-fold symmetry, for any N that is either a prime number or twice a prime number. The physics associated with weak matching rules, results on local growth rules, and the case of icosahedral symmetry are all briefly discussed. (author). 29 refs, 4 figs

  10. 2D Cooling of Magnetized Neutron Stars

    CERN Document Server

    Aguilera, Deborah N; Miralles, Juan A

    2007-01-01

    Context: Many thermally emitting isolated neutron stars have magnetic fields larger than 10^{13}G. A realistic cooling model should be reconsidered including the presence of high magnetic fields. Aims: We investigate the effects of anisotropic temperature distribution and Joule heating on the cooling of magnetized neutron stars. Methods: The 2D heat transfer equation with anisotropic thermal conductivity tensor and including all relevant neutrino emission processes is solved for realistic models of the neutron star interior and crust. Results: The presence of the magnetic field affects significantly the thermal surface distribution and the cooling history during both, the early neutrino cooling era and the late photon cooling era. Conclusions: There is a huge effect of the Joule heating on the thermal evolution of strongly magnetized neutron stars. Magnetic fields and Joule heating play a key role in maintaining magnetars warm for a long time. Moreover, this effect is also important for intermediate field neu...

  11. Alignment free characterization of 2D gratings

    CERN Document Server

    Madsen, Morten Hannibal; Hansen, Poul-Erik; Jørgensen, Jan Friis

    2015-01-01

    Fast characterization of 2-dimensional gratings is demonstrated using a Fourier lens optical system and a differential optimization algorithm. It is shown that both the grating specific parameters such as the basis vectors and the angle between them and the alignment of the sample, such as the rotation of the sample around the x-, y-, and z-axis, can be deduced from a single measurement. More specifically, the lattice vectors and the angle between them have been measured, while the corrections of the alignment parameters are used to improve the quality of the measurement, and hence reduce the measurement uncertainty. Alignment free characterization is demonstrated on both a 2D hexagonal grating with a period of 700 nm and a checkerboard grating with a pitch of 3000 nm. The method can also be used for both automatic alignment and in-line characterization of gratings.

  12. Area preserving diffeomorphisms and 2-d gravity

    CERN Document Server

    La, H S

    1995-01-01

    Area preserving diffeomorphisms of a 2-d compact Riemannian manifold with or without boundary are studied. We find two classes of decompositions of a Riemannian metric, namely, h- and g-decomposition, that help to formulate a gravitational theory which is area preserving diffeomorphism (SDiffM-) invariant but not necessarily diffeomorphism invariant. The general covariance of equations of motion of such a theory can be achieved by incorporating proper Weyl rescaling. The h-decomposition makes the conformal factor of a metric SDiffM-invariant and the rest of the metric invariant under conformal diffeomorphisms, whilst the g-decomposition makes the conformal factor a SDiffM scalar and the rest a SDiffM tensor. Using these, we reformulate Liouville gravity in SDiffM invariant way. In this context we also further clarify the dual formulation of Liouville gravity introduced by the author before, in which the affine spin connection is dual to the Liouville field.

  13. Graphene suspensions for 2D printing

    Science.gov (United States)

    Soots, R. A.; Yakimchuk, E. A.; Nebogatikova, N. A.; Kotin, I. A.; Antonova, I. V.

    2016-04-01

    It is shown that, by processing a graphite suspension in ethanol or water by ultrasound and centrifuging, it is possible to obtain particles with thicknesses within 1-6 nm and, in the most interesting cases, 1-1.5 nm. Analogous treatment of a graphite suspension in organic solvent yields eventually thicker particles (up to 6-10 nm thick) even upon long-term treatment. Using the proposed ink based on graphene and aqueous ethanol with ethylcellulose and terpineol additives for 2D printing, thin (~5 nm thick) films with sheet resistance upon annealing ~30 MΩ/□ were obtained. With the ink based on aqueous graphene suspension, the sheet resistance was ~5-12 kΩ/□ for 6- to 15-nm-thick layers with a carrier mobility of ~30-50 cm2/(V s).

  14. Numerical Evaluation of 2D Ground States

    Science.gov (United States)

    Kolkovska, Natalia

    2016-02-01

    A ground state is defined as the positive radial solution of the multidimensional nonlinear problem \\varepsilon propto k_ bot 1 - ξ with the function f being either f(u) =a|u|p-1u or f(u) =a|u|pu+b|u|2pu. The numerical evaluation of ground states is based on the shooting method applied to an equivalent dynamical system. A combination of fourth order Runge-Kutta method and Hermite extrapolation formula is applied to solving the resulting initial value problem. The efficiency of this procedure is demonstrated in the 1D case, where the maximal difference between the exact and numerical solution is ≈ 10-11 for a discretization step 0:00025. As a major application, we evaluate numerically the critical energy constant. This constant is defined as a functional of the ground state and is used in the study of the 2D Boussinesq equations.

  15. Metrology for graphene and 2D materials

    Science.gov (United States)

    Pollard, Andrew J.

    2016-09-01

    The application of graphene, a one atom-thick honeycomb lattice of carbon atoms with superlative properties, such as electrical conductivity, thermal conductivity and strength, has already shown that it can be used to benefit metrology itself as a new quantum standard for resistance. However, there are many application areas where graphene and other 2D materials, such as molybdenum disulphide (MoS2) and hexagonal boron nitride (h-BN), may be disruptive, areas such as flexible electronics, nanocomposites, sensing and energy storage. Applying metrology to the area of graphene is now critical to enable the new, emerging global graphene commercial world and bridge the gap between academia and industry. Measurement capabilities and expertise in a wide range of scientific areas are required to address this challenge. The combined and complementary approach of varied characterisation methods for structural, chemical, electrical and other properties, will allow the real-world issues of commercialising graphene and other 2D materials to be addressed. Here, examples of metrology challenges that have been overcome through a multi-technique or new approach are discussed. Firstly, the structural characterisation of defects in both graphene and MoS2 via Raman spectroscopy is described, and how nanoscale mapping of vacancy defects in graphene is also possible using tip-enhanced Raman spectroscopy (TERS). Furthermore, the chemical characterisation and removal of polymer residue on chemical vapour deposition (CVD) grown graphene via secondary ion mass spectrometry (SIMS) is detailed, as well as the chemical characterisation of iron films used to grow large domain single-layer h-BN through CVD growth, revealing how contamination of the substrate itself plays a role in the resulting h-BN layer. In addition, the role of international standardisation in this area is described, outlining the current work ongoing in both the International Organization of Standardization (ISO) and the

  16. What Is Chest MRI?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Chest MRI? Chest MRI (magnetic resonance imaging) is a safe, noninvasive test. "Noninvasive" means that ... your chest wall, heart, and blood vessels. Chest MRI uses radio waves, magnets, and a computer to ...

  17. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... your stomach on a narrow table with your breasts hanging down into cushioned openings. The table slides ...

  18. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... 8 MB) Also available in Other Language versions . Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  19. MRI visualisation by digitally reconstructed radiographs

    Science.gov (United States)

    Serrurier, Antoine; Bönsch, Andrea; Lau, Robert; Deserno, Thomas M.

    2015-03-01

    Visualising volumetric medical images such as computed tomography and magnetic resonance imaging (MRI) on picture archiving and communication systems (PACS) clients is often achieved by image browsing in sagittal, coronal or axial views or three-dimensional (3D) rendering. This latter technique requires fine thresholding for MRI. On the other hand, computing virtual radiograph images, also referred to as digitally reconstructed radiographs (DRR), provides in a single two-dimensional (2D) image a complete overview of the 3D data. It appears therefore as a powerful alternative for MRI visualisation and preview in PACS. This study describes a method to compute DRR from T1-weighted MRI. After segmentation of the background, a histogram distribution analysis is performed and each foreground MRI voxel is labeled as one of three tissues: cortical bone, also known as principal absorber of the X-rays, muscle and fat. An intensity level is attributed to each voxel according to the Hounsfield scale, linearly related to the X-ray attenuation coefficient. Each DRR pixel is computed as the accumulation of the new intensities of the MRI dataset along the corresponding X-ray. The method has been tested on 16 T1-weighted MRI sets. Anterior-posterior and lateral DRR have been computed with reasonable qualities and avoiding any manual tissue segmentations. This proof-of-concept holds for research application for use in clinical PACS.

  20. Face recognition method based on 2D-PCA and 2D-LDA%基于2D-PCA和2D-LDA的人脸识别方法

    Institute of Scientific and Technical Information of China (English)

    温福喜; 刘宏伟

    2007-01-01

    提出了基于2D-PCA、2D-LDA两种特征采用融合分类器的人脸识别方法.首先提取人脸图像的2D-PCA和2D-LDA特征,对不同特征在决策层对分类器进行融合.在ORL人脸库上的试验结果表明,分类器决策层融合方法在识别性能上优于2D-PCA和2D-LDA,更具有鲁棒性.

  1. Analysis list: Kmt2d [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Kmt2d Adipocyte,Pluripotent stem cell + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Kmt2d....1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Kmt2d.5.tsv http://dbarchiv...e.biosciencedbc.jp/kyushu-u/mm9/target/Kmt2d.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Kmt2d....Adipocyte.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Kmt2d.Pluripo

  2. Analysis list: KMT2D [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available KMT2D Blood,Digestive tract + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/KM...T2D.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/KMT2D.5.tsv http://dbarchive.biosc...iencedbc.jp/kyushu-u/hg19/target/KMT2D.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/KMT2D.Blo...od.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/KMT2D.Digestive_tract

  3. Brain Extraction and Fuzzy Tissue Segmentation in Cerebral 2D T1-Weigthed Magnetic Resonance Images

    Directory of Open Access Journals (Sweden)

    Bouchaib Cherradi

    2011-05-01

    Full Text Available In medical imaging, accurate segmentation of brain MR images is of interest for many brain manipulations. In this paper, we present a method for brain Extraction and tissues classification. An application of this method to the segmentation of simulated MRI cerebral images in three clusters will be made. The studied method is composed with different stages, first Brain Extraction from T1-weighted 2D MRI slices (TMBE is performed as pre-processing procedure, then Histogram based centroids initialization is done, and finally the fuzzy c-means clustering algorithm is applied on the results to segment the image in three clusters. The introduction of this pre-processing procedure has been made in the goal to have a targeted segmentation method. The convergence speed for tissues classification has been considerably improved by avoiding a random initialization of the cluster centres and reduction of the volume of data processing.

  4. 2D manifold-independent spinfoam theory

    International Nuclear Information System (INIS)

    A number of background-independent quantization procedures have recently been employed in 4D nonperturbative quantum gravity. We investigate and illustrate these techniques and their relation in the context of a simple 2D topological theory. We discuss canonical quantization, loop or spin network states, path integral quantization over a discretization of the manifold, spin foam formulation and the fully background-independent definition of the theory using an auxiliary field theory on a group manifold. While several of these techniques have already been applied to this theory by Witten, the last one is novel: it allows us to give a precise meaning to the sum over topologies, and to compute background-independent and, in fact, 'manifold-independent' transition amplitudes. These transition amplitudes play the role of Wightman functions of the theory. They are physical observable quantities, and the canonical structure of the theory can be reconstructed from them via a C* algebraic GNS construction. We expect an analogous structure to be relevant in 4D quantum gravity

  5. Ion Transport in 2-D Graphene Nanochannels

    Science.gov (United States)

    Xie, Quan; Foo, Elbert; Duan, Chuanhua

    2015-11-01

    Graphene membranes have recently attracted wide attention due to its great potential in water desalination and selective molecular sieving. Further developments of these membranes, including enhancing their mass transport rate and/or molecular selectivity, rely on the understanding of fundamental transport mechanisms through graphene membranes, which has not been studied experimentally before due to fabrication and measurement difficulties. Herein we report the fabrication of the basic constituent of graphene membranes, i.e. 2-D single graphene nanochannels (GNCs) and the study of ion transport in these channels. A modified bonding technique was developed to form GNCs with well-defined geometry and uniform channel height. Ion transport in such GNCs was studied using DC conductance measurement. Our preliminary results showed that the ion transport in GNCs is still governed by surface charge at low concentrations (10-6M to 10-4M). However, GNCs exhibits much higher ionic conductances than silica nanochannels with the same geometries in the surface-charge-governed regime. This conductance enhancement can be attributed to the pre-accumulation of charges on graphene surfaces. The work is supported by the Faculty Startup Fund (Boston University, USA).

  6. Intermittency in 2D soap film turbulence

    CERN Document Server

    Cerbus, R T

    2013-01-01

    The Reynolds number dependency of intermittency for 2D turbulence is studied in a flowing soap film. The Reynolds number used here is the Taylor microscale Reynolds number R_{\\lambda}, which ranges from 20 to 800. Strong intermittency is found for both the inverse energy and direct enstrophy cascades as measured by (a) the pdf of velocity differences P(\\delta u(r)) at inertial scales r, (b) the kurtosis of P(\\partial_x u), and (c) the scaling of the so-called intermittency exponent \\mu, which is zero if intermittency is absent. Measures (b) and (c) are quantitative, while (a) is qualitative. These measurements are in disagreement with some previous results but not all. The velocity derivatives are nongaussian at all R_{\\lambda} but show signs of becoming gaussian as R_{\\lambda} increases beyond the largest values that could be reached. The kurtosis of P(\\delta u(r)) at various r indicates that the intermittency is scale dependent. The structure function scaling exponents also deviate strongly from the Kraichn...

  7. 2D DIGITAL SIMPLIFIED FLOW VALVE

    Institute of Scientific and Technical Information of China (English)

    Ruan Jian; Li Sheng; Pei Xiang; Burton R; Ukrainetz P; Bitner D

    2004-01-01

    The 2D digital simplified flow valve is composed of a pilot-operated valve designed with both rotary and linear motions of a single spool,and a stepper motor under continual control.How the structural parameters affect the static and dynamic characteristics of the valve is first clarified and a criterion for stability is presented.Experiments are designed to test the performance of the valve.It is necessary to establish a balance between the static and dynamic characteristics in deciding the structural parameters.Nevertheless,it is possible to maintain the dynamic response at a fairly high level,while keeping the leakage of the pilot stage at an acceptable level.One of the features of the digital valve is stage control.In stage control the nonlinearities,such as electromagnetic saturation and hysteresis,are greatly reduced.To a large extent the dynamic response of the valve is decided by the executing cycle of the control algorithm.

  8. Resolution Independent 2D Cartoon Video Conversion

    Directory of Open Access Journals (Sweden)

    MSF. Fayaza

    2016-03-01

    Full Text Available This paper describes a novel system for vectorizing 2D raster cartoon. The output videos are the resolution independent, smaller in file size. As a first step, input video is segment to scene thereafter all processes are done for each scene separately. Every scene contains foreground and background objects so in each and every scene foreground background classification is performed. Background details can occlude by foreground objects but when foreground objects move its previous position such occluded details exposed in one of the next frame so using that frame can fill the occluded area and can generate static background. Classified foreground objects are identified and the motion of the foreground objects tracked for this simple user assistance is required from those motion details of foreground object’s animation generated. Static background and foreground objects segmented using K-means clustering and each and every cluster’s vectorized using potrace. Using vectored background and foreground object animation path vector video regenerated.

  9. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    Science.gov (United States)

    Hamamoto, Kazuhiko; Sato, Motoyoshi

    3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.

  10. Application value of multi-slice spiral CT image post-processing technique in the diagnosis of tracheal and bronchus foreign body in children%多层螺旋CT后处理技术对小儿气管、支气管异物的诊断价值

    Institute of Scientific and Technical Information of China (English)

    巫恒平; 仲建全; 郭欢

    2015-01-01

    目的:探讨多层螺旋CT图像后处理技术在小儿气管、支气管异物诊断中的应用价值。方法通过对我院25例疑似支气管异物的患儿行多层螺旋CT扫描,采用MPR、Min IP、VR及VE等后处理技术,分析并比较其在气管、支气管异物中的诊断价值。结果经临床纤维支气管镜证实为气管、支气管异物的25例患儿均获得清晰的CT图像及后处理图像,多平面重建(MPR)对异物显示较佳,显示率为100%(25/25),容积再现(VR)能明确异物的位置及与气管的关系,显示率为97%(24/25),最小密度投影(Min IP)对异物的测量较精确,显示率为97%(24/25),及仿真内窥镜(VE)能准确显示异物在气管内的位置及对气管的堵塞情况。结论 MSCT后处理技术在小儿气管、支气管异物诊断中准确率较高,可成为首选的影像学检查方法。%Objective To explore the application value of multi-slice spiral CT (MSCT) image post-process-ing technique in the diagnosis of tracheal and bronchus foreign body in children. Methods Twenty-five children sus-pected with bronchial foreign bodies in our hospital were scanned by multi-slice spiral CT. Then the imaging data were processed by techniques of multi planar reconstruction (MPR), minimum intensity projection (Min IP), volume rendering (VR) and virtual endoscopy (VE). The diagnosis value of the techniques for trachea, bronchial foreign body was analyzed and compared. Results The 25 cases all obtained clear CT images and post-processed images. MPR displayed the foreign body best, with the display rate of 100%(25/25). VR could clear display foreign body and its re-lationship with the trachea, with the display rate of 97%(24/25). Min IP was good at distinguish the accurate measure-ment of the foreign body, and the display rate was 97%(24/25). VE could show the foreign bodies in the trachea of the position and the blockage of the trachea accurately. Conclusion The MSCT image post

  11. Clinical Diagnosis and Treatment of Multi-slice Spiral CT Post-processing Techniques on the Maxillary Tooth%多排螺旋CT后处理技术对上颌骨埋伏牙的临床诊治价值

    Institute of Scientific and Technical Information of China (English)

    杨立川

    2012-01-01

    目的:研究多排螺旋CT后处理技术对上颌骨埋伏牙的临床诊治价值.方法:选取2008年1月~2011年9月期间在我院口腔科诊治的35例临床怀疑上颌骨埋伏牙患者,应用螺旋CT多平面重建(MPR)、表面成像(SSD)及容积成像(VR)图像对上颌骨埋伏牙进行观察.结果:本组35例患者共检出47颗埋伏牙,其中有阻生埋伏牙27颗、多生埋伏牙20颗.SSD、VR三维图像能全方位的显示上颌骨埋伏牙的数量、萌出方向、牙冠牙根形态、唇腭侧位置及其与邻牙的关系,MPR二维图像可以多角度地显示牙齿及与周围解剖结构.术中所见均与螺旋CT后处理图像完全一致,手术均未发生不良并发症.结论:多排螺旋CT后处理技术很好的显示牙齿结构,能立体、直观地显示上颌骨埋伏牙,对其诊治具有重要临床价值.%Objective:To study the multi-slice spiral CT post-processing techniques on the maxillary tooth of clinical value. Methods:During the dental treatment of 35 cases of clinical suspicion in patients with maxillary tooth,spiral CT multi-planar reconstruction (MPR),surface imaging (SSD) and volume imaging (VR) images of the maxillary tooth were observed.Results:The group of 35 patients were detected in 47 tooth,which has impacted tooth 27,have more tooth 20.SSD,VR three-dimensional image can display a full range of maxillary tooth number,eruption direction,crown root morphology,Chun E side of the location and relationship with adjacent teeth,MPR multi-angle two-dimensional images can be displayed with the surrounding teeth and anatomical structure.Conclusion:Multi-slice spiral CT post-processing techniques show a good tooth structure,can three-dimensional,visual display of maxillary tooth,its diagnosis has important clinical value.

  12. Application of multi slice spiral CT reconstruction technique in the fracture of the bone and rib cartilage%多层螺旋 CT 重建技术在胸骨及肋软骨骨折中的应用

    Institute of Scientific and Technical Information of China (English)

    赵晓波

    2016-01-01

    目的:分析多层螺旋 CT 重建技术在胸骨及肋软骨骨折中的应用。方法回顾分析胸骨骨折10例、肋软骨骨折16例患者,在工作站进行多种后处理重建,主要有1mm 薄层横断图像重建,多平面重组(MPR)、曲面重建(CPR)、最大密度投影法(MIP)、容积再现技术(VR)重建,并与 X 线胸片对比。结果10例胸骨骨折患者,其中胸骨柄骨折3例,胸骨体骨折7例;16例肋软骨骨折患者,单根肋软骨骨折12例,多根肋软骨骨折4例。其中 X 线胸片显示胸骨骨折8例,肋软骨骨折0例;16层螺旋 CT 多种重建技术优于 X 线检查结果。结论多层螺旋 CT 重建技术综合应用可为胸骨及肋软骨骨折患者提供可靠的影像学依据,在临床诊治中具有重要的应用价值。%Objective To discuss the application of multi slice spira CT reconstruction technology application in the sternum and costal cartilage fracture. Methods Retrospectively analyzed 10 cases of sternal fracture,costal cartilage fracture 16 patients. A variety of post-processing reconstruction in the workstation,mainly had 1 mm thin layer cross sectional image re-construction,multiplanar reconstruction(MPR),curved surface reconstruction(CPR),maximum density projection(MIP),vol-ume representation technology(VR)reconstruction,and compared with X-ray chest radiography. Results 10 cases of sternal fracture patients,the manubrium of sternum fracture in 3 cases,body of sternum fracture in 7 cases;16 cases of costal cartilage fracture patients,12 cases of single rib cartilage fracture,4 cases of multiple root costal cartilage fracture. X-ray revealed 8 ca-ses of chest X-ray,0 cases of rib cartilage fracture;16 layers spiral CT multiple reconstruction technology was superior to a vari-ety of X-ray examination results. Conclusion The integrated application of multi slice spira CT reconstruction technology can provide the sternum and costal cartilage fracture

  13. The influence of gallbladder fossa fluid accumulation on gallbladder wall thickness in liver cirrhosis on sonographic imaging correlation with multi-slice CT scanning%利用CT三维重建分析肝硬化伴胆囊窝积液对胆囊壁超声成像的影响

    Institute of Scientific and Technical Information of China (English)

    谭洁莹; 韦程纲; 谢琦

    2012-01-01

    目的:探讨肝硬化伴胆囊窝积液病者胆囊壁超声与CT三维重建在影像成像以及胆囊壁厚度测量的方面上对比差异.方法:对比39例患者于空腹状态同时行超声以及多层螺旋CT检查的影像图像,B超和CT测量胆囊厚度情况,绘制散点图,并进行Pearson相关性分析,应用配对样本t检验比较胆囊壁厚度情况.结果:①与CT三维重建图像对比,发现其中31例出现胆囊窝积液超声漏诊情况,并且发现胆囊壁厚度的超声测量值,存在高估情况的16例,低估情况2例.②B超与CT胆囊壁厚度的测量值相关系数为0.648 (P<0.000).③B超测量胆囊壁厚度((6.2±2.6)mm)较CT测量胆囊壁厚度((4.5±2.0)mm)平均值更大,测量差异具有统计学意义(t=4.465,P<0.000),变异系数分别为0.42、0.44.结论:局限性胆囊窝积液在CT检查中检出率较超声高,对肝硬化患者胆囊壁增厚与局限性胆囊窝积液能够更准确地进行鉴别诊断.%Objective: To discuss the difference of gallbladder wall thickness in liver cirrhosis with gallbladder fossa fluid accumulation on ultrasound scanning and CT multi-plane reconstruction images. Materials and Methods: Ultrasound scanning and multi-slice CT were performed in 39 patients who had gallbladder fossa fluid accumulation with liver cirrhosis, all cases were under fasting condition. Gallbladder wall thickness was measured both on ultrasonographic and multi —slice CT 3D reconstruction images. The scatter diagram was drawn and Pearson correlation analysis and paired sample t test comparison of gallbladder wall thickness were also carried out. Result: Compared with multi-plane CT reconstruction, (1) Ultrasound missed the diagnosis of gallbladder fossa fluid accumulation in 31 cases, over estimation of gallbladder wall thickness in 16 cases, and under estimation of the thickness in 2 cases. (2)The correlation coefficient of ultrasound detection of gallbladder wall thickness with CT detection was

  14. Identification of novel CYP2D7-2D6 hybrids: non-functional and functional variants

    Directory of Open Access Journals (Sweden)

    Andrea Gaedigk

    2010-10-01

    Full Text Available Polymorphic expression of CYP2D6 contributes to the wide range of activity observed for this clinically important drug metabolizing enzyme. In this report we describe novel CYP2D7/2D6 hybrid genes encoding non-functional and functional CYP2D6 protein and a CYP2D7 variant that mimics a CYP2D7/2D6 hybrid gene. Five kb long PCR products encompassing the novel genes were entirely sequenced. A quantitative assay probing in different gene regions was employed to determine CYP2D6 and 2D7 copy number variations and the relative position of the hybrid genes within the locus was assessed by long-range PCR. In addition to the previously known CYP2D6*13 and *66 hybrids, we describe three novel non-functional CYP2D7-2D6 hybrids with gene switching in exon 2 (CYP2D6*79, intron 2 (CYP2D6*80 and intron 5 (CYP2D6*67. A CYP2D7-specific T-ins in exon 1 causes a detrimental frame shift. One subject revealed a CYP2D7 conversion in the 5’-flanking region of a CYP2D6*35 allele, was otherwise unaffected (designated CYP2D6*35B. Finally, three DNAs revealed a CYP2D7 gene with a CYP2D6-like region downstream of exon 9 (designated CYP2D7[REP6]. Quantitative copy number determination, sequence analyses and long-range PCR mapping were in agreement and excluded the presence of additional gene units. Undetected hybrid genes may cause over-estimation of CYP2D6 activity (CYP2D6*1/*1 vs *1/hybrid, etc, but may also cause results that may interfere with the genotype determination. Detection of hybrid events, ‘single’ and tandem, will contribute to more accurate phenotype prediction from genotype data.

  15. 多层螺旋CT泌尿系造影诊断上尿路梗阻性疾病20例分析%Application of multi-slice spiral CT urography for diagnosis of upper urinary tract obstructive disorder in 20 cases

    Institute of Scientific and Technical Information of China (English)

    管军; 金洁; 朱文海; 陆进; 诸伟; 吴少峰

    2013-01-01

    Objective To investigate the application value of multi-slice spiral CT urography(MSCTU) in the diagnosis of upper urinary tract obstructive disorder. Methods 20 patients with upper urinary tract obstructive disorder treated from July 2008 to June 2012 were performed MSCTU scan. The primary data were performed the three dimensional reconstructions for the comparison with the results of X-ray,B-type ultrasound and IVU. Results 5 cases were developed at 1 h,1 case was postponed to develop at 2 h,3 cases had undeveloped one side and other 11 cases were normally developed. Conclusion MSCTU has the high sensitivity and high specificity,and can clearly display the upper urinary tract lesions,congenital variations and deformities.%目的 探讨多层螺旋CT泌尿系造影(MSCTU)在上尿路梗阻性疾病诊断中的应用价值.方法 选择2008年7月至2012年6月该院收治的上尿路梗阻性疾病20例,行多层螺旋CT扫描,将原始数据三维重建后进行尿路成像,并与X线平片、B超、静脉尿路造影检查结果进行对比分析.结果 5例于1 h显影,1例延迟至2 h显影,3例1侧未显影,其他11例均正常显影.结论 MSCTU是一种无创伤且安全有效的非侵袭性影像检查方法,对上尿路梗阻性疾病的诊断有重要的临床应用价值.

  16. Diagnostic Value of Multi-Slice Spiral CT Three-Dimensional Reconstruction in Rib and Costal Cartilage Injury%多层螺旋 CT 三维重建在肋骨及肋软骨损伤中诊断价值

    Institute of Scientific and Technical Information of China (English)

    张连军

    2015-01-01

    Objective The value of multi-slice spiral CT 3D reconstruction in the diagnosis of rib and costal cartilage damage in the discussion and analysis. Method In 60 patients with rib and costal cartilage fracture were retrospectively analyzed data, the VR, SSD, MIP and MIP technology, 3D reconstruction, image reconstruction display effect and value of bone fracture. Result 60 cases of rib fracture number is 203, the main four to ten rib rib fracture. The diagnosis of costal cartilage fracture in 21 cases. Conclusion: Three dimensional reconstruction of multislice spiral CT has high diagnostic value for rib and costal cartilage frac-ture.%目的:对多层螺旋 CT 的三维重建技术在肋骨和肋软骨损伤诊断中的价值进行探讨与分析。方法对60例肋骨和肋软骨骨折的患者进行资料的回顾性分析,使 VR、SSD、MIP 和 MIP 技术三维重建,比较重建的图像显示骨折的效果与价值。结果60例患者肋骨的骨折数共203根,主要发生四到十肋骨的肋骨骨折。本研究诊断出肋软骨的骨折共21例。结论多层螺旋 CT 的三维重建对于肋骨和肋软骨的骨折具有很高的诊断价值。

  17. 多层螺旋CT低剂量扫描在肺磨玻璃结节检查中的应用%Application of Low-Dose Multi-Slice Spiral CT Scan in Detecting Pulmonary Ground-Glass Nodules

    Institute of Scientific and Technical Information of China (English)

    安静; 夏玉军

    2014-01-01

    Objective To explore the application value of low-dose multi-slice spiral CT (MSCT) scan in detecting pulmonary ground-glass nodules (GGN). Methods Conventional dose MSCT scan and low-dose MSCT scan of 379 volunteers were conducted to observe the shapes, sizes, densities, internal features and boundaries of pulmonary ground-glass nodules. Results 21 ground-glass nodules were detected through conventional dose MSCT scan and 20 ground-glass nodules were detected through low-dose MSCT scan. The diameter range of the ground-glass nodules was 4~15 mm. 8 patients with pulmonary ground-glass nodules were diagnosed as primary lung cancer. Conclusion Low-dose MSCT scan which can detect pulmonary ground-glass nodules with high accuracy can be used in the screening of early lung cancer.%目的:探讨多层螺旋CT(MSCT)低剂量扫描在肺磨玻璃结节(GGN)检查中的应用价值。方法对379例志愿者进行肺部常规剂量和低剂量MSCT扫描,观察GGN的形态、大小、密度、内部特点和结节边缘等情况。结果常规剂量MSCT扫描发现21个GGN,低剂量MSCT扫描发现20个GGN,GGN直径为4~15 mm,其中8例GGN患者诊断为原发性肺癌。结论 MSCT低剂量扫描对于GGN有较高的检出率,可应用于早期肺癌的筛查。

  18. 良、恶性梗阻性黄疸应用多层螺旋CT(MSCT)的临床诊断价值研究%Clinical diagnostic and value study of multi slice spiral CT (MSCT) application for benign and malignant obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    孙赞江

    2015-01-01

    目的:探讨多层螺旋 CT(MSCT)对于良、恶性梗阻性黄疸的临床诊断价值。方法回顾分析72例梗阻性黄疸患者的临床资料与影像学资料,分析 MSCT 对于梗阻性黄疸的良恶性诊断价值。结果 MSCT 对于梗阻性黄疸的定位诊断准确率为100%,对恶性梗阻性黄疸的诊断准确率为96.43%,对良性梗阻性黄疸的诊断准确率为95.45%。结论MSCT 对于梗阻性黄疸的定位及定性诊断具有较高的准确性,值得在临床中推广应用。%Objective investigate clinical diagnostic value of multi-slice spiral CT (MSCT) for diagnosis of benign and malignant obstructive jaundice. Method analyze and review clinical and imaging data of 72 patients with obstructive jaundice, and analyze diagnostic value of MSCT for benign and malignant obstructive jaundice. Result diagnostic accuracy of MSCT for obstructive jaundice diagnosis is 100%, and for malignant obstructive jaundice is 96.43%, for benign obstructive jaundice is 95.45%. Conclusion MSCT has high accuracy for localization and qualitative diagnosis on obstructive jaundice, which is worthy of being spreaded and applied clinically.

  19. Simulation of 2D Brain's Potential Distribution Based on Two Electrodes ECVT Using Finite Element Method

    Science.gov (United States)

    Sirait, S. H.; Edison, R. E.; Baidillah, M. R.; Taruno, W. P.; Haryanto, F.

    2016-08-01

    The aim of this study is to simulate the potential distribution of 2D brain geometry based on two electrodes ECVT. ECVT (electrical capacitance tomography) is a tomography modality which produces dielectric distribution image of a subject from several capacitance electrodes measurements. This study begins by producing the geometry of 2D brain based on MRI image and then setting the boundary conditions on the boundaries of the geometry. The values of boundary conditions follow the potential values used in two electrodes brain ECVT, and for this reason the first boundary is set to 20 volt and 2.5 MHz signal and another boundary is set to ground. Poisson equation is implemented as the governing equation in the 2D brain geometry and finite element method is used to solve the equation. Simulated Hodgkin-Huxley action potential is applied as disturbance potential in the geometry. We divide this study into two which comprises simulation without disturbance potential and simulation with disturbance potential. From this study, each of time dependent potential distributions from non-disturbance and disturbance potential of the 2D brain geometry has been generated.

  20. Finite state models of constrained 2d data

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2004-01-01

    This paper considers a class of discrete finite alphabet 2D fields that can be characterized using tools front finite state machines and Markov chains. These fields have several properties that greatly simplify the analysis of 2D coding methods.......This paper considers a class of discrete finite alphabet 2D fields that can be characterized using tools front finite state machines and Markov chains. These fields have several properties that greatly simplify the analysis of 2D coding methods....

  1. Value of multi-slice spiral CT imaging and reformation in evaluating the clinical efficacy of tuina therapy in cervical spondylotic radiculopathy%MSCT颈椎扫描重建评价推拿手法治疗神经根型颈椎病疗效的研究

    Institute of Scientific and Technical Information of China (English)

    詹松华; 赵喜; 谭文莉; 杨烁慧; 张敏; 李欢欢; 龚志刚; 詹红生

    2011-01-01

    Objective: To analyze the clinical efficacy of tuina therapy in the cervical spondylotic radiculopathy by multi-slice spiral CT imaging and reformation. Methods: Image data of thirty patients with cervical spondylotic radiculopathy were collected. All patients were performed twice cervical multi-slice spiral CT study before and after the tuina therapy,and all clinical symptoms, signs and VAS score were recorded. The changes of cervical morphology in both MSCT studies were observed, including cervical curvature,atlantoaxial joint,the relationship of the spinous process and the midline of vertebral body position, interver-tebral foramen,intervertebral disc. These changes were comparatively analyzed with clinical symptoms and signs. Results: After tuina treatment,all patients had a significant improvement in the clinical symptoms and signs. VAS score was decreased by (8. 20 + 0. 92) points. The average values of cervical curvature before and after treatment were (1. 91 + 4. 99) mm and (5. 08 + 3. 61) mm,there was significant difference between them (P = 0. 000;t=- 4. 27). There was 80/300 narrow intervertebral foramen before treatment,the number was 35/300 after tuina therapy. The numbers of odontoid skew before and after treatment were 15/30 and 2/30. The distances from the spinous to centerline before and after treatment were (2. 11 + 1.68) mm and (0. 87 + 1. 70) mm (P = 0. 000;t=7. 53). The numbers of intervertebral disk hernia and slipped disc were 63/120 and 42/120 before and after tuina therapy. Conclusion: Tuina therapy is effective for cervical spondylotic radiculopathy by improving the cervical curvature,foraminal size and the relationship of facet joint position. Multi-slice CT imaging and reformation have an important referential value in the evaluation of clinical efficacy of tuina therapy in cervical spondylotic radiculopathy.%目的:探讨MSCT颈椎扫描重建在推拿手法治疗神经根型颈椎病(CSR)疗效评价中的价值.方法:30例临床确

  2. Diagnostic Value of Low Dose Multi-slice Spiral VHRCT (MSCT) CT in Children with Chronic Interstitial Lung Disease%小剂量多层螺旋CT(MSCT)VHRCT在小儿慢性肺间质病变中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李燕北; 李云秀; 王宝军

    2016-01-01

    目的:分析研讨小剂量多层螺旋CT(MSCT)VHRCT在小儿慢性肺间质病变中的诊断价值。方法:此研究中所研讨的32例患儿均随机从2013年5月至2014年11月期间我院收治的小儿慢性肺间质病变患儿中选取而出,回顾分析患儿临床病历资料,32例患儿均接受小剂量多层螺旋CT(MSCT)容积数据重组高分辨和HRCT扫描,对比此两者检查扫描方式在囊状透亮部位、网格影、结节影、肺大泡影、磨玻璃密度影等差异性,对比诊断准确性和图像质量评分状况。结果:对比同层面囊状透亮部位、网格影、结节影、肺大泡影、磨玻璃密度影、蜂窝影等显影状况,HRCT方式比MSCT方式要稍微高一点,但组间数据无统计学意义(P>0.05)。小剂量MSCT检查方式在图像质量评分上比VHRCT检查方式要稍高,但组间数据无统计学意义(P>0.05);在诊断准确率上,小剂量MSCT(93.75%)和VHRCT方式(96.87%)比较,虽后者稍高,但组间数据无统计学意义(P>0.05)。结论:HRCT检测结果比小剂量多层螺旋CTMSCT检查结果更加具有优势性,特别是针对小剂量多层螺旋CTMSCT和大龄患儿检查判定不佳时,可依据实际状况考虑是否采用HRCT,因此,建议临床在诊断疾病时,按照患儿实际状况确定检查方式,确保诊断准确性。%ABSTRACT:Objective:To analyze and discuss the value of low dose multi-slice spiral VHRCT (MSCT) CT in the diagnosis of chronic interstitial lung disease in children.Methods:32 children with this research studied were randomly from 2013 May to 2014 November period in our hospital pediatric chronic lung interstitial lesion in children with selected out, children with clin-ical data were retrospectively analyzed, 32 cases underwent low dose multislice spiral CT (MSCT) volume number according to the restructuring of high resolution scanning and HRCT, compared with the two scanning way

  3. Polynomial solution of 2D Kalman-Bucy filtering problem

    NARCIS (Netherlands)

    Sebek, M.

    1992-01-01

    The 2D version of the Kalman-Bucy filtering problem is formulated and then solved via 2D polynomial methods. The optimal filter is restricted to be a linear causal system. The design procedure is shown to consist of one 2D spectral factorization equation only. In fact, it works for n-D signals (n>2)

  4. Polynomial solution of 2D Kalman-Bucy filtering problem

    OpenAIRE

    Sebek, M.

    1992-01-01

    The 2D version of the Kalman-Bucy filtering problem is formulated and then solved via 2D polynomial methods. The optimal filter is restricted to be a linear causal system. The design procedure is shown to consist of one 2D spectral factorization equation only. In fact, it works for n-D signals (n>2) as well.

  5. FEM-2D, 2-D MultiGroup Diffusion in X-Y Geometry

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: FEM-2D solves the two-dimensional diffusion equation in x-y geometry. This is done by the finite elements method. 2 - Method of solution: FEM-2D uses triangular elements with first and second order Lagrange approximations. The systems equations are formulated in multigroup form and solved by Cholesky procedure which operates only on nonzero elements. Various acceleration techniques are available for the outer iteration. Fluxes along various lines and rates in arbitrary zones may be output. 3 - Restrictions on the complexity of the problem: The code uses variable dimensioning. Thus, the problem size is restricted by the largest array which usually is the systems matrix. Fluxes of all groups are kept in memory. This might become another restrictive data set for a large number of groups. The validity of the results is restricted by the approximations used. FEM-2D requires a finite element net which allows the approximation of fluxes by at most parabolas. The node distribution should be more dense in areas of heavy flux changes (near absorbers or the reflector)

  6. 2D-DCT的FPGA实现%Implementation of 2D-DCT using FPGA

    Institute of Scientific and Technical Information of China (English)

    郭前岗; 潘磊; 周西峰

    2012-01-01

    This paper presents an implementation for 2D-DCT using FPGA. It replaces the adders and multipliers with distributed arithmetic which is based on lookup tables, This design reduces resources and improves the operation speed. The simulation results show that the datas transformed by 2D-DCT are consistent with expectations, which is significant for the digital image and video compression.%设计了采用FPGA来实现2D—DCT的方案,对于其中的关键部分——乘加运算,给出了基于查找表的分布式算法。整个设计节省了资源,提高了运算速度。仿真结果表明,经LC-2D-DCT变换后的数据与期望值总体上是一致的,这对于数字图像和视频压缩的研究有一定的意义。

  7. Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Magnetic Resonance Imaging (MRI) KidsHealth > For Teens > Magnetic Resonance Imaging (MRI) Print A A A Text Size What's ... Exam Safety Getting Your Results What Is MRI? Magnetic resonance imaging (MRI) is a type of safe, painless testing ...

  8. Correlated Electron Phenomena in 2D Materials

    Science.gov (United States)

    Lambert, Joseph G.

    In this thesis, I present experimental results on coherent electron phenomena in layered two-dimensional materials: single layer graphene and van der Waals coupled 2D TiSe2. Graphene is a two-dimensional single-atom thick sheet of carbon atoms first derived from bulk graphite by the mechanical exfoliation technique in 2004. Low-energy charge carriers in graphene behave like massless Dirac fermions, and their density can be easily tuned between electron-rich and hole-rich quasiparticles with electrostatic gating techniques. The sharp interfaces between regions of different carrier densities form barriers with selective transmission, making them behave as partially reflecting mirrors. When two of these interfaces are set at a separation distance within the phase coherence length of the carriers, they form an electronic version of a Fabry-Perot cavity. I present measurements and analysis of multiple Fabry-Perot modes in graphene with parallel electrodes spaced a few hundred nanometers apart. Transition metal dichalcogenide (TMD) TiSe2 is part of the family of materials that coined the term "materials beyond graphene". It contains van der Waals coupled trilayer stacks of Se-Ti-Se. Many TMD materials exhibit a host of interesting correlated electronic phases. In particular, TiSe2 exhibits chiral charge density waves (CDW) below TCDW ˜ 200 K. Upon doping with copper, the CDW state gets suppressed with Cu concentration, and CuxTiSe2 becomes superconducting with critical temperature of T c = 4.15 K. There is still much debate over the mechanisms governing the coexistence of the two correlated electronic phases---CDW and superconductivity. I will present some of the first conductance spectroscopy measurements of proximity coupled superconductor-CDW systems. Measurements reveal a proximity-induced critical current at the Nb-TiSe2 interfaces, suggesting pair correlations in the pure TiSe2. The results indicate that superconducting order is present concurrently with CDW in

  9. Stability Test for 2-D Continuous-Discrete Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Models of 2-D continuous-discrete systems are introduced, which can be used to describe some complex systems. Different from classical 2-D continuous systems or 2-D discrete systems, the asymptotic stability of the continuous-discrete systems is determined by Hurwitz-Schur stability (hybrid one) of 2-D characteristic polynomials of the systems. An algebraic algorithm with simpler test procedure for Hurwitz-Schur stability test of 2-D polynomials is developed. An example to illustrate the applications of the test approach is provided.

  10. Analysis list: Mef2d [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Mef2d Muscle + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Mef2d.1.ts...v http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Mef2d.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Mef2d....10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Mef2d.Muscle.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Muscle.gml ...

  11. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI.

    Science.gov (United States)

    Motaal, Abdallah G; Noorman, Nils; de Graaf, Wolter L; Hoerr, Verena; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously with the heartbeat, resulting in a randomly undersampled kt-space that facilitates compressed sensing reconstruction. The sequence was tested in 4 healthy rats and 4 rats with chronic myocardial infarction, approximately 2 months after surgery. As a control, a non-accelerated self-gated multi-slice FLASH sequence with an echo time (TE) of 2.76 ms, 4.5 signal averages, a matrix of 192 × 192, and an acquisition time of 2 min 34 s per slice was used to obtain Cine MRI with 15 frames per heartbeat. Non-accelerated UTE MRI was performed with TE = 0.29 ms, a reconstruction matrix of 192 × 192, and an acquisition time of 3 min 47 s per slice for 3.5 averages. Accelerated imaging with 2×, 4× and 5× undersampled kt-space data was performed with 1 min, 30 and 15 s acquisitions, respectively. UTE Cine images up to 5× undersampled kt-space data could be successfully reconstructed using a compressed sensing algorithm. In contrast to the FLASH Cine images, flow artifacts in the UTE images were nearly absent due to the short echo time, simplifying segmentation of the left ventricular (LV) lumen. LV functional parameters derived from the control and the accelerated Cine movies were statistically identical.

  12. CYP2D7 sequence variation interferes with TaqMan CYP2D6*15 and *35 genotyping

    Directory of Open Access Journals (Sweden)

    Amanda K Riffel

    2016-01-01

    Full Text Available TaqMan™ genotyping assays are widely used to genotype CYP2D6, which encodes a major drug metabolizing enzyme. Assay design for CYP2D6 can be challenging owing to the presence of two pseudogenes, CYP2D7 and CYP2D8, structural and copy number variation and numerous single nucleotide polymorphisms (SNPs some of which reflect the wild-type sequence of the CYP2D7 pseudogene. The aim of this study was to identify the mechanism causing false positive CYP2D6*15 calls and remediate those by redesigning and validating alternative TaqMan genotype assays. Among 13,866 DNA samples genotyped by the CompanionDx® lab on the OpenArray platform, 70 samples were identified as heterozygotes for 137Tins, the key SNP of CYP2D6*15. However, only 15 samples were confirmed when tested with the Luminex xTAG CYP2D6 Kit and sequencing of CYP2D6-specific long range (XL-PCR products. Genotype and gene resequencing of CYP2D6 and CYP2D7-specific XL-PCR products revealed a CC>GT dinucleotide SNP in exon 1 of CYP2D7 that reverts the sequence to CYP2D6 and allows a TaqMan assay PCR primer to bind. Because CYP2D7 also carries a Tins, a false-positive mutation signal is generated. This CYP2D7 SNP was also responsible for generating false-positive signals for rs769258 (CYP2D6*35 which is also located in exon 1. Although alternative CYP2D6*15 and *35 assays resolved the issue, we discovered a novel CYP2D6*15 subvariant in one sample that carries additional SNPs preventing detection with the alternate assay. The frequency of CYP2D6*15 was 0.1% in this ethnically diverse U.S. population sample. In addition, we also discovered linkage between the CYP2D7 CC>GT dinucleotide SNP and the 77G>A (rs28371696 SNP of CYP2D6*43. The frequency of this tentatively functional allele was 0.2%. Taken together, these findings emphasize that regardless of how careful genotyping assays are designed and evaluated before being commercially marketed, rare or unknown SNPs underneath primer and/or probe

  13. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic and motor systems by high spatial resolution 7 Tesla fMRI

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R.; Setsompop, Kawin; Brown, Emery N.; Hamalainen, Matti S.; Rosen, Bruce R.; Wald, Lawrence L.

    2016-01-01

    Object To map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. Materials and Methods We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we utilized the increased contrast-to-noise ratio of 7 Tesla fMRI compared to 3 Tesla and the time efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1 mm-isotropic nominal resolution) while maintaining a short repetition time (2.5 s). Results The delineated Pearson’s correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Conclusion Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson’s disease and other motor disorders. PMID:27126248

  14. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Viallon, Magalie [Universite de Lyon, CREATIS, UMR CNRS 5220 - INSERM U1044, INSA de Lyon, Lyon (France); Universite de Lyon-Saint-Etienne, Department of Radiology, Centre Hospitalier Universitaire de Saint-Etienne, Saint Etienne (France); Cuvinciuc, Victor; Barnaure-Nachbar, Isabelle; Lovblad, Karl-Olof; Haller, Sven [University Hospital of Geneva, Department of Neuroradiology, Geneva (Switzerland); Delattre, Benedicte; Toso-Patel, Seema; Becker, Minerva [University Hospital of Geneva, Department of Radiology, Geneva (Switzerland); Merlini, Laura [University Hospital of Geneva, Department of Pediatric Radiology, Geneva (Switzerland)

    2015-05-01

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  15. In vivo confirmation of hydration based contrast mechanisms for terahertz medical imaging using MRI

    Science.gov (United States)

    Bajwa, Neha; Sung, Shijun; Garritano, James; Nowroozi, Bryan; Tewari, Priyamvada; Ennis, Daniel B.; Alger, Jeffery; Grundfest, Warren; Taylor, Zachary

    2014-09-01

    Terahertz (THz) detection has been proposed and applied to a variety of medical imaging applications in view of its unrivaled hydration profiling capabilities. Variations in tissue dielectric function have been demonstrated at THz frequencies to generate high contrast imagery of tissue, however, the source of image contrast remains to be verified using a modality with a comparable sensing scheme. To investigate the primary contrast mechanism, a pilot comparison study was performed in a burn wound rat model, widely known to create detectable gradients in tissue hydration through both injured and surrounding tissue. Parallel T2 weighted multi slice multi echo (T2w MSME) 7T Magnetic Resonance (MR) scans and THz surface reflectance maps were acquired of a full thickness skin burn in a rat model over a 5 hour time period. A comparison of uninjured and injured regions in the full thickness burn demonstrates a 3-fold increase in average T2 relaxation times and a 15% increase in average THz reflectivity, respectively. These results support the sensitivity and specificity of MRI for measuring in vivo burn tissue water content and the use of this modality to verify and understand the hydration sensing capabilities of THz imaging for acute assessments of the onset and evolution of diseases that affect the skin. A starting point for more sophisticated in vivo studies, this preliminary analysis may be used in the future to explore how and to what extent the release of unbound water affects imaging contrast in THz burn sensing.

  16. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    International Nuclear Information System (INIS)

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  17. Multi-slice CT pulmonary function evaluation in emphysema

    International Nuclear Information System (INIS)

    Objective: To explore the feasibility of evaluating the lung function by MSCT in emphysema. Methods: The MSCT scan and pulmonary function tests (PFT) were respectively performed in 147 receptors within one week. They were randomly divided into 2 groups: group A (120 receptors), including normal, mild, moderate and severe abnormal pulmonary function based on the PFT, for comparing the correlation between pulmonary quantitative indexes of MSCT pulmonary function and PFT and settingup the primary, grade criteria of abnormal pulmonary, function in emphysema, group B (27 receptors) for evaluating the diagnostic accuracy in group A. The total lung was respectively scanned at the full inspiration and full expiration with MSCT. The pulmonary quantitative indexes of MSCT were measured with Siemens Pulmo pulmonary quantitative software. Results: There was correlation between pulmonary quantitative indexes of MSCT and PFT. The Piex/in-910 showed best correlation with FEV1% (r= -0. 905, P-910 (χ20.267, P=0.966, accuracy 81.5%), and the primary criteria for abnormal pulmonary, function of emphysema was normal (0-9.9), mild (10.0-34.9), moderate (35.0-74.9) and severe (≥75.0). Conclusion: It is feasible to evaluate the abnormal lung function of emphysema with pulmonary quantitative indexes of CT. The Piex/in910 was the most effective one in various indexes. (authors)

  18. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Shaheen, Eman, E-mail: eman.shaheen@uzleuven.be; De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van [Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2014-08-15

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  19. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  20. Nonrigid registration of myocardial perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur

    2005-01-01

    This paper describes a fully automatic registration of 10 multi-slice myocardial perfusion magnetic resonance image sequences. The registration of these sequences is crucial for the clinical interpretation, which currently is subjected to manual labour. The approach used in this study is a nonrigid...... registration algorithm based on free-form deformations due to Rueckert et al. Inspection of difference images from the wash-out part of the perfusion sequences indicates that a good registration accuracy is obtained....

  1. Functional characterization of a first avian cytochrome P450 of the CYP2D subfamily (CYP2D49.

    Directory of Open Access Journals (Sweden)

    Hua Cai

    Full Text Available The CYP2D family members are instrumental in the metabolism of 20-25% of commonly prescribed drugs. Although many CYP2D isoforms have been well characterized in other animal models, research concerning the chicken CYP2Ds is limited. In this study, a cDNA encoding a novel CYP2D enzyme (CYP2D49 was cloned from the chicken liver for the first time. The CYP2D49 cDNA contained an open reading frame of 502 amino acids that shared 52%-57% identities with other CYP2Ds. The gene structure and neighboring genes of CYP2D49 are conserved and similar to those of human CYP2D6. Additionally, similar to human CYP2D6, CYP2D49 is un-inducible in the liver and expressed predominantly in the liver, kidney and small intestine, with detectable levels in several other tissues. Metabolic assays of the CYP2D49 protein heterologously expressed in E. coli and Hela cells indicated that CYP2D49 metabolized the human CYP2D6 substrate, bufuralol, but not debrisoquine. Moreover, quinidine, a potent inhibitor of human CYP2D6, only inhibited the bufuralol 1'-hydroxylation activity of CYP2D49 to a negligible degree. All these results indicated that CYP2D49 had functional characteristics similar to those of human CYP2D6 but measurably differed in the debrisoquine 4'-hydroxylation and quinidine inhibitory profile. Further structure-function investigations that employed site-directed mutagenesis and circular dichroism spectroscopy identified the importance of Val-126, Glu-222, Asp-306, Phe-486 and Phe-488 in keeping the enzymatic activity of CYP2D49 toward bufuralol as well as the importance of Asp-306, Phe-486 and Phe-488 in maintaining the conformation of CYP2D49 protein. The current study is only the first step in characterizing the metabolic mechanism of CYP2D49; further studies are still required.

  2. Development and Assessment of a New 3D Neuroanatomy Teaching Tool for MRI Training

    Science.gov (United States)

    Drapkin, Zachary A.; Lindgren, Kristen A.; Lopez, Michael J.; Stabio, Maureen E.

    2015-01-01

    A computerized three-dimensional (3D) neuroanatomy teaching tool was developed for training medical students to identify subcortical structures on a magnetic resonance imaging (MRI) series of the human brain. This program allows the user to transition rapidly between two-dimensional (2D) MRI slices, 3D object composites, and a combined model in…

  3. Maximizing entropy of image models for 2-D constrained coding

    OpenAIRE

    Forchhammer, Søren; Danieli, Matteo; Burini, Nino; Zamarin, Marco; Ukhanova, Ann

    2010-01-01

    This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite context models, which define stationary probability distributions on finite rectangles and thus allow for calculation of the entropy. We consider two binary constraints and revisit the hard square const...

  4. Study on Relationship between Gastric Multi-slice Spiral CT Perfusion Imaging and Perfusion and Tumor Factor%胃癌多层螺旋CT灌注成像及灌注参数与肿瘤因子的相关性研究

    Institute of Scientific and Technical Information of China (English)

    张颖颖; 范小波; 亓子坤

    2015-01-01

    Objective To explore the correlation between gastric cancer multi-slice spiral CT perfusion imaging and perfusion and tumor factor. Methods 32 cases of gastric cancer patients random selected from Department of oncology in our hospital from 2010 January to 2012 September as the observation group, 40 cases healthy subjects randomly chosen in the physical examination center as control group, the two groups of subjects were using CT perfusion imaging, compared blood flow perfusion software into the packet processing after the CT perfusion (Perfusion)(blood volume or per unit time per 100gin renal tissue)、blood volume (100g in renal tissue of blood within the capacity of (BV))、peak enhancement (PEI), time to peak (TTP),mean transit time (MTT), permeability surface (PS) differences and related tumor factor levels of two groups, and analyzed the correlation between CT perfusion parameters and tumor factor by using Pearson analysis method. Results The observation group and the control group Perfusion, PEI, TTP, PS with significant difference (p0.05); observation group tumor factor CEA, AFP, CA199, CA72-4 levels were significantly higher than those in the control group and the difference was statistically significant (p0.05);观察组的肿瘤因子CEA、AFP、CA199、CA72-4水平均显著的高于对照组且差异具有统计学意义(p<0.05);Perfusion、PEI、PS与肿瘤因子CEA、AFP、CA199、CA72-4呈显著的正相关性, TTP与肿瘤因子CEA、AFP、CA199、CA72-4呈显著的负相关性。结论通过对胃癌患者胃癌进行多层螺旋CT灌注成像检测,可以有效分析肿瘤因子的水平,两者间存在良好的相关性。

  5. The value of multi-slice spiral CT perfusion imaging in evaluating the changes of blood supply of hepatocellular carcinoma before and after transcatheter hepatic arterial chemoembolization%多层螺旋CT灌注成像对肝癌经导管肝动脉栓塞化疗前后血供变化的应用价值

    Institute of Scientific and Technical Information of China (English)

    周霖; 邹文远; 陈玉峰

    2010-01-01

    目的 研究多层螺旋CT灌注成像在评价肝癌经导管肝动脉栓塞化疗(TACE)前后血流动力学改变中的价值.方法 17例肝癌患者TACE术前及术后行CT灌注扫描.计算肝血流量(HBF)、肝血容量(HBV)、平均通过时间(MTT)、毛细血管表面通透性(PS)、肝动脉灌注分数(HAF),并计算肝动脉灌注量(HAP)、门静脉灌注量(PVP).根据各灌注参数值评价肝癌TACE前后血流动力学改变.结果 TACE术后,HBF、HBV和HAP[(167.89±96.06)ml/(100 g·min),(14.95±15.13)ml/100 g,(97.71±68.18)ml/(100g·min)]较TACE术前[(250.59±129.56)ml/(100 g·min),(24.44±20.03)ml/100 g,(184.61±178.83)ml/(100 g·min)]减少(P0.05).结论 肝脏灌注参数可有效评价TACE前后肝癌组织的血流灌注改变,具有重要的临床应用价值.%Objective To study the multi-slice spiral CT (MSCT) perfusion imaging in evaluating the changes of blood supply of hepatocellular carcinoma( HCC ) before and after transcatheter hepatic arterial chemoembolization (TACE). Methods Before and after TACE, MSCT perfusion was performed in 17 patients with HCC. The perfusion indexes such as hepatic blood flow (HBF), hepatic blood volume(HBV),mean transit time (MTT),hepatic arterial fracture (HAF),permeability surface (PS), hepatic artery perfusion (HAP), portal venous perfusion (PVP) were calculated. The hemodynamic changes of HCC after TACE were evaluated according to perfusion parameters. Results After TACE, HBF,HBV and HAP found in MTT and PS before and after TACE (P > 0.05). Conclusion The parameters of MSCT perfusion imaging( HBF, HBV and HAP) can effectively evaluate the hemodynamic changes of HCC after TACE, and has important value in chnical application.

  6. 多排螺旋CT(MSCT)动态增强对孤立性肺结节血流模式的评价%Evaluation of Blood Flow Patterns of Solitary Pulmonary Nodules with Dynamic Multi-slice Spiral Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    LI Shenjiang; 李慎江; XIAO Xiangsheng; 肖湘生; LI Huimin; 李惠民; LIU Shiyuan; LI Chengzhou; ZHANG Chenshi; TAO Zhiwei; YANG Chunshan

    2004-01-01

    Objective: To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT)for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs)and differentiating solitary pulmonary nodules (SPNs). Methods: 37 patients with SPNs (diameter≤4cm; 24 with maliagnant; 6 with benign; 7 with inflammatory) underwent multi-location dynamic contrast material-enhanced (90 mL, 4 mL/s) serial CT. Peak height and ratio of peak height of the SPN to that of the aorta were measured. Precontrast attenuation was recorded. Perfusion was calculated from the maximum gradient of the time-attenuation curve and the peak height of the aorta. Results: Peak heights of malignant (37.98 HU±17.97) and inflammatory (43.86 HU±14.20) SPNs were significantly higher than those of benign SPNs (5.65 HU±6.43) (P<0.001; P<0.001). No statistically significant difference in the peak height was found between malignant and inflammatory SPNs (P=0.647>0.01). SPN-to-aorta ratio in inflammatory SPNs (20.78%±4.14) was significantly higher than that in benign (2.00%±2.26) and malignant (14.63%±6.22) SPNs (P<0.001; P=0.021<0.05). SPN-to-aorta ratio in malignant SPNs was significantly higher than that in benign SPNs (P<0.001). Perfusion value in inflammatory SPNs [78.39 mL/(min.100g)±55.18] was significantly higher than that of benign [2.13 mL/(min.100g)±2.84] and malignant [33.91mL/(min.100g)±15.58] SPNs (P<0.001; P=0.001<0.01). Perfusion value in malignant SPNs was significantly higher than that in benign SPNs (P<0.001). Precontrast attenuations of inflammatory (39.36HU±9.57)and benign (37.73 HU±8.39) SPNs were lower than that of malignant SPNs (45.73 HU±4.21)(P=0.04<0.05; P=0.014<0.05). No statistically significant difference in the precontrast attenuation was found between benign and inflammatory SPNs (P=0.836>0.01). Conclusion: MSCT provides quantitative information about blood flow patterns of solitary pulmonary nodules

  7. The accuracy of linear measurements of jaw implant regions obtained by multi-slice spiral CT and dental software%MSCT及牙颌专用软件在颌骨种植区线距测量的准确性评价

    Institute of Scientific and Technical Information of China (English)

    郭凌云; 郭华艳; 张蕾; 黄远亮

    2011-01-01

    目的:评价经标记模板定位后颌骨种植区多层螺旋CT(MSCT)测量的准确性.方法:选择20名志愿者佩戴标记模板,经MSCT扫描后,应用牙颌专用测量软件测量上、下颌前牙唇舌侧龈缘中点间的距离,采用SPSS17.0软件包与游标卡尺手工测量的唇舌距进行配对t检验.结果:各牙位唇、舌侧龈缘中点间距离CT测量值与游标卡尺测量值的差值范围为-0.04~0.21 mm,无统计学差异(P>0.05).结论:经标记模板定位后,颌骨种植区高分辨率CT测量距离与实测距离具有良好的一致性,该方法为活体颌骨种植区精确测量提供了一种可靠的途径.%PURPOSE: To evaluate the measurement accuracy by multi-slice spiral CT (MSCT) and dental software as a tool for preoperative design before tooth implantations. METHODS: Twenty volunteers with marker template underwent MSCT. The diameter of the front teeth crowns in the bucco-lingual direction were measured by MSCT using a standard dental software package. Postoperatively, the same distances were clinically measured using a sliding caliper. The consistency between the two measurements was analyzed by paired t test using SPSS17.0 software package. RESULTS: The difference of measurements was -0.04-0.21mm. There was no significant difference between the CT and the manual measurement of the crown diameter in the bucco-lingual direction (P>0.05). CONCLUSIONS: The results demonstrate that MSCT and marker template promises to be a valuable method for the measurement of jaw implant regions. Supported by Grant of Science and Technology Council of Pudong New Area (PKJ2008-Y17).

  8. Sparse Non-negative Matrix Factor 2-D Deconvolution

    DEFF Research Database (Denmark)

    Mørup, Morten; Schmidt, Mikkel N.

    2006-01-01

    We introduce the non-negative matrix factor 2-D deconvolution (NMF2D) model, which decomposes a matrix into a 2-dimensional convolution of two factor matrices. This model is an extension of the non-negative matrix factor deconvolution (NMFD) recently introduced by Smaragdis (2004). We derive...... and prove the convergence of two algorithms for NMF2D based on minimizing the squared error and the Kullback-Leibler divergence respectively. Next, we introduce a sparse non-negative matrix factor 2-D deconvolution model that gives easy interpretable decompositions and devise two algorithms for computing...

  9. Klassifikation von Standardebenen in der 2D-Echokardiographie mittels 2D-3D-Bildregistrierung

    Science.gov (United States)

    Bergmeir, Christoph; Subramanian, Navneeth

    Zum Zweck der Entwicklung eines Systems, das einen unerfahrenen Anwender von Ultraschall (US) zur Aufnahme relevanter anatomischer Strukturen leitet, untersuchen wir die Machbarkeit von 2D-US zu 3D-CT Registrierung. Wir verwenden US-Aufnahmen von Standardebenen des Herzens, welche zu einem 3D-CT-Modell registriert werden. Unser Algorithmus unterzieht sowohl die US-Bilder als auch den CT-Datensatz Vorverarbeitungsschritten, welche die Daten durch Segmentierung auf wesentliche Informationen in Form von Labein für Muskel und Blut reduzieren. Anschließend werden diese Label zur Registrierung mittels der Match-Cardinality-Metrik genutzt. Durch mehrmaliges Registrieren mit verschiedenen Initialisierungen ermitteln wir die im US-Bild sichtbare Standardebene. Wir evaluierten die Methode auf sieben US-Bildern von Standardebenen. Fünf davon wurden korrekt zugeordnet.

  10. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does ... What is MRI and how does it work? Magnetic resonance imaging, or MRI, is a way of obtaining very ...

  11. 2D Four-Channel Perfect Reconstruction Filter Bank Realized with the 2D Lattice Filter Structure

    Directory of Open Access Journals (Sweden)

    Sezen S

    2006-01-01

    Full Text Available A novel orthogonal 2D lattice structure is incorporated into the design of a nonseparable 2D four-channel perfect reconstruction filter bank. The proposed filter bank is obtained by using the polyphase decomposition technique which requires the design of an orthogonal 2D lattice filter. Due to constraint of perfect reconstruction, each stage of this lattice filter bank is simply parameterized by two coefficients. The perfect reconstruction property is satisfied regardless of the actual values of these parameters and of the number of the lattice stages. It is also shown that a separable 2D four-channel perfect reconstruction lattice filter bank can be constructed from the 1D lattice filter and that this is a special case of the proposed 2D lattice filter bank under certain conditions. The perfect reconstruction property of the proposed 2D lattice filter approach is verified by computer simulations.

  12. Abdominal MRI scan

    Science.gov (United States)

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... spread. This is called staging. MRI avoids the dangers of angiography , such as too much radiation exposure ...

  13. MRI of the Chest

    Science.gov (United States)

    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  14. Interventional MRI: update

    Energy Technology Data Exchange (ETDEWEB)

    Lufkin, R.B. [Department of Radiology, University of California Los Angeles, School of Medicine, 10 833 Le Comte Avenue, Los Angeles, CA 90024-1721 (United States); Gronemeyer, D.H.W.; Seibel, R.M.M. [Institute of Diagnostic and Interventional Radiology, Medical Computerscience, University Witten/Herdecke (Germany)

    1997-12-31

    Interventional MRI is in its early stages of development. Nevertheless, the design of new interventional MRI scanners that allow maximum direct access to the patient combined with the development of new interventional MRI pulse sequences and localization systems, means that the archetypal operating rooms of the 21st century may well contain dedicated interventional MRI units for combined radiological and surgical procedures. The present article looks at the state of interventional MRI today and looks ahead to what may be forthcoming in the not-too-distant future. After briefly discussing the instrumentation necessary for practical interventional MRI, the article will go on to describe a number of different approaches to, and clinical applications for, interventional MRI. The use of MRI in guiding and controlling tumor ablation, aspiration cytology and surgical biopsy of different body parts is described. (orig.) With 13 figs., 1 tab., 114 refs.

  15. An Incompressible 2D Didactic Model with Singularity and Explicit Solutions of the 2D Boussinesq Equations

    Science.gov (United States)

    Chae, Dongho; Constantin, Peter; Wu, Jiahong

    2014-09-01

    We give an example of a well posed, finite energy, 2D incompressible active scalar equation with the same scaling as the surface quasi-geostrophic equation and prove that it can produce finite time singularities. In spite of its simplicity, this seems to be the first such example. Further, we construct explicit solutions of the 2D Boussinesq equations whose gradients grow exponentially in time for all time. In addition, we introduce a variant of the 2D Boussinesq equations which is perhaps a more faithful companion of the 3D axisymmetric Euler equations than the usual 2D Boussinesq equations.

  16. Symmetries and solvable models for evaporating 2D black holes

    OpenAIRE

    Cruz Muñoz, José Luis; Navarro-Salas, José; Navarro Navarro, Miguel; Talavera, C. F.

    1997-01-01

    We study the evaporation process of a 2D black hole in thermal equilibrium when the ingoing radiation is suddenly switched off. We also introduce global symmetries of generic 2D dilaton gravity models which generalize the extra symmetry of the CGHS model. © Elsevier Science B.V

  17. New Type of 2-D Laser Doppler Vibrometer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The fundamentals and method of 2-D laser Doppler vibrometer are introduced.The factors influencing the measuring accuracy are analyzed. Moreover, the circuit for signal processing is designed. The vibrating amplitude and frequency of 2-D vibration in wider range can be measured simultaneously in non-contact means,the measuring results are accurate.

  18. Statische verweking talud: Handleiding Windows versie SLIQ2D

    NARCIS (Netherlands)

    Van den Ham, G.

    2009-01-01

    SLIQ2D is een quasi-2D computerprogramma waarmee het optreden voorspeld kan worden van een verwekingsvloeiing ofwel een instabiliteit van een onderwatertalud ten gevolge van verweking, gegeven de taludhelling, relatieve dichtheid en materiaaleigenschappen van het zand. Dit programma is in 1994 door

  19. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes....... Numerical results for the capacities are presented....

  20. From 2D Lithography to 3D Patterning

    NARCIS (Netherlands)

    Van Zeijl, H.W.; Wei, J.; Shen, C.; Verhaar, T.M.; Sarro, P.M.

    2010-01-01

    Lithography as developed for IC device fabrication is a high volume high accuracy patterning technology with strong 2 dimensional (2D) characteristics. This 2D nature makes it a challenge to integrate this technology in a 3 dimensional (3D) manufacturing environment. This article addresses the perfo

  1. The relation between Euclidean and Lorentzian 2D quantum gravity

    NARCIS (Netherlands)

    Ambjørn, J.; Correia, J.; Kristjansen, C.; Loll, R.

    2006-01-01

    Starting from 2D Euclidean quantum gravity, we show that one recovers 2D Lorentzian quantum gravity by removing all baby universes. Using a peeling procedure to decompose the discrete, triangulated geometries along a one-dimensional path, we explicitly associate with each Euclidean space-time a (gen

  2. Getting an MRI

    Medline Plus

    Full Text Available ... Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed ...

  3. Getting an MRI

    Science.gov (United States)

    ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  4. Getting an MRI

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  5. MRI in acute poliomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Kornreich, L. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Dagan, O. [The Intensive Care Unit, The Schneider Children`s Medical Centre of Israel, Beilinson Medical Campus, Petah Tiqva (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Grunebaum, M. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

    1996-05-01

    MRI can be used in the diagnosis of anterior horn infection and for assessing the extent of disease. There are no specific MRI signs to differentiate between the various possible pathogens. This is demonstrated in the present case of poliomyelitis, in which MRI of the spine played an important role in establishing the diagnosis. (orig.). With 1 fig.

  6. fMRI Neuroinformatics

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Christensen, Mark Schram; Madsen, Kristoffer M.;

    2006-01-01

    Functional magnetic resonance imaging (fMRI) generates vast amounts of data. The handling, processing, and analysis of fMRI data would be inconceivable without computer-based methods. fMRI neuroinformatics is concerned with research, development, and operation of these methods. Reconstruction...

  7. Van der Waals stacked 2D layered materials for optoelectronics

    Science.gov (United States)

    Zhang, Wenjing; Wang, Qixing; Chen, Yu; Wang, Zhuo; Wee, Andrew T. S.

    2016-06-01

    The band gaps of many atomically thin 2D layered materials such as graphene, black phosphorus, monolayer semiconducting transition metal dichalcogenides and hBN range from 0 to 6 eV. These isolated atomic planes can be reassembled into hybrid heterostructures made layer by layer in a precisely chosen sequence. Thus, the electronic properties of 2D materials can be engineered by van der Waals stacking, and the interlayer coupling can be tuned, which opens up avenues for creating new material systems with rich functionalities and novel physical properties. Early studies suggest that van der Waals stacked 2D materials work exceptionally well, dramatically enriching the optoelectronics applications of 2D materials. Here we review recent progress in van der Waals stacked 2D materials, and discuss their potential applications in optoelectronics.

  8. Clinical application of 2D-FIESTA cine imaging in the treatment of lumbar disc herniation%腰椎间盘突出症2D-FIESTA Cine成像的临床应用

    Institute of Scientific and Technical Information of China (English)

    刘春红; 杜铁桥; 董杰; 李海梅; 张宇

    2011-01-01

    Objective To investigate the clinical application of 2D- fiesta cine imaging in the treatment of lumbar disc herniation.Methods 18 patients with lumbar disc hemiation underwent T1- and T2-weighted Spin-Echo (SE) MR images, fat saturation FSE T2WI, FS-FSE T2WI ( FSE T2WI) cine and Fast Imaging Employing Steady state Acquisition (2D-FIESTA) cine MR imaging.We retrospectively analysed the presentations on 2D-FIESTA cine images of all patients who were confirmed to have lumbar disc herniation through surgical histological examination or follow-up,and compare the scanning time with that of other general sequencing MR imaging.Results 18 patients had 33 affected discs.They were present with low signal on SE TiWI, but medium signal on FS-FSE T2WI, FSE T2WI and FIESTA.Except for showing the condition of the herniated disc, 2D-FIESTA cine could also clearly show the compressed spine nerves.The scanning time of 2D-FIESTA cine was only 13.3% of that of T2WI, and 17.9% of that of T1WI.Thus it was significant that the scanning time of 2D-FIESTA cine was shorter than conventional MRI scan.Conclusions 2D-FIESTA cine can provide valuable information regarding lumbar disc hemiation.It is an effective supplement for conventional MRI.%目的 评价2D-FIESTA cine成像在腰椎间盘突出症中的临床应用价值.方法 18例腰椎间盘突出症患者分别行矢状位SE T1WI,快速SE(FSE)T2WI,脂肪抑制FSE T2WI(fat saturation FSE T2WI,FS-FSE T2WI)及2D-FIESTA(fast imaging employing steady-state acquisition,FIESTA)cine.回顾性分析18例经手术病理或随访证实腰椎间盘突出症的2D-FIESTA cine表现,并与其他常规序列的MR扫描时间进行比较.结果 18例腰椎间盘突出症患者,共33个椎间盘受累.在SE T1WI上,病变均呈低信号,FS-FSE T2WI、FSE T2WI和FIESTA呈中等信号或低信号.2D-FIESTA cine除可动态显示突出椎间盘的情况,并可清楚显示受压的脊神经.2D-FIESTA的扫描时间仅为T2WI的13.3%;为T1WI的17.9%.2D

  9. Targeted fluorescence imaging enhanced by 2D materials: a comparison between 2D MoS2 and graphene oxide.

    Science.gov (United States)

    Xie, Donghao; Ji, Ding-Kun; Zhang, Yue; Cao, Jun; Zheng, Hu; Liu, Lin; Zang, Yi; Li, Jia; Chen, Guo-Rong; James, Tony D; He, Xiao-Peng

    2016-08-01

    Here we demonstrate that 2D MoS2 can enhance the receptor-targeting and imaging ability of a fluorophore-labelled ligand. The 2D MoS2 has an enhanced working concentration range when compared with graphene oxide, resulting in the improved imaging of both cell and tissue samples. PMID:27378648

  10. Comparison of 3D cube FLAIR with 2D FLAIR for multiple sclerosis imaging at 3 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Patzig, M.; Brueckmann, H.; Fesl, G. [Muenchen Univ. (Germany). Dept. of Neuroradiology; Burke, M. [GE Healthcare, Solingen (Germany)

    2014-05-15

    Purpose: Three-dimensional (3 D) MRI sequences allow improved spatial resolution with good signal and contrast properties as well as multiplanar reconstruction. We sought to compare Cube, a 3 D FLAIR sequence, to a standard 2 D FLAIR sequence in multiple sclerosis (MS) imaging. Materials and Methods: Examinations were performed in the clinical routine on a 3.0 Tesla scanner. 12 patients with definite MS were included. Lesions with MS-typical properties on the images of Cube FLAIR and 2 D FLAIR sequences were counted and allocated to different brain regions. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Results: With 384 the overall number of lesions found with Cube FLAIR was significantly higher than with 2 D FLAIR (N = 221). The difference was mostly accounted for by supratentorial lesions (N = 372 vs. N = 216) while the infratentorial lesion counts were low in both sequences. SNRs and CNRs were significantly higher in CUBE FLAIR with the exception of the CNR of lesion to gray matter, which was not significantly different. Conclusion: Cube FLAIR showed a higher sensitivity for MS lesions compared to a 2 D FLAIR sequence. 3 D FLAIR might replace 2 D FLAIR sequences in MS imaging in the future. (orig.)

  11. Comparison of 3D cube FLAIR with 2D FLAIR for multiple sclerosis imaging at 3 tesla

    International Nuclear Information System (INIS)

    Purpose: Three-dimensional (3 D) MRI sequences allow improved spatial resolution with good signal and contrast properties as well as multiplanar reconstruction. We sought to compare Cube, a 3 D FLAIR sequence, to a standard 2 D FLAIR sequence in multiple sclerosis (MS) imaging. Materials and Methods: Examinations were performed in the clinical routine on a 3.0 Tesla scanner. 12 patients with definite MS were included. Lesions with MS-typical properties on the images of Cube FLAIR and 2 D FLAIR sequences were counted and allocated to different brain regions. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Results: With 384 the overall number of lesions found with Cube FLAIR was significantly higher than with 2 D FLAIR (N = 221). The difference was mostly accounted for by supratentorial lesions (N = 372 vs. N = 216) while the infratentorial lesion counts were low in both sequences. SNRs and CNRs were significantly higher in CUBE FLAIR with the exception of the CNR of lesion to gray matter, which was not significantly different. Conclusion: Cube FLAIR showed a higher sensitivity for MS lesions compared to a 2 D FLAIR sequence. 3 D FLAIR might replace 2 D FLAIR sequences in MS imaging in the future. (orig.)

  12. Distributed Computing on Gadgetron: A new paradigm for MRI reconstruction

    DEFF Research Database (Denmark)

    Xue, Hui; Kelmann, Peter; Inati, Souheil;

    cloud computing. With this extension (named GT-Plus), any number of Gadgetron processes can run cooperatively across multiple computers. GT-Plus framework was deployed on Amazon EC2 cloud and NIH’s Biowulf system. We demonstrate that with the GT-Plus cloud, a multi-slice free-breathing myocardial cine...

  13. Introduction to game physics with Box2D

    CERN Document Server

    Parberry, Ian

    2013-01-01

    Written by a pioneer of game development in academia, Introduction to Game Physics with Box2D covers the theory and practice of 2D game physics in a relaxed and entertaining yet instructional style. It offers a cohesive treatment of the topics and code involved in programming the physics for 2D video games. Focusing on writing elementary game physics code, the first half of the book helps you grasp the challenges of programming game physics from scratch, without libraries or outside help. It examines the mathematical foundation of game physics and illustrates how it is applied in practice thro

  14. Maximizing entropy of image models for 2-D constrained coding

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Danieli, Matteo; Burini, Nino;

    2010-01-01

    This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite...... £ 2 squares contains all 0s or all 1s. The maximum values of the entropy for the constraints are estimated and binary PRF satisfying the constraint are characterized and optimized w.r.t. the entropy. The maximum binary PRF entropy is 0.839 bits/symbol for the no uniform squares constraint. The entropy...

  15. The NH$_2$D hyperfine structure revealed by astrophysical observations

    OpenAIRE

    Daniel, F.; Coudert, L. H.; Punanova, A.; Harju, J.; Faure, A.; Roueff, E.; Sipilä, O.; Caselli, P.; Güsten, R.; Pon, A.; Pineda, J E

    2016-01-01

    The 1$_{11}$-1$_{01}$ lines of ortho and para--NH$_2$D (o/p-NH$_2$D), respectively at 86 and 110 GHz, are commonly observed to provide constraints on the deuterium fractionation in the interstellar medium. In cold regions, the hyperfine structure due to the nitrogen ($^{14}$N) nucleus is resolved. To date, this splitting is the only one which is taken into account in the NH$_2$D column density estimates. We investigate how the inclusion of the hyperfine splitting caused by the deuterium (D) n...

  16. Kalman Filter for Generalized 2-D Roesser Models

    Institute of Scientific and Technical Information of China (English)

    SHENG Mei; ZOU Yun

    2007-01-01

    The design problem of the state filter for the generalized stochastic 2-D Roesser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discussed. The wellknown Kalman filter design is extended to the generalized 2-D Roesser models. Based on the method of "scanning line by line", the filtering problem of generalized 2-D Roesser models with mode-energy reconstruction is solved. The formula of the optimal filtering, which minimizes the variance of the estimation error of the state vectors, is derived. The validity of the designed filter is verified by the calculation steps and the examples are introduced.

  17. Optimization and practical implementation of ultrafast 2D NMR experiments

    Directory of Open Access Journals (Sweden)

    Luiz H. K. Queiroz Júnior

    2013-01-01

    Full Text Available Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively.

  18. Materials for Flexible, Stretchable Electronics: Graphene and 2D Materials

    Science.gov (United States)

    Kim, Sang Jin; Choi, Kyoungjun; Lee, Bora; Kim, Yuna; Hong, Byung Hee

    2015-07-01

    Recently, 2D materials have been intensively studied as emerging materials for future electronics, including flexible electronics, photonics, and electrochemical energy storage devices. Among representative 2D materials (such as graphene, boron nitride, and transition metal dichalcogenides) that exhibit extraordinary properties, graphene stands out in the flexible electronics field due to its combination of high electron mobility, high thermal conductivity, high specific surface area, high optical transparency, excellent mechanical flexibility, and environmental stability. This review covers the synthesis, transfer, and characterization methods of graphene and 2D materials and graphene's application to flexible devices as well as comparison with other competing materials.

  19. Optimization and practical implementation of ultrafast 2D NMR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz Junior, Luiz H. K., E-mail: professorkeng@gmail.com [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Inst. de Quimica; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Giraudeau, Patrick [Universite de Nantes (France). CNRS, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation

    2013-09-01

    Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively. (author)

  20. 2D electron cyclotron emission imaging at ASDEX Upgrade (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Classen, I. G. J. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Boom, J. E.; Vries, P. C. de [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Suttrop, W.; Schmid, E.; Garcia-Munoz, M.; Schneider, P. A. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); Tobias, B.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Donne, A. J. H. [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Jaspers, R. J. E. [Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Park, H. K. [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Munsat, T. [University of Colorado, Boulder, Colorado 80309 (United States)

    2010-10-15

    The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfven eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

  1. Correlation study of multi-slice spiral CT perfusion imaging in liver cirrhosis and portal morphology%肝硬化多层螺旋CT灌注成像及与门静脉形态学的相关研究

    Institute of Scientific and Technical Information of China (English)

    肖平; 娄明武; 谭理连; 李扬彬; 李泳; 高立; 林焕兴

    2009-01-01

    Objective To discuss correlation of hemodynamic changes and portal vein diameter with multi-slice spiral CT peffusion imaging in liver cirrhosis. Method 31 cases liver cirrhosis were enrolled in this study. The first porta hepatis were selected for target lay of CT perfusion scan. Liver perfusion parameters were obtained by color perfusion map method. Right to left diameter and occipitofrontal diame-ter of portal vein were measured. 30 cases of normal persons were used as control group. Result Hepatic arterial perfusion (HAP) in liver 0.05). Hepatic perfusion index (HPI) were (19.13±3.33)% and (20.61±8.56)%, which had no statistically significant difference with the other two groups (P>0.05). Conclusion Multi-spiral CT perfnsion imaging is an effectively noninvasive method to evaluate the hemodynamic changes of liver cirrhosis. Occipitofrontal diameter of portal vein with liver cirrhosis can reflect the state of liver hemodynamics.%目的 利用多层CT灌注成像探讨肝硬化血流灌注变化及与门静脉径线的相关性.方法 肝硬化31例,选取第一肝门层面作为CT灌注扫描靶层面,采用彩色灌注图法获得各肝脏灌注参数并对门静脉径线进行均值测量;30例正常人作对照组.结果 正常组与肝硬化组肝脏灌注参数分别为:肝动脉灌注量(HAP)(24.80±5.84)、(19.49±7.30)ml/(min·100ml),门静脉灌注量(PVP)(104.91±21.70)、(79.17±23.05)ml/(min·100ml),总肝灌注量(TLP)(129.90±25.19)、(98.67±22.74)ml/(min·100ml),2组比较,差异均有统计学意义(P0.05).肝硬化患者的TLP与门静脉前后径呈负相关(r=-0.46,P<0.05).结论 多层螺旋CT灌注成像是评价肝硬化血流灌注变化的一种有效的非创伤性的检查方法.肝硬化时门静脉前后径的变化反映其肝脏血流灌注状况.

  2. Clinical value of multi-slice spiral CT perfusion imaging in evaluation of the interventional therapy of lung cancer%多层螺旋CT灌注成像评价肺癌介入治疗效果的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    殷好治; 梁付奎; 傅晓琴; 伦俊杰; 刘明标

    2012-01-01

    目的 研究多层螺旋CT灌注成像评价肺癌介入治疗效果的临床应用价值.方法 选择50例中晚期肺癌病人,介入治疗前及治疗后1个月行灌注扫描,对瘤体中心层面进行动态灌注扫描,计算血流量(BF)、血容量(BV)、平均通过时间(MTT)、毛细血管表面通透性(PS),比较介入治疗前后各项灌注参数的变化,3个月后行常规CT检查观察肿瘤大小有无变化.结果 35例肺癌介入治疗后,肿瘤BF、BV降低,MTT显著升高(差异有统计学意义,P<0.05),但PS 变化不明显(P>0.05),3个月后随访观察瘤体组织出现不同程度缩小;15例肺癌BF、BV、MTT、PS均无明显变化(P>0.05),3个月后随访观察瘤体显示不同程度增大或无明显变化.结论 MSCT灌注成像参数变化可早期判断和预测治疗肺癌介入治疗效果.%Objective To evaluate the clinical value of multi-slice spiral CT(MSCT) perfusion imaging in vealuation of the interventional therapy of lung cancer. Methods Fifty patients with advanced lung cander were involved in the study. All patients underwent MSCT perfusion scanning preoperatively and postoperatively in one month, which was focused on the central area of lesions. The pre- and post-operative factors including tissue blood flow(BF) , blood volume(BV) , mean transit time(MTT) and vascular permeability surface (PS) were compared. The volume changes of the lesions 3 months after the intervention were obtained by conventional CT scanning. Results After interventional therapy, the BF and BV in 35 patiens significantly reduced, while MTT rised(P0. 05) ,the volumes of lesions reduced after 3 months. In 15 patiens,BF,BV,MTT and PS showed no significant variation (P>0. 05) , the lesion's volume increased or had no significant changes after 3 months. Conclusion MSCT perfusion imaging can earlier evaluate the therapeutic effect on the intervention of advanced lung cancer.

  3. 多层螺旋 CT 灌注成像在脑胶质瘤分级中的价值与微血管密度的相关性研究%Application value of multi-slice spiral CT perfusion imaging in brain gliomas and its relation with microvessel density

    Institute of Scientific and Technical Information of China (English)

    洪建斌; 许乃滔; 侯志雄

    2014-01-01

    Objective To study the value of multi-slice spiral CT (MSCT ) perfusion imaging in grading of brain glioma(BG) and its correlation with microvessel density (MVD) .Methods A total of 89 BG patients ,treated in this hospital from March 2010 to March 2013 ,were enrolled and divided into high grade group and low grade group , according to the grading levels .MSCT parameters and MVD ,vascular endothelial growth factor(VEGF) levels were compared ,and the correlation between relative cerebral blood flow (rCBV) and MVD ,VEGF were analyzed .Results Levels of cerebral blood flow (CBF) ,rCBF ,cerebral blood volume(CBV) ,relative CBV(rCBV) of high grade group were significantly higher than low grade group (P< 0 .05) .The positive rate of VEGF in high grade group was 89 .13% (41/46) ,higher than the 55 .81% (24/43) of low grade group(P<0 .05) .Level of MVD in high grade group was 70 .76 ± 8 .85 ,significantly higher than the 37 .75 ± 5 .65 of low grade group(P<0 .05) .rCBV level was positive-ly correlated with MVD and VEGF expression level (r= 0 .610 and r= 0 .631 ,P< 0 .05) .Conclusion rCBV level could be positively correlated with MVD and VEGF expression level in patients wit BG .MSCT could provide fine im-aging evidence for the grading of BG .%目的:研究多层螺旋CT(MSCT)灌注成像在脑胶质瘤(BG)分级中的价值与微血管密度(MVD)的相关性。方法选择该院2010年3月至2013年3月诊治的89例BG患者作为观察对象,根据BG分级标准分成高级别组以及低级别组。对比两组MSCT参数以及MVD、血管内皮生长因子(VEGF);分析相对脑血容量(rCBV)和MVD、VEGF的相关性。结果高级别组的脑血流量(CBF)、相对脑血流量(rCBF)、脑血容量(CBV)、rCBV均明显高于低级别组;高级别组VEGF阳性率为89.13%(41/46),明显高于低级别组的55.81%(24/43);高级别组MVD为70.76±8.85,明显高于低级别组的37.75±5.65,差

  4. Multi-slice CT evaluation of glenoid bone loss in patients with recurrent anterior shoulder dislocation%多层螺旋CT评价复发性肩关节前方脱位的前方关节盂骨质缺损的临床意义

    Institute of Scientific and Technical Information of China (English)

    崔志新; 张悦; 郑卓肇; 任阿红

    2012-01-01

    目的 在复发性肩关节前方脱位中,利用MSCT评估关节盂前方骨质缺损情况.方法 回顾分析108例复发性肩关节前脱位和12例单次肩关节脱位患者的MSCT检查,对比评价前方关节盂骨质缺损的发生率、程度及位置.利用Fisher精确概率法分析前方关节盂骨质缺损的发生率,利用Wilcoxon秩和检验比较前方关节盂骨质缺损的上下长径、深度及比例.结果 在复发性肩关节前脱位中,91.7%(99/108)存在前方关节盂的骨质缺损,缺损比例为(16.0±6.0)%,缺损中心位置介于时钟分区的2:20~ 4:25点(平均3:20点),62.0%(67/108)前方出现骨性Bankart病变,包括游离型39例(58.2%)及黏附型28例(41.8%).12例单次肩关节脱位中,9例出现前方关节盂骨质缺损,其缺损发生率(9/12;P=0.100)和缺损比例[(15.2±7.1)%;P=0.453]与复发性肩关节脱位比较差异均无统计学意义.结论 前方关节盂骨质缺损为复发性肩关节前方脱位的常见表现.%Objective To evaluate multi-slice CT (MSCT) in glenoid bone loss of patients with recurrent anterior shoulder dislocation.Methods MSCT findings of 108 patients with recurrent anterior shoulder dislocation and 12 with single anterior shoulder dislocation were retrospectively studied.The incidence,degrees and locations of glenoid bone losses were recorded.The incidence was analyzed with Fisher exact test.The maximum length,depth and proportion were compared with Wilcoxon rank sum test.Results Glenoid bone loss was detected in 91.7% (99/108)patients with recurrent anterior shoulder dislocation.The proportion of glenoid bone loss was ( 16.0 ± 6.0)%,and the central locations of glenoid bone loss were from 2: 20 to 4: 25 ( mean 3: 20).Sixty-two percent (67/108) patients had bony Bankart lesions in which 58.2% (39/67) bony fragments were free and 41.8% (28/67) were adherent to the anterior border of the glenoid cavity.Seventy-five percent (9/12) patients with single

  5. 多层螺旋CT在儿童完全性肺静脉异位引流诊断中的研究%Application of multi-slice spiral CT in diagnosis of total anomalous pulmonary venous drainage in children

    Institute of Scientific and Technical Information of China (English)

    樊国峰; 赵鑫; 张小安; 叶自青; 刘晓晨

    2011-01-01

    目的:探讨多层螺旋CT在完全性肺静脉异位引流中的诊断价值.方法:回顾性分析2005年5月~2010年4月经心脏外科手术证实的30例完全性肺静脉异位引流患儿的MSCT图像特点,探讨MSCT在完全性肺静脉异位引流及并发畸形诊断中的价值,为术前诊断、手术方式选择及术后随访提供信息.结果:30例中心上型15例,心内型12例,心下型2例,混合型1例;术前经MSCT诊断为完全型28例(心上型15例,心内型10例,心下型2例,混合型1例),漏诊2例,诊断符合率为93.3%;TTE诊断心上型11例,心内型9例,心下型1例,漏诊9例,诊断符合率为70.0%.结论:多层螺旋CT.是完全性肺静脉异位引流准确、重要的检查方法.%Objective: To explore the value of multi - slice spiral CT (MSCT) in diagnosis of total anomalous pulmonary venous drainnge (TAPVD) in children.Methods: The imaging characteristics of MSCT among 30 children with TAPVD who were diagnosed definitely by department of cardiac surgery in the hospital from May 2005 to April 2010 were analyzed retrospectively, the value of MSCT in diagnosis of TAPVD combined with abnormality was explored, then the information was provided for preoperative dingnosis, choice of operative medes and postoperative follow -up.Results: The types of TAPVD among 30 children: 15 children with supra - cardiac type, 12 children with intra- cardiac type, 2 children with infra- cardiac type and 1 child with mixed type; 28 children were diagnosed as complete type by MSCT before surgery ( 15 children with supra -cardiac type, 10 children with intra -cardiac type, 2 children with infra -cardiac type and 1 child with mixed type), 2 children were missed, the diagnostic accordance rate was 93.3%.The results of TTE: 11 children with supra -cardiac type, 9 children with intra- cardiac type, 1 child with infra -cardiac type, 9 children were missed, the diagnostic accordance rate was 70.0%.Conclusion: MSCT is a accurate and important

  6. Value of combining 64 multi-slice spiral computer tomography and serum amyloid A protein in surgical decision-making in rectal cancer%多层螺旋CT联合血清淀粉样蛋白A术前评估直肠癌在外科决策中的价值

    Institute of Scientific and Technical Information of China (English)

    汪晓东; 吕东昊; 宋欢; 秦昌龙; 吴俊华; 李臻辉; 李立

    2009-01-01

    目的 探讨64排多层螺旋CT(MSCT)和血清淀粉样蛋白A(SAA)联合术前评估进行直肠癌术前分期的准确性及其临床应用价值.方法 前瞻性纳入2007年10月至2008年10月期间住院的225例直肠癌患者,将患者随机分为MSCT组和MSCT与SAA联合组,联合组术前行MSCT和SAA联合评估,MSCT组术前只行MSCT评估.分别将两组术前T、N、M、TNM分期准确度进行比较,并比较两组手术方案的预测符合率.结果 本研究实际纳入病例225例,MSCT和SAA联合组110例,MSCT组115例,两组基线情况具有可比性.联合组术前T、N、M和TNM分期的准确度分别为87.3%、85.2%、100%和86.4%,MSCT组的准确度分别为85.2%、67.0%、100%和66.1%;两组术前N分期和TNM分期准确度差异具有统计学意义(P=0.009、0.001).两组手术方案的预测符合率分别为94.7%和81.7%,差异具有统计学意义(P=0.003).结论 MSCT和SAA联合评估的策略可以提高直肠癌患者术前分期N、TNM的准确性,并可提高预测手术方案的符合率.%Objective To determine the accuracy and clinical value of combining 64 multi-slice spiral computer tomography (MSCT) and serum amyloid A protein (SAA) in the preoperative staging of rectal cancer.Methods Prospectively enrolled patients with rectal cancer from October 2007 to October 2008.The patients were randomly assigned into two groups:MSCT and SAA combined group:both MSCT and SAA combinative assessment were performed for preoperative evaluation; MSCT group:only MSCT was performed preoperatively for tumor staging.The accuracy of the preoperative T,N,M,and TNM staging and the concordance rate of predictive operative strategy were compared between the two groups.Results Total of 225 cases with rectal cancer were enrolled in this study.There were 110 cases in MSCT and SAA combined group and 115 cases in MSCT group.The baseline characteristics was comparable between the two groups.For MSCT and SAA combined group,the accuracies of

  7. ROC分析在多层螺旋CT综合性诊断孤立性肺结节良恶性中的应用%Role of ROC analysis in comprehensive diagnosis to differentiate malignant from benign solitary pulmonary nodules with multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    杨玉海; 邵广瑞; 宋磊; 张伟

    2011-01-01

    Objective To study the role of receiver operating characteristic (ROC) analysis in comprehensive diagnosis to differentiate malignant from benign solitary pulmonary nodules (SPNs) with multi-slice spiral computed tomography (MSCT).Methods 177 SPNs were examined with MSCT and pathologically confirmed by surgery and/or needle biopsy.All MSCT images were assessed and graded by three senior radiologists on the basis of malignant likelihood of morphological and density characteristics.According to the maximum diameter (D), ROC curves were constructed and optimal thresholds were determined for diagnosis of malignancy in SPNS of D≤3.0 cm, 2.0 cm < D≤3.0 cm and D≤2.0 cm.ROC analysis was used to evaluate the efficiency of MSCT in differentiating malignant from benign SPNs.The area under the ROC curve ( Az ) was used as an index for diagnostic efficiency with MSCT.Az values were statistically analyzed by Z-test.Results A, values of ROC curves were 0.879 ± 0.030 in SPNs of D ≤3.0 cm, 0.899 ± 0.039 in SPNs of 2.0 cm < D≤3.0 cm and 0.867 ± 0.044 in SPNs of D≤2.0 cm.The differences were statistically significant according to the Z-test ( P < 0.05).The three optimal thresholds for diagnosis of malignancy were 3.0, 3.5 and 2.5.Conclusion Application of ROC analysis is of obvious value in the differential diagnosis of SPNs with comprehensive imaging characteristics obtained by MSCT.It is favorable to combine the diagnosis of SPNs by MSCT with the malignant probability and to improve the treatment of SPNs in clinical practice.%目的 探讨在孤立性肺结节(SPN)良恶性的多层螺旋CT(MSCT)综合性诊断中ROC分析的应用价值.方法 经手术和/或穿刺活检组织病理结果 证实的SPN 177个,由3位资深的CT诊断医师分别对每个SPN的MSCT图像进行全面分析,依其影像特征进行综合评分,根据SPN的最大径(D),以MSCT评分为分类值,分别绘制D≤3.0 cm、2.0 cm<D≤3.0 cm和D≤2.0 cm SPN良恶性诊断的ROC曲

  8. Application of Multi-slice Spiral CT Angiography in Diagnosis and Preoperative Evaluation of Abdominal Aortic Aneurysm%多层螺旋CT血管成像在腹主动脉瘤诊断及术前评估中的应用价值

    Institute of Scientific and Technical Information of China (English)

    刘继峰; 郭旺明

    2015-01-01

    Objective To explore the effectiveness of application of multi-slice spiral CT angiography (CTA) in diagnosis and preoperative evaluation of abdominal aortic aneurysm. Methods Altogether 82 patients conifrmed as abdominal aortic aneurysm by surgery or digital subtraction angiography (DSA) were chosen. CTA was performed to observe abdominal aorta and its branches. Multiplanar reconstruction, maximum intensity projection and volume rendering were used to reconstruct images. Then classiifcation was made, lesion sites and involved scope were located. Results Among 82 patients with abdominal aortic aneurysm, 76 cases were detected by CTA, 82 cases were detected by DSA, the difference was signiifcant (P>0.05). With evaluation by CTA, 8 cases wereⅠtype, 7 cases wereⅡA type, 9 cases wereⅡB type, 40 cases wereⅡC type, 12 cases wereⅢtype;10 cases were proximal kidney type, 66 cases were infrarenal type. Compared with DSA results, there was no statistically signiifcant difference (P>0.05). Conclusion CTA technique which could accurately evaluate the shape, site, and size of abdominal aortic aneurysm, had a high accuracy rate in diagnosis of abdominal aortic aneurysm. CTA technique could direct the selection of treatment methods and determine the surgical indications.%目的:探讨多层螺旋CT血管成像(CTA)在腹主动脉瘤诊断及术前评估中的应用价值。方法选择经手术或数字减影血管造影(DSA)证实的82例腹主动脉瘤患者作为研究对象。采用CTA技术对患者的腹主动脉及其分支进行扫描,应用多平面重建、最大密度投影、容积成像等技术对图像进行重建,并进行分型、病灶位置和累及范围等定位。结果82例腹主动脉瘤中,CTA检出76例,与DSA检查结果相比,差异无统计学意义(P>0.05)。CTA评估Ⅰ型8例、ⅡA型7例、ⅡB型9例、ⅡC型40例、Ⅲ型12例,近肾型10例,肾下型66例,与DSA检查结果相比,

  9. The correlation between periodontal diseases and carotid arteries atherosclerosis by three-dimensional reconstruction technique of multi-slice spiral CT in elderly people%三维CT成像评价老年人牙齿残缺与颈动脉粥样硬化的关系

    Institute of Scientific and Technical Information of China (English)

    王瑾; 刘海霞; 孙静华; 付英杰

    2013-01-01

    目的 探讨三维CT成像技术显示牙齿残缺的临床应用价值,并通过三维CT成像评价老年人牙齿残缺与颈动脉粥样硬化的关系. 方法 从年龄大于60岁的三维CT血管造影检查者中随机选择60例颈部动脉粥样硬化患者为病例组,颈部动脉正常者60例为对照组,采用多种图像后处理技术,分别观察两组牙齿残缺情况和颈部动脉情况. 结果 病例组患龋人数、缺齿人数、无牙颌人数均多于对照组(P<0.05).牙齿完整人数对照组(19例)高于病例组(7例),患龋者病组(7.3±3.0)颗高于对照组(6.0±2.1)颗,缺齿者均数病例组(45例)高于对照组(39例)(P<0.05);牙齿疾患与颈动脉粥样硬化疾病相关,三维CT成像技术观察颌骨牙齿情况,可以全面展示牙齿立体形态和内部结构,为牙周疾病提供有价值的资料. 结论 老年人龋齿、牙缺失与动脉粥样硬化密切相关.三维CT成像技术可为研究外周血管疾病与牙周疾病提供有价值的方法.%Objective To explore the possible correlation between periodontal disease and carotid arteries atherosclerosis in old people,and to study the diagnostic value for periodontal disease using three-dimensional (3D) reconstruction technique of multi-slice spiral CT (MSCT).Methods Patients underwent multi-detector row CT angiography with carotid arteries atherosclerosis (control group) and without carotid arteries atherosclerosis (case group) were evaluated with the stereoscopic configuration of teeth,and the number of decayed teeth and lost teeth were recorded.Results Bythe 3D reconstruction technique,the number of decayed teeth and lost teeth between two groups were significantly different (P<0.05).The number of dental integrity patients was higher in control group (19 cases) than in case group(7 cases).The mean of dental caries was higher in control group(7.3±3.0) than in case group(6.0±2.1).The mean of hypodontia was higher in control group(45 cases) than

  10. 多层螺旋CT及多维重建技术对隐匿性肋骨骨折的诊断价值探讨%Study of the multi-slice CT and for multi-dimensional reconstruction techniques the diagnosis of occult rib fracture

    Institute of Scientific and Technical Information of China (English)

    蔡洪涛

    2014-01-01

    目的:考察多层螺旋CT(MSCT)联合多维重建技术对隐匿性肋骨骨折的临床诊断价值,为该类疾病临床诊断提供参考。方法:以我院2012年7月至2014年2月间收治的73例隐匿性肋骨骨折患者为研究对象,使用MSCT联合VR、SSD、CRP等多种重建技术对患者进行检查,统计并分析影像学检查结果。结果:73例患者经MSCT检查确诊隐匿性肋骨骨折107处,骨折多发于肋骨角(59.81%)且以非完全线性骨折为主(91.59%)。所用多维重建技术的诊断精度依次为:CRP(100.0%)>MPR(97.19%)>SSD(85.89%)>VR(78.50%)>MIP(27.88%)。结论:MSCT联合多维重建技术对隐匿性肋骨骨折具有较为明确的诊断价值,MSCT与CRP/MPR及VR等联用可获得较为理想的诊断率。%Objective:To investigate the clinical value of the multi-slice CT and for multi-dimensional reconstruction techniques the diagnosis of occult rib fracture, to provide a reference for the diagnosis of occult rib fracture.Methods:73 cases patients with occult rib fracture which received treatment during 2012.07 to 2014. 02, were the objects for this study, used MSCT joint VR, SSD, CRP and other reconstruction techniques to detected the occult rib fracture of all the patients, and then the imaging results of the patients were analyzed. Results:The results of MSCT showed 107 occult rib fracture were detected for 73 cases patients, and about 59.81% occult rib fracture were occurred in the rib angle, and the non- fully linear fracture dominated 91.59%. The diagnostic accuracy of all the multi-dimensional reconstruction techniques used in this study were: CRP (100.0%)> MPR (97.19%)>SSD (85.89%)> VR (78.50%)> MIP (27.88%).Conclusions:The MSCT joint multi-dimensional reconstruction techniques has a speciifc diagnostic value for the occult rib fractures, MSCT combined with MSCT CRP / MPR and VR, etc. could received a ideal diagnostic accuracy.

  11. Multi-slice Spiral CT in Cochlear Implantation on Clinical Significance of Display Cochlear Inner Electrode%多排螺旋CT在人工耳蜗植入术后对蜗内电极显示的临床意义

    Institute of Scientific and Technical Information of China (English)

    周万勇; 马玉; 巩武贤

    2013-01-01

    目的 探讨多排螺旋CT (MSCT)在人工耳蜗植入术后对蜗内电极显示的应用价值及临床意义.方法 对28例已行人工耳蜗植入术的患者做MSCT横断扫描,MPR重组及容积再现技术(VRT)重建,扫描参数为120kv,80mas,0.6mm准直器宽度,重建图像厚度0.6mm,间隔0.1mm,骨算法重建,对特殊患者行VRT三维重建.结果 25例显示植入电极在耳蜗内呈点状高密度影,VRT图像显示电极在耳蜗内呈自然螺旋状,无扭曲、滑脱与耳蜗走形一致,其中23例患者,耳蜗内显示植入电极12对,2例显示11对.2例植入失败,其中1例并发中耳炎,电极脱落仅于耳蜗底转,1例电极位于耳蜗外.内耳畸形成功植入1例,VRT图像显示植入耳蜗前段4-5电极.结论 MSCT扫描结合MPR及VRT重建对人工耳蜗植入术后植入电极在耳蜗内形态、位置、数目有准确、清晰、直观显示,对术后患者的康复评估有重要帮助.%Objective To investigate the multi-slice spiral CT in the cochlear implantation on application value display cochlear inner electrode and its clinical significance.Methods Patients with have cochlear implantation was performed in 28 cases of MSCT transverse scanning,MPR recombination and volume rendering technique (VRT) reconstruction,scanning parameters for 120kv,80mas,0.6mm collimation,reconstruction thickness 0.6mm,interval 0.1 mm,bone algorithm reconstruction,for special patients underwent VRT three-dimensional reconstruction.Results Of the 25 cases showed punctate hyperdense electrodes implanted in the cochlea,VRT image display electrode is natural spiral in the cochlea,no distortion,spondylolisthesis and cochlear out of shape,in which 23 cases,cochlear implanted electrodes to display 12,2 cases showed that 11 of the.2 cases of implant failure,of which 1 cases complicated by otitis media,electrode off only in the basal turn of the cochlea,1 cases located in the outer electrode.In 1 cases with inner ear malformation successful

  12. 多层螺旋CT(MSCT)灌注评估糖尿病肾病患者肾功能的临床研究%Clinical Study on Multi-slice Spiral CT (MSCT) in Evaluation of Renal Function in Patients with Diabetic Nephropathy

    Institute of Scientific and Technical Information of China (English)

    刘乃全; 孙广萍

    2016-01-01

    Objective To investigate the clinical value of multi-slice spiral CT (MSCT) perfusion in evaluation of renal function in patients with diabetic nephropathy (DN). Methods 31 cases of patients with clinically diagnosed DN and 26 normal volunteers were selected as the study subjects. All of them underwent bilateral renal perfusion scan with 64 slice spiral CT. The relationship between renal cortical perfusion parameters and clinical examination indicators in the two groups was compared. The changes in clinical examination indicators before and after perfusion scan were analyzed.Results The renal blood flow (BF), renal blood volume (BV) and renal permeability surface (PS) in DN group were significantly lower than those in control group. The mean transit time (MTT) of renal contrast agent was significantly longer than that of control group (P<0.05); BF, BV, MTT, PS and microalbumin, 24h urinary protein quantitation, creatinine and fasting blood glucose were correlated. BF and BV had no correlation (P<0.05).Conclusion MSCT renal perfusion parameters and microalbumin, 24h urinary protein quantitation and fasting blood glucose have certain correlation, which can be used for evaluation of renal function damage in patients with DN.%目的:探讨多层螺旋CT(MSCT)灌注评估糖尿病肾病(DN)患者肾功能的临床价值。方法选取31例临床确诊为DN患者及26例正常志愿者作为研究对象,均行64层螺旋CT双侧肾脏灌注扫描,对比两组肾皮质灌注参数与临床检验指标的关系,分析灌注扫描前后临床检验指标变化。结果 DN组肾血流量(BF)、肾血容量(BV)、脏表面通透性(PS)均明显低于对照组,肾造影剂的平均通过时间(MTT)明显高于对照组(P<0.05);BF、BV、MTT、PS与微量白蛋白、24h尿蛋白定量、肌酐、空腹血糖存在相关性,BF、BV与肌酐存在相关性(P<0.05)。结论 MSCT肾脏灌注指标与微量白蛋白、24h尿蛋白定量、空腹血糖具有一定相

  13. 前后交叉韧带及半月板损伤的MDCT与关节镜的对比研究%Comparative study between multi-slice spiral CT and knee arthroscopy in diagnosis of anterior and posterior cruciate ligament injury and meniscus injury

    Institute of Scientific and Technical Information of China (English)

    黄瑞庭; 刘玉涛; 张德佳; 杜中立; 张应鹏; 郭宗义; 黄海松

    2013-01-01

    目的 探讨多层螺旋CT在膝关节外伤中前后交叉韧带与半月板损伤的诊断价值.方法 回顾性分析45例经膝关节镜证实的前后交叉韧带和半月板损伤的多层螺旋CT直接征象和间接征象.结果 前后交叉韧带损伤的直接征象表现为韧带断裂、密度欠均匀,韧带附着点撕脱性骨折,间接征象表现为韧带肿胀,周围脂肪间隙模糊欠清;半月板损伤的MDCT直接征象是形态失常、密度不均匀及裂隙征,间接征象是膝关节滑膜增厚、关节囊关节腔内积液、损伤的半月板周围软组织肿胀等.45例患者中,MDCT显示前交叉韧带损伤14例(14/20),后交叉韧带损伤11例(11/15),内侧半月板损伤8个(8/12),外侧半月板损伤12个(12/20),交叉韧带与半月板同时损伤10例,韧带附着点及胫骨平台骨折18例.结论 多层螺旋CT在膝关节外伤中的前后交叉韧带及半月板的损伤有一定的诊断价值,可为缺少磁共振设备的基层医院提供一有用的检查方法.%Objective To evaluate the diagnotic value of multi-slice spiral CT(MDCT) in anterior and posterior cruciate ligament injury and meniscus injury. Methods Retrospective analysis of the CT direct signs and indirect signs in 45 cases diagnosed with anterior and posterior cruciate ligament injury and meniscus injury confirmed by knee arthroscopic was conducted. Results MDCT findings of the direct signs of the anterior and posterior cruciate ligament injury included the ligament rupture, less uniform density, ligament attachment points avulsion fracture. Indirect signs included ligament swelling, fuzzy around the fat space less clear; MDCT findings of the direct signs of the meniscus injury included morphological disorders, uneven density and broken sign. Indirect signs included thickening of the synovium, joint capsule effusion, soft tissue swelling of the injuryed meniscus. In 45 patients, MDCT showed the anterior cruciate ligament injury in 14 cases (14

  14. Orbifold Reduction and 2d (0,2) Gauge Theories

    CERN Document Server

    Franco, Sebastian; Seong, Rak-Kyeong

    2016-01-01

    We introduce Orbifold Reduction, a new method for generating $2d$ $(0,2)$ gauge theories associated to D1-branes probing singular toric Calabi-Yau 4-folds starting from $4d$ $\\mathcal{N}=1$ gauge theories on D3-branes probing toric Calabi-Yau 3-folds. The new procedure generalizes dimensional reduction and orbifolding. In terms of T-dual configurations, it generates brane brick models starting from brane tilings. Orbifold reduction provides an agile approach for generating $2d$ $(0,2)$ theories with a brane realization. We present three practical applications of the new algorithm: the connection between $4d$ Seiberg duality and $2d$ triality, a combinatorial method for generating theories related by triality and a $2d$ $(0,2)$ generalization of the Klebanov-Witten mass deformation.

  15. Emerging and potential opportunities for 2D flexible nanoelectronics

    Science.gov (United States)

    Zhu, Weinan; Park, Saungeun; Akinwande, Deji

    2016-05-01

    The last 10 years have seen the emergence of two-dimensional (2D) nanomaterials such as graphene, transition metal dichalcogenides (TMDs), and black phosphorus (BP) among the growing portfolio of layered van der Waals thin films. Graphene, the prototypical 2D material has advanced rapidly in device, circuit and system studies that has resulted in commercial large-area applications. In this work, we provide a perspective of the emerging and potential translational applications of 2D materials including semiconductors, semimetals, and insulators that comprise the basic material set for diverse nanosystems. Applications include RF transceivers, smart systems, the so-called internet of things, and neurotechnology. We will review the DC and RF electronic performance of graphene and BP thin film transistors. 2D materials at sub-um channel length have so far enabled cut-off frequencies from baseband to 100GHz suitable for low-power RF and sub-THz concepts.

  16. Double resonance rotational spectroscopy of CH2D+

    Science.gov (United States)

    Töpfer, Matthias; Jusko, Pavol; Schlemmer, Stephan; Asvany, Oskar

    2016-09-01

    Context. Deuterated forms of CH are thought to be responsible for deuterium enrichment in lukewarm astronomical environments. There is no unambiguous detection of CH2D+ in space to date. Aims: Four submillimetre rotational lines of CH2D+ are documented in the literature. Our aim is to present a complete dataset of highly resolved rotational lines, including millimetre (mm) lines needed for a potential detection. Methods: We used a low-temperature ion trap and applied a novel IR-mm-wave double resonance method to measure the rotational lines of CH2D+. Results: We measured 21 low-lying (J ≤ 4) rotational transitions of CH2D+ between 23 GHz and 1.1 THz with accuracies close to 2 ppb.

  17. 2D gels still have a niche in proteomics

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, Adelina; Le Bihan, Marie-Catherine; Thaysen-Andersen, Morten;

    2013-01-01

    With the rapid advance of MS-based proteomics one might think that 2D gel-based proteomics is dead. This is far from the truth. Current research has shown that there are still a number of places in the field of protein and molecular biology where 2D gels still play a leading role. The aim...... of this review is to highlight some of these applications. Examples from our own research as well as from other published works are used to illustrate the 2D gel driven research in the areas of: 1) de novo sequencing and protein identification from organisms with no or incomplete genome sequences available; 2......) alternative detection methods for modification specific proteomics; 3) identification of protein isoforms and modified proteins. With an example of the glycoprotein TIMP-1 protein we illustrate the unique properties of 2D gels for the separation and characterisation of multiply modified proteins. We also show...

  18. Technical Review of the UNET2D Hydraulic Model

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, William A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, Marshall C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-05-18

    The Kansas City District of the US Army Corps of Engineers is engaged in a broad range of river management projects that require knowledge of spatially-varied hydraulic conditions such as velocities and water surface elevations. This information is needed to design new structures, improve existing operations, and assess aquatic habitat. Two-dimensional (2D) depth-averaged numerical hydraulic models are a common tool that can be used to provide velocity and depth information. Kansas City District is currently using a specific 2D model, UNET2D, that has been developed to meet the needs of their river engineering applications. This report documents a tech- nical review of UNET2D.

  19. Illumination Compensation for 2-D Barcode Recognition Basing Morphologic

    Directory of Open Access Journals (Sweden)

    Jian-Hua Li

    2013-04-01

    Full Text Available Improvement of image quality has been highly demanded in digital imaging systems. This study presents a novel illumination normalization approach for 2-D barcode recognition under varying lighting conditions. MMs (Morphological transformations are employed to original images using big scale multiple SEs (structuring elements. Then we make use of entropy to fuse images. The performance of proposed methodology is illustrated through the processing of images with different kinds of 2-D barcodes under different backgrounds. The experimental results show that this approach can process different kinds of 2-D barcodes under varying lighting conditions adaptively. Compared with other conventional methods, our proposed approach does a better job in processing 2-D barcode under non-uniform illumination.

  20. Recent developments in 2D layered inorganic nanomaterials for sensing

    Science.gov (United States)

    Kannan, Padmanathan Karthick; Late, Dattatray J.; Morgan, Hywel; Rout, Chandra Sekhar

    2015-08-01

    Two dimensional layered inorganic nanomaterials (2D-LINs) have recently attracted huge interest because of their unique thickness dependent physical and chemical properties and potential technological applications. The properties of these layered materials can be tuned via both physical and chemical processes. Some 2D layered inorganic nanomaterials like MoS2, WS2 and SnS2 have been recently developed and employed in various applications, including new sensors because of their layer-dependent electrical properties. This article presents a comprehensive overview of recent developments in the application of 2D layered inorganic nanomaterials as sensors. Some of the salient features of 2D materials for different sensing applications are discussed, including gas sensing, electrochemical sensing, SERS and biosensing, SERS sensing and photodetection. The working principles of the sensors are also discussed together with examples.

  1. 多层螺旋CT血管成像评价肝移植受者移植前后血管结构%Evaluation of vascular structure using multi-slice spiral CT angiography prior to and after liver transplantation

    Institute of Scientific and Technical Information of China (English)

    李占军; 周智洋; 章作铨; 邱建平; 谢学斌; 邹学农

    2009-01-01

    背景:多层螺旋CT具有先进的扫描技术和强大的图像后处理功能,其亚秒级的扫描速度及各向同性的成像功能,在血管成像上有很多优势.目的:探讨多层螺旋CT血管成像技术对肝移植受者移植前后血管结构评价的应用价值.设计、时间及地点:回顾性分析,以肝移植受者肝脏血管为观察对象,自身对照观察,于2003-10/2006-12在中山大学附属第五医院放射科完成.对象:选择拟行原位肝移植患者27例,年龄31~67岁,男17例,女10例.方法:轴位螺旋扫描范围为膈顶上方2 cm至双肾下极以下.电压120 kV,动脉期准直0.75 mm,平扫、门脉期、肝静脉期准直1.5 cm;使用非离子型对比剂优维显,注射速度为3 mL/s,三期增强扫描延迟时间分别为20~25 s,50~55 s,75~80 s.重建增强的薄层图像序列,动脉期层厚1 mm,间隔0.7 mm;门脉期、肝静脉期层厚2 mm,间隔1 mm.将图像序列传入后处理工作站,以MIP、VR等方式显示腹腔干系、门脉系、肝静脉及下腔静脉血管的三维结构.主要观察指标:肝移植前后患者血管三维结构.结果:移植前所有患者腹腔干系均得到良好显示,21例肝动脉走形正常,6例患者肝动脉变异,其中门静脉海绵样变2例,门脉多发血栓1例,因不适宜手术此3例未进行肝移植.24例患者第二肝门及下腔静脉肝内段血管结构显示清楚,肝右静脉单独汇入下腔静脉、肝左静脉和肝中静脉先汇合后再注入下腔静脉18例,肝有静脉、肝中静脉及肝左静脉分别单独汇入下腔静脉6例,下腔静脉肝后段狭窄2例.17例肝移植后CT血管成像发现肝动脉吻合口部狭窄2例,门脉高压侧支迂曲缓解10例,另7例患者因检查费用问题选择B超检查.结论:多层螺旋CT血管成像能够清晰显示肝移植患者移植前后血管结构,对适宜手术的病例筛选、指导手术方案及移植后血管结构的评价具有重要意义.%BACKGROUND:Multi-slice

  2. 2d quantum gravity and black hole formation

    International Nuclear Information System (INIS)

    The quantum integral of generic 2d quantum gravity can be performed exactly. The equivalence of dilaton theories to 2d theories with torsion and the use of a light cone gauge are crucial. Scalar matter can be treated perturbatively. A generalization of the Polyakov action emerges. For scattering of scalars in a flat background already in the tree approximation for the first time the intermediate formation of a black hole is observed in an ab initio quantum gravity computation

  3. Excitation of 2D plasmons in Cs/W(110)

    CERN Document Server

    Benemanskaya, G V; Frank-Kamenetskaya, G E

    2001-01-01

    One studied the evolution of surface photoemission spectra for Cs/W(110) system at metastable Cs coatings exceeding monolayer. One showed possibility to observe 2D plasmons by means of threshold photoemission spectroscopy. One detected three photoemission peaks characterized by complicated behavior depending on Cd adsorption dose. The nature of peaks may be related to plasmon photoinduced excitation in quasi-2D Cs clusters, surface Cs plasmon and interface Cs-W plasmon

  4. The Branching of Graphs in 2-d Quantum Gravity

    OpenAIRE

    Harris, M. G.

    1996-01-01

    The branching ratio is calculated for three different models of 2d gravity, using dynamical planar phi-cubed graphs. These models are pure gravity, the D=-2 Gaussian model coupled to gravity and the single spin Ising model coupled to gravity. The ratio gives a measure of how branched the graphs dominating the partition function are. Hence it can be used to estimate the location of the branched polymer phase for the multiple Ising model coupled to 2d gravity.

  5. Illumination Compensation for 2-D Barcode Recognition Basing Morphologic

    OpenAIRE

    Jian-Hua Li; Yi-Wen Wang; Yi Chen; Meng Zhang

    2013-01-01

    Improvement of image quality has been highly demanded in digital imaging systems. This study presents a novel illumination normalization approach for 2-D barcode recognition under varying lighting conditions. MMs (Morphological transformations) are employed to original images using big scale multiple SEs (structuring elements). Then we make use of entropy to fuse images. The performance of proposed methodology is illustrated through the processing of images with different kinds of 2-D barcode...

  6. Collins Model and Phase Diagram of 2D Ternary System

    Institute of Scientific and Technical Information of China (English)

    XIE Chuan-Mei; CHEN Li-Rong

    2004-01-01

    The Collins model is introduced into the two-dimensional (2D) alternative ternary system having the Lennard-Jones (L-J) potential. The Gibbs free energy of this ternary system is calculated, and according to thermodynamic theory, a group of equations that determine the solid-liquid diagram of ternary system are derived, some isothermal sectional diagrams of the 2D ternary system are obtained. The results are quite similar to the behavior of three-dimensional substances.

  7. Technique of Embedding Depth Maps into 2D Images

    Institute of Scientific and Technical Information of China (English)

    Kazutake Uehira; Hiroshi Unno; Youichi Takashima

    2014-01-01

    This paper proposes a new technique that is used to embed depth maps into corresponding 2-dimensional (2D) images. Since a 2D image and its depth map are integrated into one type of image format, they can be treated as if they were one 2D image. Thereby, it can reduce the amount of data in 3D images by half and simplify the processes for sending them through networks because the synchronization between images for the left and right eyes becomes unnecessary. We embed depth maps in the quantized discrete cosine transform (DCT) data of 2D images. The key to this technique is whether the depth maps could be embedded into 2D images without perceivably deteriorating their quality. We try to reduce their deterioration by compressing the depth map data by using the differences from the next pixel to the left. We assume that there is only one non-zero pixel at most on one horizontal line in the DCT block because the depth map values change abruptly. We conduct an experiment to evaluate the quality of the 2D images embedded with depth maps and find that satisfactory quality could be achieved.

  8. Measurement of femoral torsion and tibial torsion using magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    A new MRI method for the measurement of femoral torsion and tibial torsion is presented. Axial images were generated using a standard gradient echo sequence (FLASH 2D). Otherwise measurement of femoral and tibial torsion was performed according to an established CT method. The torsion angles measured using MRI were in accordance with the angles measured using the CT method. The MRI method was not more time-consuming than the CT method. In respect of radiation exposure, MRI determination of femoral and tibial torsion should be considered particularly in children and patients who have to undergo repeated torsion measurements. (orig.)

  9. MRI in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Mulert, Christoph [UKE, Hamburg (Germany). Psychiatry Neuroimaging Branch; Shenton, Martha E. (ed.) [Harvard Medical School, Boston, MA (United States). Dept. of Psychiatry and Radiology

    2014-07-01

    This is the first comprehensive textbook on the use of MRI in psychiatry covering imaging techniques, brain systems and a review of findings in different psychiatric disorders. The book is divided into three sections, the first of which covers in detail all the major MRI-based methodological approaches available today, including fMRI, EEG-fMRI, DTI, and MR spectroscopy. In addition, the role of MRI in imaging genetics and combined brain stimulation and imaging is carefully explained. The second section provides an overview of the different brain systems that are relevant for psychiatric disorders, including the systems for perception, emotion, cognition, and reward. The final part of the book presents the MRI findings that are obtained in all the major psychiatric disorders using the previously discussed techniques. Numerous carefully chosen images support the informative text, making this an ideal reference work for all practitioners and trainees with an interest in this flourishing field.

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  11. MRI brain imaging.

    Science.gov (United States)

    Skinner, Sarah

    2013-11-01

    General practitioners (GPs) are expected to be allowed to request MRI scans for adults for selected clinically appropriate indications from November 2013 as part of the expansion of Medicare-funded MRI services announced by the Federal Government in 2011. This article aims to give a brief overview of MRI brain imaging relevant to GPs, which will facilitate explanation of scan findings and management planning with their patients. Basic imaging techniques, common findings and terminology are presented using some illustrative case examples.

  12. Sparse Non-negative Tensor 2D Deconvolution (SNTF2D) for multi channel time-frequency analysis

    DEFF Research Database (Denmark)

    Mørup, Morten; Schmidt, Mikkel N.

    2006-01-01

    We recently introduced two algorithms for sparse non-negative matrix factor 2-D deconvolution (SNMF2D) that are useful for single channel source separation and music transcription. We here extend this approach to the analysis of the log-frequency spectrograms of a multichannel recording. The model...... algorithms are demonstrated to successfully identify the components of both artificially generated as well as real stereo music....

  13. MRI assessment program

    International Nuclear Information System (INIS)

    Usage, cost and efficacy data from the MRI Assessment Program to 30 March 1988 is presented, as a continuation of an earlier analysis. Analysis has been performed on data from 8565 examinations relating to 7997 patients at 4 hospitals. MRI was used mainly for examination of the head and spine. Some details of the follow up studies being conducted on selected patients and disease categories are given. A consensus statement is included which summaries the view of the Technical Committee on the potential applications of MRI in Australia. The MRI unit quench incident at Royal Adelaide Hospital is described. Refs., 10 figs., tabs

  14. MRI for the evaluation of pectus excavatum

    Energy Technology Data Exchange (ETDEWEB)

    Marcovici, Peter A. [University of California, San Diego, Department of Radiology, San Diego, CA (United States); LoSasso, Barry E. [Children' s Hospital and Health Center, Department of Surgery, San Diego, CA (United States); Kruk, Peter; Dwek, Jerry R. [Children' s Hospital and Health Center, Department of Radiology, San Diego, CA (United States)

    2011-06-15

    Pectus excavatum, the most common congenital deformity of the anterior chest wall, is both a cosmetic and functional abnormality. The degree of abnormal chest wall deformity determines its functional effect, particularly its cardiac and pulmonary impact. Although CT scanning is the most widely used cross-sectional imaging technique used to measure the Haller index, the radiation exposure is reason to seek other alternatives. At our institution, we have introduced a rapid MRI technique for this purpose, which utilizes a single-axial 2-D FIESTA acquisition. (orig.)

  15. Pushing the limits of high-resolution functional MRI using a simple high-density multi-element coil design.

    Science.gov (United States)

    Petridou, N; Italiaander, M; van de Bank, B L; Siero, J C W; Luijten, P R; Klomp, D W J

    2013-01-01

    Recent studies have shown that functional MRI (fMRI) can be sensitive to the laminar and columnar organization of the cortex based on differences in the spatial and temporal characteristics of the blood oxygenation level-dependent (BOLD) signal originating from the macrovasculature and the neuronal-specific microvasculature. Human fMRI studies at this scale of the cortical architecture, however, are very rare because the high spatial/temporal resolution required to explore these properties of the BOLD signal are limited by the signal-to-noise ratio. Here, we show that it is possible to detect BOLD signal changes at an isotropic spatial resolution as high as 0.55 mm at 7 T using a high-density multi-element surface coil with minimal electronics, which allows close proximity to the head. The coil comprises of very small, 1 × 2-cm(2) , elements arranged in four flexible modules of four elements each (16-channel) that can be positioned within 1 mm from the head. As a result of this proximity, tissue losses were five-fold greater than coil losses and sufficient to exclude preamplifier decoupling. When compared with a standard 16-channel head coil, the BOLD sensitivity was approximately 2.2-fold higher for a high spatial/temporal resolution (1 mm isotropic/0.4 s), multi-slice, echo planar acquisition, and approximately three- and six-fold higher for three-dimensional echo planar images acquired with isotropic resolutions of 0.7 and 0.55 mm, respectively. Improvements in parallel imaging performance (geometry factor) were up to around 1.5-fold with increasing acceleration factor, and improvements in fMRI detectability (temporal signal-to-noise ratio) were up to around four-fold depending on the distance to the coil. Although deeper lying structures may not benefit from the design, most fMRI questions pertain to the neocortex which lies within approximately 4 cm from the surface. These results suggest that the resolution of fMRI (at 7 T) can approximate levels that are

  16. MRI simulation: end-to-end testing for prostate radiation therapy using geometric pelvic MRI phantoms

    Science.gov (United States)

    Sun, Jidi; Dowling, Jason; Pichler, Peter; Menk, Fred; Rivest-Henault, David; Lambert, Jonathan; Parker, Joel; Arm, Jameen; Best, Leah; Martin, Jarad; Denham, James W.; Greer, Peter B.

    2015-04-01

    To clinically implement MRI simulation or MRI-alone treatment planning requires comprehensive end-to-end testing to ensure an accurate process. The purpose of this study was to design and build a geometric phantom simulating a human male pelvis that is suitable for both CT and MRI scanning and use it to test geometric and dosimetric aspects of MRI simulation including treatment planning and digitally reconstructed radiograph (DRR) generation. A liquid filled pelvic shaped phantom with simulated pelvic organs was scanned in a 3T MRI simulator with dedicated radiotherapy couch-top, laser bridge and pelvic coil mounts. A second phantom with the same external shape but with an internal distortion grid was used to quantify the distortion of the MR image. Both phantoms were also CT scanned as the gold-standard for both geometry and dosimetry. Deformable image registration was used to quantify the MR distortion. Dose comparison was made using a seven-field IMRT plan developed on the CT scan with the fluences copied to the MR image and recalculated using bulk electron densities. Without correction the maximum distortion of the MR compared with the CT scan was 7.5 mm across the pelvis, while this was reduced to 2.6 and 1.7 mm by the vendor’s 2D and 3D correction algorithms, respectively. Within the locations of the internal organs of interest, the distortion was phantom allows end-to-end testing of the MRI simulation workflow with comparison to the gold-standard CT based process. MRI simulation was found to be geometrically accurate with organ dimensions, dose distributions and DRR based setup within acceptable limits compared to CT.

  17. 2D nanostructures for water purification: graphene and beyond.

    Science.gov (United States)

    Dervin, Saoirse; Dionysiou, Dionysios D; Pillai, Suresh C

    2016-08-18

    Owing to their atomically thin structure, large surface area and mechanical strength, 2D nanoporous materials are considered to be suitable alternatives for existing desalination and water purification membrane materials. Recent progress in the development of nanoporous graphene based materials has generated enormous potential for water purification technologies. Progress in the development of nanoporous graphene and graphene oxide (GO) membranes, the mechanism of graphene molecular sieve action, structural design, hydrophilic nature, mechanical strength and antifouling properties and the principal challenges associated with nanopore generation are discussed in detail. Subsequently, the recent applications and performance of newly developed 2D materials such as 2D boron nitride (BN) nanosheets, graphyne, molybdenum disulfide (MoS2), tungsten chalcogenides (WS2) and titanium carbide (Ti3C2Tx) are highlighted. In addition, the challenges affecting 2D nanostructures for water purification are highlighted and their applications in the water purification industry are discussed. Though only a few 2D materials have been explored so far for water treatment applications, this emerging field of research is set to attract a great deal of attention in the near future. PMID:27506268

  18. KOREAN MOBILE OPERATORS' VALUE MAP FOR LTE D2D

    Directory of Open Access Journals (Sweden)

    Taisiya Kim

    2015-04-01

    Full Text Available Managing the wireless data traffic is a main concern for mobile network operators in Information of Things (IoT environment. Long Term Evolution Device to Device (LTE D2D is regarding as a solution for the spectrum problem. It will bring an impact on providers and the whole mobile environment. The main purpose of this study is to analyze the role of key players, who share spectrum with mobile operators, and to present the value map of relationship among Korean mobile operators and other key players in LTE D2D discovery (commercial channel, as complicated relationships of key players are expected. Then, this study suggests scenario for ‘Targeted Advertising’ service of LTE D2D. LTE D2D is early discussion stage and scenario has limitation of specific business model. However, results of this study are significant for the present stage and provide implications for future researches on strategies for LTE D2D environment.

  19. Failure Mechanism of True 2D Granular Flows

    CERN Document Server

    Nguyen, Cuong T; Fukagawa, R

    2015-01-01

    Most previous experimental investigations of two-dimensional (2D) granular column collapses have been conducted using three-dimensional (3D) granular materials in narrow horizontal channels (i.e., quasi-2D condition). Our recent research on 2D granular column collapses by using 2D granular materials (i.e., aluminum rods) has revealed results that differ markedly from those reported in the literature. We assume a 2D column with an initial height of h0 and initial width of d0, a defined as their ratio (a =h0/d0), a final height of h , and maximum run-out distance of d . The experimental data suggest that for the low a regime (a 0.65), the ratio of a to (d-d0)/d0, h0/h , or d/d0 is expressed by power-law relations. In particular, the following power-function ratios (h0/h=1.42a^2/3 and d/d0=4.30a^0.72) are proposed for every a >0.65. In contrast, the ratio (d-d0)/d0=3.25a^0.96 only holds for 0.651.5. In addition, the influence of ground contact surfaces (hard or soft beds) on the final run-out distance and destru...

  20. The NH$_2$D hyperfine structure revealed by astrophysical observations

    CERN Document Server

    Daniel, F; Punanova, A; Harju, J; Faure, A; Roueff, E; Sipilä, O; Caselli, P; Güsten, R; Pon, A; Pineda, J E

    2016-01-01

    The 1$_{11}$-1$_{01}$ lines of ortho and para--NH$_2$D (o/p-NH$_2$D), respectively at 86 and 110 GHz, are commonly observed to provide constraints on the deuterium fractionation in the interstellar medium. In cold regions, the hyperfine structure due to the nitrogen ($^{14}$N) nucleus is resolved. To date, this splitting is the only one which is taken into account in the NH$_2$D column density estimates. We investigate how the inclusion of the hyperfine splitting caused by the deuterium (D) nucleus affects the analysis of the rotational lines of NH$_2$D. We present 30m IRAM observations of the above mentioned lines, as well as APEX o/p-NH$_2$D observations of the 1$_{01}$-0$_{00}$ lines at 333 GHz. The hyperfine spectra are first analyzed with a line list that only includes the hyperfine splitting due to the $^{14}$N nucleus. We find inconsistencies between the line widths of the 1$_{01}$-0$_{00}$ and 1$_{11}$-1$_{01}$ lines, the latter being larger by a factor of $\\sim$1.6$\\pm0.3$. Such a large difference is...

  1. Ultrafast 2D NMR: An Emerging Tool in Analytical Spectroscopy

    Science.gov (United States)

    Giraudeau, Patrick; Frydman, Lucio

    2014-06-01

    Two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy is widely used in chemical and biochemical analyses. Multidimensional NMR is also witnessing increased use in quantitative and metabolic screening applications. Conventional 2D NMR experiments, however, are affected by inherently long acquisition durations, arising from their need to sample the frequencies involved along their indirect domains in an incremented, scan-by-scan nature. A decade ago, a so-called ultrafast (UF) approach was proposed, capable of delivering arbitrary 2D NMR spectra involving any kind of homo- or heteronuclear correlation, in a single scan. During the intervening years, the performance of this subsecond 2D NMR methodology has been greatly improved, and UF 2D NMR is rapidly becoming a powerful analytical tool experiencing an expanded scope of applications. This review summarizes the principles and main developments that have contributed to the success of this approach and focuses on applications that have been recently demonstrated in various areas of analytical chemistry—from the real-time monitoring of chemical and biochemical processes, to extensions in hyphenated techniques and in quantitative applications.

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  3. 2D materials for photon conversion and nanophotonics

    Science.gov (United States)

    Tahersima, Mohammad H.; Sorger, Volker J.

    2015-09-01

    The field of two-dimensional (2D) materials has the potential to enable unique applications across a wide range of the electromagnetic spectrum. While 2D-layered materials hold promise for next-generation photon-conversion intrinsic limitations and challenges exist that shall be overcome. Here we discuss the intrinsic limitations as well as application opportunities of this new class of materials, and is sponsored by the NSF program Designing Materials to Revolutionize and Engineer our Future (DMREF) program, which links to the President's Materials Genome Initiative. We present general material-related details for photon conversion, and show that taking advantage of the mechanical flexibility of 2D materials by rolling MoS2/graphene/hexagonal boron nitride stack to a spiral solar cell allows for solar absorption up to 90%.

  4. Graphene based 2D-materials for supercapacitors

    Science.gov (United States)

    Palaniselvam, Thangavelu; Baek, Jong-Beom

    2015-09-01

    Ever-increasing energy demands and the depletion of fossil fuels are compelling humanity toward the development of suitable electrochemical energy conversion and storage devices to attain a more sustainable society with adequate renewable energy and zero environmental pollution. In this regard, supercapacitors are being contemplated as potential energy storage devices to afford cleaner, environmentally friendly energy. Recently, a great deal of attention has been paid to two-dimensional (2D) nanomaterials, including 2D graphene and its inorganic analogues (transition metal double layer hydroxides, chalcogenides, etc), as potential electrodes for the development of supercapacitors with high electrochemical performance. This review provides an overview of the recent progress in using these graphene-based 2D materials as potential electrodes for supercapacitors. In addition, future research trends including notable challenges and opportunities are also discussed.

  5. Simultaneous 2D Strain Sensing Using Polymer Planar Bragg Gratings

    Directory of Open Access Journals (Sweden)

    Manuel Rosenberger

    2015-02-01

    Full Text Available We demonstrate the application of polymer planar Bragg gratings for multi-axial strain sensing and particularly highlight simultaneous 2D strain measurement. A polymer planar Bragg grating (PPBG fabricated with a single writing step in bulk polymethylmethacrylate is used for measuring both tensile and compressive strain at various angles. It is shown that the sensitivity of the PPBG strongly depends on the angle between the optical waveguide into which the grating is inscribed and the direction along which the mechanical load is applied. Additionally, a 2D PPBG fabricated by writing two Bragg gratings angularly displaced from each other into a single polymer platelet is bonded to a stainless steel plate. The two reflected wavelengths exhibit different sensitivities while tested toward tensile and compressive strain. These characteristics make 2D PPBG suitable for measuring multi-axial tensile and compressive strain.

  6. Cluster algebras in Scattering Amplitudes with special 2D kinematics

    CERN Document Server

    Torres, Marcus A C

    2013-01-01

    We study the cluster algebra of the kinematic configuration space $Conf_n(\\mathbb{P}^3)$ of a n-particle scattering amplitude restricted to the special 2D kinematics. We found that the n-points two loop MHV remainder function found in special 2D kinematics depend on a selection of \\XX-coordinates that are part of a special structure of the cluster algebra related to snake triangulations of polygons. This structure forms a necklace of hypercubes beads in the corresponding Stasheff polytope. Furthermore in $n = 12$, the cluster algebra and the selection of \\XX-coordinates in special 2D kinematics replicates the cluster algebra and the selection of \\XX-coordinates of $n=6$ two loop MHV amplitude in 4D kinematics.

  7. 2D growth processes: SLE and Loewner chains

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Michel [Service de Physique Theorique de Saclay, CE-Saclay, 91191 Gif-sur-Yvette (France) and Laboratoire de Physique Theorique, Ecole Normale Superieure, 24 rue Lhomond, 75005 Paris (France)]. E-mail: michel.bauer@cea.fr; Bernard, Denis [Service de Physique Theorique de Saclay, CE-Saclay, 91191 Gif-sur-Yvette (France) and Laboratoire de Physique Theorique, Ecole Normale Superieure, 24 rue Lhomond, 75005 Paris (France)]. E-mail: denis.bernard@cea.fr

    2006-10-15

    This review provides an introduction to two dimensional growth processes. Although it covers a variety of processes such as diffusion limited aggregation, it is mostly devoted to a detailed presentation of stochastic Schramm-Loewner evolutions (SLE) which are Markov processes describing interfaces in 2D critical systems. It starts with an informal discussion, using numerical simulations, of various examples of 2D growth processes and their connections with statistical mechanics. SLE is then introduced and Schramm's argument mapping conformally invariant interfaces to SLE is explained. A substantial part of the review is devoted to reveal the deep connections between statistical mechanics and processes, and more specifically to the present context, between 2D critical systems and SLE. Some of the remarkable properties of SLE are explained, together with the tools for computing with it. This review has been written with the aim of filling the gap between the mathematical and the physical literature on the subject.

  8. UPLAND EROSION MODELING WITH CASC2D-SED

    Institute of Scientific and Technical Information of China (English)

    Pierre JULIEN; Rosalía ROJAS

    2002-01-01

    Developed at Colorado State University, CASC2D-SED is a physically-based model simulating the hydrologic response of a watershed to a distributed rainfall field. The time-dependent processes include:precipitation, interception, infiltration, surface runoff and channel routing, upland erosion, transport and sedimentation. CASC2D-SED is applied to Goodwin Creek, Mississippi. The watershed covers 21 km2and has been extensively monitored both at the outlet and at several internal locations by the ARS-NSL at Oxford, MS. The model has been calibrated and validated using rainfall data from 16 meteorological stations, 6 stream gauging stations and 6 sediment gauging stations. Sediment erosion/deposition rates by size fraction are predicted both in space and time. Geovisualization, a powerful data exploration technique based on GIS technology, is used to analyze and display the dynamic output time series generated by the CASC2D-SED model.

  9. Design and Realization of Dynamic Obstacle on URWPSSim2D

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2013-07-01

    Full Text Available Simulation system is charged with the strategy validation and dual team meets, and as the 2-dimensional simulation platform for underwater robotic fish game, URWPGSim2D is the assigned platform for Chinese underwater robot contest and Robot cup underwater program. By now on URWPGSim2D, there is only static obstacles,thus short of changeableness. In order to improve the changeableness and innovation of robotic fish contest, to extend the space for the programming of contest strategy, and to increase the interest, this paper study the design of dynamic obstacles on URWPGSim2D, and design and implement two kinds of dynamic obstacles, which are the evadible dynamic obstacle and the forcing dribbling obstacle.  

  10. 2D bifurcations and Newtonian properties of memristive Chua's circuits

    Science.gov (United States)

    Marszalek, W.; Podhaisky, H.

    2016-01-01

    Two interesting properties of Chua's circuits are presented. First, two-parameter bifurcation diagrams of Chua's oscillatory circuits with memristors are presented. To obtain various 2D bifurcation images a substantial numerical effort, possibly with parallel computations, is needed. The numerical algorithm is described first and its numerical code for 2D bifurcation image creation is available for free downloading. Several color 2D images and the corresponding 1D greyscale bifurcation diagrams are included. Secondly, Chua's circuits are linked to Newton's law φ ''= F(t,φ,φ')/m with φ=\\text{flux} , constant m > 0, and the force term F(t,φ,φ') containing memory terms. Finally, the jounce scalar equations for Chua's circuits are also discussed.

  11. MRI of Listeria rhombencephalitis

    International Nuclear Information System (INIS)

    A case of Listeria rhombencephalitis in a patient, who was evaluated by MRI, is reported. MRI shows areas of high signal intensity on T2-weighted images in the rhombencephalon and confirmed the clinical diagnosis of a brainstem affection by Listeria monocytogenes. (orig.)

  12. Getting an MRI

    Medline Plus

    Full Text Available ... School Butterflies? Read This Chloe & Nurb Meet The Brain (Movie) Quiz: Do You Need a Flu Shot? Got Homework? Here's Help White House Lunch Recipes Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) ...

  13. Getting an MRI

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A ...

  14. Play the MRI Game

    Science.gov (United States)

    ... Play MRI the Magnetic Miracle Game About the game In the MRI imaging technique, strong magnets and radio waves are used for getting images of inner organs made of soft tissue, compared to X-ray imaging where you get images of hard tissue, ...

  15. MRI of atherosclerose

    NARCIS (Netherlands)

    te Boekhorst, B.C.M.

    2010-01-01

    This thesis is aimed at visualization of atherosclerotic plaques with MRI. Noninvasive screening for subclinical atherosclerosis as well as detection of high-risk atherosclerotic plaque in an established population of cardiovascular patients is important for patient management. Anatomical MRI utiliz

  16. W$_{\\infty}$ structures of 2D string theory

    CERN Document Server

    Hamada, K J

    1996-01-01

    The Ward identities of the W_{\\infty} symmetry in 2D string theory in the tachyon background are studied in the continuum approach. Comparing the solutions with the matrix model results, it is verified that 2D string amplitudes are different from the matrix model amplitudes only by the external leg factors even in higher genus. This talk is based on the recent work [1] and also [2] for the c_M <1 model. (Talk given at the workshop on ``Frontiers in Quantum Field Theory'', Osaka, Japan, December 1995.)

  17. CH2D+, the Search for the Holy Grail

    Science.gov (United States)

    Roueff, Evelyne; Gerin, Maryvonne; Lis, Dariusz C.; Wootten, Alwyn; Marcelino, Nuria; Cernicharo, Jose; Tercero, Belen

    2013-10-01

    CH2D+, the singly deuterated counterpart of CH3+, offers an alternative way to mediate formation of deuterated species at temperatures of several tens of Kelvin, as compared to the release of deuterated species from grains. We report a longstanding observational search for this molecular ion, whose rotational spectroscopy is not yet completely secure. We summarize the main spectroscopic properties of this molecule and discuss the chemical network leading to the formation of CH2D+, with explicit account of the ortho/para forms of H2, H3+, and CH3+. Astrochemical models support the presence of this molecular ion in moderately warm environments at a marginal level.

  18. Isotropic 2D quadrangle meshing with size and orientation control

    KAUST Repository

    Pellenard, Bertrand

    2011-12-01

    We propose an approach for automatically generating isotropic 2D quadrangle meshes from arbitrary domains with a fine control over sizing and orientation of the elements. At the heart of our algorithm is an optimization procedure that, from a coarse initial tiling of the 2D domain, enforces each of the desirable mesh quality criteria (size, shape, orientation, degree, regularity) one at a time, in an order designed not to undo previous enhancements. Our experiments demonstrate how well our resulting quadrangle meshes conform to a wide range of input sizing and orientation fields.

  19. Design of the LRP airfoil series using 2D CFD

    DEFF Research Database (Denmark)

    Zahle, Frederik; Bak, Christian; Sørensen, Niels N.;

    2014-01-01

    This paper describes the design and wind tunnel testing of a high-Reynolds number, high lift airfoil series designed for wind turbines. The airfoils were designed using direct gradient- based numerical multi-point optimization based on a Bezier parameterization of the shape, coupled to the 2D...... Navier-Stokes flow solver EllipSys2D. The resulting airfoils, the LRP2-30 and LRP2-36, achieve both higher operational lift coefficients and higher lift to drag ratios compared to the equivalent FFA-W3 airfoils....

  20. EEG simulation by 2D interconnected chaotic oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Kubany, Adam, E-mail: adamku@bgu.ac.i [Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel); Mhabary, Ziv; Gontar, Vladimir [Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel)

    2011-01-15

    Research highlights: ANN of 2D interconnected chaotic oscillators is explored for EEG simulation. An inverse problem solution (PRCGA) is proposed. Good matching between the simulated and experimental EEG signals has been achieved. - Abstract: An artificial neuronal network composed by 2D interconnected chaotic oscillators is explored for brain waves (EEG) simulation. For the inverse problem solution a parallel real-coded genetic algorithm (PRCGA) is proposed. In order to conduct thorough comparison between the simulated and target signal characteristics, a spectrum analysis of the signals is undertaken. A good matching between the theoretical and experimental EEG signals has been achieved. Numerical results of calculations are presented and discussed.

  1. Self-dual Strings and 2D SYM

    CERN Document Server

    Hosomichi, Kazuo

    2014-01-01

    We study the system of M2-branes suspended between parallel M5-branes using ABJM model with a natural half-BPS boundary condition. For small separation between M5-branes, the worldvolume theory is shown to reduce to a 2D N=(4,4) super Yang-Mills theory with some similarity to q-deformed Yang-Mills theory. The gauge coupling is related to the position of the branes in an interesting manner. The theory is considerably different from the 2D theory proposed for multiple "M-strings". We make a detailed comparison of elliptic genus of the two descriptions and find only a partial agreement.

  2. 2D-ACAR investigations of PPT aramid fibres

    International Nuclear Information System (INIS)

    2D-ACAR spectra of PPT (poly(p-phenylene terephthalamide)) fibres which contain structural elongated open spaces in the crystallographic unit cell show a p-Ps peak with an elliptical cross-section and side lobes. Peak broadening suggests dimensions of ∝14-17 by 7-9 A for the open spaces and indicates some penetration of Ps into the interlayer spacing. The side lobes can be related to projected reciprocal lattice points and indicate Ps delocalization. 2D-ACAR has also been used to study the evolution of water release from the open spaces. (orig.)

  3. EEG simulation by 2D interconnected chaotic oscillators

    International Nuclear Information System (INIS)

    Research highlights: → ANN of 2D interconnected chaotic oscillators is explored for EEG simulation. → An inverse problem solution (PRCGA) is proposed. → Good matching between the simulated and experimental EEG signals has been achieved. - Abstract: An artificial neuronal network composed by 2D interconnected chaotic oscillators is explored for brain waves (EEG) simulation. For the inverse problem solution a parallel real-coded genetic algorithm (PRCGA) is proposed. In order to conduct thorough comparison between the simulated and target signal characteristics, a spectrum analysis of the signals is undertaken. A good matching between the theoretical and experimental EEG signals has been achieved. Numerical results of calculations are presented and discussed.

  4. Quantum process tomography by 2D fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Marcus, Andrew H. [Department of Chemistry and Biochemistry, Oregon Center for Optics, Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403 (United States); Aspuru-Guzik, Alán [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2015-06-07

    Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter Γ of the doubly excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

  5. CH2D+, the Search for the Holy Grail

    CERN Document Server

    Roueff, E; Lis, D C; Wootten, A; Marcelino, N; cernicharo, J; Tercero, B

    2013-01-01

    CH2D+, the singly deuterated counterpart of CH3+, offers an alternative way to mediate formation of deuterated species at temperatures of several tens of K, as compared to the release of deuterated species from grains. We report a longstanding observational search for this molecular ion, whose rotational spectroscopy is not yet completely secure. We summarize the main spectroscopic properties of this molecule and discuss the chemical network leading to the formation of CH2D+, with explicit account of the ortho/para forms of H2, H3+ and CH3+. Astrochemical models support the presence of this molecular ion in moderately warm environments at a marginal level.

  6. GENERALIZED VARIATIONAL OPTIMAZATION ANALYSIS FOR 2-D FLOW FIELD

    Institute of Scientific and Technical Information of China (English)

    HUANG Si-xun; XU Ding-hua; LAN Wei-ren; TENG Jia-jun

    2005-01-01

    The Variational Optimization Analysis Method (VOAM) for 2-D flow field suggested by Sasaki was reviewed first. It is known that the VOAM can be used efficiently in most cases. However, in the cases where there are high frequency noises in 2-D flow field, it appears to be inefficient. In the present paper, based on Sasaki's VOAM, a Generalized Variational Optimization Analysis Method (GVOAM) was proposed with regularization ideas, which could deal well with flow fields containing high frequency noises. A numerical test shows that observational data can be both variationally optimized and filtered, and therefore the GVOAM is an efficient method.

  7. QSAR Models for P-450 (2D6) Substrate Activity

    DEFF Research Database (Denmark)

    Ringsted, Tine; Nikolov, Nikolai Georgiev; Jensen, Gunde Egeskov;

    2009-01-01

    drugs and other chemicals. A training set of 747 chemicals primarily based on in vivo human data for the CYP isoenzyme 2D6 was collected from the literature. QSAR models focusing on substrate/non substrate activity were constructed by the use of MultiCASE, Leadscope and MDL quantitative structure......Human Cytochrome P450 (CYP) is a large group of enzymes that possess an essential function in metabolising different exogenous and endogenous compounds. Humans have more than 50 different genes encoding CYP enzymes, among these a gene encoding for the CYP isoenzyme 2D6, a CYP able to metabolise...

  8. SKIMO: corto de animación 2D

    OpenAIRE

    VALERO BALLESTER, AIDA AMPARO

    2015-01-01

    El siguiente Trabajo Final de Grado llamado “Skimo” consiste en un teaser de animación 2D enfocado a ser finalizado el próximo año durante la realización del Diploma en Animación de personajes 2D del Máster de animación. Realizado en solitario como reto personal durante el curso presente, siendo la primera vez que trabajaba la animación. Para este proyecto he realizado toda la preproducción (layout, animática, storyboard, diseño de personajes, fondos, etc), animación en pape...

  9. Transmission properties of 2D metamaterial photonic crystals

    Science.gov (United States)

    Mejía-Salazar, Jorge; Porras-Montenegro, Nelson

    2014-03-01

    By using the finite difference time domain technique, we have performed a theoretical study of the transmission properties in 2D photonic crystals composed by circular cilyndrical metamaterial rods. Numerical transmission spectra was compared with its corresponding photonic band structure in the case of an infinite periodic 2D array obtaining a very good agreement. On the other hand, we have characterized the corresponding symmetries for this system and the results were compared with its corresponding conventional plasmonic metamaterial counterpart. J.R. M-S is funded by the Colombian Agency COLCIENCIAS.

  10. Nomenclature for human CYP2D6 alleles.

    Science.gov (United States)

    Daly, A K; Brockmöller, J; Broly, F; Eichelbaum, M; Evans, W E; Gonzalez, F J; Huang, J D; Idle, J R; Ingelman-Sundberg, M; Ishizaki, T; Jacqz-Aigrain, E; Meyer, U A; Nebert, D W; Steen, V M; Wolf, C R; Zanger, U M

    1996-06-01

    To standardize CYP2D6 allele nomenclature, and to conform with international human gene nomenclature guidelines, an alternative to the current arbitrary system is described. Based on recommendations for human genome nomenclature, we propose that alleles be designated by CYP2D6 followed by an asterisk and a combination of roman letters and arabic numerals distinct for each allele with the number specifying the key mutation and, where appropriate, a letter specifying additional mutations. Criteria for classification as a separate allele and protein nomenclature are also presented. PMID:8807658

  11. CYP2D6基因与药物代谢%CYP2D6 gene and drug metabolism

    Institute of Scientific and Technical Information of China (English)

    施安国

    2003-01-01

    细胞色素P-450(CYP)中的CYP2D6酶在抗抑郁药、安定药及某些抗心律失常药的代谢中起重要作用,CYP2D6基因位于22号常染色体上为隐性遗传,CYP2D6基因呈多态性约有70余种等位基因变异型,也存在特异人群差别,因而导致所编码的酶活性不同,这些数据有助于理解药物代谢的个体差异、有助于预测药物之间的相互作用.

  12. Overlapping patterns of brain activation to food and cocaine cues in cocaine abusers: association to striatal D2/D3 receptors

    OpenAIRE

    Tomasi, Dardo; Wang, Gene-Jack; Wang, Ruiliang; Caparelli, Elisabeth C.; Logan, Jean; Volkow, Nora D.

    2014-01-01

    Cocaine, through its activation of dopamine (DA) signaling, usurps pathways that process natural rewards. However, the extent to which there is overlap between the networks that process natural and drug rewards and whether DA signaling associated with cocaine abuse influences these networks have not been investigated in humans. We measured brain activation responses to food and cocaine cues with fMRI, and D2/D3 receptors in the striatum with [11C]raclopride and PET in 20 active cocaine abuser...

  13. Use of inflammatory factors combined with multi-slice spiral computer tomography for preoperative staging and operative strategy in colon cancer%三种不同炎性因子联合多层螺旋CT对结肠癌术前分期与术式预测的比较研究

    Institute of Scientific and Technical Information of China (English)

    汪晓东; 欧阳书睿; 吕东昊; 刘丹; 李立

    2010-01-01

    Objective To determine the clinical value of C-reactive protein(CRP), fibrinogen (FIB), or serum amyloid A protein (SAA) combined with 64 multi-slice computed tomography (MSCT) for preoperative staging and operative strategy in colon cancer. Methods Patients with colon cancer were prospectively enrolled at the West China Hospital of Sichuan University from November 2007 to July 2009,and were equally randomized into 3 groups undergoing different preoperative evaluation: MSCT combined with CRP(CRP group), MSCT combined with FIB (FIB group), and MSCT combined with SAA (SAA group). The agreement between preoperative staging and postoperative pathologic staging and that between expected surgical procedure and procedure adopted were compared. Results Baseline characteristics among three groups were similar(P>0.05). In CRP group, the accuracies of preoperative staging T, N, M and TNM were 65.7%, 72.4%, 100% and 66.7%, respectively. In FIB group, the accuracies of preoperative staging T, N, M and TNM were 71.4%, 74.3%, 99.0% and 65.7%, respectively. In SAA group, the accuracies of preoperative staging T, N, M and TNM were 60.0%, 55.2%, 96.2%and 51.4%, respectively. The accuracies of N and TNM staging in CRP group and FIB group were significantly higher than those in SAA group(P<0.05). However, there were no significant differences between FIB and CRP group(P>0.05). There were no significant differences in accuracy of predicting surgical procedures among three groups(93.3%, 92.3% and 87.6%, P>0.05). Conclusion Combined assessment of MSCT and CRP or FIB may improve the accuracy of preoperative staging and procedure prediction, and is superior to MSCT combined with SAA.%目的 探讨纤维蛋白原(FIB)、血清淀粉样蛋白(SAA)和C反应蛋白(CRP)联合64排多层螺旋CT(MSCT)在结肠癌术前评估与术式预测中的临床价值.方法 前瞻性纳入2007年11月至2009年7月期间四川大学华西医院结直肠外科专业组

  14. A study of the relationship between the portal vein thrombosis and clinical progression in portal hypertension on multi-slice CT portal venography%MSCT门静脉成像对门脉高压症中门静脉血栓形成与临床病情关系的研究

    Institute of Scientific and Technical Information of China (English)

    王克扬; 贺文; 赵丽琴

    2012-01-01

    目的:采用64排螺旋CT门静脉成像探讨肝硬化(LC)门脉高压症(PH)门静脉血栓(PVT)形成对临床病程进展的影响.方法:对183例LC患者行CT检查,其中并发PVT者109例,无血栓者74例,应用MIP、MPR、CPR方法多角度多层面显示门静脉系统血管结构和侧支循环,测量血栓范围和狭窄程度.分别比较PVT组和对照组之间、不同Child-Pugh(CP)分级亚组间的肝功能、凝血功能、门脉系统血管宽度、侧支循环、脾脏大小的差异,分析PVT组各影像特之间及其与肝功能的相关性.结果:PVT组与对照组间的血清总胆红素、门静脉和脾静脉宽度、脾面积、脾/胃-肾分流的差异均有统计学意义(t=-2.830、P=0.005;t=3.576、P0.05);前腹壁静脉曲张在各分级中差异均有统计学意义(χ2=4.485,P=0.034).PVT组肠系膜上静脉血栓与肠壁水肿有一定的相关性(r=0.227,P=0.018);脾静脉与胃左静脉宽度有一定的相关性(r=0.371,P<0.001).结论:门静脉血栓形成与门脉高压症病情密切相关,可能为促进肝硬化临床病程发展的重要因素.%Objective: To investigate the effect of the portal vein thrombosis (PVT) on disease progression of liver cirrhosis (LC) portal hypertension (PH) using CT portal venography (CTPV). Methods:183 patients with LC,divided into PVT group (n = 109) and control group (n = 74) ,were performed by multi slice CT (MSCT). MIP,MPR and CPR were used to display the portal venous system and collateral circulations,and to measure the thrombosis as well as stenosis. The liver function,coagulation function,the imaging features of portal veins and PVT were compared between these two groups, then in different Child Pugh (CP) classifications. Results. There were significant differences between the two groups in total serum bilirubin,the width of main portal vein (MPV) and spleen vein (SPV),sectional area of spleen,splenic or gastric re nal shunt (t = - 2. 830,P = 0. 005 ; t=3. 576,P<0. 001;t=0. 780

  15. The value of multi-slice spiral computed tomography portography in assessing severity of liver cirrhosis and predicting episode risks of hepatic encephalopathy%多层螺旋CT门静脉造影评估肝硬化病变程度及预测肝性脑病发病风险的价值

    Institute of Scientific and Technical Information of China (English)

    刘文娜; 王剑; 冯义朝; 戴光荣; 宁涛

    2014-01-01

    Objective To explore the clinical value of multi-slice spiral computed tomography portography (MSCTP) in assessing severity of liver cirrhosis and predicting episode risks of hepatic encephalopathy (HE).Methods Eighty-six patients with liver cirrhosis who were hospitalized in the Department of Gastroenterology at the Affiliated Hospital of Yan'an University were included in the study.All patients underwent 64-slice MSCTP to grade the portal vein anatomy.The West Haven criteria were used for semi-quantitative assessment of each patient's mental state.The Child-Pugh grading system was used to assess the extent of cirrhosis.Comparison of measurement data between multiple groups was made by one-way ANOVA analysis,and comparison of such between two groups was made by the Mann-Whitney U test,Ranked data were compared with the rank-sum test,and count data were compared by the Chi-Square test.Correlation analysis was performed with Spearman's correlation test.Results Comparison of the HE grade Ⅲ group and the HE grade Ⅰ group showed significant differences between the two in the diameters of left gastric vein,the splenic vein,the intrahepatic left portal vein and the intrahepatic right portal vein (P < 0.05).Comparison of the Child-Pugh grade C group and the Child-Pugh grade A group showed significant differences between the two in diameters of the left gastric vein,the splenic vein,the intrahepatic left portal vein and the intrahepatic right portal vein (P < 0.05).The diameters of the main portal vein were not significantly different between the ChildPugh grades and HE classifications (P > 0.05).The results of MSCTP did show significant differences between different HE classifications in patients with liver cirrhosis and the rate of formation of portal vein thrombosis and fistulas of the hepatic artery-portal vein (P < 0.05),.but no significant differences with the esophageal and gastric varices,varicose veins around the esophagus,and periumbilical varicose

  16. Influence of Isotope Effects on Product Polarizations of N(2D)+D2,N(2D)+H2 and N(2D)+HD Reactive Systems

    Institute of Scientific and Technical Information of China (English)

    NIE Shan-shan; CHU Tian-shu

    2012-01-01

    To figure out the influence of isotope effect on product polarizations of the N(2D)+D2 reactive system and its isotope variants,quasi-classical trajectory(QCT) calculation was performed on Ho's potential energy surfacc(PES) of 2A" state.Product polarizations such as product distributions ofP(θr),P(φr) and P(θr,φr),as well as the generalized polarization-dependent differential cross sections(PDDCSs) were discussed and compared in detail among the four product channels of the title reactions.Both the intermolecular and intramolecular isotope effects were proved to be influential on product polarizations.

  17. Wilson loop in 2d noncommutative gauge theories

    OpenAIRE

    Valtancoli, Paolo

    2009-01-01

    We reconsider the perturbative expansion of the Wilson loop in 2d noncommutative gauge theories, using an improved integration method. For the class of maximally crossed diagrams in the $\\theta \\to \\infty$ limit we find an intriguing formula, easily generalizable to all orders in perturbation theory.

  18. The 2dF Galaxy Redshift Survey: Preliminary Results

    OpenAIRE

    Maddox, S.

    1997-01-01

    Spectroscopic observations for a new survey of 250 000 galaxy redshifts are underway, using the 2dF instrument at the AAT. The input galaxy catalogue and commissioning data are described. The first result from the preliminary data is a new estimate of the galaxy luminosity function at =0.1.

  19. H on He: sticking and 2d-superfluidity

    International Nuclear Information System (INIS)

    The sticking coefficient, which governs the sticking time τs, is discussed for high surface-coverage conditions. We point out that τs must remain large compared to a characteristic vortex diffusion time, if the system is to display 2d-superfluidity

  20. 2D Static Light Scattering for Dairy Based Applications

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke

    Throughout this thesis we investigate a recently introduced optical technique denoted 2D static light scattering (2DSLS). The technique is remote sensing, non-invasive, highly flexible, and appears to be well suited for in-line process control. Moreover, the output signal contains contributions...

  1. CFD code comparison for 2D airfoil flows

    DEFF Research Database (Denmark)

    Sørensen, Niels N.; Méndez, B.; Muñoz, A.;

    2016-01-01

    The current paper presents the effort, in the EU AVATAR project, to establish the necessary requirements to obtain consistent lift over drag ratios among seven CFD codes. The flow around a 2D airfoil case is studied, for both transitional and fully turbulent conditions at Reynolds numbers of 3 × ...

  2. Fiber Drawn 2D Polymeric Photonic Crystal THz Filters

    DEFF Research Database (Denmark)

    Stecher, Matthias; Jansen, Christian; Ahmadi-Boroujeni, Mehdi;

    2012-01-01

    In this paper, we report on different polymeric 2D photonic crystal filters for THz frequencies which are fabricated by a standard fiber drawing technique. The bandstop filters were simulated and designed by the generalized multipole technique (GMT). The frequency and angle dependent transmission...

  3. Horns Rev II, 2D-Model Tests

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Brorsen, Michael

    This report is an extension of the study presented in Lykke Andersen and Brorsen, 2006 and includes results from the irregular wave tests, where Lykke Andersen & Brorsen, 2006 focused on regular waves. The 2D physical model tests were carried out in the shallow wave flume at Dept. of Civil...

  4. 2D InP photonic crystal fabrication process development

    NARCIS (Netherlands)

    Rong, B.; Van der Drift, E.; Van der Heijden, R.W.; Salemink, H.W.M.

    2006-01-01

    We have developed a reliable process to fabricate high quality 2D air-hole and dielectric column InP photonic crystals with a high aspect ratio on a STS production tool using ICP N2+Cl2 plasma. The photonic crystals have a triangular lattice with lattice constant of 400 nm and air-hole and dielectri

  5. Interactive Exploratory Visualization of 2D Vector Fields

    NARCIS (Netherlands)

    Isenberg, Tobias; Everts, Maarten H.; Grubert, Jens; Carpendale, Sheelagh

    2008-01-01

    In this paper we present several techniques to interactively explore representations of 2D vector fields. Through a set of simple hand postures used on large, touch-sensitive displays, our approach allows individuals to custom-design glyphs (arrows, lines, etc.) that best reveal patterns of the unde

  6. CANONICAL COMPUTATIONAL FORMS FOR AR 2-D SYSTEMS

    NARCIS (Netherlands)

    ROCHA, P; WILLEMS, JC

    1990-01-01

    A canonical form for AR 2-D systems representations is introduced. This yields a method for computing the system trajectories by means of a line-by-line recursion, and displays some relevant information about the system structure such as the choice of inputs and initial conditions.

  7. Resolution deconvolution method applied to 2D-ACAR measurements

    International Nuclear Information System (INIS)

    An inexpensive way to achieve high resolution 2D-ACAR measurements is to utilize resolution deconvolution techniques. We developed a resolution deconvolution method which avoids noise amplification and is applicable to the 3D reconstruction method using Fourier-Bessel transforms. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. The toroidal Hausdorff dimension of 2d Euclidean quantum gravity

    DEFF Research Database (Denmark)

    Ambjorn, Jan; Budd, Timothy George

    2013-01-01

    The lengths of shortest non-contractible loops are studied numerically in 2d Euclidean quantum gravity on a torus coupled to conformal field theories with central charge less than one. We find that the distribution of these geodesic lengths displays a scaling in agreement with a Hausdorff dimensi...

  9. 2D kinematics of simulated disc merger remnants

    NARCIS (Netherlands)

    Jesseit, Roland; Naab, Thorsten; Peletier, Reynier F.; Burkert, Andreas

    2007-01-01

    We present a 2D kinematic analysis for a sample of simulated binary disc merger remnants with mass ratios 1:1 and 3:1. For the progenitor discs we used pure stellar models as well as models with 10 per cent of their mass in gas. A multitude of phenomena also observed in real galaxies are found in th

  10. High resolution 2D image upconversion of incoherent light

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    An optimized method for continuous wave 2-dimensional (2-D) upconversion of incoherent or thermal light is demonstrated and quantified. Using standard resolution targets a resolution of 200×1000 pixels is obtained. The suggested method is viewed in scope of modern CCD cameras operating in the nea...

  11. A VARIATIONAL MODEL FOR 2-D MICROPOLAR BLOOD FLOW

    Institute of Scientific and Technical Information of China (English)

    He Ji-huan

    2003-01-01

    The micropolar fluid model is an essential generalization of the well-established Navier-Stokes model in the sense that it takes into account the microstructure of the fluid.This paper is devolted to establishing a variational principle for 2-D incompressible micropolar blood flow.

  12. NKG2D ligands mediate immunosurveillance of senescent cells.

    Science.gov (United States)

    Sagiv, Adi; Burton, Dominick G A; Moshayev, Zhana; Vadai, Ezra; Wensveen, Felix; Ben-Dor, Shifra; Golani, Ofra; Polic, Bojan; Krizhanovsky, Valery

    2016-02-01

    Cellular senescence is a stress response mechanism that limits tumorigenesis and tissue damage. Induction of cellular senescence commonly coincides with an immunogenic phenotype that promotes self-elimination by components of the immune system, thereby facilitating tumor suppression and limiting excess fibrosis during wound repair. The mechanisms by which senescent cells regulate their immune surveillance are not completely understood. Here we show that ligands of an activating Natural Killer (NK) cell receptor (NKG2D), MICA and ULBP2 are consistently up-regulated following induction of replicative senescence, oncogene-induced senescence and DNA damage - induced senescence. MICA and ULBP2 proteins are necessary for efficient NK-mediated cytotoxicity towards senescent fibroblasts. The mechanisms regulating the initial expression of NKG2D ligands in senescent cells are dependent on a DNA damage response, whilst continuous expression of these ligands is regulated by the ERK signaling pathway. In liver fibrosis, the accumulation of senescent activated stellate cells is increased in mice lacking NKG2D receptor leading to increased fibrosis. Overall, our results provide new insights into the mechanisms regulating the expression of immune ligands in senescent cells and reveal the importance of NKG2D receptor-ligand interaction in protecting against liver fibrosis. PMID:26878797

  13. ELLIPT2D: A Flexible Finite Element Code Written Python

    International Nuclear Information System (INIS)

    The use of the Python scripting language for scientific applications and in particular to solve partial differential equations is explored. It is shown that Python's rich data structure and object-oriented features can be exploited to write programs that are not only significantly more concise than their counter parts written in Fortran, C or C++, but are also numerically efficient. To illustrate this, a two-dimensional finite element code (ELLIPT2D) has been written. ELLIPT2D provides a flexible and easy-to-use framework for solving a large class of second-order elliptic problems. The program allows for structured or unstructured meshes. All functions defining the elliptic operator are user supplied and so are the boundary conditions, which can be of Dirichlet, Neumann or Robbins type. ELLIPT2D makes extensive use of dictionaries (hash tables) as a way to represent sparse matrices.Other key features of the Python language that have been widely used include: operator over loading, error handling, array slicing, and the Tkinter module for building graphical use interfaces. As an example of the utility of ELLIPT2D, a nonlinear solution of the Grad-Shafranov equation is computed using a Newton iterative scheme. A second application focuses on a solution of the toroidal Laplace equation coupled to a magnetohydrodynamic stability code, a problem arising in the context of magnetic fusion research

  14. 2D signature for detection and identification of drugs

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Varentsova, Svetlana A.; Shen, Jingling; Zhang, Cunlin; Zhou, Qingli; Shi, Yulei

    2011-06-01

    The method of spectral dynamics analysis (SDA-method) is used for obtaining the2D THz signature of drugs. This signature is used for the detection and identification of drugs with similar Fourier spectra by transmitted THz signal. We discuss the efficiency of SDA method for the identification problem of pure methamphetamine (MA), methylenedioxyamphetamine (MDA), 3, 4-methylenedioxymethamphetamine (MDMA) and Ketamine.

  15. Computational study of interfaces and edges of 2D materials

    NARCIS (Netherlands)

    Farmanbar Gelepordsari, M.

    2016-01-01

    The discovery of graphene and its intriguing properties has given birth to the field of two-dimensional (2D) materials. These materials are characterized by a strong covalent bonding between the atoms within a plane, but weak, van derWaals, bonding between the planes. Such materials can be isolated

  16. 2D molybdenum disulphide (2D-MoS2) modified electrodes explored towards the oxygen reduction reaction

    Science.gov (United States)

    Rowley-Neale, Samuel J.; Fearn, Jamie M.; Brownson, Dale A. C.; Smith, Graham C.; Ji, Xiaobo; Banks, Craig E.

    2016-08-01

    Two-dimensional molybdenum disulphide nanosheets (2D-MoS2) have proven to be an effective electrocatalyst, with particular attention being focused on their use towards increasing the efficiency of the reactions associated with hydrogen fuel cells. Whilst the majority of research has focused on the Hydrogen Evolution Reaction (HER), herein we explore the use of 2D-MoS2 as a potential electrocatalyst for the much less researched Oxygen Reduction Reaction (ORR). We stray from literature conventions and perform experiments in 0.1 M H2SO4 acidic electrolyte for the first time, evaluating the electrochemical performance of the ORR with 2D-MoS2 electrically wired/immobilised upon several carbon based electrodes (namely; Boron Doped Diamond (BDD), Edge Plane Pyrolytic Graphite (EPPG), Glassy Carbon (GC) and Screen-Printed Electrodes (SPE)) whilst exploring a range of 2D-MoS2 coverages/masses. Consequently, the findings of this study are highly applicable to real world fuel cell applications. We show that significant improvements in ORR activity can be achieved through the careful selection of the underlying/supporting carbon materials that electrically wire the 2D-MoS2 and utilisation of an optimal mass of 2D-MoS2. The ORR onset is observed to be reduced to ca. +0.10 V for EPPG, GC and SPEs at 2D-MoS2 (1524 ng cm-2 modification), which is far closer to Pt at +0.46 V compared to bare/unmodified EPPG, GC and SPE counterparts. This report is the first to demonstrate such beneficial electrochemical responses in acidic conditions using a 2D-MoS2 based electrocatalyst material on a carbon-based substrate (SPEs in this case). Investigation of the beneficial reaction mechanism reveals the ORR to occur via a 4 electron process in specific conditions; elsewhere a 2 electron process is observed. This work offers valuable insights for those wishing to design, fabricate and/or electrochemically test 2D-nanosheet materials towards the ORR.Two-dimensional molybdenum disulphide nanosheets

  17. Half-metallicity in 2D organometallic honeycomb frameworks

    Science.gov (United States)

    Sun, Hao; Li, Bin; Zhao, Jin

    2016-10-01

    Half-metallic materials with a high Curie temperature (T C) have many potential applications in spintronics. Magnetic metal free two-dimensional (2D) half-metallic materials with a honeycomb structure contain graphene-like Dirac bands with π orbitals and show excellent aspects in transport properties. In this article, by investigating a series of 2D organometallic frameworks with a honeycomb structure using first principles calculations, we study the origin of forming half-metallicity in this kind of 2D organometallic framework. Our analysis shows that charge transfer and covalent bonding are two crucial factors in the formation of half-metallicity in organometallic frameworks. (i) Sufficient charge transfer from metal atoms to the molecules is essential to form the magnetic centers. (ii) These magnetic centers need to be connected through covalent bonding, which guarantee the strong ferromagnetic (FM) coupling. As examples, the organometallic frameworks composed by (1,3,5)-benzenetricarbonitrile (TCB) molecules with noble metals (Au, Ag, Cu) show half-metallic properties with T C as high as 325 K. In these organometallic frameworks, the strong electronegative cyano-groups (CN groups) drive the charge transfer from metal atoms to the TCB molecules, forming the local magnetic centers. These magnetic centers experience strong FM coupling through the d-p covalent bonding. We propose that most of the 2D organometallic frameworks composed by molecule—CN—noble metal honeycomb structures contain similar half metallicity. This is verified by replacing TCB molecules with other organic molecules. Although the TCB-noble metal organometallic framework has not yet been synthesized, we believe the development of synthesizing techniques and facility will enable the realization of them. Our study provides new insight into the 2D half-metallic material design for the potential applications in nanotechnology.

  18. Half-metallicity in 2D organometallic honeycomb frameworks.

    Science.gov (United States)

    Sun, Hao; Li, Bin; Zhao, Jin

    2016-10-26

    Half-metallic materials with a high Curie temperature (T C) have many potential applications in spintronics. Magnetic metal free two-dimensional (2D) half-metallic materials with a honeycomb structure contain graphene-like Dirac bands with π orbitals and show excellent aspects in transport properties. In this article, by investigating a series of 2D organometallic frameworks with a honeycomb structure using first principles calculations, we study the origin of forming half-metallicity in this kind of 2D organometallic framework. Our analysis shows that charge transfer and covalent bonding are two crucial factors in the formation of half-metallicity in organometallic frameworks. (i) Sufficient charge transfer from metal atoms to the molecules is essential to form the magnetic centers. (ii) These magnetic centers need to be connected through covalent bonding, which guarantee the strong ferromagnetic (FM) coupling. As examples, the organometallic frameworks composed by (1,3,5)-benzenetricarbonitrile (TCB) molecules with noble metals (Au, Ag, Cu) show half-metallic properties with T C as high as 325 K. In these organometallic frameworks, the strong electronegative cyano-groups (CN groups) drive the charge transfer from metal atoms to the TCB molecules, forming the local magnetic centers. These magnetic centers experience strong FM coupling through the d-p covalent bonding. We propose that most of the 2D organometallic frameworks composed by molecule-CN-noble metal honeycomb structures contain similar half metallicity. This is verified by replacing TCB molecules with other organic molecules. Although the TCB-noble metal organometallic framework has not yet been synthesized, we believe the development of synthesizing techniques and facility will enable the realization of them. Our study provides new insight into the 2D half-metallic material design for the potential applications in nanotechnology. PMID:27541575

  19. Fetal Brain MRI

    Directory of Open Access Journals (Sweden)

    Ahmad Tahmasebpour

    2010-05-01

    Full Text Available MRI is a useful supplement to ultrasonography for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive ultrasonography abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI. "nThe database comprises MR images of a total of 26 fetuses (gestational age 22-23 weeks reformed be-cause of suspected abnormalities due to ultrasonic findings, family history or maternal illness and scanned on a 1.5T MR system using single-shot fast spin echo "SSFSE, HASTE" T2 sequence, slice thick-ness 3mm, no gap. "HASTE=fourier acquisition single shotturbospinecho". In the normal fetus the ventricular size or volume did not vary with the gestational age but cerebral and cerebellar volumes increase during the same period "Grossman et al." Diagnostic accuracy is about 48%. "OB/GYN news, Chicago". Today it is not necessary to use sedatives or muscle relaxants to control fetal movement "ultra-fast MRI techniques". Modified technique for 50% reduction in the time necessary to take MRI images of the fetal brain is dedicated by Kianosh Hosseinzadeh, by using a line of reference through the eyes "AJR 2005"."nOur fetuses are 22-23 weeks in gestational age, 26 in number and we found agenesis of corpus callosum, hydrocephaly, holoprosencephaly, mega-cisterna magna, occipital meningocele, Arnold Chiari malformation type 1, Dandy Walker syndrome and lissencephaly

  20. Explaining MRI examinations DVD

    International Nuclear Information System (INIS)

    When conducting MRI examinations, there are various things to be careful of. There is often stress related to the MRI examinations, so in order to perform an examination safely and smoothly, sufficient explanation must be given. An explanation of what to do and what not to do during an examination should be outlined in a brochure given to patients before the examination. There may be many patients who have misgivings about their MRI examinations, so to reduce their anxiousness and deepen their understanding of MRI examinations and to improve the safety and effiency of MRI examinations,; we created a DVD about MRI examinations. We gathered MRI-related safety information and instructions, and assessed the effect that the information might have on patients. We started a workgroup for a project to plan and record a video according to the Storyboard. When editing, we reviewed the length of each segment, the amount of information on screen, and the overall length of the DVD. We discussed the issue within the workgroup and had hospital approval. It was possible for us to complete it without depending on the supplier and the cost was kept to a minimum. Finally, we decided on a viewing location. We asked a hospital volunteers to see a complete DVD and we evaluated their responses by questionnaires. As the result, their understanding and anxieties related to MRI examinations were alleviated, as expected. Their anxiety seemed to be eased. Patients also seemed to have a deeper understanding of MRI examinations having seen an examination being conducted. (author)

  1. MRI in perianal fistulae

    International Nuclear Information System (INIS)

    MRI has become the method of choice for evaluating perianal fistulae due to its ability to display the anatomy of the sphincter muscles orthogonally, with good contrast resolution. In this article we give an outline of the classification of perianal fistulae and present a pictorial assay of sphincter anatomy and the MRI findings in perianal fistulae. This study is based on a retrospective analysis of 43 patients with a clinical diagnosis of perianal fistula. MRI revealed a total of 44 fistulae in 35 patients; eight patients had only perianal sinuses

  2. MRI of brachial plexopathies

    Energy Technology Data Exchange (ETDEWEB)

    Sureka, J. [Department of Radiology, Christian Medical College, Vellore (India)], E-mail: drjyoticmch@rediffmail.com; Cherian, R.A.; Alexander, M.; Thomas, B.P. [Department of Radiology, Christian Medical College, Vellore (India)

    2009-02-15

    Magnetic resonance imaging (MRI) has become the primary imaging technique in the evaluation of brachial plexus pathology, and plays an important role in the identification, localization, and characterization of the cause. Improvements in MRI technique have helped in detecting changes in the signal intensity of nerves, subtle enhancement, and in detecting perineural pathology, thereby refining the differential diagnosis. The present review of the visualization of brachial plexus abnormalities using MRI is based on a review of 26 cases. The causes include trauma and a spectrum of non-traumatic causes, such as acute idiopathic/viral plexitis, metastases, immune-mediated plexitis, and mass lesions compressing the brachial plexus.

  3. MRI in perianal fistulae

    Directory of Open Access Journals (Sweden)

    Khera Pushpinder

    2010-01-01

    Full Text Available MRI has become the method of choice for evaluating perianal fistulae due to its ability to display the anatomy of the sphincter muscles orthogonally, with good contrast resolution. In this article we give an outline of the classification of perianal fistulae and present a pictorial assay of sphincter anatomy and the MRI findings in perianal fistulae. This study is based on a retrospective analysis of 43 patients with a clinical diagnosis of perianal fistula. MRI revealed a total of 44 fistulae in 35 patients; eight patients had only perianal sinuses.

  4. Dust dynamics in 2D gravito-turbulent disks

    CERN Document Server

    Shi, Ji-Ming; Stone, James M; Chiang, Eugene

    2016-01-01

    The dynamics of solid bodies in protoplanetary disks are subject to the properties of any underlying gas turbulence. Turbulence driven by disk self-gravity shows features distinct from those driven by the magnetorotational instability (MRI). We study the dynamics of solids in gravito-turbulent disks with two-dimensional (in the disk plane), hybrid (particle and gas) simulations. Gravito-turbulent disks can exhibit stronger gravitational stirring than MRI-active disks, resulting in greater radial diffusion and larger eccentricities and relative speeds for large particles (those with dimensionless stopping times $t_{stop} \\Omega > 1$, where $\\Omega$ is the orbital frequency). The agglomeration of large particles into planetesimals by pairwise collisions is therefore disfavored in gravito-turbulent disks. However, the relative speeds of intermediate-size particles $t_{stop} \\Omega \\sim 1$ are significantly reduced as such particles are collected by gas drag and gas gravity into coherent filament-like structures ...

  5. 2D-2D tunneling field-effect transistors using WSe2/SnSe2 heterostructures

    Science.gov (United States)

    Roy, Tania; Tosun, Mahmut; Hettick, Mark; Ahn, Geun Ho; Hu, Chenming; Javey, Ali

    2016-02-01

    Two-dimensional materials present a versatile platform for developing steep transistors due to their uniform thickness and sharp band edges. We demonstrate 2D-2D tunneling in a WSe2/SnSe2 van der Waals vertical heterojunction device, where WSe2 is used as the gate controlled p-layer and SnSe2 is the degenerately n-type layer. The van der Waals gap facilitates the regulation of band alignment at the heterojunction, without the necessity of a tunneling barrier. ZrO2 is used as the gate dielectric, allowing the scaling of gate oxide to improve device subthreshold swing. Efficient gate control and clean interfaces yield a subthreshold swing of ˜100 mV/dec for >2 decades of drain current at room temperature, hitherto unobserved in 2D-2D tunneling devices. The subthreshold swing is independent of temperature, which is a clear signature of band-to-band tunneling at the heterojunction. A maximum switching ratio ION/IOFF of 107 is obtained. Negative differential resistance in the forward bias characteristics is observed at 77 K. This work bodes well for the possibilities of two-dimensional materials for the realization of energy-efficient future-generation electronics.

  6. Novel Hydrogen-bonded Three-dimensional Supramolecular Architectures Containing 2D Honeycomb Networks or 2D Grids

    Institute of Scientific and Technical Information of China (English)

    LI Dong-Sheng; ZHOU Cai-Hua; WANG Yao-Yu; FU Feng; WU Ya-Pan; QI Guang-Cai; SHI Qi-Zhen

    2006-01-01

    Two new supramolecular complexes, [Cu(H2dhbd)(3-pyOH)(H2O)]2·3-pyOH·2H2O (1) and [Cu2(dhbd)(dpa)2-(H2O)]·6H2O (2) (H4dhbd=2,3-dihydroxybutanedioic acid, 3-pyOH=3-hydroxypyridine, dpa=2,2'-dipyridylamine),have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses,H-O hydrogen bonds, the cyclic dinuclear units in 1 together with four adjacent neighbors are connected into a 2D honeycomb network encapsulating free 3-pyOH ligands. Unexpectedly, the water-dimers are fixed in interlayers of 2D honeycomb network and act as hydrogen-bond bridging to further extend these 2D networks into 3D hydrogen-bonded framework. Complex 2 includes interesting 2D grids constructed from chiral dinuclear units through cules into three dimension with channels. Variable-temperature magnetic susceptibility measurements for both complexes indicate the presence of weak antiferromagnetic exchange interactions between adjacent copper(Ⅱ) ions.

  7. Brain MRI in Parkinson's disease

    NARCIS (Netherlands)

    Meijer, F.J.A.; Goraj, B.M.

    2014-01-01

    In this review article, conventional brain MRI and advanced MRI techniques in Parkinson`s disease (PD) are discussed, with emphasis on clinical relevance. Conventional brain MRI sequences generally demonstrate limited abnormalities specific for PD and in clinical practice brain MRI is mainly used to

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  10. Quality assurance in functional MRI

    DEFF Research Database (Denmark)

    Liu, Thomas T; Glover, Gary H; Mueller, Bryon A;

    2015-01-01

    Over the past 20 years, functional magnetic resonance imaging (fMRI) has ben- efited greatly from improvements in MRI hardware and software. At the same time, fMRI researchers have pushed the technical limits of MRI systems and greatly in- fluenced the development of state-of-the-art systems. Min...

  11. 2-D linear motion system. Innovative technology summary report

    International Nuclear Information System (INIS)

    The US Department of Energy's (DOE's) nuclear facility decontamination and decommissioning (D and D) program requires buildings to be decontaminated, decommissioned, and surveyed for radiological contamination in an expeditious and cost-effective manner. Simultaneously, the health and safety of personnel involved in the D and D activities is of primary concern. D and D workers must perform duties high off the ground, requiring the use of manlifts or scaffolding, often, in radiologically or chemically contaminated areas or in areas with limited access. Survey and decontamination instruments that are used are sometimes heavy or awkward to use, particularly when the worker is operating from a manlift or scaffolding. Finding alternative methods of performing such work on manlifts or scaffolding is important. The 2-D Linear Motion System (2-D LMS), also known as the Wall Walker trademark, is designed to remotely position tools and instruments on walls for use in such activities as radiation surveys, decontamination, and painting. Traditional (baseline) methods for operating equipment for these tasks require workers to perform duties on elevated platforms, sometimes several meters above the ground surface and near potential sources of contamination. The Wall Walker 2-D LMS significantly improves health and safety conditions by facilitating remote operation of equipment. The Wall Walker 2-D LMS performed well in a demonstration of its precision, accuracy, maneuverability, payload capacity, and ease of use. Thus, this innovative technology is demonstrated to be a viable alternative to standard methods of performing work on large, high walls, especially those that have potential contamination concerns. The Wall Walker was used to perform a final release radiological survey on over 167 m2 of walls. In this application, surveying using a traditional (baseline) method that employs an aerial lift for manual access was 64% of the total cost of the improved technology. However

  12. Development and application of methods to quantify spatial and temporal hyperpolarized 3He MRI ventilation dynamics: preliminary results in chronic obstructive pulmonary disease

    Science.gov (United States)

    Kirby, Miranda; Wheatley, Andrew; McCormack, David G.; Parraga, Grace

    2010-03-01

    Hyperpolarized helium-3 (3He) magnetic resonance imaging (MRI) has emerged as a non-invasive research method for quantifying lung structural and functional changes, enabling direct visualization in vivo at high spatial and temporal resolution. Here we described the development of methods for quantifying ventilation dynamics in response to salbutamol in Chronic Obstructive Pulmonary Disease (COPD). Whole body 3.0 Tesla Excite 12.0 MRI system was used to obtain multi-slice coronal images acquired immediately after subjects inhaled hyperpolarized 3He gas. Ventilated volume (VV), ventilation defect volume (VDV) and thoracic cavity volume (TCV) were recorded following segmentation of 3He and 1H images respectively, and used to calculate percent ventilated volume (PVV) and ventilation defect percent (VDP). Manual segmentation and Otsu thresholding were significantly correlated for VV (r=.82, p=.001), VDV (r=.87 p=.0002), PVV (r=.85, p=.0005), and VDP (r=.85, p=.0005). The level of agreement between these segmentation methods was also evaluated using Bland-Altman analysis and this showed that manual segmentation was consistently higher for VV (Mean=.22 L, SD=.05) and consistently lower for VDV (Mean=-.13, SD=.05) measurements than Otsu thresholding. To automate the quantification of newly ventilated pixels (NVp) post-bronchodilator, we used translation, rotation, and scaling transformations to register pre-and post-salbutamol images. There was a significant correlation between NVp and VDV (r=-.94 p=.005) and between percent newly ventilated pixels (PNVp) and VDP (r=- .89, p=.02), but not for VV or PVV. Evaluation of 3He MRI ventilation dynamics using Otsu thresholding and landmark-based image registration provides a way to regionally quantify functional changes in COPD subjects after treatment with beta-agonist bronchodilators, a common COPD and asthma therapy.

  13. 2D time-of-flight MR angiography using concatenated saturation bands for determining direction of flow in the intracranial vessels

    Energy Technology Data Exchange (ETDEWEB)

    Nesbit, G.M. [Department of Radiology and Clinical Investigation Department, Naval Medical Center San Diego, San Diego, CA 92134 (United States); DeMarco, J.K. [Department of Radiology and Clinical Investigation Department, Naval Medical Center San Diego, San Diego, CA 92134 (United States)

    1997-07-10

    We prospectively studied 15 patients to assess 2D time-of-flight (TOF) magnetic resonance angiography (MRA) with concatenated saturation bands for determining the direction of intracranial blood flow. This MRA sequence was compared to T2-weighted spin-echo MRI, 3D-TOF MRA, and intra-arterial angiography (IAA) as regards demonstration of vessels and determination of the direction of flow in the circle of Willis and its branches. The 2D-TOF MRA sequence demonstrated flow in 98.5 % vessel segments identified on IAA, 3D-TOF demonstrating 92 % and spin-echo images 77 %. The direction of flow shown on the 2D-TOF sequence was correct in 94 % when compared to conventional angiography, the remaining six segments not demonstrating flow. In ten patients, the flow abnormalities demonstrated by this MRA technique provided clinical information similar to that of conventional angiography in nine, but it was incomplete in three, and misleading in one. Slow retrograde flow in ophthalmic artery collaterals and differentiation of arteries and veins presented some problems. 2D-TOF MRA with concatenated saturation bands provides flow direction information using widely available, easily applicable TOF techniques, and can be a useful adjunct to MRI and MRA if information on flow direction is needed. (orig.). With 5 figs., 3 tabs.

  14. MRI of myelitis

    OpenAIRE

    Hodel, J.; Outteryck, O; Jissendi, P; Zins, M.; Leclerc, X; Pruvo, J P

    2012-01-01

    The diagnosis of myelitis relies on MRI. The purpose of this review is to describe the imaging findings in patients with myelitis through clinical cases. MR findings in Multiple Sclerosis, Neuromyelitis Optica and others Transverse Myelitis are highlighted.

  15. MRI of the shoulder

    International Nuclear Information System (INIS)

    Magnetic resonance imaging has become available at a time in which shoulder pathology is more frequently seen. It is a noninvasive procedure that does not use ionizing radiation. It provides detailed visualization of soft-tissue structures that is not possible with other imaging modalities. Though not as widely available as conventional radiographs or computed tomography scanning, the number of MRI units worldwide is increasing steadily. The main features of the present book are as follows: The physical basis of Magnetic Resonance Imaging (MRI), normal shoulder anatomy and MRI, diagnosis of shoulder disorders, MRI of patients with shoulder pain or instability, case studies as well as treatment of shoulder disorders. (orig./MG) With 145 figs

  16. DT-MRI segmentation using graph cuts

    Science.gov (United States)

    Weldeselassie, Yonas T.; Hamarneh, Ghassan

    2007-03-01

    An important problem in medical image analysis is the segmentation of anatomical regions of interest. Once regions of interest are segmented, one can extract shape, appearance, and structural features that can be analyzed for disease diagnosis or treatment evaluation. Diffusion tensor magnetic resonance imaging (DT-MRI) is a relatively new medical imaging modality that captures unique water diffusion properties and fiber orientation information of the imaged tissues. In this paper, we extend the interactive multidimensional graph cuts segmentation technique to operate on DT-MRI data by utilizing latest advances in tensor calculus and diffusion tensor dissimilarity metrics. The user interactively selects certain tensors as object ("obj") or background ("bkg") to provide hard constraints for the segmentation. Additional soft constraints incorporate information about both regional tissue diffusion as well as boundaries between tissues of different diffusion properties. Graph cuts are used to find globally optimal segmentation of the underlying 3D DT-MR image among all segmentations satisfying the constraints. We develop a graph structure from the underlying DT-MR image with the tensor voxels corresponding to the graph vertices and with graph edge weights computed using either Log-Euclidean or the J-divergence tensor dissimilarity metric. The topology of our segmentation is unrestricted and both obj and bkg segments may consist of several isolated parts. We test our method on synthetic DT data and apply it to real 2D and 3D MRI, providing segmentations of the corpus callosum in the brain and the ventricles of the heart.

  17. MRI of intracranial calcifications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin Wha; Chang, Kee Hyun; Park, Jung Mi; Han, Moon Hee; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1988-12-15

    Recently computed tomography(CT) has been rapidly replaced by magnetic resonance imaging (MRI) in diagnosis of majority of intracranial diseases. But MRI still has some limitation, one of which is its inferiority in detecting calcification. MRI of intracranial calcification has been known to be variable in signal intensity. We retrospectively analyzed the MRI of 26 patients with intracranial calcified lesions in order to evaluate the MR intensity of calcification and to assess the capability of MRI in detecting calcification in various intracranial lesions. All the MRI were obtained using routine T1-and T2-weighted spin eco pulse sequences on 2.0T superconducting system. The 26 patients consisted of 13 brain tumors (4 oligodendrogliomas, 2 craniopharyngiomas, 2 astrocytomas, 1 gem cell tumor, 1 medulloblastoma, 1 ependympma, and pathologically unconfirmed 2 cases), 11 infectious diseases (1 paragonimiasis, 1 sparganosis, 2 cysticercosis, 3 tuberculosis, and 4 unknown cases), and 2 undetermined pathologies. Eighty-two percent (9/11) of infections disease, and 50% (1/2) of undetermined group showed signal diminution or signal void on both T1-and T2-weighted image (T1W1, T2W1). Twenty-four percent (3/13) of brain tumors showed signal diminution on both T1W1 and T2W1. In 46% (6/13) and 61% (8/13) of brain tumors the signal intensities were isointense on T1W1 and T1W1, respectively. Unexpectedly, 3 oligodendrogliomas showed high signal intensity on T1W1, two of which showed com plexed signal intensity mixed with high, iso, and low signal intensities on T2W1. In remained cases (18% (2/11) of infectious diseases and 50% (1/2) of undetermined group) the signal intensities were mixed. With simultaneous review of CT and MRI in each case, the calcification (at least one in cases showing multiple ones) was identifiable on MRI in 62% (8/13) of rumors, 82% (9/11) of infectious diseases, and 100% (2/2) in undetermined group. In 36% (4/11) of infectious diseases, fewer number of

  18. Security Issues for 2D Barcodes Ticketing Systems

    Directory of Open Access Journals (Sweden)

    Cristian Toma

    2011-03-01

    Full Text Available The paper presents a solution for endcoding/decoding access to the subway public transportation systems. First part of the paper is dedicated through section one and two to the most used 2D barcodes used in the market – QR and DataMatrix. The sample for DataMatrix is author propietary and the QR sample is from the QR standard [2]. The section three presents MMS and Digital Rights Management topics used for issuing the 2D barcodes tickets. The second part of the paper, starting with section four shows the architecture of Subway Ticketing Systems and the proposed procedure for the ticket issuing. The conclusions identify trends of the security topics in the public transportation systems.

  19. Characterization of steady solutions to the 2D Euler equation

    CERN Document Server

    Izosimov, Anton

    2015-01-01

    Steady fluid flows have very special topology. In this paper we describe necessary and sufficient conditions on the vorticity function of a 2D ideal flow on a surface with or without boundary, for which there exists a steady flow among isovorticed fields. For this we introduce the notion of an antiderivative (or circulation function) on a measured graph, the Reeb graph associated to the vorticity function on the surface, while the criterion is related to the total negativity of this antiderivative. It turns out that given topology of the vorticity function, the set of coadjoint orbits of the symplectomorphism group admitting steady flows with this topology forms a convex polytope. As a byproduct of the proposed construction, we also describe a complete list of Casimirs for the 2D Euler hydrodynamics: we define generalized enstrophies which, along with circulations, form a complete set of invariants for coadjoint orbits of area-preserving diffeomorphisms on a surface.

  20. TRO-2D - A code for rational transonic aerodynamic optimization

    Science.gov (United States)

    Davis, W. H., Jr.

    1985-01-01

    Features and sample applications of the transonic rational optimization (TRO-2D) code are outlined. TRO-2D includes the airfoil analysis code FLO-36, the CONMIN optimization code and a rational approach to defining aero-function shapes for geometry modification. The program is part of an effort to develop an aerodynamically smart optimizer that will simplify and shorten the design process. The user has a selection of drag minimization and associated minimum lift, moment, and the pressure distribution, a choice among 14 resident aero-function shapes, and options on aerodynamic and geometric constraints. Design variables such as the angle of attack, leading edge radius and camber, shock strength and movement, supersonic pressure plateau control, etc., are discussed. The results of calculations of a reduced leading edge camber transonic airfoil and an airfoil with a natural laminar flow are provided, showing that only four design variables need be specified to obtain satisfactory results.

  1. Simulation of corium concrete interaction in 2D geometry

    Energy Technology Data Exchange (ETDEWEB)

    Cranga, M. [IRSN, DPAM, F-13115 St Paul Les Durance (France); Spindler, B.; Dufour, E. [CEA Grenoble, DEN, F-38000 Grenoble (France); Dimov, Dimitar [Bulgarian Acad Sci, Inst Nucl Res and Nucl Energy, NPPSAL, BU-1784 Sofia (Bulgaria); Atkhen, Kresna [EDF, SEPTEN, F-69628 Villeurbanne (France); Foit, Jerzy [Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany); Garcia-Martin, M. [Univ Politecn Madrid, E-28006 Madrid (Spain); Sevon, Tuomo [Tech Res Ctr Finland VTT, FI-02044 Helsinki (Finland); Schmidt, W. [AREVA, D-91058 Erlangen (Germany); Spengler, C. [Gesell Anlagen and Reaktorsicherheit GRS mbH, D-50667 Cologne (Germany)

    2010-07-01

    Benchmarking work was recently performed for the issue of molten corium concrete interaction (MCCI). A synthesis is given here. It concerns first the 2D CCI-2 test with a homogeneous pool and a limestone concrete, which was used for a blind benchmark. Secondly, the COMET-L2 and COMET-L3 2D experiments in a stratified configuration were used as a post-test (L2) and a blind-test (L3) benchmark. More details are given here for the recent benchmark considering a matrix of four reactor cases, with both a homogeneous and a stratified configuration, and with both a limestone and a siliceous concrete. A short overview is given on the different models used in the codes, and the consistency between the benchmark actions on experiments and reactor situations is discussed. Finally, the major uncertainties concerning MCCI are also pointed out. (authors)

  2. 2D/3D Program work summary report

    International Nuclear Information System (INIS)

    The 2D/3D Program was carried out by Germany, Japan and the United States to investigate the thermal-hydraulics of a PWR large-break LOCA. A contributory approach was utilized in which each country contributed significant effort to the program and all three countries shared the research results. Germany constructed and operated the Upper Plenum Test Facility (UPTF), and Japan constructed and operated the Cylindrical Core Test Facility (CCTF) and the Slab Core Test Facility (SCTF). The US contribution consisted of provision of advanced instrumentation to each of the three test facilities, and assessment of the TRAC computer code against the test results. Evaluations of the test results were carried out in all three countries. This report summarizes the 2D/3D Program in terms of the contributing efforts of the participants, and was prepared in a coordination among three countries. US and Germany have published the report as NUREG/IA-0126 and GRS-100, respectively. (author)

  3. Functionalized 2D atomic sheets with new properties

    Science.gov (United States)

    Sun, Qiang; Zhou, Jian; Wang, Qian; Jena, Puru

    2011-03-01

    Due to the unique atomic structure and novel physical and chemical properties, graphene has sparked tremendous theoretical and experimental efforts to explore other 2D atomic sheets like B-N, Al-N, and Zn-O, where the two components offer much more complexities and flexibilities in surface modifications. Using First principles calculations based on density functional theory, we have systematically studied the semi- and fully-decorated 2D sheets with H and F and Cl. We have found that the electronic structures and magnetic properties can be effectively tuned, and the system can be a direct or an indirect semiconductor or even a half-metal, and the system can be made ferromagnetic, antiferromagnetic, or magnetically degenerate depending upon how the surface is functionalized. Discussions are made for the possible device applications.

  4. 2D-immunoblotting analysis of Sporothrix schenckii cell wall

    Directory of Open Access Journals (Sweden)

    Estela Ruiz-Baca

    2011-03-01

    Full Text Available We utilized two-dimensional gel electrophoresis and immunoblotting (2D-immunoblotting with anti-Sporothrix schenckii antibodies to identify antigenic proteins in cell wall preparations obtained from the mycelial and yeast-like morphologies of the fungus. Results showed that a 70-kDa glycoprotein (Gp70 was the major antigen detected in the cell wall of both morphologies and that a 60-kDa glycoprotein was present only in yeast-like cells. In addition to the Gp70, the wall from filament cells showed four proteins with molecular weights of 48, 55, 66 and 67 kDa, some of which exhibited several isoforms. To our knowledge, this is the first 2D-immunoblotting analysis of the S. schenckii cell wall.

  5. Defect Dynamics in Active 2D Nematic Liquid Crystals

    Science.gov (United States)

    Decamp, Stephen; Redner, Gabriel; Hagan, Michael; Dogic, Zvonimir

    2014-03-01

    Active materials are assemblies of animate, energy-consuming objects that exhibit continuous dynamics. As such, they have properties that are dramatically different from those found in conventional materials made of inanimate objects. We present a 2D active nematic liquid crystal composed of bundled microtubules and kinesin motor proteins that exists in a dynamic steady-state far from equilibrium. The active nematic exhibits spontaneous binding and unbinding of charge +1/2 and -1/2 disclination defects as well as streaming of +1/2 defects. By tuning ATP concentration, we precisely control the amount of activity, a key parameter of the system. We characterize the dynamics of streaming defects on a large, flat, 2D interface using quantitative polarization light microscopy. We report fundamental characteristics of the active nematics such as defect velocities, defect creation and annihilation rates, and emergent length scales in the system.

  6. Wave propagation in pantographic 2D lattices with internal discontinuities

    CERN Document Server

    Madeo, A; Neff, P

    2014-01-01

    In the present paper we consider a 2D pantographic structure composed by two orthogonal families of Euler beams. Pantographic rectangular 'long' waveguides are considered in which imposed boundary displacements can induce the onset of traveling (possibly non-linear) waves. We performed numerical simulations concerning a set of dynamically interesting cases. The system undergoes large rotations which may involve geometrical non-linearities, possibly opening the path to appealing phenomena such as propagation of solitary waves. Boundary conditions dramatically influence the transmission of the considered waves at discontinuity surfaces. The theoretical study of this kind of objects looks critical, as the concept of pantographic 2D sheets seems to have promising possible applications in a number of fields, e.g. acoustic filters, vascular prostheses and aeronautic/aerospace panels.

  7. Bulk correlation functions in 2D quantum gravity

    CERN Document Server

    Kostov, I K

    2005-01-01

    We compute bulk 3- and 4-point tachyon correlators in the 2d Liouville gravity with non-rational matter central charge c<1, following and comparing two approaches. The continuous CFT approach exploits the action on the tachyons of the ground ring generators deformed by Liouville and matter ``screening charges''. A by-product general formula for the matter 3-point OPE structure constants is derived. We also consider a ``diagonal'' CFT of 2D quantum gravity, in which the degenerate fields are restricted to the diagonal of the semi-infinite Kac table. The discrete formulation of the theory is a generalization of the ADE string theories, in which the target space is the semi-infinite chain of points.

  8. Planar maps, circle patterns and 2d gravity

    CERN Document Server

    David, Francois

    2013-01-01

    Via circle pattern techniques, random planar triangulations (with angle variables) are mapped onto Delaunay triangulations in the complex plane. The uniform measure on triangulations is mapped onto a conformally invariant spatial point process. We show that this measure can be expressed as: (1) a sum over 3-spanning-trees partitions of the edges of the Delaunay triangulations; (2) the volume form of a K\\"ahler metric over the space of Delaunay triangulations, whose prepotential has a simple formulation in term of ideal tessellations of the 3d hyperbolic space; (3) a discretized version (involving finite difference complex derivative operators) of Polyakov's conformal Fadeev-Popov determinant in 2d gravity; (4) a combination of Chern classes, thus also establishing a link with topological 2d gravity.

  9. A SUBARRAY-SYNTHESIS BASED 2D DOA ESTIMATION METHOD

    Institute of Scientific and Technical Information of China (English)

    Xu Wenlong; Jiang Wei; Li Zengfu; Shang Yong; Xiang Haige

    2006-01-01

    In some satellite communications, we need to perform Direction Of Arrival (DOA) angle estimation under the restriction that the number of receivers is less than that of the array elements in an array antenna.To solve the conundrum, a method named subarray-synthesis-based Two-Dimensional DOA (2D DOA) angle estimation is proposed. In the method, firstly, the array antenna is divided into a series of subarray antennas based on the total number of receivers; secondly, the subarray antennas' output covariance matrices are estimated; thirdly, an equivalent covariance matrix is synthesized based on the subarray output covariance matrices; then 2D DOA estimation is performed. Monte Carlo simulations showed that the estimation method is effective.

  10. 2D Models for Dust-driven AGB Star Winds

    CERN Document Server

    Woitke, P

    2006-01-01

    New axisymmetric (2D) models for dust-driven winds of C-stars are presented which include hydrodynamics with radiation pressure on dust, equilibrium chemistry and time-dependent dust formation with coupled grey Monte Carlo radiative transfer. Considering the most simple case without stellar pulsation (hydrostatic inner boundary condition) these models reveal a more complex picture of the dust formation and wind acceleration as compared to earlier published spherically symmetric (1D) models. The so-called exterior $\\kappa$-mechanism causes radial oscillations with short phases of active dust formation between longer phases without appreciable dust formation, just like in the 1D models. However, in 2D geometry, the oscillations can be out-of-phase at different places above the stellar atmosphere which result in the formation of dust arcs or smaller caps that only occupy a certain fraction of the total solid angle. These dust structures are accelerated outward by radiation pressure, expanding radially and tangen...

  11. Estimating 2-D Vector Velocities Using Multidimensional Spectrum Analysis

    DEFF Research Database (Denmark)

    Oddershede, Niels; Løvstakken, Lasse; Torp, Hans;

    2008-01-01

    new velocity estimators for finding both the axial and lateral velocity components. The estimators essentially search for the plane in the 3-D Fourier space, where the integrated power spectrum is largest. The first uses the 3-D Fourier transform to find the power spectrum, while the second uses......Wilson (1991) presented an ultrasonic wide-band estimator for axial blood flow velocity estimation through the use of the 2-D Fourier transform. It was shown how a single velocity component was concentrated along a line in the 2-D Fourier space, where the slope was given by the axial velocity....... Later, it was shown that this approach could also be used for finding the lateral velocity component by also including a lateral sampling. A single velocity component would then be concentrated along a plane in the 3-D Fourier space, tilted according to the 2 velocity components. This paper presents 2...

  12. Simulation of corium concrete interaction in 2D geometry

    International Nuclear Information System (INIS)

    Benchmarking work was recently performed for the issue of molten corium concrete interaction (MCCI). A synthesis is given here. It concerns first the 2D CCI-2 test with a homogeneous pool and a limestone concrete, which was used for a blind benchmark. Secondly, the COMET-L2 and COMET-L3 2D experiments in a stratified configuration were used as a post-test (L2) and a blind-test (L3) benchmark. More details are given here for the recent benchmark considering a matrix of four reactor cases, with both a homogeneous and a stratified configuration, and with both a limestone and a siliceous concrete. A short overview is given on the different models used in the codes, and the consistency between the benchmark actions on experiments and reactor situations is discussed. Finally, the major uncertainties concerning MCCI are also pointed out. (authors)

  13. A brief review of the 2d/4d correspondences

    CERN Document Server

    Tachikawa, Yuji

    2016-01-01

    An elementary introduction to the 2d/4d correspondences is given. After quickly reviewing the 2d q-deformed Yang-Mills theory and the Liouville theory, we will introduce 4d theories obtained by coupling trifundamentals to SU(2) gauge fields. We will then see concretely that the supersymmetric partition function of these theories on S^3 x S^1 and on S^4 is given respectively by the q-deformed Yang-Mills theory and the Liouville theory. After giving a short discussion on how this correspondence may be understood from the viewpoint of the 6d N=(2,0) theory, we conclude the review by enumerating future directions. Most of the technical points will be referred to more detailed review articles.

  14. MRI of plantar fasciitis

    Energy Technology Data Exchange (ETDEWEB)

    Roger, B.; Grenier, P. [Service de Radiologie Polyvalente Diagnostique et Interventionelle, Hopital de la Pitie, 83, boulevard de l`Hopital, F-75651 Paris Cedex 13 (France)

    1997-12-01

    At present, MRI is the only imaging method that can precisely visualize lesions of the superficial plantar aponeurosis, whether they be musculoaponeurositides, enthesopathies or tears, and whether they be acute or chronic, with or without complications. By its direct visualization of the lesion, MRI enables an accurate assessment of the injury to be made and thereby better orients the therapeutic strategy. (orig.) With 11 figs., 15 refs.

  15. MRI of the penis

    OpenAIRE

    Kirkham, A

    2012-01-01

    MRI of the penis is an expensive test that is not always superior to clinical examination or ultrasound. However, it shows many of the important structures, and in particular the combination of tumescence from intracavernosal alprostadil, and high-resolution T2 sequences show the glans, corpora and the tunica albuginea well. In this paper we summarise the radiological anatomy and discuss the indications for MRI. For penile cancer, it may be useful in cases where the local stage is not apparen...

  16. study on the significance of application of multi - slice spiral CT(MsCT)angiography in diagnosis of aortic dissecting aneurysm%多层螺旋 CT 血管成像技术在主动脉夹层动脉瘤中的应用价值

    Institute of Scientific and Technical Information of China (English)

    张喜军; 李淳成; 吴耀军

    2015-01-01

    供立体及精确的解剖信息,故 MSCTA 可作为 AD 首选的影像学检查方法。%Objectine To explore the diagnostic performance and clinical significance of multi - slice spiral CT(MSCT)angiography and computed tomography angiography(CTA)in diagnosis of aortic dissecting aneurysm. Methods The Clinical data of 68 cases diagnosed with aor-tic dissections(AD)were retrospectively analyzed. All these patients were examined with 64 - detector CTA using intelligent tracking technique for rapid volume enhanced scanning,and primary data were processed with multiplannar reformation( MPR),curved plannar reconstruction (CRP),the maximum intensity projection(MIP),volume representation technical reconstruction(VR),CT virtual endoscopy(CTVE)and vol-ume representative technical reconstruction(VR). The true and false lumens,intimal flap and tears were analyzed. Results There were 21 cases with Stanford A type,and 47 cases with B type;the average strengthening value of AD in true lumen group(279. 00 ± 46. 55 HU)was significant-ly higher than the average strengthening value of false lumen group(260. 06 ± 49. 59 HU,t = 2. 2963,P = 2. 2963). It could be seen in 66 ca-ses(97. 06% )of first tear and 60 cases(88. 24% )of re - entry tears. In 42 cases of true lumen value which strengthening value was greater than that of false lumen,the first tear size was 12. 05 ± 6. 48 mm,which was much smaller than the size of first tear(19. 08 ± 8. 56 mm,t = 3. 8394, P = 3. 8394)in 26 cases with true lumen,in which strengthening value was almost the same to that of false lumen. The true and false lumens of 60 patients with AD were spirally contorted,another 8 cases were parallel contortion,their size was differed. Enhanced scanning of 68 patients showed mezzanine intimal flap was clearly performed,and the movement was in accordance with that of true and false lumens. Bilateral common il-iac arteries were most easily affected. The rates of breach in MPR,CPR,CTVE and VR were 92. 65% ,95

  17. 2DBase: 2D-PAGE database of Escherichia coli

    OpenAIRE

    Vijayendran, Chandran; Burgemeister, Sebastian; Friehs, Karl; Niehaus, Karsten; Flaschel, Erwin

    2007-01-01

    We present a web-based integrated proteome database, termed 2DBase of Escherichia coli which was designed to store, compare, analyse, and retrieve various information obtained by 2D polyacrylamide gel electrophoresis and mass spectrometry. The main objectives of this database are (1) to provide the features for query and data-mining applications to access the stored proteomics data (2) to efficiently compare the specific protein spots present in the comparable proteome maps and (3) to analyse...

  18. 2D and 3D Traveling Salesman Problem

    Science.gov (United States)

    Haxhimusa, Yll; Carpenter, Edward; Catrambone, Joseph; Foldes, David; Stefanov, Emil; Arns, Laura; Pizlo, Zygmunt

    2011-01-01

    When a two-dimensional (2D) traveling salesman problem (TSP) is presented on a computer screen, human subjects can produce near-optimal tours in linear time. In this study we tested human performance on a real and virtual floor, as well as in a three-dimensional (3D) virtual space. Human performance on the real floor is as good as that on a…

  19. Controllable and Observable Polynomial Description for 2D Noncausal Systems

    Directory of Open Access Journals (Sweden)

    M. S. Boudellioua

    2007-01-01

    Full Text Available Two-dimensional state-space systems arise in applications such as image processing, iterative circuits, seismic data processing, or more generally systems described by partial differential equations. In this paper, a new direct method is presented for the polynomial realization of a class of noncausal 2D transfer functions. It is shown that the resulting realization is both controllable and observable.

  20. An inverse design method for 2D airfoil

    Science.gov (United States)

    Liang, Zhi-Yong; Cui, Peng; Zhang, Gen-Bao

    2010-03-01

    The computational method for aerodynamic design of aircraft is applied more universally than before, in which the design of an airfoil is a hot problem. The forward problem is discussed by most relative papers, but inverse method is more useful in practical designs. In this paper, the inverse design of 2D airfoil was investigated. A finite element method based on the variational principle was used for carrying out. Through the simulation, it was shown that the method was fit for the design.