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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

    with sufficient spatial and temporal resolution. To overcome this problem our method predicts pixel intensities in multiple 2D slices, acquired with high spatial and temporal resolution, and subsequently assembles these into volumetric data sets. The prediction is based on external motion sensors, in our case...

  2. 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...

  3. 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...

  4. 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.

  5. Global and regional left ventricular function: a comparison between gated SPECT, 2D echocardiography and multi-slice computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Henneman, Maureen M.; Bax, Jeroen J.; Holman, Eduard R. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Schuijf, Joanne D.; Jukema, J.W.; Wall, Ernst E. van der [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Stokkel, Marcel P.M. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Lamb, Hildo J.; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

    2006-12-15

    Global and regional left ventricular (LV) function are important indicators of the cardiac status in patients with coronary artery disease (CAD). Therapy and prognosis are to a large extent dependent on LV function. Multi-slice computed tomography (MSCT) has already earned its place as an imaging modality for non-invasive assessment of the coronary arteries, but since retrospective gating to the patient's ECG is performed, information on LV function can be derived. In 49 patients with known or suspected CAD, coronary angiography with MSCT imaging was performed, in addition to gated SPECT and 2D echocardiography. LV end-diastolic and LV end-systolic volumes and LV ejection fraction were analysed with dedicated software (CMR Analytical Software System, Medis, Leiden, The Netherlands for MSCT; gated SPECT by QGS, Cedars-Sinai Medical Center, Los Angeles, CA, USA), and by the biplane Simpson's rule for 2D echocardiography. Regional wall motion was evaluated according to a 17-segment model and a three-point score system. Correlations were fairly good between gated SPECT and MSCT (LVEDV: r=0.65; LVESV: r=0.63; LVEF: r=0.60), and excellent between 2D echocardiography and MSCT (LVEDV: r=0.92; LVESV: r=0.93; LVEF: r=0.80). Agreement for regional wall motion was 95% ({kappa}=0.66) between gated SPECT and MSCT, and 96% ({kappa}=0.73) between 2D echocardiography and MSCT. Global and regional LV function and LV volumes can be adequately assessed with MSCT. Correlations with 2D echocardiography are stronger than with gated SPECT. (orig.)

  6. 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.

  7. Virtopsy post-mortem multi-slice computed tomograhy (MSCT) and magnetic resonance imaging (MRI) demonstrating descending tonsillar herniation: comparison to clinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Aghayev, Emin; Yen, Kathrin; Thali, Michael; Jackowski, Christian; Dirnhofer, Richard [Institute of Forensic Medicine, University of Bern, IRM-Buehlstrasse 20, 3012, Bern (Switzerland); Sonnenschein, Martin [Institute of Diagnostic Radiology, Inselspital, 3010, Bern (Switzerland); Ozdoba, Christoph [Department of Neuroradiology, Inselspital, 3010, Bern (Switzerland)

    2004-07-01

    Descending cerebellar tonsillar herniation is a serious and common complication of intracranial mass lesions. We documented three cases of fatal blunt head injury using post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI). The results showed massive bone and soft-tissue injuries of the head and signs of high intracranial pressure with herniation of the cerebellar tonsils. The diagnosis of tonsillar herniation by post-mortem radiological examination was performed prior to autopsy. This paper describes the detailed retrospective evaluation of the position of the cerebellar tonsils in post-mortem imaging in comparison to clinical studies. (orig.)

  8. 直接采用二维多截面时步法有限元的斜槽异步电机模型%Direct Modeling of Induction Motors with Skewed Rotor Slots Using 2-D Multi-Slice Model and Time Stepping FEM

    Institute of Scientific and Technical Information of China (English)

    傅为农; 江建中

    2000-01-01

    The geometrical feature of the skewed rotor slots in induction motors makes the 2-dimensional (2-D) finite element method (FEM) not directly applicable. Based on the multi-slice model in this paper, a time stepping 2-D eddy-current FEM is described to study the steady-state operation and the starting process of induction machines with skewed rotor slots. The fields of the multi-slices are solved in parallel, and thus the effects of skewed slots and eddy-current can be taken into account directly. The basic formulas for the multi-slice model are derived. Special technique to reduce computation time in solving the coupled system equations is also described. The results obtained by using the program developed have very good correlation with the test data.

  9. On-site Rapid Diagnosis of Intracranial Hematoma using Portable Multi-slice Microwave Imaging System

    Science.gov (United States)

    Mobashsher, Ahmed Toaha; Abbosh, A. M.

    2016-11-01

    Rapid, on-the-spot diagnostic and monitoring systems are vital for the survival of patients with intracranial hematoma, as their conditions drastically deteriorate with time. To address the limited accessibility, high costs and static structure of currently used MRI and CT scanners, a portable non-invasive multi-slice microwave imaging system is presented for accurate 3D localization of hematoma inside human head. This diagnostic system provides fast data acquisition and imaging compared to the existing systems by means of a compact array of low-profile, unidirectional antennas with wideband operation. The 3D printed low-cost and portable system can be installed in an ambulance for rapid on-site diagnosis by paramedics. In this paper, the multi-slice head imaging system’s operating principle is numerically analysed and experimentally validated on realistic head phantoms. Quantitative analyses demonstrate that the multi-slice head imaging system is able to generate better quality reconstructed images providing 70% higher average signal to clutter ratio, 25% enhanced maximum signal to clutter ratio and with around 60% hematoma target localization compared to the previous head imaging systems. Nevertheless, numerical and experimental results demonstrate that previous reported 2D imaging systems are vulnerable to localization error, which is overcome in the presented multi-slice 3D imaging system. The non-ionizing system, which uses safe levels of very low microwave power, is also tested on human subjects. Results of realistic phantom and subjects demonstrate the feasibility of the system in future preclinical trials.

  10. 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.

  11. 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

  12. 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.

  13. The value of multi-slice CT and MRI for early complications of inguinal hernia repair%MSCT 和 MRI 对腹股沟疝修补术后早期并发症的诊断价值

    Institute of Scientific and Technical Information of China (English)

    张勇; 周玉梅; 陈淑君; 李洪; 王周旋; 惠庆涛; 邓鸿义; 倪帮高; 明兵

    2015-01-01

    Objective To evaluate the value of MSCT and MRI in diagnosis of early postoperative complications of inguinal hernia repair (IHR).Methods Imaging and clinical data in 1 6 patients with early complications of IHR were analyzed retrospectively.Re-sults Among the complications,postoperative infection in 2 was found including incision infection in 1 and groin cellulitis in other 1. CT showed swelling abdominal wall and heterogeneous enhancement for incision infection,and inguinal mass,deep inguinal ring thickening,edema of residual sac with fluid and air collections for groin cellulitis.Seroma was found in 8,and CT and MRI demon-strated residual sac effusion,spermatic cord thickening and spermatic vascular tortuosity.Residual sac edema was found in 4,and CT and MRI showed thickening spermatic cord without effusion in residual sac or scrotum.Effusions between patch and anterior abdom-inal wall were detected by MRI in 2,one of which was accompanied by patch shrinking.Conclusion With specific clinical background for early complications of IHR,MSCT and MRI provide more anatomical information of inguinal region,which may contribute to di-agnosis and treatment of early postoperative complications.%目的:探讨 MSCT 和 MRI 对腹股沟疝修补术后早期并发症的诊断价值。方法回顾性分析16例腹股沟疝修补术后出现早期并发症患者的临床和影像资料。结果16例中包括术后感染2例,其中1例为切口感染,CT 表现为腹壁软组织肿胀,增强不均匀强化,1例为腹股沟蜂窝组织炎,CT 表现为腹股沟肿块,腹股沟管内环增厚,残留疝囊水肿伴疝囊积液、积气;血清肿8例, CT 和 MRI 表现为残留疝囊积液,精索增粗,精索血管迂曲;残留疝囊水肿4例,CT 和 MRI 显示精索增粗,残留疝囊或阴囊内未见积液;补片周围积液2例,MRI 显示补片与前腹壁之间少量积液,其中1例伴有补片皱缩。结论腹股沟疝修补术后早期并发症

  14. Sub-Millimeter T2 Weighted fMRI at 7 T: Comparison of 3D-GRASE and 2D SE-EPI

    Directory of Open Access Journals (Sweden)

    Valentin G. Kemper

    2015-05-01

    Full Text Available Functional magnetic resonance imaging (fMRI allows studying human brain function non-invasively up to the spatial resolution of cortical columns and layers. Most fMRI acquisitions rely on the blood oxygenation level dependent (BOLD contrast employing T2* weighted 2D multi-slice echo-planar imaging (EPI. At ultra-high magnetic field (i.e. 7 T and above, it has been shown experimentally and by simulation, that T2 weighted acquisitions yield a signal that is spatially more specific to the site of neuronal activity at the cost of functional sensitivity. This study compared two T2 weighted imaging sequences, inner-volume 3D Gradient-and-Spin-Echo (3D-GRASE and 2D Spin-Echo EPI (SE-EPI, with evaluation of their imaging point-spread function, functional specificity, and functional sensitivity at sub-millimeter resolution. Simulations and measurements of the imaging point-spread function revealed that the strongest anisotropic blurring in 3D-GRASE (along the second phase-encoding direction was about 60 % higher than the strongest anisotropic blurring in 2D SE-EPI (along the phase-encoding direction In a visual paradigm, the BOLD sensitivity of 3D-GRASE was found to be superior due to its higher temporal signal-to-noise ratio. High resolution cortical depth profiles suggested that the contrast mechanisms are similar between the two sequences, however, 2D SE-EPI had a higher surface bias owing to the higher T2* contribution of the longer in-plane EPI echo-train for full field of view compared to the reduced field of view of zoomed 3D-GRASE.

  15. Framework for 2D-3D image fusion of infrared thermography with preoperative MRI.

    Science.gov (United States)

    Hoffmann, Nico; Weidner, Florian; Urban, Peter; Meyer, Tobias; Schnabel, Christian; Radev, Yordan; Schackert, Gabriele; Petersohn, Uwe; Koch, Edmund; Gumhold, Stefan; Steiner, Gerald; Kirsch, Matthias

    2017-01-23

    Multimodal medical image fusion combines information of one or more images in order to improve the diagnostic value. While previous applications mainly focus on merging images from computed tomography, magnetic resonance imaging (MRI), ultrasonic and single-photon emission computed tomography, we propose a novel approach for the registration and fusion of preoperative 3D MRI with intraoperative 2D infrared thermography. Image-guided neurosurgeries are based on neuronavigation systems, which further allow us track the position and orientation of arbitrary cameras. Hereby, we are able to relate the 2D coordinate system of the infrared camera with the 3D MRI coordinate system. The registered image data are now combined by calibration-based image fusion in order to map our intraoperative 2D thermographic images onto the respective brain surface recovered from preoperative MRI. In extensive accuracy measurements, we found that the proposed framework achieves a mean accuracy of 2.46 mm.

  16. FPGA-Based Architecture for a Generalized Parallel 2-D MRI Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    Sami Hasan

    2011-01-01

    Full Text Available Problem statement: Current Neuroimaging developments, in biological research and diagnostics, demand an edge-defined and noise-free MRI scans. Thus, this study presents a generalized parallel 2-D MRI filtering algorithm with their FPGA-based implementation in a single unified architecture. The parallel 2-D MRI filtering algorithms are Edge, Sobel X, Sobel Y, Sobel X-Y, Blur, Smooth, Sharpen, Gaussian and Beta (HYB. Then, the nine MRI image filtering algorithm, has empirically improved to generate enhanced MRI scans filtering results without significantly affecting the developed performance indices of high throughput and low power consumption at maximum operating frequency. Approach: The parallel 2-d MRI filtering algorithms are developed and FPGA implemented using Xilinx System Generator tool within the ISE 12.3 development suite. Two unified architectures are behaviorally developed, depending on the abstraction level of implementation. For performance indices comparison, two Virtex-6 FPGA boards, namely, xc6vlX240Tl-1lff1759 and xc6vlX130Tl-1lff1156 are behaviorally targeted. Results: The improved parallel 2-D filtering algorithms enhanced the filtered MRI scans to be edge-defined and noise free grayscale imaging. The single architecture is efficiently prototyped to achieve: high filtering performance of (11230 frames/second throughput for 64*64 MRI grayscale scan, minimum power consumption of 0.86 Watt with a junction temperature of 52°C and a maximum frequency of up to (230 MHz. Conclusion: The improved parallel MRI filtering algorithms which are developed as a single unified architecture provide visibility enhancement within the filtered MRI scan to aid the physician in detecting brain diseases, e.g., trauma or intracranial haemorrhage. The high filtering throughput is feasibly nominee the nine parallel MRI filtering algorithms for applications such as real-time MRI potential future applications. Future Work: a set of parallel 3-D fMRI

  17. 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

    responses and receptor occupancies. The distinct CBV magnitudes between putamen and caudate at matched occupancies approximately matched literature differences in basal dopamine levels, suggesting that the relative fMRI measurements reflect basal D2/D3 dopamine receptor occupancy. These results can provide...

  18. 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.

  19. 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.

  20. Eigenvalues of collective emission in multi-slice slab configurations

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, Richard [Department of Physics, Columbia University, New York, NY 10027 (United States); Manassah, Jamal T. [HMS Consultants, Inc., PO Box 592, New York, NY 10028 (United States)], E-mail: jmanassah@gmail.com

    2008-06-02

    We compute the eigenmodes of collective emission from multi-slice slab configurations, using the transfer matrix formalism. We elucidate within this formalism the phenomena of 'Invisible Gaps' in multiple-slice configuration and of 'Precocious Superradiance' in periodic structures previously observed in numerical solutions of Maxwell-Bloch equations.

  1. Real-time 2D spatially selective MRI experiments: Comparative analysis of optimal control design methods.

    Science.gov (United States)

    Maximov, Ivan I; Vinding, Mads S; Tse, Desmond H Y; Nielsen, Niels Chr; Shah, N Jon

    2015-05-01

    There is an increasing need for development of advanced radio-frequency (RF) pulse techniques in modern magnetic resonance imaging (MRI) systems driven by recent advancements in ultra-high magnetic field systems, new parallel transmit/receive coil designs, and accessible powerful computational facilities. 2D spatially selective RF pulses are an example of advanced pulses that have many applications of clinical relevance, e.g., reduced field of view imaging, and MR spectroscopy. The 2D spatially selective RF pulses are mostly generated and optimised with numerical methods that can handle vast controls and multiple constraints. With this study we aim at demonstrating that numerical, optimal control (OC) algorithms are efficient for the design of 2D spatially selective MRI experiments, when robustness towards e.g. field inhomogeneity is in focus. We have chosen three popular OC algorithms; two which are gradient-based, concurrent methods using first- and second-order derivatives, respectively; and a third that belongs to the sequential, monotonically convergent family. We used two experimental models: a water phantom, and an in vivo human head. Taking into consideration the challenging experimental setup, our analysis suggests the use of the sequential, monotonic approach and the second-order gradient-based approach as computational speed, experimental robustness, and image quality is key. All algorithms used in this work were implemented in the MATLAB environment and are freely available to the MRI community.

  2. 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.

  3. 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.)

  4. Intracranial artery velocity measurement using 4D PC MRI at 3 T: comparison with transcranial ultrasound techniques and 2D PC MRI

    Energy Technology Data Exchange (ETDEWEB)

    Meckel, Stephan [University Hospital Freiburg, Department of Neuroradiology, Freiburg (Germany); Leitner, Lorenz; Schubert, Tilman [University Hospital Basel, Institute of Radiology, Basel (Switzerland); Bonati, Leo H.; Lyrer, Philippe [University Hospital Basel, Department of Neurology, Basel (Switzerland); Santini, Francesco [University Hospital Basel, Department of Radiological Physics, Institute of Radiology, Basel (Switzerland); Stalder, Aurelien F. [Xuanwu Hospital - Capital Medical University, Department of Radiology, Beijing (China); Markl, Michael [Northwestern University Feinberg School of Medicine, Departments of Radiology and Biomedical Engineering, Chicago (United States); Wetzel, Stephan G. [Neuroradiology, Swiss Neuro Institute, Klinik Hirslanden, Zurich (Switzerland)

    2013-04-15

    4D phase contrast MR imaging (4D PC MRI) has been introduced for spatiotemporal evaluation of intracranial hemodynamics in various cerebrovascular diseases. However, it still lacks validation with standards of reference. Our goal was to compare blood flow quantification derived from 4D PC MRI with transcranial ultrasound and 2D PC MRI. Velocity measurements within large intracranial arteries [internal carotid artery (ICA), basilar artery (BA), and middle cerebral artery (MCA)] were obtained in 20 young healthy volunteers with 4D and 2D PC MRI, transcranial Doppler sonography (TCD), and transcranial color-coded duplex sonography (TCCD). Maximum velocities at peak systole (PSV) and end diastole (EDV) were compared using regression analysis and Bland-Altman plots. Correlation of 4D PC MRI measured velocities was higher in comparison with TCD (r = 0.49-0.66) than with TCCD (0.35-0.44) and 2D PC MRI (0.52-0.60). In mid-BA and ICA C7 segment, a significant correlation was found with TCD (0.68-0.81 and 0.65-0.71, respectively). No significant correlation was found in carotid siphon. On average over all volunteers, PSVs and EDVs in MCA were minimally underestimated compared with TCD/TCCD. Minimal overestimation of velocities was found compared to TCD in mid-BA and ICA C7 segment. 4D PC MRI appears as valid alternative for intracranial velocity measurement consistent with previous reference standards, foremost with TCD. Spatiotemporal averaging effects might contribute to vessel size-dependent mild underestimation of velocities in smaller (MCA), and overestimation in larger-sized (BA and ICA) arteries, respectively. Complete spatiotemporal flow analysis may be advantageous in anatomically complex regions (e.g. carotid siphon) relative to restrictions of ultrasound techniques. (orig.)

  5. 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.

  6. Local 2D Particle-in-cell simulations of the collisionless MRI

    CERN Document Server

    Riquelme, Mario A; Sharma, Prateek; Spitkovsky, Anatoly

    2012-01-01

    The magnetorotational instability (MRI) is a crucial mechanism of angular momentum transport in a variety of astrophysical accretion disks. In systems accreting at well below the Eddington rate, such as the central black hole in the Milky Way (Sgr A*), the rate of Coulomb collisions between particles is very small, making the disk evolve essentially as a collisionless plasma. We present a nonlinear study of the collisionless MRI using first-principles particle-in-cell (PIC) plasma simulations. In this initial study we focus on local two-dimensional (axisymmetric) simulations, deferring more realistic three-dimensional simulations to future work. For simulations with net vertical magnetic flux, the MRI continuously amplifies the magnetic field until the Alfv\\'en velocity, v_A, is comparable to the speed of light, c (independent of the initial value of v_A/c). This is consistent with the lack of saturation of MRI channel modes in analogous axisymmetric MHD simulations. The amplification of the magnetic field by...

  7. Imaging Agonist-Induced D2/D3 Receptor Desensitization and Internalization In Vivo with PET/fMRI.

    Science.gov (United States)

    Sander, Christin Y; Hooker, Jacob M; Catana, Ciprian; Rosen, Bruce R; Mandeville, Joseph B

    2016-04-01

    This study investigated the dynamics of dopamine receptor desensitization and internalization, thereby proposing a new technique for non-invasive, in vivo measurements of receptor adaptations. The D2/D3 agonist quinpirole, which induces receptor internalization in vitro, was administered at graded doses in non-human primates while imaging with simultaneous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). A pronounced temporal divergence between receptor occupancy and fMRI signal was observed: occupancy remained elevated while fMRI responded transiently. Analogous experiments with an antagonist (prochlorperazine) and a lower-affinity agonist (ropinirole) exhibited reduced temporal dissociation between occupancy and function, consistent with a mechanism of desensitization and internalization that depends upon drug efficacy and affinity. We postulated a model that incorporates internalization into a neurovascular-coupling relationship. This model yielded in vivo desensitization/internalization rates (0.2/min for quinpirole) consistent with published in vitro measurements. Overall, these results suggest that simultaneous PET/fMRI enables characterization of dynamic neuroreceptor adaptations in vivo, and may offer a first non-invasive method for assessing receptor desensitization and internalization.

  8. 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).

  9. 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.)

  10. Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stephane; Maldague, Baudouin [Department of Radiology, St. Luc Hospital, UCL, Avenue Hippocrate, 10, 1200 Brussels (Belgium)

    2003-04-01

    Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries. (orig.)

  11. Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction.

    Science.gov (United States)

    Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stéphane; Maldague, Baudouin

    2003-04-01

    Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries.

  12. 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

  13. 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...

  14. 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

  15. 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

  16. Direct Modeling of Induction Motors with Skewed Rotor Slots Using 2-D Multi-Slice Model and Time Stepping FEM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    1  Introduction Thetraditionalmethodtostudytheperformancesofinductionmotorsisbasedontheconceptofequivalentcircuit.Theparametersintheequivalentcircuitareusuallyobtainedbymagneticcircuitcomputation .Inre centyearsithasbecomepracticaltousefiniteelementmethods (FEM )with 2 dimensional (2 D )magneto staticmodeland 2 DeddycurrentFEMinfrequencydo mainstoestimatetheparameters[1,2 ] .However,theprecisionofthismethodislimitedbytheconceptoftheequivalentcircuit .Thefollowingeffectsaredifficulttobeincluded :  (1)Ther...

  17. 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.

  18. Development of Multi-slice Analytical Tool to Support BIM-based Design Process

    Science.gov (United States)

    Atmodiwirjo, P.; Johanes, M.; Yatmo, Y. A.

    2017-03-01

    This paper describes the on-going development of computational tool to analyse architecture and interior space based on multi-slice representation approach that is integrated with Building Information Modelling (BIM). Architecture and interior space is experienced as a dynamic entity, which have the spatial properties that might be variable from one part of space to another, therefore the representation of space through standard architectural drawings is sometimes not sufficient. The representation of space as a series of slices with certain properties in each slice becomes important, so that the different characteristics in each part of space could inform the design process. The analytical tool is developed for use as a stand-alone application that utilises the data exported from generic BIM modelling tool. The tool would be useful to assist design development process that applies BIM, particularly for the design of architecture and interior spaces that are experienced as continuous spaces. The tool allows the identification of how the spatial properties change dynamically throughout the space and allows the prediction of the potential design problems. Integrating the multi-slice analytical tool in BIM-based design process thereby could assist the architects to generate better design and to avoid unnecessary costs that are often caused by failure to identify problems during design development stages.

  19. Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Petersen, Claus Leth; Kjaer, Andreas;

    2005-01-01

    AIMS: Radionuclide techniques, and recently MRI, have been used for clinical evaluation of right ventricular (RV) volumes function (RVEF) and volumes; but with the introduction of 3D echocardiography, new echocardiographic possibilities for RV evaluation independent of geometrical assumptions have...... emerged. This study compared classic and new echocardiographic and radionuclide estimates, including gated blood pool single-photon emission computed tomography (SPECT) of RV size and function to RV volumes, and ejection fraction (RVEF) measured by magnetic resonance imaging (MRI). METHODS AND RESULTS...

  20. 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

  1. 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

    Directory of Open Access Journals (Sweden)

    Francisco Abaeté Chagas-Neto

    2016-04-01

    Full Text Available Abstract 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.

  2. Diagnosis of traumatic hemarthrosis lipemia by multi-slice spiral CT and magnetic resonance imaging features%创伤性关节积脂血症的多排螺旋CT及磁共振成像诊断

    Institute of Scientific and Technical Information of China (English)

    沈丽荣; 姜兆候; 张立云; 刘永明

    2014-01-01

    Objective To evaluated traumatic hemarthrosis lipemia multi-slice spiral CT and magnetic resonance imaging (MRI) features and diagnostic value. Methods A retrospective analysis of multi-slice spiral CT and MRI features in 23 cases patients with traumatic hemarthrosis hyperlipidemia. All patients were examinated after injury bet-ween one hour to one week by 16-slice spiral CT or MRI, of which 19 cases of knee, hip 4 cases, all patients under-went multi-slice spiral CT, images were transmitted to a workstation for multi-planar reconstruction (MPR), shaded surface display (SSD), volume rendering (VR) and other three-dimensional restructuring, 15 cases of parallel MRI. Results Twenty three patients were joint capsule appeared fat-blood interface sign, including one case of suspected fracture CT, MRI was clear. In 23 patients, a single liquid-liquid plane 17 cases, two liquid-liquid flat 6 cases, liquid-liquid flat top were fat. Conclusion There are characteristic imaging findings of traumatic hemarthrosis lipemia examined by multi-slice spiral CT and MRI , three-dimensional multi-slice spiral CT examination and restructuring can be used as the preferred; MRI is the best imaging method in diagnostic plot lipemia traumatic knee; Plot lipemia can be used as a indirect dia-gnostic signs of intraarticular fractures.%目的:探讨创伤性关节积脂血症的多排螺旋CT及磁共振成像(MRI)影像学特点及诊断价值。方法回顾性分析23例创伤性关节积脂血症患者的多排螺旋CT及MRI影像学特征。所有患者于受伤后1 h至1周内行16排螺旋CT和(或)MRI检查,其中,膝关节19例,髋关节4例,所有患者均行多排螺旋CT检查,图像均传递到工作站进行多平面重组、表面遮盖法、容积再现等三维重建,15例并行MRI检查。结果23例患者关节囊均出现脂肪-血液界面征,其中1例CT可疑骨折,行MRI检查明确诊断。23例患者中,单液-液平面的17

  3. 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.

  4. 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.

  5. Multi-slice computed tomography urography after diuretic injection in children with urinary tract dilatation

    Energy Technology Data Exchange (ETDEWEB)

    Kosucu, P.; Ahmetoglu, A.; Imamoglu, M.; Cay, A.; Ozdemir, O.; Dinc, H.; Kosucu, M.; Sari, A.; Saruhan, H.; Gumele, H.R. [Farabi Hospital, Trabzon (Turkey). Dept. of Radiology

    2004-02-01

    To evaluate the potential use of multi-slice computed tomography urography (MSCTU) after diuretic injection in children with urinary tract dilatation. MSCTU was performed in 19 patients (11 boys, 8 girls, mean age 5.4 years) with suspicion of urinary tract obstruction and dilatation. Furosemide, 1 mg/kg, was injected 3 min before contrast material administration and followed by a bolus of 30 ml of physiologic saline solution immediately after application of contrast material. Excretory-phase images were obtained through the abdomen and pelvis beginning 10 min after initiation of the injection of contrast material. Maximum intensity projection (MIP) and volume rendering (VR) images were post-processed to obtain urographic views. MSCTU revealed pathology in 16 of 19 patients, while 3 patients had normal findings. Ureteropelvic obstruction was found in 4 patients, obstructive megaureter in 8. Both ureteropelvic obstruction and obstructive megaureter were disclosed in 1 patient, partial ureteral duplication in 1 patient, and both complete ureteral duplication and ureterocele in 2 patients. In all patients, MIP and VR images could satisfactorily show the pathologies of the urinary tract. The estimated effective average doses of MSCTU were higher than IVU. Preliminary results of furosemide-enhanced MSCTU demonstrated consistently dilated urinary tracts, obstruction levels, and underlying pathologies better than US and IVU.

  6. Virtual colonoscopy with multi-slice computed tomography; Virtuelle Koloskopie mit der Mehrschichtcomputertomographie. Vorlaeufige Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Rust, G.-F.; Eisele, O.; Reiser, M. [Institut fuer Klinische Radiologie, Klinikum Grosshadern, Muenchen Univ. (Germany); Hoffmann, J.N.; Kopp, R.; Fuerst, H. [Chirurgische Klinik und Poliklinik, Klinikum der Univ. Muenchen (Germany)

    2000-03-01

    Subject: Using multi-slice computed tomography (MSCT) large body areas can scanned with high spatial resolution. In this study, MSCT was employed for virtual colonoscopy in various pathologies of the colon. Results: Nine polyps and four of five colon carcinomas were detected using MSCT virtual colonoscopy. In three patients with ulcerative colitis virtual coloscopy revealed morphological alterations compatible with this disease. In two of four patients with multiple diverticula of the colon the true extent of the disorder could be assessed in virtual colonoscopy. (orig.) [German] Fragestellung: Die Mehrschichtcomputertomographie (MSCT) vermag, grosse Organbereiche mit hoher raeumlicher Aufloesung zu untersuchen. Daher koennen auch fuer die virtuelle Koloskopie eine bisher nicht erreichbare Ortsaufloesung und Detailtreue erwartet werden. Die ersten Ergebnisse mit der MSCT-Koloskopie bei unterschiedlichen pathologischen Veraenderungen des Kolons werden vorgestellt. Ergebnisse: 4 von 5 Kolonkarzinomen konnten mit der virtuellen Koloskopie dargestellt werden. Bei 3 Patienten wurden mit der virtuellen Koloskopie typische Veraenderungen der Colitis ulcerosa dargestellt, wovon ein Patient die konventionelle Koloskopie nicht tolerierte. Bei 9 Patienten mit Kolonpolypen stimmten die virtuelle und konventionelle Koloksopie vollstaendig ueberein. Bei 4 Patienten mit Divertikulose war mit der virtuellen Koloskopie nur in 2 Faellen der Befund vollstaendig zu sichern. (orig.)

  7. A Hybrid Method for Segmentation and Visualization of Teeth in Multi-Slice CT scan Images

    Directory of Open Access Journals (Sweden)

    Mohammad Hosntalab

    2009-12-01

    Full Text Available Introduction: Various computer assisted medical procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries require automatic quantification and volumetric visualization of teeth. In this regard, segmentation is a major step. Material and Methods: In this paper, inspired by our previous experiences and considering the anatomical knowledge of teeth and jaws, we propose a hybrid technique for teeth segmentation and visualization in CT volumetric data. The major steps of the proposed techniques are as follows: (1 Separation of teeth in CT dataset; (2 Initial segmentation of teeth in panoramic projection; (3 Final segmentation of teeth in CT dataset; (4 3D visualization of teeth. Results: The proposed algorithm was evaluated in 30 multi-slice CT datasets. Segmented images were compared with manually outlined contours. In order to evaluate the proposed method, we utilized several common performance measures such as sensitivity, specificity, precision, accuracy and mean error rate. The experimental results reveal the effectiveness of the proposed method. Discussion and Conclusion: In the proposed algorithm, the variationallevel set technique was utilized to trace the contour of the teeth. In view of the fact that this technique is based on the characteristics of the overall region of the tooth image, it is possible to extract a very smooth and accurate tooth contour using this technique. For the available datasets, the proposed technique was more successful in teeth segmentation compared to previous techniques.

  8. 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.

  9. Scanning protocol optimization and dose evaluation in coronary stenosis using multi-slices computed tomography

    Science.gov (United States)

    Huang, Yung-hui; Chen, Chia-lin; Sheu, Chin-yin; Lee, Jason J. S.

    2007-02-01

    Cardiovascular diseases are the most common incidence for premature death in developed countries. A major fraction is attributable to atherosclerotic coronary artery disease, which may result in sudden cardiac failure. A reduction of mortality caused by myocardial infarction may be achieved if coronary atherosclerosis can be detected and treated at an early stage before symptoms occur. Therefore, there is need for an effective tool that allows identification of patients at increased risk for future cardiac events. The current multi-detector CT has been widely used for detection and quantification of coronary calcifications as a sign of coronary atherosclerosis. The aim of this study is to optimize the diagnostic values and radiation exposure in coronary artery calcium-screening examination using multi-slice CT (MSCT) with different image scan protocols. The radiation exposure for all protocols is evaluated by using computed tomography dose index (CTDI) phantom measurements. We chose an optimal scanning protocol and evaluated patient radiation dose in the MSCT coronary artery screenings and preserved its expecting diagnostic accuracy. These changes make the MSCT have more operation flexibility and provide more diagnostic values in current practice.

  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 myelin water imaging for practical clinical applications at 3.0 T.

    Science.gov (United States)

    Guo, Junyu; Ji, Qing; Reddick, Wilburn E

    2013-09-01

    Myelin water imaging is a promising, noninvasive technique for evaluating white matter diseases such as multiple sclerosis and other leukoencephalopathies (LE), and monitoring myelination in early childhood. Unfortunately, poor image quality and a long acquisition time are major obstacles to practical clinical applications. In this study, a novel postprocessing method with an efficient multi-slice acquisition scheme, called T2 spectrum analysis using a weighted regularized non-negative least squares algorithm and nonlocal mean filter (T2SPARC), is presented to overcome these obstacles and achieve a shorter acquisition time, higher image quality, and large volume coverage. In vivo results from healthy volunteers and a patient with LE showed that the T2SPARC method can generate robust and high-quality myelin water fraction maps of 10 slices within 11 min. This method also yields some useful byproducts such as intra- and extracellular water fraction and long T2 tissue water fraction maps, which can quantify lesions in different brain diseases.

  12. 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.

  13. 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.

  14. 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.

  15. 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

    2006-01-21

    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.

  16. 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.

  17. 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

  18. Quantitative Comparison of 2D and 3D MRI Techniques for the Evaluation of Chondromalacia Patellae in 3.0T MR Imaging of the Knee

    Directory of Open Access Journals (Sweden)

    Ali Özgen

    2016-09-01

    Full Text Available INTRODUCTION: Chondromalacia patellae is a very common disorder of patellar cartilage. Magnetic resonance imaging (MRI is a powerful non-invasive tool to investigate patellar cartilage lesions. Although many MRI sequences have been used in MR imaging of the patellar cartilage and the optimal pulse sequence is controversial, fat-saturated proton density images have been considered very valuable to evaluate patellar cartilage. The purpose of this study is to quantitatively compare the diagnostic performance of various widely used 2D and 3D MRI techniques for the evaluation of chondromalacia patellae in 3.0T MR imaging of the knee using T2 mapping images as the reference standard. METHODS: Sevety-five knee MRI exams of 69 adult consecutive were included in the study. Fat-saturated T2-weighted (FST2, fat-saturated proton density (FSPD, water-only T2-weighted DIXON (T2mD, T2-weighted 3 dimensional steady state (3DT2FFE, merged multi-echo steady state (3DmFFE, and water selective T1-weighted fat-supressed (WATSc images were acquired. Quantitative comparison of grade 1 and grade 5 lesions were made using contrast-to-noise (CNR ratios. Grade 2-4 lesions were scored qualitatively and scorings of the lesions were compared statistically. Analysis of variance and Tukey’s tests were used to compare CNR data. Two sample z-test was used to compare the ratio of MR exams positive for grade 1 lesions noted on T2-mapping and other conventional sequences. Paired samples t-test was used to compare two different pulse sequences. RESULTS: In detecting grade 1 lesions, FSPD, FST2 and T2mD images were superior in comparison to other sequences. FSPD and FST2 images were statistically superior in detecting grade 2-4 lesions. Although all grade 5 lesions were noted in every single sequence, FST2 images have the highest mean CNR followed by 3DT2FFE images. DISCUSSION AND CONCLUSION: FST2 sequence is equal or superior in detecting every grade of patellar chondromalacia in

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

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2015-07-01

    Full Text Available 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 13e88 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 MSCT 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.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. DREAM - A Novel Approach for Robust, Ultra-Fast, Multi-Slice B1 Mapping

    NARCIS (Netherlands)

    Nehrke, K.; Boernert, P.

    2012-01-01

    Fast and robust in vivo B1 mapping is an essential prerequisite forquantitative MRI or multi-element transmit applications like RF-shimming or accelerated multi-dimensional RF pulses. However, especially at higher field strength, the acquisition speed of current B1-mapping approaches is typicall

  6. 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

  7. 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

  8. 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.

  9. MRI of respiratory dynamics with 2D steady-state free-precession and 2D gradient echo sequences at 1.5 and 3 Tesla: an observer preference study

    Energy Technology Data Exchange (ETDEWEB)

    Fabel, M.; Biederer, J. [University Hospital Schleswig-Holstein, Department of Diagnostic Radiology, Kiel (Germany); Wintersperger, B.J.; Dietrich, O. [University Hospital Munich, Department of Clinical Radiology, Munich (Germany); Eichinger, M.; Puderbach, M. [German Cancer Research Center, Department of Oncological Diagnostics and Therapy, Heidelberg (Germany); Fink, C.; Schoenberg, S.O. [University Hospital Heidelberg-Mannheim, Department of Clinical Radiology, Mannheim (Germany); Kauczor, H.U. [University Hospital Heidelberg, Department of Diagnostic Radiology, Heidelberg (Germany)

    2009-02-15

    To compare the image quality of dynamic lung MRI with variations of steady-state free-precession (SSFP) and gradient echo (GRE) cine techniques at 1.5 T and 3 T. Ventilated porcine lungs with simulated lesions inside a chest phantom and four healthy human subjects were assessed with SSFP (TR/TE = 2.9/1.22 ms; 3 ima/s) and GRE sequences (TR/TE=2.34/0.96 ms; 8 ima/s) as baseline at 1.5 and 3 T. Modified SSFPs were performed with nine to ten images/s (parallel imaging factors 2 and 3). Image quality for representative structures and artifacts was ranked by three observers independently. At 1.5 T, standard SSFP achieved the best image quality with superior spatial resolution and signal, but equal temporal resolution to GRE. SSFP with improved temporal resolution was ranked second best. Further acceleration (PI factor 3) was of no benefit, but increased artifacts. At 3 T, GRE outranged SSFP imaging with high lesion signal intensity, while artifacts on SSFP images increased visibly. At 1.5 T, a modified SSFP with moderate parallel imaging (PI factor 2) was considered the best compromise of temporal and spatial resolution. At 3 T, GRE sequences remain the best choice for dynamic lung MRI. (orig.)

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

    NARCIS (Netherlands)

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

    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,

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

    NARCIS (Netherlands)

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

    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

  12. 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.)

  13. MRI

    Science.gov (United States)

    MRI does not use ionizing radiation. No side effects from the magnetic fields and radio waves have been reported. The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions rarely ...

  14. 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

  15. Semi-automatic segmentation for 3D motion analysis of the tongue with dynamic MRI.

    Science.gov (United States)

    Lee, Junghoon; Woo, Jonghye; Xing, Fangxu; Murano, Emi Z; Stone, Maureen; Prince, Jerry L

    2014-12-01

    Dynamic MRI has been widely used to track the motion of the tongue and measure its internal deformation during speech and swallowing. Accurate segmentation of the tongue is a prerequisite step to define the target boundary and constrain the tracking to tissue points within the tongue. Segmentation of 2D slices or 3D volumes is challenging because of the large number of slices and time frames involved in the segmentation, as well as the incorporation of numerous local deformations that occur throughout the tongue during motion. In this paper, we propose a semi-automatic approach to segment 3D dynamic MRI of the tongue. The algorithm steps include seeding a few slices at one time frame, propagating seeds to the same slices at different time frames using deformable registration, and random walker segmentation based on these seed positions. This method was validated on the tongue of five normal subjects carrying out the same speech task with multi-slice 2D dynamic cine-MR images obtained at three orthogonal orientations and 26 time frames. The resulting semi-automatic segmentations of a total of 130 volumes showed an average dice similarity coefficient (DSC) score of 0.92 with less segmented volume variability between time frames than in manual segmentations.

  16. Water Flow Investigation on Quartz Sand with 13-interval Stimulated Echo Multi Slice Imaging

    Science.gov (United States)

    Spindler, Natascha; Pohlmeier, Andreas; Galvosas, Petrik

    2011-03-01

    Understanding root water uptake in soils is of high importance for securing nutrition in the context of climate change and linked phenomena like stronger varying weather conditions (draught, strong rain). One step to understand how root water uptake occurs is the knowledge of the water flow in soil towards plant roots. Magnetic Resonance Imaging (MRI) in combination with q-space imaging is potentially the most powerful analytical tool for non-invasive three dimensional visualization of flow and transport in porous media. Numerous attempts have been made to measure local velocity in porous media by combining velocity phase encoding with fast imaging methods, where flow velocities in the vascular bundles of plant stems were investigated. In contrast to water situated in the cellular structure of plants, NMR signal arising from water in the pore space in soil may be much more affected by the presence of internal magnetic field gradients. In this work we account for the existence of these gradients by employing bipolar pulsed field magnetic gradients for velocity encoding. This enables one to study flow through sand (as a model system for soil) at flow rates relevant for the water uptake of plant roots.

  17. 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.

  18. 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.

  19. 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)

  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. 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.

  3. Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Obenauer, S.; Alamo, L.; Herold, T.; Funke, M.; Kopka, L.; Grabbe, E. [Department of Radiology, Georg August-University Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen (Germany)

    2002-08-01

    Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. (orig.)

  4. Indication for and accuracy of CT and MRI of the temporomandibular joint; Indikation und Aussagekraft von Computertomographie und Magnetresonanztomographie des Kiefergelenks

    Energy Technology Data Exchange (ETDEWEB)

    Greess, H.; Anders, K. [Erlangen-Nuernberg Univ. (Germany). Inst. fuer Diagnostische Radiologie

    2005-07-01

    Recurrent pains of the temporomandibular joint represent a frequent symptom with numerous different causes. CT and MRI can reliably show the cause of these disorders and therefore have substituted conventional X-ray imaging. Modern multi-slice-CT (MSCT) allows for examination of the skull base including the mandible in a very short time with thinnest slice collimation (0.75 mm). With 2D- and 3D- reformations reconstructed out of this volume data set in parasagittal, coronal or any other arbitrary slice orientation excellent imaging of fractures and bony changes of arthrosis as well as benign and malignant tumors of the temporomandibular joint can be performed. MRI offers very good soft tissue contrast in order to visualize the intra-articular disc, the ligaments and muscles, as well the possibility to acquire cross sectional images in any user-defined orientation. MRI is the method of choice to diagnose 'internal derangement', particularly displacement of the intra-articular disc and inflammatory disease of the temporomandibular joint. The present paper will provide diagnostic strategies for the use of MSCT or MRI imaging concerning the different causes of disorders to the temporomandibular joint. (orig.)

  5. WE-G-BRD-01: A Data-Driven 4D-MRI Motion Model to Estimate Full Field-Of-View Abdominal Motion From 2D Image Navigators During MR-Linac Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Stemkens, B; Tijssen, RHN; Denis de Senneville, B Denis; Lagendijk, JJW; Berg, CAT van den [University Medical Center Utrecht, Utrecht (Netherlands)

    2015-06-15

    Purpose: To estimate full field-of-view abdominal respiratory motion from fast 2D image navigators using a 4D-MRI based motion model. This will allow for radiation dose accumulation mapping during MR-Linac treatment. Methods: Experiments were conducted on a Philips Ingenia 1.5T MRI. First, a retrospectively ordered 4D-MRI was constructed using 3D transient-bSSFP with radial in-plane sampling. Motion fields were calculated through 3D non-rigid registration. From these motion fields a PCA-based abdominal motion model was constructed and used to warp a 3D reference volume to fast 2D cine-MR image navigators that can be used for real-time tracking. To test this procedure, a time-series consisting of two interleaved orthogonal slices (sagittal and coronal), positioned on the pancreas or kidneys, were acquired for 1m38s (dynamic scan-time=0.196ms), during normal, shallow, or deep breathing. The coronal slices were used to update the optimal weights for the first two PCA components, in order to warp the 3D reference image and construct a dynamic 4D-MRI time-series. The interleaved sagittal slices served as an independent measure to test the model’s accuracy and fit. Spatial maps of the root-mean-squared error (RMSE) and histograms of the motion differences within the pancreas and kidneys were used to evaluate the method. Results: Cranio-caudal motion was accurately calculated within the pancreas using the model for normal and shallow breathing with an RMSE of 1.6mm and 1.5mm and a histogram median and standard deviation below 0.2 and 1.7mm, respectively. For deep-breathing an underestimation of the inhale amplitude was observed (RMSE=4.1mm). Respiratory-induced antero-posterior and lateral motion were correctly mapped (RMSE=0.6/0.5mm). Kidney motion demonstrated good motion estimation with RMSE-values of 0.95 and 2.4mm for the right and left kidney, respectively. Conclusion: We have demonstrated a method that can calculate dynamic 3D abdominal motion in a large volume

  6. Values of multi-slice spiral computed tomography on predicting hypovolemic shock in patients with severe multiple trauma

    Directory of Open Access Journals (Sweden)

    Yang LI

    2013-01-01

    Full Text Available Objective  To investigate the value of multi-slice spiral computed tomography (MSCT on predicting hypovolemic shock in patients with severe multiple trauma. Methods  The clinical and MSCT data of 63 patients with severe multiple trauma admitted to the Trauma Center from Jan. 2008 to Dec. 2011 were retrospectively reviewed. According to the occurrence of hypovolemic shock in 24 hours after CT scan, the patients were divided into shock group (n=34 and stable group (n=29. Blood pressure, heart rate, shock index and injury severity score (ISS on admission were collected and analyzed. Transverse (T and anteroposterior (AP diameter of inferior vena cava (IVC, diameter of abdominal aorta, CT values of enhanced CT of abdominal organs both in early and late phase were measured. The differences of aforementioned parameters between the two groups were compared by Student's ttest. The values of above indexes showing significant difference between the two groups on predicting hypovolemic shock were analyzed by using receiver operating characteristic (ROC curve and logistic regression analysis. Results  The shock index, ISS and collapsibility index (T/AP of IVC in 4 abdominal levels were significantly greater in shock group than in stable group (P<0.05. In early phase of enhanced CT, the mean CT value of spleen was significantly lower in shock group (93±16HU than in stable group (112±24HU, P<0.01, while the mean CT value of adrenal gland was higher in shock group (153±35HU than in stable group (131±24HU, P<0.01. In delayed phase, the mean CT value of renal medulla was significantly lower in shock group (193±57HU than in stable group (228±53HU, P<0.05. The diagnostic cutoff value of ROC curve of shock index, ISS, collapsibility index (T/AP of IVC, CT value of spleen and adrenal gland in early phase, CT value of renal medulla in delayed phase were 1.19, 19.5, 3.02, 115HU, 150HU and 184HU, respectively. Logistic regression analysis showed that ISS, T

  7. 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

  8. The value of fast low-angle shot 2-dimensional sequence with sliding multi-slice technique in the detection of abdominal metastasis of rectal cancer%滑动多层技术的二维快速小角度激发成像序列在直肠癌腹部转移诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    熊斌; Tobias Baumann; 冯敢生; Arnd-Oliver Schaefer; Mathias Langer

    2008-01-01

    目的 探讨采用滑动多层(SMS)技术的二维快速小角度激发成像(FLASH-2D)序列在直肠癌腹部转移灶诊断中的价值.方法 由2名放射科医师回顾性分析15例经手术病理证实的直肠癌患者资料,15例均接受SMS FLASH-2D MRI和多层螺旋CT(MSCT)检查(4例进行了2次检查).以SMS和MSCT及6个月内所有随诊检查的最终一致意见作为疾病诊断的参考标准.采用Kappa检验评价2种检查方法对于直肠癌肝转移、淋巴结转移和骨转移诊断的一致性和不同观察者对疾病诊断的一致性,并比较2种方法对各种转移病灶诊断的灵敏度.结果 2名医师采用SMS技术都发现了60个病灶中的56个转移灶,灵敏度均为93.33%(56/60);采用MSCT均发现了50个病灶,灵敏度均为83.33%(50/60).对于肝转移灶的诊断,2名医师采用SMS诊断的灵敏度分别为97.44%(38/39)和100%(39/39);采用MSCT诊断的灵敏度均为100%(39/39).对于淋巴结转移的诊断,SMS诊断的灵敏度为85.71%(12/14)和71.43%(10/14);MSCT分别为78.57%(11/14)和71.43%(10/14).对骨转移灶的诊断,SMS的灵敏度分别为85.71%(6/7)和100%(7/7);MSCT分别为0(0/7)和14.29%(1/7).结论 SMS FLASH-2D序列在对直肠癌肝转移和淋巴结转移诊断上有和MSCT相同的能力,对于骨转移灶的诊断则明显较MSCT敏感.%Objective To evaluate the potential of a sliding multi-slice (SMS)fast low-angbe shot 2-dimensional (FLASH-2D) sequence for abdominal lesion detection in patients with rectal cancer.Methods Nineteen paired SMS MRI( FLASH-2D sequnce) and MSCT examinations of the whole abdomen and pelvis in 15 patients (four of them were examined twice) with rectal cancer were retrospectively analyzed by two radiologists.While the lesion-based agreement between the two methods and the diagnostic agreement between two observers were tested by means of Kappa statistics,the sensitivities of SMS FLASH-2D and MSCT to detect liver metastases,lymph node metastases and bone

  9. Diagnostic value of multi-slice spiral CT in sternum fracture%多层螺旋CT对胸骨骨折诊断价值

    Institute of Scientific and Technical Information of China (English)

    黎健樟; 郭冬梅

    2014-01-01

    Objective:To explore the clinical value of multi-slice spiral CT expedition in the diagnosis of sternum fracture. Methods:28 cases with sternum fracture were selected from 2011 to 2013.They were as the research objects.At the same time,the multi-slice spiral CT diagnosis data were comprehensively reviewed and analyzed.Results:28 cases in this group were confirmed by multi-slice spiral CT and multiplanar reconstruction (MPR).The diagnose accordance rate was 100%.18 cases(64.29%) were diagnosed manubrium fracture.10 cases(35.71% ) were diagnosed mesosternum fracture.5 cases(17.86% ) were combined with substernal mediastinal emphesema.12 cases(42.86%) were combined with substernal mediastinal hematoma by CT scan and MPR reestablishment.Conclusion:The multi-slice spiral CT in the diagnosis of sternum fracture has ideal and reliable diagnosis effect.It is the key for clinical diagnosis of the disease as early as possible and formulating targeted treatment schedule in the future.It suggests strengthen the popularization in clinical.%目的:探讨在胸骨骨折的诊断中应用多层螺旋CT探查的临床价值。方法:2011-2013年收治胸骨骨折患者28例,作为本次研究对象,同时与其多层螺旋CT诊断资料相结合,进行综合性回顾与分析。结果:本组28例病例均经多层螺旋 CT 检查或多平面重建(MPR)后确诊,诊断符合率100%。包括18例(64.29%)诊断为胸骨柄骨折,10例(35.71%)诊断为胸骨体骨折。其中5例(17.86%)合并胸骨后纵隔气肿,12例(42.86%)经CT扫描、MPR重建后提示合并胸骨后纵隔血肿。结论:为胸部骨折患者提供多层螺旋CT诊断,能够起到理想、可靠的诊断效果,是今后临床尽早诊断本病并制定有针对性治疗方案的关键,建议临床加强普及。

  10. Multi-slice spiral CT in routine diagnosis of suspected acute left-sided colonic diverticulitis: a prospective study of 120 patients

    Energy Technology Data Exchange (ETDEWEB)

    Werner, A.; Diehl, S.J.; Dueber, C. [Institut fuer Klinische Radiologie, Universitaetsklinikum Mannheim, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim (Germany); Farag-Soliman, M. [Chirurgische Klinik, Universitaetsklinikum Mannheim, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim (Germany)

    2003-12-01

    This prospective study evaluated the use of multi-slice CT (MSCT) for detection of clinically suspected left-sided colonic diverticulitis with regard to diagnosis, complications and alternative diagnoses. One hundred twenty patients with clinically suspected acute left-colonic diverticulitis underwent MSCT of the lower abdomen with IV contrast after rectal application of iodic contrast. The MSCT results were compared with histopathological and intraoperative findings or other radiological or endoscopic methods and clinical outcome. Acute diverticulitis was proven in 67 of the 120 (55.8%) patients, which was detected by MSCT with an accuracy of 98% (sensitivity 97%, specificity 98%). Contained perforation or abscess formation were detected with an accuracy of 96% (sensitivity 100%, specificity 91%) and 98% (sensitivity 100%, specificity 97%), respectively. In 31 of 120 (25.8%) patients diagnoses other than diverticulitis caused abdominal pain, which was correctly diagnosed by MSCT in 71%. The MSCT as well as other concurrently performed diagnostic methods showed normal findings and no causes for the patients symptoms in 22 of the 120 (18.4%) patients. Multi-slice CT is reliable in detecting diverticulitis, including extracolic complications, and often reveals other diagnoses; therefore, MSCT is recommended as standard diagnostic procedure in suspected acute diverticulitis. (orig.)

  11. 胰腺导管内乳头状黏液性肿瘤的MSCT和MRCP诊断%Multi-slice CT and MR cholangio-pancreatographic diagnosis of intraductal papillary mucinous neoplasm of the pancreas

    Institute of Scientific and Technical Information of China (English)

    张超; 弓静; 郭帅; 殷长均

    2011-01-01

    Objective To evaluate the multi- slice CT (MSCT) and magnetic resonance cholangio- pancreatography (MRCP) features of intraductal papillary mucinous neoplasm (IPMN) ofthe pancreas.Methods The CT and MRCP of 26 cases of IPMN including adenocarcinoma (6 cases), borderline malignancy (2), and adenoma (1) were reviewed.Results CT and MRI of IPMN in the pancreatic ductal branches (12 cases) showed solitary or multiple cystic lesions with septa or nodules in the ducts.In the 5 patients with main pancreatic duct IPMN, there was dilation of the main pancreatic duct with mural nodule.In 9 patients with mixed type pancreatic IPMN, dilation of the main pancreatic duct and cystic lesions were noted.Conclusion MSCT and MRCP are useful in the diagnosis ofpancreatic IPMN.%目的 探讨胰腺导管内乳头状黏液性肿瘤 (IPMN)的MSCT和MRCP影像学表现.方法 对26例经内镜或手术病理证实的IPMT患者的CT和MRCP表现进行回顾性分析.结果 分支胰管型IPMN12 例,表现为单发囊性病变或葡萄串样多发囊性病变伴腔内分隔或结节样突起;主胰管型 IPMN 5 例,表现为主胰管扩张伴管壁结节样突起;混合型IPMN 9例,表现为主胰管扩张和囊性病变合并存在.9例手术病理结果为腺瘤1例,交界性肿瘤2例,腺癌6例.结论 MSCT和MRCP对发现和诊断胰腺 IPMN具有较高价值.

  12. 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.

  13. Detachment within subducted continental crust and multi-slice successive exhumation of ultrahigh-pressure metamorphic rocks: Evidence from the Dabie-Sulu orogenic belt

    Institute of Scientific and Technical Information of China (English)

    LIU YiCan; LI ShuGuang

    2008-01-01

    Although tectonic models were presented for exhumation of ultrahigh-pressure (UHP) metamorphic rocks during the continental collision, there is increasing evidence for the decoupling between crustal slices at various depths within deeply subducted continental crust. This lends support to the multi-slice successive exhumation model of the UHP metamorphic rocks in the Dabie-Sulu orogen. The available evidence is summarized as follows: (1) the low-grade metamorphic slices, which have geotectonic af-finity to the South China Block and part of them records the Triassic metamorphism, occur in the northern margin of the Dabie-Sulu UHP metamorphic zone, suggesting decoupling of the upper crust from the underlying basement during the initial stages of continental subduction; (2) the Dabie and Sulu HP to UHP metamorphic zones comprise several HP to UHP slices, which have an increased trend of metamorphic grade from south to north but a decreased trend of peak metamorphic ages corre-spondingly; and (3) the Chinese Continental Science Drilling (CCSD) project at Donghai in the Sulu orogen reveals that the UHP metamorphic zone is composed of several stacked slices, which display distinctive high and low radiogenic Pb from upper to lower parts in the profile, suggesting that these UHP crustal slices were derived from the subducted upper and middle crusts, respectively. Detachment surfaces within the deeply subducted crust may occur either along an ancient fault as a channel of fluid flow, which resulted in weakening of mechanic strength of the rocks adjacent to the fault due to fluid-rock interaction, or along the low-viscosity zones which resulted from variations of geotherms and lithospheric compositions at different depths. The multi-slice successive exhumation model is different from the traditional exhumation model of the UHP metamorphic rocks in that the latter as-sumes the detachment of the entire subducted continental crust from the underlying mantle lithosphere and its

  14. 多层螺旋CT重建技术诊断齿状突骨折%Diagnostic Value of Multi-slice CT in Odontoid Process Fracture

    Institute of Scientific and Technical Information of China (English)

    赵晖; 王林森; 陈思; 潘涛; 蔡琳

    2013-01-01

      Objective To evaluate the value of reconstruction of multi-slice CT in the diagnosis of odon⁃toid process fracture. Methods CT imaging of 43 patients with odontoid process fracture were analysed,and then three-dimentional reconstruction were made. Results The patients were classified into 3 types according to the part of fracture. Type I was shown in 1 case, type II was in 28 cases and type III was in the other 14 cas⁃es. Odontoid were displaced posteriorly and anteriorly in 17 and 13 cases, and there were no displacement in 13 cases. Conclusion Three-dimentional reconstruction of multi-slice CT has great value in the diagnostic part⁃ing and treating plan of odontoid process fracture.%  目的:探讨多层螺旋CT重建技术在诊断齿状突骨折中的价值。方法:分析43例齿状突骨折患者的CT资料,以及三维重建资料。结果:根据骨折部位将齿状突骨折分为3型,I型1例,II型28例,III型14例,齿状突向前移位17例,向后移位13例,无移位13例。结论:多层螺旋CT三维重建技术对于齿状突骨折的诊断分型及治疗方案的确定有指导作用。

  15. The relationship between MRI and PET changes and cognitive disturbances in MS

    DEFF Research Database (Denmark)

    Sørensen, Per Soelberg; Jønsson, Agnete; Kahr Mathiesen, Henrik

    2006-01-01

    of the brain including abnormalities in normal appearing white matter (NAWM) and cortical grey matter, which is undetected with conventional magnetic resonance imaging (MRI). Hence, imaging techniques that embrace such abnormalities are needed to achieve better correlation with cognitive dysfunction. MR...... grey matter. Measurements of global NAA using multi-slice EPSI is a new promising method for measurement of the global neuron capacity and can be repeated with only little discomfort and without any risk for the patient....

  16. 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

  17. 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

  18. 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.

  19. Finite element modeling of stress distributions and problems for multi-slice longwall mining in Bangladesh, with special reference to the Barapukuria coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Rafiqul; Hayashi, Daigoro [Simulation Tectonics Laboratory, Department of Physics and Earth Sciences, University of the Ryukyus, Okinawa, 903-0213 (Japan); Kamruzzaman, A.B.M. [Geology Division, Barapukuria Coal Mining Company Limited, Chowhati, Parbatipur, Dinajpur (Bangladesh)

    2009-04-01

    This paper deals with current coal mining operations under a mega-aquifer in NW Bangladesh, and presents a case study of underground mining in Barapukuria. The study uses numerical analyses to evaluate stress redistribution, strata failure, and water inflow enhancements that result from these coal extraction operations. A total of three models (A, B, and C) are presented in this study. Two-dimensional numerical modeling was performed to analyze the deformation and failure behavior of rock elements for two different models (A and B). For model A, we used an elastic finite element software package considering a Mohr-Coulomb failure criterion. For model B, we used boundary element method (BEM). The first two models were applied to determine the stress patterns. Model A provides the tectonic stress pattern of the basin, whereas model B represents the mining-induced stress field. The third model is a schematic model. The results of model A show that tensional failure of rock elements is concentrated in the Gondwana coal sequences as well as within the Eastern Boundary Fault (EBF) and its surroundings. Failure occurs in the middle to lower part of the model, and the magnitude of tensional stress in the shallow part is much greater than in the deeper part. Contours of {tau}{sub max} magnitudes are attributed to up-bending of the overburden, which would create numerous upward propagating fissures/fractures. The results of model B show that fracture propagation would be about 240 m upward for single-slice (height 3 m) mining extraction. From the contours of mean stress magnitudes, it is observed that the high range of fracture propagation increased upward for multi-slice extraction of coal. It is apparent from the fracture heights that large amounts of caving would occur towards the roof due to the multi-slice extraction of coal, and finally would be linked with the water-bearing Dupi Tila Formation. If this happened, it would ultimately cause a major water inflow hazard in

  20. Long-term follow-up of surgically excluded popliteal artery aneurysms with multi-slice CT angiography and Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Deglise, Sebastien; Haller, Claude; Corpataux, Jean-Marc [CHUV, Department of Thoracic and Vascular Surgery, Lausanne (Switzerland); Qanadli, Salah D.; Rizzo, Elena; Doenz, Francesco; Denys, Alban [University Hospital CHUV-University of Lausanne, Department of Radiology, Lausanne (Switzerland); Ducrey, Nicolas [CHUV, Department of Angiology, Lausanne (Switzerland)

    2006-06-15

    The purpose of this study was to evaluate the role of multi-slice computed tomography (MSCT) angiography in the follow-up of popliteal artery aneurysms (PAAs) that have been operated on. Aneurysm exclusion and progression, graft patency and graft-related complications were analyzed. Fourteen patients with 21 surgically excluded PAAs were evaluated with MSCT angiography with slice thickness of 1.25 mm. The mean follow-up time was 67 months. MSCT demonstrated blood flow in six non-excluded PAAs (24%), with an average increase in the diameter of 21 mm over time. Fifteen PAAs demonstrated no blood flow and revealed an average decrease of 7 mm in diameter. The origin of this residual perfusion was demonstrated, and collaterals were involved in five of six non-excluded PAAs. In addition, MSCT demonstrated three graft stenoses. Furthermore, two occluded grafts were visualized. Twenty-four percent of the patients after surgical exclusion of PAAs revealed residual perfusion within the aneurysmal sac during follow-up, with a significant increase in the aneurysmal size with MSCT. Moreover, evaluation of the graft patency could also be done as could demonstration of anastomotic abnormalities. Thus, MSCT might be considered as a new tool to evaluate residual collateral feeding of popliteal aneurysmal sac and could be useful in identification and localization of feeding vessels. (orig.)

  1. Physical dose distribution due to multi-sliced kV X-ray beam in labeled tissue-like media: An experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, M., E-mail: mghasemi@nrcam.or [Agricultural Medical and Industrial Research School, NSTRI, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of); Kakuee, O.R.; Fathollahi, V. [Van de Graaff Laboratory, Nuclear Science Research School, NSTRI, P.O. Box 14395-836, Tehran (Iran, Islamic Republic of); Shahvar, A.; Mohati, M.; Ghafoori, M. [Agricultural Medical and Industrial Research School, NSTRI, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of)

    2011-02-15

    Radiotherapy remains a major modality of cancer therapy. Thanks to high flux and high brilliance of synchrotron-generated X-ray, laboratory research with planar microscopically thin X-ray beam promise exciting new opportunities for treatment of cancer. High tolerance of normal tissues at doses up to several hundred Gy in a single dose fraction and preferential damage of tumors at very high doses have been uniquely observed in animal models exposed to microbeams. The fact that beams as thick as 0.68 mm could retain a part of these effects, opens the possibility that the required beam can be produced by high power X-ray tubes besides a dedicated synchrotron. Fortunately, dose distribution due to kilovolt X-rays could be enhanced by the introduction of high-Z contrast agents to tissue-like media. In this work, dose deposition in a phantom-partially loaded with Au and I as contrast agents-irradiated by multi-sliced kV X-ray beam was experimentally investigated in the peak and valley regions both on the surface and in the depth of phantom. The results of experimental dosimetry using Gaf-chromic films were compared with corresponding Monte-Carlo simulation. Relative reduction in the deposited dose in the peak regions downstream the area containing contrast agents in comparison with the adjacent areas was experimentally observed.

  2. Physical dose distribution due to multi-sliced kV X-ray beam in labeled tissue-like media: an experimental approach.

    Science.gov (United States)

    Ghasemi, M; Kakuee, O R; Fathollahi, V; Shahvar, A; Mohati, M; Ghafoori, M

    2011-02-01

    Radiotherapy remains a major modality of cancer therapy. Thanks to high flux and high brilliance of synchrotron-generated X-ray, laboratory research with planar microscopically thin X-ray beam promise exciting new opportunities for treatment of cancer. High tolerance of normal tissues at doses up to several hundred Gy in a single dose fraction and preferential damage of tumors at very high doses have been uniquely observed in animal models exposed to microbeams. The fact that beams as thick as 0.68 mm could retain a part of these effects, opens the possibility that the required beam can be produced by high power X-ray tubes besides a dedicated synchrotron. Fortunately, dose distribution due to kilovolt X-rays could be enhanced by the introduction of high-Z contrast agents to tissue-like media. In this work, dose deposition in a phantom--partially loaded with Au and I as contrast agents--irradiated by multi-sliced kV X-ray beam was experimentally investigated in the peak and valley regions both on the surface and in the depth of phantom. The results of experimental dosimetry using Gaf-chromic films were compared with corresponding Monte-Carlo simulation. Relative reduction in the deposited dose in the peak regions downstream the area containing contrast agents in comparison with the adjacent areas was experimentally observed.

  3. Trabecular bone structure parameters from 3D image processing of clinical multi-slice and cone-beam computed tomography data

    Energy Technology Data Exchange (ETDEWEB)

    Klintstroem, Eva; Smedby, Oerjan [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); UHL County Council of Oestergoetland, Department of Radiology, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Moreno, Rodrigo [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Brismar, Torkel B. [KUS Huddinge, Department of Clinical Science, Intervention and Technology at Karolinska Institutet and Department of Radiology, Stockholm (Sweden)

    2014-02-15

    Bone strength depends on both mineral content and bone structure. The aim of this in vitro study was to develop a method of quantitatively assessing trabecular bone structure by applying three-dimensional image processing to data acquired with multi-slice and cone-beam computed tomography using micro-computed tomography as a reference. Fifteen bone samples from the radius were examined. After segmentation, quantitative measures of bone volume, trabecular thickness, trabecular separation, trabecular number, trabecular nodes, and trabecular termini were obtained. The clinical machines overestimated bone volume and trabecular thickness and underestimated trabecular nodes and number, but cone-beam CT to a lesser extent. Parameters obtained from cone beam CT were strongly correlated with μCT, with correlation coefficients between 0.93 and 0.98 for all parameters except trabecular termini. The high correlation between cone-beam CT and micro-CT suggest the possibility of quantifying and monitoring changes of trabecular bone microarchitecture in vivo using cone beam CT. (orig.)

  4. 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.

  5. 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.

  6. 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。

  7. 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.

  8. Development of modern human subadult age and sex estimation standards using multi-slice computed tomography images from medical examiner's offices

    Science.gov (United States)

    Stock, Michala K.; Stull, Kyra E.; Garvin, Heather M.; Klales, Alexandra R.

    2016-10-01

    Forensic anthropologists are routinely asked to estimate a biological profile (i.e., age, sex, ancestry and stature) from a set of unidentified remains. In contrast to the abundance of collections and techniques associated with adult skeletons, there is a paucity of modern, documented subadult skeletal material, which limits the creation and validation of appropriate forensic standards. Many are forced to use antiquated methods derived from small sample sizes, which given documented secular changes in the growth and development of children, are not appropriate for application in the medico-legal setting. Therefore, the aim of this project is to use multi-slice computed tomography (MSCT) data from a large, diverse sample of modern subadults to develop new methods to estimate subadult age and sex for practical forensic applications. The research sample will consist of over 1,500 full-body MSCT scans of modern subadult individuals (aged birth to 20 years) obtained from two U.S. medical examiner's offices. Statistical analysis of epiphyseal union scores, long bone osteometrics, and os coxae landmark data will be used to develop modern subadult age and sex estimation standards. This project will result in a database of information gathered from the MSCT scans, as well as the creation of modern, statistically rigorous standards for skeletal age and sex estimation in subadults. Furthermore, the research and methods developed in this project will be applicable to dry bone specimens, MSCT scans, and radiographic images, thus providing both tools and continued access to data for forensic practitioners in a variety of settings.

  9. Value of multi-slice helical CT for diagnosing colonic diverticulitis%多层螺旋CT在结肠憩室炎诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    万荣超; 邓德茂; 袁文昭; 陈文福; 李敏; 廖海; 陈加军

    2014-01-01

    Objective To determine the multi-slice spiral computed tomography(MSCT)features of colonic diverticulitis. Methods The clinical information and MSCT of 11 patients with pathologically confirmed colonic diverticulitis were retrospectively analyzed.Results CT showed colonic diverticula with surrounding fat stranding(10)and fecalith in the diverticula(7),pericolonic fat stranding and pneumoperitoneum(1),colon wall thickening(9),bowel perforation(5)with pneumoperitoneum(3)and hematoma(1). Conclusion MSCT displays clearly the pathological changes and complications of colonic diverticulitis.%目的:分析结肠憩室炎MSCT表现,以提高对该病的认识和诊断水平。方法回顾性分析11例经结肠镜检或手术病理证实结肠憩室炎病例的临床及MSCT资料,并结合文献复习。所有病例均作腹盆部CT平扫检查,其中2例加作CT增强检查,总结结肠憩室炎的MSCT表现特征。结果 CT表现为结肠肠壁囊袋状突出并周围脂肪密度增高10例,其中憩室内粪石7例,仅表现为肠壁周围脂肪密度增高及气腹征者1例,结肠肠壁增厚9例,憩室炎穿孔5例,其中气腹3例,合并出血1例。结论 MSCT能较好的显示结肠憩室炎病变及其并发症,对结肠憩室炎有较高的诊断价值。

  10. Diagnostic Value of Multi-slice CT for Thoracic Trauma%多排螺旋CT在胸部外伤诊断中的价值分析

    Institute of Scientific and Technical Information of China (English)

    王兵萍; 吴涛; 朱海峰; 贾亚男

    2016-01-01

    目的:探讨多排螺旋CT在胸部外伤中的应用价值。方法回顾性分析200例胸部外伤患者的常规X线平片和胸部CT(包括肋骨三维重建)图像,对两种检查方法发现的肋骨骨折、肺挫裂伤、气胸、胸腔积液、软组织肿等征象进行统计学分析。结果两种检查方法在肋骨骨折、肺挫裂伤、气胸、胸腔积液、软组织肿等方面均有显著性差异。结论多排螺旋CT能够对胸部外伤患者做出更加精准的伤情诊断,与X线平片相比有更高的应用价值。%Objective To discuss the clinical application of multi-slice CT in the thoracic trauma.Methods Retrospective analysis of 200 cases of thoracic trauma patients with conventional X-ray plain film, chest CT (includ ribs three-dimensional reconstruction image). Found two inspection methods for affected side thoracic bone fractures, pulmonary contusion, pneumothorax, hydrothorax, soft tissue swelling of signs for statistics and analysis.Result Two methods of checking in affected side fractured ribs, pulmonary contusion, pneumothorax, hydrothorax, soft tissue swelling, etc ,have significant difference.Conclusion MSCT can make more accurate judgment injury in patients with thoracic trauma, compared with X-ray plain film has a higher application value.

  11. 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.

  12. Comparison of Cone Beam Computed Tomography and Multi Slice Computed Tomography Image Quality of Human Dried Mandible using 10 Anatomical Landmarks

    Science.gov (United States)

    Saati, Samira; Kaveh, Fatemeh

    2017-01-01

    Introduction Cone Beam Computed Tomography (CBCT) has gained a broad acceptance in dentomaxillofacial imaging. Computed Tomography (CT) is another imaging modality for diagnosis and preoperative assessments of the head and neck region. Aim Considering the increased radiation exposure and high cost of CT, this study sought to subjectively assess the image quality of CBCT and Multi Slice CT (MSCT). Materials and Methods A dry human mandible was scanned by five CBCT systems (New Tom 3G, Scanora, CRANEX 3D, Promax and Galileos) and one MSCT system. Three independent oral and maxillofacial radiologists reviewed the CBCT and MSCT scans for the quality of 10 landmarks namely mental foramen, trabecular bone, Periodontal Ligament (PDL), dentin, incisive canal, mandibular canal, dental pulp, enamel, lamina dura and cortical bone using a five-point scale. Results Significant differences were found between MSCT and CBCT and among the five CBCT systems (p<0.05) in visualization of different anatomical structures. A fine structure such as the incisive canal was significantly less visible and more variable among the systems in comparison with other anatomical landmarks such as the mental foramen, mandibular canal, cortical bone, dental pulp, enamel and dentin (p<0.05). The Cranex 3D and Promax systems were superior to MSCT and all other CBCT systems in visualizing anatomical structures. Conclusion The CBCT image quality was superior to that of MSCT even though some variability existed among different CBCT systems in visualizing fine structures. Considering the low radiation dose and high resolution, CBCT may be beneficial for dentomaxillofacial imaging. PMID:28384972

  13. 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.)

  14. 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

  15. 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

  16. 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

  17. Evaluation of multi-slice spiral CT in diagnosis of abdominal cocoon%多层螺旋CT在诊断腹茧症中的价值

    Institute of Scientific and Technical Information of China (English)

    何剑; 沈健; 周玮; 祝跃明

    2015-01-01

    目的:探讨多层螺旋 CT(MSCT)在诊断腹茧症中的价值。方法回顾性分析6例经手术病理证实为腹茧症患者的MSCT 资料,采集数据在工作站用平面重建(MPR)、最大密度投影(MIP)及容积重建(VR)技术进行三维重建,观察病灶的空间解剖关系。结果6例均可见局部小肠及其系膜结构聚集成团,肠管折叠盘绕排列呈“手风琴”状或“香蕉”状。肠袢周围可见低密度的纤细纤维包膜,包膜厚薄不一,增强后纤维包膜强化轻度。受累小肠系膜血管走行异常,呈现肠系膜及其血管聚集、牵拉。结论MSCT 可以提供丰富的诊断信息,是腹茧症的首选检查方法。%Objective To investigate the value of multi-slice CT in diagnosis of abdominal cocoon.Methods CT findings of six cases with pathologically proved abdominal cocoon were collected and analyzed retrospectively.The three-dimensional imagines were obtained including multi-planar reconstruction(MPR),maximum intensity projection(MIP)and volume rendering(VR)at workstation,the rela-tionships between the lesions and surrounding structure were observed.Results A group of local small intestine were seen gathered in all six cases,the coiled intestine arranged in"accordion"shape or"banana"shape.The fibrous capsule were seen around them with different thickness,which were low density and slightly enhancement.Mesenteric arteries showed abnormal changes,showing ten-sion,aggregation.Conclusion MSCT can provide a wealth of diagnostic information and is the best method of examination abdomi-nal cocoon.

  18. Value of multi-slice CT in patients with congenital inner ear malformation before cochlear implantation%多层螺旋CT在内耳畸形的人工耳蜗植入术前评估中的价值

    Institute of Scientific and Technical Information of China (English)

    吴琛; 熊玉伟; 周运锋

    2015-01-01

    目的:探讨多层螺旋CT在患有内耳畸形的人工耳蜗植入术前评估中的价值。方法:搜集我院因听力障碍拟行人工耳蜗植入的患者34例,所有患者均行多层螺旋CT检查。结果:34例患者中患内耳畸形的有10例共19耳,多数病耳合并多种畸形,其中耳蜗畸形8耳,前庭导水管扩大畸形8耳,前庭、半规管畸形4耳,内听道发育异常3耳。结论:多层螺旋CT扫描结合后处理技术可以更加准确地对内耳畸形做出诊断,在人工耳蜗植入术前具有重要的指导价值。%Objective:To evaluate the value of multi-slice CT in patients with congenital inner ear malformation before cochlear implantation .Methods:Multi-slice CT was performed in 34 patients with hearing impairment before cochlear implantation .Results:In 34 patients,inner ear malformation was de-tected in 10(19 ears),and more cases were complicated with multiple malformations,in which 8 cases were cochlear malformations,8 enlarged vestibular aqueduct malformation,4 vestibule and semi-circular canal malformations,and 3 internal auditory cannal malformations.Conclusion:Multi-slice CT can make accurate diagnosis of congenital inner ear malformations before cochlear implantation .

  19. 多排螺旋CT在胃肠道肿瘤及并发症的诊断价值%Multi-slice Spiral CT in the Diagnosis of Gastrointestinal Tumor and Complications

    Institute of Scientific and Technical Information of China (English)

    高云; 郑晓林; 尹昌媛

    2013-01-01

    目的 探讨多排螺旋CT在胃肠道肿瘤及并发症的诊断价值. 材料和方法 回顾性分析43例胃肠道肿瘤的多排螺旋CT表现,观察分析胃肠道肿瘤的直接CT征象及并发症征象.结果 CT可以直接发现胃肠道肿块的32例,肠管壁增厚11例,肠梗阻18例,肠套叠3例,肠扭转5例,消化道出血1例,肠系膜血管增粗26,肠系膜淋巴结肿大15例,肝脏转移7例,大网膜转移3例.结论 多排螺旋CT在消化道肿瘤的诊断方面有较高的临床实用价值,值得推广应用.%Objective To investigate diagnostic value of multi-slice spiral CT on the gastrointestinal tumor and complications.Materials and methods Multi-slice spiral CT performance of 43 patients with gastrointestinal tumors were retrospectively analyzed,to observe and analyze direct CT findings and complications CT findings of gastrointestinal tumors.Results 32 cases of the gastrointestinal masses could be directly found by multislice spiral CT; 11 cases of bowel wall thickening; 27 cases of intestinal obstruction; 3 cases of intussusception; 5 cases of volvulus; 1 case of gastrointestinal bleeding; 26 cases of mesenteric vascular thickening; 15 cases of mesenteric lymph nodes; 7 cases of liver metastases; 3 cases of omentum metastasis.Conclusion Multi-slice spiral CT in the diagnosis of gastrointestinal tumors had higher clinical value,should be widely applied.

  20. Multi-slice spiral CT of aortocoronary grafts and internal mammary artery bypasses: Assessment of bypasses and their anastomoses; Mehrzeilen-Spiral-CT von aortokoronaren Venenbypaessen und Mammaria-interna-Bypaessen: Beurteilung der Bypaesse und ihrer Anastomosen

    Energy Technology Data Exchange (ETDEWEB)

    Froehner, S.; Wagner, M.; Schmitt, R.; Christopoulos, G.; Coblenz, G. [Inst. fuer Diagnostische und Interventionelle Radiologie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany); Brunn, J.; Mueller, M.; Kerber, S. [Fachbereich Kardiologie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany); Urbanski, P. [Klinik fuer Herzchirurgie, Herz- und Gefaessklinik GmbH, Bad Neustadt an der Saale (Germany)

    2002-07-01

    Objective: To assess aortocoronary grafts and internal mammary artery bypasses by means of EKG-triggered contrast-enhanced multi-slice spiral CT, and to evaluate the diagnostic accuracy of this new imaging modality. Material and methods: 59 patients with up to 5 aortocoronary grafts and/or internal mammary artery bypasses per patient were examined with regard to bypass morphology, the free passage, and the proximal as well as the distal anastomoses using multi-slice computed tomography. Axial source images were calculated by means of retrospective triggering at different diastolic delay times, and were postprocessed in several planes with the multiplanar volume reconstruction (MPVR) software. Results: On the pre-condition that data sets were acquired at sinus rhythm and at a heart rate lower than 65/min, aortocoronary grafts and internal mammary artery bypasses could be depicted in adequate diagnostic quality in about 80% of all cases with contrast-enhanced multi-slice spiral CT. Both, the free passage of the bypasses as well as the morphology of the proximal anastomoses were sufficiently assessed with multiplanar volume reconstruction (MPVR), whereas the distal anastomoses couldn't be depicted sufficiently in 20% of all cases. Conclusion: As a non-invasive method, contrast-enhanced and ECG-triggered multi-slice spiral computed tomography has gained diagnostic potential for the accurate visualization of aortocoronary grafts and the internal mammary artery bypasses. (orig.) [German] Ziel: Die vorliegende Arbeit stellt die Moeglichkeiten der kontrastmittelverstaerkten, EKG-getriggerten Mehrzeilen-Computertomographie in der Beurteilung von aortokoronaren Venenbypaessen und Mammaria-interna-Bypaessen dar. Material und Methode: Bei 59 Patienten mit 1 bis 5 aortokoronaren Venen-Bypaessen bzw. Mammaria-interna-Bypaessen wurden deren Morphologie, Durchgaengigkeit, die proximalen Anastomosen und die distalen Insertionsstellen mittels Mehrzeilen-Spiral-CT untersucht

  1. 2D semiconductor optoelectronics

    Science.gov (United States)

    Novoselov, Kostya

    The advent of graphene and related 2D materials has recently led to a new technology: heterostructures based on these atomically thin crystals. The paradigm proved itself extremely versatile and led to rapid demonstration of tunnelling diodes with negative differential resistance, tunnelling transistors, photovoltaic devices, etc. By taking the complexity and functionality of such van der Waals heterostructures to the next level we introduce quantum wells engineered with one atomic plane precision. Light emission from such quantum wells, quantum dots and polaritonic effects will be discussed.

  2. 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

  3. Diagnosis of acute mesenteric ischemia with multi-slice spiral CT%急性肠系膜缺血的MSCT诊断

    Institute of Scientific and Technical Information of China (English)

    贾乾君; 梁长虹; 张水兴; 刘再毅

    2011-01-01

    目的:探讨MSCT对急性肠系膜缺血的诊断价值.方法:回顾性分析经手术或介入治疗证实的36例急性肠系膜缺血患者的CT表现.所有患者均行CT检查,包括平扫、增强扫描动脉期、增强扫描门脉期并进行血管重建.后处理采用容积显示技术(VRT)、多平面重组(MPR)和薄层最大密度投影(MIP)进行动脉和门脉成像.结果:肠系膜上动脉栓塞5例,肠系膜上动脉狭窄6例,肠系膜上静脉血栓形成25例.CT直接征象为血管内充盈缺损(30例)或狭窄(6例).间接征象包括:肠管扩张、肠腔内积液积气(22例),肠壁增厚(14例),肠壁薄纸样改变(3例),肠壁积气(3例).肠系膜脂肪水肿及渗出(4例).结论:MSCT与其三维重组技术相结合是诊断急性肠系膜缺血的一种有效且无创的影像检查方法,可以明确阻塞动脉的部位及范围,对手术有较高的指导价值.%Objective : To study the clinical value of multi-slice spiral CT(MSCT) in the diagnosis of acute mesenteric ischemia. Methods:The CT features of 36 patients with surgery/interventional therapy proved acute mesenteric ischemia were reviewed retrospectively. All patients underwent MSCT scanning,including plain scan, arterial phase and portal vein phase scanning after contrast administration. Post-processing techniques including volume rendering, multi-planar reformation and thin-section maximum intensity projection were performed to assess the mesenteric artery and vein, as well as the portal vein. Results:There were 5 cases of superior mesenteric artery embolism,6 cases of superior mesenteric artery stenosis and 25 cases of superior mesenteric vein thrombosis. The direct CT signs were filling defect (n=30) or stenosis (n=6)of mesenteric vessels. The indirect CT signs includcd: dilatation of bowel loops with air-fluid levels (n=22) , bowel wall thickening ( n= 14) , paper-like thin wall sign ( n= 3) , pneumatosis of bowel wall ( n= 3) , edema and exudation of mesenteric

  4. 小儿消化道重复畸形的MSCT表现%Multi-slice CT characteristics of gastro-intestinal tract duplication in children

    Institute of Scientific and Technical Information of China (English)

    谢婵来; 龚英; 李国平; 帕米尔; 张大江; 王莉; 乔中伟; 缪飞

    2013-01-01

    目的:探讨MSCT对小儿消化道重复畸形的诊断价值.方法:回顾性分析27例经手术病理证实的小儿消化道重复畸形病例,分析其CT表现,包括囊肿部位、形态、密度和囊壁厚度,并分析其相关并发症.结果:27例消化道重复畸形中发生在食管2例,胃3例,胃合并食管1例,小肠19例,结肠2例.囊肿形态在CT上表现为圆形23例、管形3例、圆形-管形复合型1例.25例囊肿CT平扫为液性低密度,1例合并囊内出血呈高密度,1例囊内可见气体.囊壁厚度大于同层面肠壁者有22例,囊壁均有强化,2例囊壁可见钙化.27例囊肿中,6例出现并发症,包括囊内出血1例,囊肿破裂穿孔伴胰腺炎1例,继发肠梗阻4例.结论:低密度液性囊肿(偶见气体)、厚壁、管形或圆形-管形复合型形态是消化道重复畸形特征性的CT表现.CT对诊断消化道重复畸形合并肠旋转不良、肠闭锁等畸形和(或)伴发肠梗阻、肠扭转等病变颇具优势.%Objective:To assess the value of multi-slice CT (MSCT) in the diagnosis of gastro-intestinal tract (GI tract) duplication in children. Methods: The MSCT findings of 27 children with surgery and pathology proven GI tract duplication were retrospectively analyzed,including the location,size,density and wall thickness of duplication cyst,as well as the complications. Results:In Of these 27 cases, the duplication located at esophagus (n= 2) , storach and esophagus (n=1) , stomach (n=3) ,small intestine (n=19) and colon (n=2). The shape of duplication cyst was round (n=23) ,tubular (n= 3) and round-tubular (n=l). On plain CT,the density of duplication cyst was fluid-like with low attenuation (n=25) , but one presented as high density due to intra-cystic hemorrhage,and one with small amount of intra-cystic air. The cystic wall was thicker than the intestinal wall on the same slice (n=22) and all of the cystic wall enhanced after contrast administration. Calcification of cystic wall was

  5. 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.

  6. 腮腺腺淋巴瘤的多排螺旋CT表现特点%Characteristics of parotid gland lymphoma observed by multi-slice spiral CT

    Institute of Scientific and Technical Information of China (English)

    薛晶; 邹新农; 崔兴宇

    2012-01-01

    目的:探讨腮腺腺淋巴瘤的多排螺旋CT表现特点.方法:对我院经手术病理证实的18例腮腺腺淋巴瘤患者的临床和CT图像资料进行总结分析,所有病例均行CT平扫和增强.结果:男16例,女2例;平均年龄58.7岁,在50岁以上者14例.单侧发病15例,双侧发病3例,共23个病灶;位于腮腺后下象限16个,非后下象限7个;呈类圆形17个,圆形5个,有明显分叶状1个;平均最大径为2.4 cm;境界均清晰光整;密度均匀16个,密度不均伴囊变坏死区7个,CT值为16.2~43.5 Hu.增强扫描早期病灶明显强化18个,中度强化5个,CT值上升平均值为(50.3±15.8)Hu;均匀强化16个,不均匀强化7个;延迟期病灶密度迅速降低21个,缓慢降低2个.结论:腮腺腺淋巴瘤好发于50岁以上男性,多位于腮腺后下象限,CT平扫病灶边界清楚光整,呈均匀或者不均匀稍高密度,增强扫描多明显强化,呈"快进快出"特点.%Objective To evaluate the characteristics of parotid gland lymphoma observed by multi-slice spiral CT. Methods Clinical and CT image data of 18 patients with parotid gland lymphoma which were pathologically confirmed in our hospital were analyzed, all patients received CT scan and enhanced scan. Results Among the 18 patients, 16 were males, 2 were females; the average age was 58.7 years, and 14 patients over the age of 50. Fifteen patients with unilateral lymphoma, and 3 patients with bilateral lymphoma, all accounted to a total of 23 lesions. Among all the 23 lesions, 16 located in the following quadrant, 7 located in the following non-inferior quadrant; 17 were similarly round, 5 were round, and 1 was obviously lobulated; the average maximum diameter was 2.4 cm and the boundaries were clear finishing. The density of 16 lesions were uniform, 7 lesions were uneven with cystic necrosis, and the CT value was 16.2 ~ 43.5 Hu. Enhanced scan showed that 18 lesions were significantly enhanced early, 5 lesions were moderately enhanced, and the

  7. 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.

  8. Multi-slice CT in the diagnosis of blunt laryngotracheal trauma%钝性喉气管损伤的MSCT诊断

    Institute of Scientific and Technical Information of China (English)

    王小鹏; 杨军; 刘伟

    2011-01-01

    目的:探讨多层螺旋CT在钝性喉气管损伤(B-LTT)中的临床应用价值.方法:对喉颈部外伤后156例患者使用GE LightSpeed 16层及32层螺旋CT设备行CT检查,其中平扫111例和对比剂增强扫描45例,并通过最大密度投影(MIP)、多平面重组(MPR)、仿真内镜(VE)及客积再现(VR)等影像后处理技术进行喉软骨、喉部软组织三维成像.结果:共发现43例患者喉部损伤,包括软组织损伤28例,喉软骨骨折14例及舌骨骨折1例.喉软骨骨折14例中,甲状软骨骨折12例(右侧甲状软骨5例,左侧甲状软骨骨折3例,甲状软骨前部正中骨折4例).同时合并环状软骨骨折3例,杓状软骨骨折2例,环杓关节脱位3例,环甲关节脱住2例.甲状腺损伤2例,皮下气肿12例,咽喉部血肿3例,颈2椎体骨折1例.MSCT显示喉软骨骨折的直接征象为喉软骨边缘不连续,可见低密度骨折线影,也可伴移位.软组织损伤表现为声门及气道狭窄,伴咽喉部血肿、皮下气肿.喉周围软组织内出现气泡是喉黏膜撕裂的间接征象.结论:螺旋CT可多方位显示喉软骨骨折部位、程度以及气道狭窄和喉黏膜撕裂情况,是诊断喉损伤快速有效的方法.%Objective : To evaluate the value of multi-slice spiral computed tomography (MSCT) in blunt laryngotracheal trauma ( B-LTT). Methods: MSCT was performed in 156 patients with BLTT including 111 patients had plain CT and 45 patients had enhanced CT.3-dimcnsional images of laryngeal cartilages and soft tissues were obtained with post-processing reconstruction techniques including MIP 、 MPR 、 VE and VR. Results: Altogether 43 patients were found to have laryngeal injuries including soft tissue injury ( n=28) ,laryngcal cartilage fracture ( n=14) and hyoid fracture ( n=1). In 14 patients having laryngeal cartilage fracture , there were thyroid cartilage fracture (n= 12 ; with right side , n= 5 ,left side.n= 3 ,anterior-median area n= 4). Concurrently complicated

  9. 多层螺旋CT小肠造影在小肠梗阻诊断中的应用分析%Analysis of Multi-slice Spiral CT and Enterography in Diagnosis of Small Bowel Obstruction

    Institute of Scientific and Technical Information of China (English)

    詹志勇; 王大维; 张鹏; 倪彩红

    2016-01-01

    目的:对小肠梗阻患者应用多层螺旋CT小肠造影诊断的临床效果进行分析研究。方法选取于2014年3月~2015年11月在我院接受治疗的小肠梗阻患者122例,并随机分为对照组和实验组各61例,对分别应用单气囊小肠镜检查以及多层螺旋CT小肠造影检查的效果进行对照研究。结果实验组患者检查诊断小肠梗阻的灵敏度、特异度、阳性预测值、阴性预测值均高于对照组(86.75%、100.00%、100.00%、43.57%vs.78.52%、69.58%、87.89%、31.56%),组间差异有统计学意义(P<0.05)。结论小肠梗阻患者应用多层螺旋CT小肠造影诊断的临床效果十分满意。%Objective Clinical effect of Multi-slice spiral CT and enterography in diagnosis of smal bowel obstruction(SBO)is to be studied and analyzed. Methods Chose 122 patients with smal bowel obstruction(SBO)who were treated in hospital from March 2014 to November 2015 and separated them into control group and study group randomly with 61 patients in each group,and then compared single baloon endoscopy application effect to Multi-slice CT enterography of effect between two groups.ResultsThe sensibility and specificity rate,positive-testing rate and negative -testing rate in study group were much higher than counterparts in control group(86.75%、100.00%、100.00%、43.57%vs. 78.52%、69.58%、87.89%、31.56%). There was a differential between two groups and such a differential had statistic value according to T-Check(P<0.05).Conclusion Multi-slice CT and enterography is quite effective in diagnosis of smal bowel obstruction.

  10. 多层螺旋CT后处理技术在诊断肺隔离症中的应用%Application of Multi-slice Spiral CT Post-processing Technique in the Diagnosis of Pulmonary Sequestration

    Institute of Scientific and Technical Information of China (English)

    杨珂

    2015-01-01

    目的:探讨多层螺旋CT(MSCT)增强簿层扫描及图像后处理技术在肺隔离症(PS)的诊断价值。方法分析经临床手术病理、主动脉造影证实的21例肺隔离症患者的胸部多层螺旋CT平扫及CTA检查,并进行多平面重建(MPR)、最大密度投影法重建(MIP)、容积重建(VR)。结果21例病例均为单发,肺隔离症(PS)位于左肺下叶14例,右肺下叶7例;表现为肺野内团片、实性肿块者15例,囊样病灶者6例;21例孕杂的供血动脉均来自自体动脉,其中18例来自胸主动脉分支,3例来自腹主动脉。结论多层螺旋CT(MSCT)后处理技术能较准确、直观显示肺隔离症的供血动脉,可以取代有创DSA检查。%Objective To evaluate the multi-slice spiral CT (MSCT) reinforced thin layer scanning and image processing technique in the diagnosis of pulmonary sequestration (PS) value. Methods Analysis the clinical operation pathology, aortic angiography confirmed 21 cases of chest multi-slice spiral CT plain scan and CTA of pulmonary sequestration were examined, multi planar reconstruction (MPR), and the reconstruction of maximum intensity projection (MIP), volume rendering (VR). Results 21 cases were solitary, pulmonary sequestration (PS) located in the left lower lobe in 14 cases, right pulmonary lower lobe in 7 cases;for the performance of lung field of tanacu, solid mass in 15 cases, 6 cases of cystic lesion; artery in 21 cases of PS were derived from autologous artery, including 18 cases from aortic branch, 3 cases from the abdominal aorta. Conclusion Multi slice spiral CT (MSCT) after treatment technology can accurately, visual display of pulmonary sequestration artery, can replace invasive DSA examination.

  11. 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.

  12. 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......). This extension of ASM2 allows for improved modeling of the processes, especially with respect to the dynamics of nitrate and phosphate. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  13. Comparative Analysis on Two Intestinal Preparation Methods in Multi-Slice Spiral CT Enterography%两种肠道准备方法在多层螺旋CT小肠造影中的对比分析

    Institute of Scientific and Technical Information of China (English)

    杜志顺

    2014-01-01

    目的:探讨两种肠道准备方法在多层螺旋CT小肠造影中的对比效果.方法选取行多层螺旋CT小肠造影的患者152例,根据肠道准备方法分为两组,76例患者先行肥皂水清洁灌肠后口服泛影葡胺充盈肠道为对照组,76例患者口服甘露醇和泛影葡胺混合水溶液充盈肠道为观察组,比较两组患者的服药依从性、检查舒适度、肠道充盈效果、造影图像质量、不良反应情况.结果观察组患者的服药依从性、检查舒适度、肠道充盈效果的有效性均明显好于对照组,观察组患者造影图像质量的优良率明显高于对照组,观察组患者不良反应发生率明显低于对照组,差异均有统计学意义(P<0.05).结论甘露醇和泛影葡胺混合水溶液充盈肠道是多层螺旋CT小肠造影的有效肠道准备方法,可显著提高患者的服药依从性和检查舒适度,明显改善患者的肠道充盈效果和造影图像质量,引发的不良反应较少,具有较高的操作安全性,值得临床推广使用.%Objective To investigate the comparative effect of two intestinal preparation methods used in multi-slice spiral CT enterography. Method 152 patients who underwent multi-slice CT enterography were divided into two groups. 76 patients treated with oral urografin intestinal tract filling after the cleaning enema by soap solution were taken as control group. 76 patients treated with oral mixed mannitol and meglumine diatrizoate water solution intestinal tract filling gut were taken as observation group. The compliance,degree of comfort,intestinal tract filling effect, image quality and adverse reactions of patients in two groups were compared. Results The compliance,degree of comfort and effect of intestinal tract filling in the observation group were significantly better than those in the control group. The excellent and good rates of angiography image quality in the observation group were significantly higher than those in the

  14. 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

  15. The value of multi-slice spiral CT enterography in the diagnosis of small bowel tumors%多层螺旋CT小肠造影对常见小肠肿瘤的诊断价值

    Institute of Scientific and Technical Information of China (English)

    饶圣祥; 曾蒙苏; 张利军; 陈刚; 陆秀良; 刘红春

    2012-01-01

    目的 探讨口服甘露醇多层螺旋CT小肠造影(multi-slice spiral CT enterography,MSCTE)对小肠肿瘤检出的价值以及分析常见小肠肿瘤的CT特征.方法 回顾性分析135例患者的MSCTE图像,由2名放射科医生评价,分析小肠是否存在肿瘤和小肠肿瘤MSCTE表现特点.结果 最终证实小肠肿瘤26例,包括胃肠道间质瘤10例,淋巴瘤8例,腺癌6例,类癌2例.2位阅片者的敏感性、特异性、阳性预测值及阴性预测值平均值分别为90.39%,97.25%,88.75%及97.7%.2位阅片者之间结果 的一致性的Kappa值为0.925.胃肠道间质瘤、淋巴瘤和腺癌在强化方式、形态改变以及是否伴淋巴结肿大等具有各自的特点.结论 口服甘露醇MSCTE对小肠肿瘤的检出准确性高,对常见小肠肿瘤的诊断与鉴别诊断有重要的临床应用价值.%Objective To evaluate the diagnostic accuracy of multi-slice spiral CT enterography (MSCTE) with orally administrated isosmotic mannitol in the detection of small bowel tumors, and to identify characteristics of common small bowel tumors through images of MSCTE. Methods MSCTE images of 135 patients were independently reviewed retrospectively by 2 radiologists and MSCTE findings of different types of small bowel tumors were analyzed. Results Histopathologic diagnoses were as follows:gastrointestinal stromal tumors(GIST) (n=10), lymphoma (n=8), primary small-bowel adenocarcinoma (n=6), carcinoid tumor (n= 2). The mean sensitivity, specificity ,PPV,NPVwere 90.39%,97.25%,88.75%,97.7% respectively. The value of Kappa was 0. 925 between the two readers. The common small bowel tumors mainly including GIST, lymphoma and adenocarcinoma had respective characteristics in the enhancement pattern , tumor shape and mesenteric lymph nodes at MSCTE. Conclusion MSCTE with orally administrated isosmotic mannitol is an accurate modality for detecting and characterizing small bowel tumors.

  16. 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.

  17. Effect of Multi Slice Spiral CT in the Diagnosis of Gastrointestinal Tract Perforation%多层螺旋CT在胃肠道穿孔诊断中的应用效果

    Institute of Scientific and Technical Information of China (English)

    高运英

    2014-01-01

    Objective To explore the clinical application of multislice spiral CT in the diagnosis of gastrointestinal tract perforation in effect. Methods In our hospital diagnosed as gastrointestinal perforation in 42 cases of the disease, to get the related information of their multi slice spiral CT scanning. Research on MSCT the image data, analyze the internal various features of abdominal and free gas ratio. Results In all 42 patients, diagnosed by MSCT were 39 cases, accounting for about 92.86%. In addition to, accurately determine the position of the 25 cases, about 59.52%. Also observe gastrointestinal tumor, abscess, and effusion lesions. Conclusion The clinical application of multi slice spiral CT in the diagnosis of gastrointestinal tract perforation has very good effect, can improve the diagnosis rate and hole position accuracy. This method is suitable for use in clinical practice.%目的:探讨多层螺旋CT在胃肠道穿孔中的诊断效果。方法回顾性分析经病理确诊为胃肠穿孔患者的多层螺旋CT扫描的相关资料共42例,探究MSCT所得影像资料,分析腹腔内部各种特征和游离气体比例等。结果在所有42例病患中,经MSCT确诊的有39例,约占92.86%。此外,准确确定穿孔位置的有25例,约占59.52%。同时观察到胃肠道有肿块、脓肿、积液等病变。结论多层螺旋CT应用于胃肠道穿孔诊断方面有很好的效果,有利于提高确诊率和孔道位置准确率,此方法适合在临床上推广使用。

  18. 多排CT对小儿支气管内异物的诊断价值%Value of Multi Slice CT in Diagnosis of Bronchial Foreign Bodies in Children

    Institute of Scientific and Technical Information of China (English)

    冯锦兰

    2015-01-01

    Objective Comparative analysis of the diagnosis value of multi slice CT in the diagnosis of foreign bodies in children with bronchiolitis.Methods 76 children who were confirmed by fiberbronchoscope in our hospital were chosen, X-ray examination and 16 slice spiral CT examination were performed respectively, diagnosis accuracy of two methods were compared.Results The accordance rate of 16 slice spiral CT in the diagnosis of middle left bronchus, bronchus and right main bronchus were 100%, The direct indication of tracheal foreign body accounted for 88.1%, The indirect signs accounted for 11.9%; Clinical X-ray diagnosis coincidence rate was 85.5%, The direct signs accounted for 18.4%, The indirect signs accounted for 81.6%.the diagnosis rates of spiral CT were obviously higher than the X-ray, The difference had statistically significant(P<0.05). Conclusion Multi slice CT has high value in the diagnosis of bronchial foreign bodies in children.%目的:对比分析多排CT在诊断小儿支气管炎内异物的诊断价值。方法对我院进行治疗的经纤支镜确诊为支气管异物的患儿76例,分别对其进行X线检查及16排螺旋CT检查,对比观察两种检查方式的诊断准确性。结果76例患儿左支气管、主支气管及右主支气管异物应用16排螺旋CT诊断符合率为100%,其中直接提示气管异物占88.1%,间接征象占11.9%;X线临床诊断符合率为85.5%,其中直接征象占18.4%,间接征象占81.6%。螺旋CT对左支气管、中段支气管、右主支气管异物及总的诊断符合率均明显高于X线诊断符合率,差异有统计学意义(P<0.05)。结论多排CT对小儿支气管内异物具有较高的临床应用价值。

  19. 多层螺旋CT MPR、MIP及VRT剖切技术在腰椎峡部裂中的应用%Multi Slice Spiral CTMPR,MIP and VRT Cutting Technique in the Application of Iumbar Spondylolysis

    Institute of Scientific and Technical Information of China (English)

    公维云

    2013-01-01

    Objective:To investigate the multi-slice spiral CT post-processing method MPR,MIP and VRT combined cutting technique in lumbar spondylolysis application effect. Method:From October to 2012 in our hospital in 2010 August included 87 cases of lumbar spondylolysis with multi-slice spiral CT,and took MPR,MIP and VRT processing,to observe the effect of the clinical diagnosis. Result:Through the comparative analysis, of which,MPR and MIP display rate was 100%,while the VRT cutting front display rate was 94%,VRT after cutting display rate of 100%. Conclusion:Clinical application of lumbar spondylolysis patients taking spiral CT of the MPR,MIP and VRT cutting technology can effectively observed in patients with lesion site,MPR,MIP is the diagnosis of spondylolysis optimal method,three-dimensional sense of strong VRT.%  目的:探讨多层螺旋CT后处理方法MPR、MIP及VRT结合剖切技术在腰椎峡部裂中的应用效果。方法:选取本院2010年10月-2012年8月收治的87例腰椎峡部裂患者进行多层螺旋CT检查,并采取MPR、MIP及VRT进行处理,观察其临床诊断效果。结果:通过比较分析,其中,MPR和MIP的显示率均为100%,而VRT切割前显示率为94.0%,VRT切割后显示率为100%。结论:临床中腰椎峡部裂患者采取多层螺旋CT的MPR、MIP及VRT剖切技术能够有效的观察患者病变部位,MPR、MIP是诊断椎弓峡部裂的最佳方法,VRT的立体感较强。

  20. HypGrid2D. A 2-d mesh generator

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, N.N.

    1998-03-01

    The implementation of a hyperbolic mesh generation procedure, based on an equation for orthogonality and an equation for the cell face area is described. The method is fast, robust and gives meshes with good smoothness and orthogonality. The procedure is implemented in a program called HypGrid2D. The HypGrid2D program is capable of generating C-, O- and `H`-meshes for use in connection with the EllipSys2D Navier-Stokes solver. To illustrate the capabilities of the program, some test examples are shown. First a series of C-meshes are generated around a NACA-0012 airfoil. Secondly a series of O-meshes are generated around a NACA-65-418 airfoil. Finally `H`-meshes are generated over a Gaussian hill and a linear escarpment. (au)

  1. Effects of Sennae Folium Combined with Mannitol on Multi-slice Spiral CT Bowel Imaging%番泻叶联合甘露醇肠道清洁对多层螺旋CT肠道成像的影响

    Institute of Scientific and Technical Information of China (English)

    项微微; 刘克昌; 殷焱

    2016-01-01

    OBJECTIVE:To evaluate the effects of Sennae Folium combined with mannitol for bowel cleaning on multi-slice spiral CT bowel imaging. METHODS:52 patients receiving multi-slice spiral CT imaging examination in our hospital during Jun. 2011 to Jun. 2012 were collected retrospectively,and then divided into control group(22 cases)and observation group(30 cases) according to the methods of bowel preparation. Both groups fasted for 12 h before examination. Sennae Folium 20 g soaked in boiled water 500 ml for half an hour was given to patients in control group 12 h before examination,and then was soaked in boiled water 500 ml again for drinking and other pure water 1 000 ml was also given to patients. Sennae Folium 10 g soaked in boiled wa-ter 500 ml was given to patients in observation group 1 d before examination and 2 h after breakfast;soaked in boiled water 500 ml again 2 h after lunch;10% mannitol 500 ml and pure water 1 000 ml were given to patients after supper. Both groups received multi-slice spiral CT bowel imaging until the patients defecated watery stool after medication. The effective rate of bowl cleaning, image quality and the incidence of ADR were compared between 2 groups. RESULTS:The effective rate of bowel cleaning was 100% in observation group,which was significantly higher than that of control group(81.82%),with statistical significance(P<0.05). The excellent and good rate of imaging quality was 96.67% in observation group,which was significantly better than that of control group(81.82%),with statistical significance(P<0.05). The incidence of ADR as abdominal distension,nausea,intestinal mucosa damage in observation group were significantly lower than those of control group,with statistical significance (P<0.05). CONCLUSIONS:Sennae Folium combined with mannitol is effective method to prepare enteric multi-slice spiral CT imaging exam-ination,and perform good bowl cleaning effect,high image quality and low incidence of ADR.%目的:评价番泻叶联合

  2. 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

  3. 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 ...

  4. 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 ...

  5. 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.

  6. 腹股沟疝和股疝的多层螺旋CT表现%The Findings of Inguinal Hernia and Femoral Hernia on Multi-slice Spiral CT

    Institute of Scientific and Technical Information of China (English)

    潘华山; 匡楚龙; 蔡云国; 陈容; 孙春梅

    2012-01-01

    目的 研究腹股沟疝和股疝的多层螺旋CT (multi-slice spiral CT,MSCT)表现,探讨如何通过MSCT对腹股沟疝和股疝做出诊断与鉴别诊断.方法 回顾性分析30例经手术证实的腹股沟疝和股疝MSCT包括多平面重组(multiplanar reformation,MPR)表现,重点观察疝的位置、形态、走行、内容物及与周围结构间的关系以及继发征象.结果 MSCT诊断腹股沟斜疝16例,腹股沟直疝11例,股疝3例.16斜疝中12例有腹股沟深环的扩大,16例显示腹股沟管的扩大.以耻骨结节为参考点,10例斜疝和4例直疝跨越中线位于外上象限和内上象限,3例股疝则位于外下象限.3例股疝中2例显示股静脉受压变形.结论 MSCT能够显示腹股沟疝和股疝的位置、形态、走行、内容物、与周围结构之间的关系及并发症,能够为腹股沟疝和股疝的诊断与鉴别诊断提供有价值的信息.对于腹股沟疝和股疝的诊断与鉴别诊断,应综合观察腹股沟管、腹股沟管深环的改变以及疝与腹壁下血管、股血管、腹股沟韧带的关系,并重视多平面重组在诊断中的应用价值.%Objective To study the multi-slice spiral CT (MSCT) features of hernia of inguinal hernia and femoral hernia, and to explore the diagnosis and differential diagnosis of inguinal hernia and femoral hernia with MSCT. Methods 30 cases with inguinal hernia and femoral hernia confirmed by operation were retrospectively analyzed. All cases were undergone the MSCT examination. The key point of observation was the position, course, herniated contents, adjacent structures as well as complications. Result A total of 30 subjects were enrolled in this study, 16 were indirect inguinal hernia, 11 were direct hernia, 3 were femoral hernia. 12 indirect hernia displayed enlargment of the groin deep ring, and 16 indirect hernia showed enlargment of the inguinal canal. When took the pubic tubercle as the point of reference, 10 indirect hernia and 4 direct

  7. 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

  8. 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

  9. 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

  10. 多层螺旋CT肠道造影在溃疡性结肠炎活动期的影像分析%The analysis for images of multi-slice spiral CTE performance levels in active ulcerative ;colitis

    Institute of Scientific and Technical Information of China (English)

    赵宾; 王继红

    2016-01-01

    Objective: To investigate the imaging characteristics of the intestinal multi-slice spiral CT enterography (CTE) in active ulcerative colitis(UC), analyze and summarize its application value. Methods: A total 43 cases diagnosed with active UC from April 2014 to April 2015 in our hospital were selected and divided into mild, moderate and severe three levels with each level as a group, treated by multi-slice spiral CTE examination system based on the improved Mayo system, comparing different performances of CTE levels. Results:43 cases of UC patients participating in the study, eight patients were mild, 16 cases were moderate and 19 cases were severe. There was statistically different in the intestinal mucosa in the presence of air bubbles between the mild and moderate group (x2=21.62; P0.05). Conclusion:UC patients CTE examination, which can effectively conduct a comprehensive assessment against bowel, intestinal and parenteral, provide favorable conditions for the activity of UC clinical diagnosis and classification.%目的:观察多层螺旋CT肠道造影(CTE)在溃疡性结肠炎活动期(UC)中的成像特点,分析探讨其应用价值。方法:选取43例确诊的活动期UC患者,对其行多层螺旋CTE检查,依据改良后的Mayo系统将患者分为轻、中、重三个等级,每个等级为一组,对比不同等级患者CTE的表现。结果:43例UC患者中,8例为轻度,16例为中度,19例为重度,将三组患者多层螺旋CTE检查结果进行对比,其中轻度组与中度组对比,于肠黏膜下气泡一项上差异存在统计学意义(x2=21.62,P<0.05);中度组与重度组进行对比,于结肠袋消失情况、淋巴结肿大情况以及肠壁分层情况3个项目上差异有统计学意义(x2=25.95,x2=17.46,x2=19.46;P<0.05);而于肠黏膜强化程度增加、肠壁增厚、直肠周围脂肪沉积以及肠腔狭窄等项目上,差异均无统计学意义(F=0.36,F=1.58,F=0.31,P>0.05)

  11. 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.

  12. Application Research on Multi-slice Spiral CT Perfusion Imaging in Patients with Acute Cerebral Infarction%多层螺旋 CT 灌注成像在急性脑梗死患者的应用研究

    Institute of Scientific and Technical Information of China (English)

    罗友琛

    2014-01-01

    目的:探讨急性脑梗死患者多层螺旋 CT 灌注成像特点,及其与临床预后的关系。方法选择符合标准的患者40例,行 CT 灌注成像检查,计算脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)及峰值时间(TTP);分别在入院时和治疗后14d 采用美国国立卫生研究院卒中量表(NIHSS)评价临床神经功能缺损,计算缺血脑组织的可恢复比率(PRR)和神经功能恢复比率。结果脑梗死病灶中心 CBV 及 CBF 最低,健侧最高,而缺血半暗带居中,差异有统计学意义(P 0.05);PRR 与患者治疗14d 时 NIHSS 评分存在负相关性(r =-0.340, P 0. 05),negatively dependent of those at day 14 after treatment (r = - 0. 340,P < 0. 05) and positive-ly dependent of patient’s neural functional recovery ratio (r = 0. 467,P < 0. 05). Conclusion Multi-slice spiral CT perfusion im-aging can reflecthemodynamic changes in acute cerebral infarction lesions and their perihemodynamic changes. PRR is closely de-pendent of the neural functional recovery. It can serve as a reliable theoretical basis for clinical treatment.

  13. 肺挫伤患者多层螺旋CT影像学表现与预后%Association of multi-slice spiral CT images of occult pulmonary contusion with disease prognosis

    Institute of Scientific and Technical Information of China (English)

    王凌; 唐怨; 孔德会; 陈友强; 付子文; 杨华

    2014-01-01

    探讨肺挫伤(occult pulmonary contusion,OPC)患者多层螺旋CT(multi-slice spiral CT,MSCT)影像学表现与预后.对143例胸部钝性伤后行常规胸部正位平片和MSCT检查患者影像及临床资料进行回顾性分析.共87例患者检出肺挫伤,其中显性挫伤58例,24例继发肺炎,13例继发脓胸,16例继续发展为急性呼吸窘迫综合征(ARDS);隐匿性肺挫伤(OPC)29例,6例继发肺炎,1例发展为ARDS,未见继发脓胸患者;其余56例中7例继发肺炎,1例继发ARDS,未见继发脓胸患者.在OPC患者中,所有挫伤局限于一个肺叶的患者临床预后均较好;所有继发肺炎的患者挫伤范围均大于两个肺叶.OPC患者总体临床预后较好,MSCT能可靠的评价挫伤的范围,对OPC患者的临床治疗具有一定的指导意义.

  14. Improvement Techniques and Experiment Research of Multi-detector of Multi-slice CT%对多层CT的多排探测器的改进技术及实验研究

    Institute of Scientific and Technical Information of China (English)

    苏重清; 刘东红; 杨立国; 乔驰; 陶行成; 崔力元; 郑伟; 郭媛媛

    2013-01-01

    Objective To design a new kind of multidetector for multi-slice CT, so as to decrease X-ray dosage and increase resolution. Methods Laid additional detectors under the detectors of CT, to obtain new X-ray energy and new resolution data through the upper detectors and make various images with original detector data. Results Laid a layer of X-ray attenuation material on the present detectors of CT as the first layer detector and regarded the present detector as the second layer detector in the design to scan, the second layer detector data is testified available. Conclusion Through simulating tests on present CT scanner, the design is testified to be feasible.%目的 设计一种新型多层CT机的多排探测器,降低X线剂量和提高分辨率.方法在CT探测器下面再加探测器,接收穿透上层探测器的X线获得能量与分辨率不同的额外数据,和原来探测器数据做各种形式的叠加成像.结果在现有CT探测器上加X线衰减层模拟第1层探测器而视现有CT探测器为本设计的第2层探测器扫描,证明了第2层探测器的数据可用.结论通过在现有CT上的模拟实验,证明此设计是可行的.

  15. 胃间质瘤MSCT诊断及临床应用价值%Diagnosis and clinical value of multi-slice spiral computed tomography in gastrointestinal stromal tumor

    Institute of Scientific and Technical Information of China (English)

    李小龙; 杨铁; 王巍; 卓家驹; 刘刚; 吴坚

    2013-01-01

    Objective To discuss the diagnostic value and clinical application value of multi-slice spiral computed tomography about gastrointestinal stromal tumor.Methods We analyze 38 cases with stomach stromal tumor which are confirmed by pathology and immunohistochemistry retrospectively,observe the size,shape,density,reinforcement of lesion or focus and other organ invaded and secondary changes,and decide that it is benign tumor or malignant tumor.Results The maximum diameter of tumor is smaller than 5 cm (4 cases),the maximum diameter of tumor is from 5 cm to 10 cm (22 cases),the maximum diameter of tumor is bigger than 10 cm (12 cases).There is necrosis and cystic change (13 cases) and hemorrhage (8 cases) in the lesion.The normal membrana mucosa is not existed in the gastral cavity (10 cases).The focus is communicated with gastral cavity because of ulcer formation (8 cases) but there is not any ulcer of stomach although air is in gastral cavity (2 cases).It is asymmetry reinforcement of the tumor and the center of the focus is without any reinforcement sometime.The tumor has adhesion to tissue or organ around it (28 cases).The preoperative diagnoses are benign tumor (5 cases),anaplastic tumor or borderline tumors (23 cases),malignant tumor (10 cases) according to size,density and contiguity.Conclusion It is possible to display stomach stromal tumor focus by multi-slice spiral computed tomography definitely and to supply effective information about diagnosis and grading.Image of multi-slice spiral computed tomography is effective measure about preoperative evaluation and postoperative follow-up and curative effect assessment to stomach stromal tumor.It is effective supplement of endoscopy.%目的 探讨多层螺旋CT对胃间质瘤的诊断价值及临床应用价值.方法 回顾性分析经手术病理学及免疫组织化学证实的胃间质瘤患者38例,观察其病灶大小、形态、密度、病灶强化特点、肿瘤累及范围以及其他继发改变

  16. 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

  17. 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.

  18. 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.

  19. Evaluation of MRI-based Polymer Gel Dosimetry for Measurement of CT Dose Index (CTDI on 64 slices CT Scanners

    Directory of Open Access Journals (Sweden)

    Leaila Karimi-Afshar

    2009-06-01

    Full Text Available Introduction: Computed tomography (CT has numerous applications in clinical procedures but its main problem is its high radiation dose to the patients compared to other imaging modalities using x-ray. CT delivers approximately high doses to the nearby tissues due to the scattering effect, fan beam (beam divergence and limited collimator efficiency. The radiation dose from multi-slice scanners is greater than the single-slice scanners and since multi-slice scanners increasingly employ a wide beam, 100 mm ion chambers currently used in measuring the CTDI100, are not capable of accurately measuring the total dose profile of the slice width. Therefore, the CT dose is underestimated by using them. The purpose of this study is to measure the Computed Tomography Dose Index (CTDI of a GE multi-slice CT scanner (64-slice using polymer gel dosimetry based on MRI imaging (MRPD. CTDI is the sum of point doses along the central axis and estimates the average patient dose during CT scanning. Materials and Methods: For measuring CTDI, after designing and fabricating the phantom and preparing the MAGIC gel, MRI imaging using a 1.5 T Siemens MRI scanner was performed with the imaging parameters of ST = 2 mm, NEX = 1, TE = 20-640 ms and TR = 2000 ms. CTDI was measured with a 100 mm ion chamber (CTDI100 and also the MAGIC gel with MRPD method for 10 mm and 40 mm CT scan nominal widths. Results: Following the measurement of the CTDI100 for 10 mm and 40 mm nominal slice widths of the multi-slice scanner using both ion chamber and MAGIC gel, the results showed that the ion chamber underestimates CTDI100 by 28.71% and 14.03% compared to gel for 10 mm and 40 mm respectively. Discussion and Conclusion: It was concluded from this study that gel dosimeters have the capability to measure CTDI in wide beams of multi-slice CT scanners whereas 100 mm standard ion chamber due to its limited length is not reliable even for a 10 mm beam width. In addition, due to the 3

  20. Quantum coherence selective 2D Raman-2D electronic spectroscopy.

    Science.gov (United States)

    Spencer, Austin P; Hutson, William O; Harel, Elad

    2017-03-10

    Electronic and vibrational correlations report on the dynamics and structure of molecular species, yet revealing these correlations experimentally has proved extremely challenging. Here, we demonstrate a method that probes correlations between states within the vibrational and electronic manifold with quantum coherence selectivity. Specifically, we measure a fully coherent four-dimensional spectrum which simultaneously encodes vibrational-vibrational, electronic-vibrational and electronic-electronic interactions. By combining near-impulsive resonant and non-resonant excitation, the desired fifth-order signal of a complex organic molecule in solution is measured free of unwanted lower-order contamination. A critical feature of this method is electronic and vibrational frequency resolution, enabling isolation and assignment of individual quantum coherence pathways. The vibronic structure of the system is then revealed within an otherwise broad and featureless 2D electronic spectrum. This method is suited for studying elusive quantum effects in which electronic transitions strongly couple to phonons and vibrations, such as energy transfer in photosynthetic pigment-protein complexes.

  1. Comparative analysis of multi-slice computer tomography enterography (MSCTE) and digestive endoscopy on the involved site of Crohn disease%MSCTE与消化内镜检查发现Crohn病累及部位的比较分析

    Institute of Scientific and Technical Information of China (English)

    张燕红; 叶文卫; 陈毅斌; 张锡迎; 杨宇峰; 刘琴

    2016-01-01

    目的:探讨多层螺旋CT口服小肠造影(MSCTE)与消化内镜检查发现Crohn病累及部位的临床价值。方法选取两家医院临床随访证实为 Crohn 病患者30例,行消化内镜检查为 A组,行MSCTE检查为B组,A、B两组发现Crohn病累及部位进行比较分析。结果 A组无异常6例,累及单独小肠5例,小肠及结直肠10例,单独结直肠9例;B组累及单独小肠14例,小肠及结直肠9例,单独结直肠7例。A、B两组发现Crohn病累及部位的比较有统计学意义(P<0.05)。结论 MSCTE诊断Crohn病累及部位较消化内镜具有更高的临床价值。%ObjectiveThe aim of the present study was to evaluate the clinical value of multi-slice computer tomography enterography (MSCTE) and digestive endoscopy on the involved site of Crohn disease(CD).MethodsSelected 30 patients with CD from two hospitals confirmed by clinical follow-up. Digestive endoscopy as group A, MSCTE examination as group B, involved site of two groups of CD were compared and analyzed.ResultsIn group A, 6 cases had been found normal, 5 cases had been found that lesion site was in the small intestine, 10 cases in the small intestine and colorectal, 9 cases only in the colorectal. In group B, 14 cases had been found the lesion site was in the small intestine only, 9 cases in the small intestine and colorectal, 7 cases in the colorectal only. There had statistical significance between group A and group B (P<0.05).ConclusionThe MSCTE has higher clinical value to diagnose the involved site of CD.

  2. 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.

  3. The diagnostic value of VR techniques of multi-slice spiral CT in the pulmonary sequestration%多层螺旋CT容积再现对肺隔离症的应用价值

    Institute of Scientific and Technical Information of China (English)

    刘玉芳

    2012-01-01

    Objective To evaluate the diagnostic value of VR techniques with multi - slice spiral CT in the pulmonary sequestration. Methods MSCT angiography were performed and reconstructed imaging VR in 11 patients with surgically confirmed pulmonary se-questration( PS ), The emphasis was shown the relationship between abnormal vessels and lesions. Results Among 11 cases PS,the lesion was located at the left lower lobe in 7 and at the right lower lobe in 4 cases, abnormal supplying arteries were from the thoracic aorta. On plain CT scan images,the mass-like lesions were found in 6 cases,irregular shape lesions in 5 cases. On VR images clearly displayed abnormal supplying arteries from systemic arteries in all patients. Conclusion MSCT angiographytechnology can accurately and directly display the blood - supply of the segregation tissue. So this method is very important value in PS.%目的 研究多层螺旋CT容积对肺隔离症的应用价值.方法 对经外科手术及病理证实的11例肺隔离症患者多层螺旋CT血管造影,利用容积再现(VR)技术,分析异常血管与病灶的关系.结果 11例患者中,7例病灶位于左下叶,4例病灶位于右下叶,异常供血全部来自胸主动脉.MSCT平扫表现为囊实性肿块6例,其他不规则形5例.VR重组技术中11例能明确显示异常体动脉供血及肺内血管网.结论 多层螺旋CT血管造影及结合容积再现重组技术能直观显示肺隔离症的异常体动脉供血及肺内血管网,具有重要的临床应用价值.

  4. Analysis of multi-slice spiral CT images in patients with esophageal cancer after surgery or radiotherapy%食管癌患者术后或放疗后多排螺旋 CT 影像分析

    Institute of Scientific and Technical Information of China (English)

    王锋

    2016-01-01

    Objective To explore the application value of multi-detector row spiral CT after the operation or radiotherapy in patients with esophageal carcinoma .Methods From August 2014 to March 2015,23 patients with esophageal cancer treated in our hospital received the examination of multi-detector row spiral CT after the operation or radiotherapy .Results After operation,CT re-sults showed that there were 4 cases with postoperative lymph node metastasis ,2 with lung metastasis and 3 with bone metastases ,2 with pericardial effusion ,1 with pleural effusion ,1 with esophageal mediastinum fistula and 1 with anastomotic recurrence .CT results also showed that after radiotherapy there were 12 with lymph node metastasis ,2 with liver metastasis ,3 with lung metastasis ,1 with radioac-tive pneumonia and 2 with pleural effusion .Conclusion The multi-slice helical CT can display a number of clinical manifestations such as complications ,recurrence and metastasis after operation and radiotherapy .It has an important clinical value .%目的:探讨多排螺旋CT在食管癌患者术后或放疗中的应用价值。方法2014年8月至2015年3月我院收治的23例食管癌患者,术后或放疗后均行多部位多排螺旋CT检查。结果 CT结果显示:术后患者出现淋巴结转移4例,肺部转移2例,骨转移3例,心包积液2例,胸腔积液1例,食管纵膈瘘1例,吻合口复发1例;而放疗后患者出现淋巴结转移12例,肝脏转移2例,肺部转移3例,放射性肺炎1例,胸腔积液2例。结论多排螺旋CT可显示出食管癌患者术后或放疗后的并发症、复发及转移等临床表现,具有重要的临床应用价值。

  5. 多层螺旋CT对甲状旁腺腺瘤的诊断价值%The value of multi-slice spiral CT in diagnosis of parathyroid adenoma

    Institute of Scientific and Technical Information of China (English)

    于永慧; 朱吉高; 贾志东; 王立兴; 吴海涛

    2011-01-01

    Objective:To study the value of multi-slice spiral CT (MSCT) in diagnosis of parathyroid adenoma. Methods: Retrospective analysis was performed in clinical data and CT images of 10 cases of parathyroid adenoma proved surgically and pathologically. Results: All of the parathyroid adenomas were originated from the inferior pole of parathyroid gland with 4 cases at the right side and 6 cases at the left side. All located at the recess between trachea and esophagus. The sizes of adenomas ranged from 0. 9 cm× 1. 0 cm~3. 0 cm×8. 0 cm. The tumors were round or oval. Well-demarcated. Iso-attenuated yet higher than that of thyroid gland on plain CT scan. After contrast medium administration, the adenomas revealed enhancement with various degrees but lower than that of thyroid and adjacent blood vessels. 8 cases of adenomas were enhanced homogeneously. 2 cases showed no enhancement in necrosis. Conclusion: The location. Shape. Size. And the relationship with surrounding structures of parathyroid adenoma could be precisely displayed on enhanced MSCT and 3D reconstruction, which is valuable for surgery.%目的:探讨多层螺旋CT(MSCT)对甲状旁腺腺瘤的诊断价值.方法:回顾性分析10例经手术病理证实为甲状旁腺腺瘤的CT及临床资料.结果:10例甲状旁腺腺瘤均起源于下甲状旁腺.右侧4例,左侧6例,均位于气管食管沟内.肿瘤大小约0.9cm×1.0cm~3.0cm×8.0cm.呈圆形或卵圆形,边缘光滑完整.平扫肿瘤呈等密度.较正常甲状腺为低密度.增强后10例肿瘤均有不同程度强化,但均较周围血管密度及正常甲状腺密度低.增强后肿瘤呈均匀强化者8例,坏死不均匀强化者2例.结论:MSCT增强及三维重建检查可准确显示甲状旁腺腺瘤的部位、形态、大小及其与周围结构的关系,对临床手术有重要的指导意义.

  6. Clinical application of dental panoramic imaging by multi-slice spiral CT%多排螺旋CT全景齿科成像技术的临床价值探讨

    Institute of Scientific and Technical Information of China (English)

    徐刚; 胡海菁; 徐新超; 杜丽云

    2011-01-01

    目的 探讨多排螺旋CT(MSCT)全景齿科成像技术的临床应用价值.方法 对38例患者的牙齿、颌骨部位的容积数据进行后处理,重建出全景齿科图像和牙槽骨的矢状面和冠状曲面图像,与原始图像结合,对牙科疾病进行分析.结果 行MSCT检查的38例口腔疾病患者中,均能全方位立体再现齿科全貌:包括牙冠、牙体、牙根、牙髓腔的局部细节以及牙齿排列及咬合关系,可以从多个角度完整地显示了单个牙体的表面形态、各牙所在的位置、倾斜角度以及各牙之间的距离、牙列的整体形态和牙根的走行方向.结论 多排螺旋CT全景齿科成像可对牙、颌骨内微小病变的诊断治疗提供重要的客观依据,为牙科疾病提供了一种新的先进的检查手段及诊断方法.%Objective To investigate the clinical application of dental panoramic imaging by multi-slice spiral CT (MSCT).Methods Dental panoramic images, coronal and sagittal images of alveolar bone were reconstructed from initial data of tooth and jaw MSCT scanning in 38 patients with oral disease, and the results were compared with original images.Results All these 38 patients accepted MSCT scaning, the panorama of dental could be display clearly, including local details of the crown, dental body, root and pulp cavity, the teeth alignment and occlusal relationship.The surface morphology of each single dental body, the location, inclination angle and distance of each tooth, the dentural integral shape and the root walking direction could be displayed completely.Conclusions As an advanced examinational means and diagnosis method, dental panoramic imaging by MSCT could provide important objective basis?for clinical diagnosis and treatment of minute lesion of the tooth and jaw.

  7. 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 .

  8. 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 ...

  9. Shoulder MRI

    Science.gov (United States)

    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  10. 肝细胞癌合并近端肝动脉-门静脉分流的多层螺旋CT诊断及临床意义%Diagnosis and clinical significance of multi-slice spiral CT in hepatocellular carcinoma combined with proximal hepatic artery portal vein shunt

    Institute of Scientific and Technical Information of China (English)

    王长河

    2015-01-01

    目的 探讨多层螺旋CT在肝细胞癌(HCC)合并近端肝动脉-门静脉分流(APS)中的临床诊断价值和意义.方法 选取驻马店市中心医院收治的84例肝细胞癌患者作为研究对象,对其分别进行多层螺旋CT及肝动脉数字减影血管造影(DSA)检查,对两种方法的临床诊断准确性进行观察比较,并以DSA诊断近端APS为标准,对多层螺旋CT诊断的CT表现特征进行对比分析.结果 经DSA检查,65例患者检查出合并近端APS,占77.4%,经多层螺旋CT检查,57例检测出合并近端APS,占67.9%,多层螺旋CT与DSA两种检查方式对比临床诊断准确性差异未见统计学意义(P>0.05).多层螺旋CT对于周围型肝APS的检出率明显高于DSA检查,组间检测情况差异有统计学意义(P<0.05).结论 肝细胞癌合并近端肝动脉-门静脉分流经多层螺旋CT检查诊断的准确性可与DSA相比,其对肝癌临床治疗具有重要指导意义.%Objective To evaluate the clinical diagnostic value and clinical significance of multi-slice spiral CT in hepatocellular carcinoma (HCC) combined with proximal arterioportal shunt (APS).Methods Eighty-four cases of hepatocellular carcinoma in our hospital were selected as the research objects,and were given the multi-slice spiral CT and hepatic arterial digital subtraction angiography (DSA) examination.The diagnostic accuracy of the two methods were observed and compared.DSA diagnosis of proximal APS as the standard,CT features of multi-slice spiral CT were andyzed and compared.Results Sixty-five patients had combined with proximal APS,accounting for 77.4% through the DSA examination.Fifty-seven cases were detected with proximal APS,accounting for 67.9% through the multi slice spiral CT examination.No significant difference between the two kinds of inspection methods of comparative clinical diagnostic accuracy (P > 0.05).The detection rate of multi slice spiral CT for peripheral hepatic APS was significantly higher

  11. 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

  12. 多排螺旋CT后处理技术在胆源性胆囊-十二指肠瘘诊断中的应用%Multi-slice CT in diagnosing cholecysto-duodenal fistula

    Institute of Scientific and Technical Information of China (English)

    王均庆; 陆风旗; 张雷; 张追阳; 丁忠; 余迅

    2015-01-01

    目的 应用多排螺旋CT(MSCT)后处理技术分析胆源性胆囊-十二指肠瘘的典型影像学特征,探讨其临床价值.方法 回顾性分析2011年1月到2015年7月南京医科大学附属第二医院收治的33例胆源性胆囊-十二指肠瘘患者资料,所有患者均行MSCT平扫及增强检查,用CT后处理技术分析其影像学特征性改变.结果 33例患者胆源性胆囊-十二指肠瘘发生部位:十二指肠球部15例(45.5%),十二指肠球降部3例(9.1%),降部10例(30.3%),水平部5例(15.1%).胆源性胆囊-十二指肠瘘直接征象:瘘道清楚显示,部分呈哑铃型,共有16例显示了瘘道.胆源性胆囊-十二指肠瘘间接征象:2例胆囊显示不清,1例因胆囊癌体积增大,1例因急性胆囊炎胆囊增大;29例胆囊体积明显缩小,体积为6 cm×2 cm~2 cm×1 cm;胆囊壁增厚,平均厚度5 cm;胆囊与十二指肠粘连,分解不清,胆囊周围结构紊乱,可见积液.26例胆道系统积气,其中胆囊积气22例次,胆管积气19例次;胆道系统结石26例次,胆囊结石22例次,胆囊颈部结石6例次,胆总管结石13例次,肝内外胆管结石1例次.十二指肠与胆囊粘连处见憩室样征改变,11例十二指肠出现憩室样征.胆源性胆囊-十二指肠瘘并发症:5例胆石性肠梗阻,2例肝多发脓肿.结论 多层螺旋CT扫描及后处理技术的应用不但可有效显示胆源性胆囊-十二指肠瘘的部位、有无瘘道及形态、胆囊形态、胆囊及胆管积气、结石及周围情况,还可充分显示其并发症,对手术方案的制定有指导意义,具有较高的临床应用价值.%Objective To study the radiologic features and the diagnostic value of multi-slice spiral CT (Multi-slice CT, MSCT) in cholecysto-duodenal fistula.Methods A retrospective analysis was conducted on 33 patients with cholecysto-duodenum fistula.Plain and IV enhanced MSCT were carried out on these patients.Results Of the 33 patients, the fistula was located at

  13. 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

  14. 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.

  15. 多层螺旋CT在肠道Crohn病诊断中的应用价值%The Value of Multi-slice Spiral CT Enterography in Diagnosing Crohn's Disease

    Institute of Scientific and Technical Information of China (English)

    杨春; 姚倩东; 郑敏文

    2013-01-01

    Objective To investigate the value of multi-slice spiral CT (MSCT) enterography in diagnosing Crohn 's disease (CD). Methods The manifestations on routine CT enterography of 41 patients diagnosed to have CD with comprehensive methods between February 2009 and February 2012 were analyzed retrospectively, including location of the involved bowel segment, thickness of bowel wall and degree of contrast enhancement of the bowel wall as well as the existence of complications. Results Among the 41 cases, there were 36 (87.8%) of skip lesions, 16 (39.0%) of lesions limited to the small intestine, 23 (56.2%) of lesions involving both small intestine and colon, 2 (4.8%) of lesions limited to the colon, 36 (87.8%) of lesions involving the terminal ileum, and 22 (53.7%) of lesions involving cecum or ascending colon. The findings of those patients on MSCT were 41 cases (100%) of bowel wall thickening and mural hyperenhancement, 28 cases (68.3%) of mural stratification, 23 cases (56.1%) of fibrofatty proliferation or para-bowel phlegmon, 16 cases (39.0%) of increased mesenteric vascularity (comb sign), 20 cases of mesenteric lymphadenopathy, 6 cases of incomplete bowel obstruction, and 1 case of fistula. Conclusions MSCT can demonstrate lesions of the small intestine and the colon simultaneously, and it proves to have advantages in depicting mural abnormalities and evaluating extramural abnormalities and activity of CD. Thus, MSCT is helpful in evaluating the course of CD and guiding clinical treatment.%目的 探讨多层螺旋CT (MSCT)在肠道Crohn病(CD)诊断中的应用价值.方法 回顾性分析2009年2月-2012年2月经综合方法确诊为CD的41例患者的MSCT表现,分析病变肠管的部位、肠壁的厚度和增强后病变肠壁的强化程度及并发症.结果 41例中,患病肠段多节段性受累36例(87.8%),单独小肠受累16例(39.0%),小肠和结肠同时受累23例(56.2%),单独结肠受累2例(4.8%),回肠末段受累36例(87.8

  16. 28例儿童漏斗胸术前多层螺旋CT的诊断与评估%Preoperative diagnosis and assessment of 28 children with pectus excavatum Multi-Slice CT

    Institute of Scientific and Technical Information of China (English)

    白林; 彭泽华; 梁洪; 高燕

    2012-01-01

    Objective To evaluate the preoperative diagnosis of multi-slice CT (MSCT) in children with pectus excavatum. Methods We retrospectively analyzed 28 cases of funnel chest diagnosed by MSCT examination. All the cases were divided into three groups with pathogenetic condition in mild, moderate, serious degree respectively according to the depression of the chest diagnosed by CT. We measured the degree of sternal depression, CT depression index, the angle of sternal depression, cardiac rotation angle, Haller index,compare those five indicators among the three groups,and analyzed the correlation between cardiac rotation angle and the other four indices. Results Varying degrees of pectus excavatum were found in the 28 cases including 14 cases of mild depression,9 cases of moderrate depression, and 5 cases of serious depression. The five indicators between each of the two groups were significantly different ( P < 0.01). Cardiac rotation angle was positively correlated to sternal depression depth, CT depression index and Haller index ( rs = 0. 736,0. 873,0. 881 ,P < 0.01) ,and was negative correlated to sternal depression angle (rt = -0.731 ,P < 0.01). Conclusion MSCT can accurately display the deformity of funnel chest and the rotation of cardiac compression, to provide effective help for clinical treatment.%目的 评价多层螺旋CT(MSCT)在儿童漏斗胸术前诊断中的价值.方法 回顾性分析28例经MSCT检查并诊断为漏斗胸患儿的CT资料,根据CT凹陷指数,将其分为轻、中、重度三组,测量并比较三组患儿胸骨凹陷深度、CT凹陷指数、胸骨凹陷角度、心脏旋转角度及Haller指数五项指标的差异,分析心脏旋转角与其它四项指标的相关性.结果 ①28例均有不同程度胸骨凹陷,其中轻度凹陷14例,中度凹陷9例,重度凹陷5例;②胸骨凹陷深度、CT凹陷指数、胸骨凹陷角度、心脏旋转角度及Haller指数五项指标在轻、中、重度三组间差异均有统计学

  17. 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

  18. 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.

  19. 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

  20. Diagnostic value of multi-slice CT in solitary fibrous tumor of the pleura%多层螺旋CT对胸部孤立性纤维瘤的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李会菊; 李晓阳; 邢国凤; 张德江; 付敬华

    2015-01-01

    Objective To explore the value of multi-slice CT in the diagnosis of solitary fibrous tumor of the pleura (SFTP). Methods The clinical symptoms and CT imaging features of 8 patients clinically and pathologically diagnosed as SFTP were retrospectively analyzed, which were compared with histopathological results. Results All the lesions of the 8 patients were located in dirty pleura. CT-scan showed 6 cases of mass boundary finishing, 1 case of lobulated rim, 1 case of irregular shape, 5 cases of uniform density, and 3 cases with low density area in mass center. Six patients underwent contrast-enhanced CT, of which 4 showed non-uniform reinforcement and 2 showed uniform reinforcement, including 3 cases of tumors with enhancement of blood vessels. Pathological examination showed that the tumor was composed of spindle cells, with a number of arrangements:immunohistochemical Vimentin (+) in 7 cas-es, CD34 (+) in 8 cases, the bcl-2 positive (+) in 8 cases, Sl00 (-) in 7 cases. Conclusion SFTP patients have certain characteristic CT manifestations. CT examination has a certain value for SFTP positioning and the relationship be-tween tumor and surrounding tissue structure.%目的:探讨多层螺旋CT对胸部孤立性纤维瘤(SFTP)的诊断价值。方法回顾性分析经临床和肿瘤病理学确诊的8例SFTP患者的临床症状、螺旋CT影像特点,并与组织病理学结果进行对照。结果所有8例患者病变均位于脏层胸膜,CT平扫显示6例肿块边界光整,1例边缘呈分叶状,1例呈不规则形状;5例密度较均匀,3例肿块中心有低密度区。6例行对比增强后4例不均匀强化,2例强化均匀,其中3例肿块内出现增强的血管。病理学检查显示,肿瘤由梭形细胞构成,有多种排列方式;免疫组化Vimentin(+)7例、CD34(+)8例、bcl-2阳性(+)8例,Sl00(-)7例。结论 SFTP患者的CT表现具有一定的特征性,CT检查对SFTP的定位以及明确肿瘤与周围组织结构的关系有一定价值。

  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. Multi-slice Spiral Computed Tomography Manifestations of Brain and Cerebral Hemodynamics in Chronic Mountain Sickness%慢性高原病脑部MSCT表现与血流动力学研究

    Institute of Scientific and Technical Information of China (English)

    王铎尧; 鲍海华; 赵希鹏; 李文方

    2011-01-01

    significantly highcr in CMS group than that in normal group (t=4. 551, P<0. 01 and t= 2. 898,P<0. 01 , respectively) . In CMS group , the CT value of superior sagittal sinus and bilateral middle cerebral artery with hemoglobin level (r=0. 758 and r=0. 740 , both P<0. 01). (2) The changes of CBF were obviously in grey matter than in white matter. In grey matter,CBF reduced more in CMS group than in normal group(P<0. 01). TTP in grey matter prolonged obviously in CMS group (P<0. 05 ). MTT in grey matter and white matter both prolonged obviously in CMS group (P<0. 01 ). Conclusion Multi-slice spiral CT is a valuable tool to study the state of the whole brain and the cercbral hemodvnamics in CMS patients.

  4. 多层螺旋CT在腹股沟区解剖中的应用%Application of multi-slice spiral CT in the study of the anatomy of inguinal region

    Institute of Scientific and Technical Information of China (English)

    沈超; 张联合; 陈文辉; 俞一歆

    2011-01-01

    Objective:To evaluate multi-slice spiral CT (MSCT) with three-dimensional reconstruction techniques in the study of the anatomy of inguinal region. Methods: MSCT three-dimensional reconstruction images of inguinal region in order to display the inguinal ligament (IL) .inferior epigastric artery (IEA) and round ligament or spermatic cord on the axial, coronal,and sagittal views in 20 patients were retrospectively analyzed. Results:The inferior epigastric artery was identified in all planes of all 20 patients (100%). The inguinal ligament and the round ligament or spermatic cord could only be well identified on axial plane in 70% of 20 patients. On coronal views, the inguinal ligament could be revealed in 100%, whereas the round ligament or spermatic cord could only be showed in 77. 5 % of the patients. The inguinal ligament was Identifiable in 90% and the round ligament or spermatic cord in 72. 5% of the patients on sagittal view. Conclusion: Combination of the axial, coronal and sagittal reconstruction images of MSCT could display the key anatomic structures of inguinal region,and is significant in the diagnosis and classification of inguinal hernia.%目的:探讨多层螺旋CT三维重建在腹股沟区解剖的应用.方法:回顾性分析20例行多层螺旋CT腹股沟区扫描的三维重建图像,观察在横断面、冠状面及矢状面上腹股沟韧带、腹壁下动脉、圆韧带或精索的显示情况.结果:20例病例中腹壁下动脉在3个轴面上均能显示,显示率100%.横断面不能很好的显示腹股沟韧带,圆韧带或精索的显示率为70%.冠状面能100%显示腹股沟韧带,圆韧带或精索的显示率为77.5%.矢状面腹股沟韧带的显示率为90%,圆韧带或精索的显示率为72.5%.结论:结合多层螺旋CT重建的横断面、冠状面及矢状面图像能满意显示腹股沟区的关键解剖结构,对诊断分型腹股沟疝有较大意义.

  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. MSCTV直接静脉造影诊断静脉受阻性病变的价值%Value of direct multi-slice computed tomography venography in diagnosing venous obstructive disease

    Institute of Scientific and Technical Information of China (English)

    赖伟; 刘建新; 林晓平

    2015-01-01

    目的:探讨多层螺旋CT直接静脉造影(MSCTV)诊断静脉受阻性病变的临床价值。方法收集35例应用直接MSCTV诊断并经临床证实的静脉受阻性病变患者的临床及影像学资料,研究MSCTV成像方法,分析静脉受阻性病变的影像学表现特征。结果本组共35例患者,其中下肢深静脉血栓19例,上肢深静脉血栓2例,深静脉瘤栓3例,单纯性下肢静脉曲张11例。MSCTV深静脉血栓表现为静脉腔内的充盈缺损,管腔中断,侧支循环形成。深静脉瘤栓表现为静脉腔内和/或腔外软组织肿块影,管腔不规则狭窄并充盈缺损。单纯性下肢静脉曲张表现为静脉血管增多、增粗、纡曲。结论静脉受阻性病变具有一定的MSCT征象,MSCTV对诊断静脉受阻性病变具有较大的临床价值。%Objective To explore the clinical value of direct multi-slice computed tomography venography (MSCTV) in diagnosing venous obstructive disease. Methods The clinical and imaging data of 35 cases of venous obstructive disease diagnosed by MSCTV and confirmed in clinic were reviewed. The imaging features of venous ob-structive disease were analyzed. Results There were a total of 35 cases, with 19 cases located in deep venous throm-bosis of lower extremity, 2 cases located in deep venous thrombosis of upper extremity, 3 cases located in deep venous tumor thrombus, and 11 cases located in simple vein varicosis of lower extremity. MSCTV manifestations of deep ve-nous thrombosis included filling defect in vein intraluminal, luminal interrupt, and formation of collateral circulation. MSCTV manifestations of deep venous tumor thrombus showed soft tissue mass in the vein cavity and/or extralumi-nal, irregular filling defect and stenosis in lumen. Simple varicose veins of lower extremity showed increased number of veins, as well as thickening and tortuosity. Conclusion MSCTV manifestations of venous obstructive disease have some specific features

  7. 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.

  8. 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.

  9. 口腔颌面锥形束CT与螺旋CT辐射剂量的比较研究%Comparative dosimetry of dental cone-beam computed tomography and multi-slice computed tomography for oral and maxillofacial radiology

    Institute of Scientific and Technical Information of China (English)

    曲兴民; 李刚; 张祖燕; 马绪臣

    2011-01-01

    Objective To compare the effective radiation dose levels of cone beam computed tomography (CBCT) with those of multi-slice computed tomography (MSCT) when scanning the same maxillofacial regions.Methods The effective doses of 2 CBCT( NewTom 9000 and DCT Pro) and 1 MSCT (bright speed edge select 8 slice) scanners were calculated using thermoluminescent dosimeters (TLD) that were placed in a head and neck phantom,and expressed according to the International Commission on Radiation Protection(ICRP) 2007 guidelines.Results Effective dose values ranged from 41.8 to 249.1 μSv for CBCT.The doses of MSCT scanning for maxilla,mandible and maxilla + mandible were 506.7,829.9 and 1066.1 μSv,respectively.Dose levels of scanning only for maxilla or mandible were significantly lower than those for maxilla + mandible.Conclusions When scanning the same maxillofacial regions,the dose levels for NewTom 9000 and DCT Pro CBCT images were lower than those for Bright speed edge select 8 slice MSCT images.Dose levels reduction could be obtained when smaller regions were scanned.%目的 比较口腔颌面锥形束CT与螺旋CT在扫描口腔颌面部相同部位时的辐射剂量,为临床安全有效应用提供实验数据.方法 使用热释光剂量芯片测量两种口腔颌面锥形束CT和一种螺旋CT在扫描头颈部体模上颌、下颌、上颌+下颌时的吸收剂量.按照国际放射防护委员会2007年推荐的组织权重因子,计算各个扫描程序的有效剂量.使用单因素方差分析对所有扫描程序得到的有效剂量进行比较分析,P<0.05为差异有统计学意义.结果 两种口腔颌面锥形束CT的辐射剂量范围41.8 ~249.1 μSv.螺旋CT对上颌、下颌及上颌+下颌进行扫描时的有效剂量分别为506.7、829.9和1066.1 μSv,螺旋CT辐射剂量显著高于两种口腔颌面锥形束CT(P <0.001).同一机型仅进行上颌或下颌扫描的辐射剂量显著低于同时扫描上颌+下颌时

  10. 多层螺旋CT血管成像容积重建技术在Moyamoya病中的诊断价值%The diagnostic value of multi-slice computed tomographic angiography with volume rendering for Moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    林伯法; 奚玉平; 曹国全

    2008-01-01

    Objective To evaluate the diagnostic value of multi-slice thrce-dimensional computed tomographic angiography(MS-CTA) with volume rendering(VR) for Moyamoya disease.Methods MS-CTA of 25 patients with Moyamoya disease verified by DSA were restrospectively analyzed.Source images were got by GE Lightspeed pro scanner.VR was adopted to reconstruct 3D images in all cases.Results Of 25 CT precontrast,13,12 cases showed infarction and hemorrhage respectively,while 11 cases had dialated vessels in thalamus-basal ganglia region on CT.Accuracy of stenosis or occlusion of the bifurcation of ICA, proximal portion of the ACA or MCA was 88.0% (22/25) by MS-CTA.MS-CTA overestimated the degree of stenosis,MS-CTA misdiagnosed 3 cases(12.0%)with stenosis to occlusion.MS-CTA showed fewer small Moyamoya vessels than DSA.MS-CTA only demonstrated 6 cases(25.0%)with collateral vessels.Conclusion CT is still the conventional method for detecting secondary lesions to Moyamoya disease.CT and MS-CTA can accurately diagnose Moyamoya disease.%目的 探讨多层螺旋CT血管造影(MS-CTA)容积重建(VR)技术在Moyamoya病中的诊断价值.方法 对经DSA证实的25例Moyamoya患者的MS-CTA影像资料进行回顾性分析,使用GE Lightspeed pro 16层螺旋CT扫描仪获得原始图像,所有病例均采用VR技术对图像进行三维重建.结果 25例CT平扫患者中,脑梗死13例,脑出血12例,其中11例可见丘脑一基底节区有扩张的血管;MS-CTA VR重建显示Moyamoya病颈内动脉(ICA)末端、大脑中动脉(MCA)或大脑前动脉(ACA)近端闭塞或狭窄的准确率为88.0%(22/25).与DSA相比,MS-CTA VR重建高估动脉狭窄程度,将ICA狭窄误诊为闭塞3例(12.0%);在显示Moyamoya血管数目及分支方面,MS-CTA VR重建显示细小分支数目较少;在显示侧支循环方面,MS-CTA VR重建仅显示6例(25.0%).结论 CT平扫仍是发现Moyamoya病继发病变的常规方法,与MS-CTA VR重建相结合可正确诊断Moyamoya病.

  11. 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)°

  12. 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

  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. Differential patterns of 2D location versus depth decoding along the visual hierarchy.

    Science.gov (United States)

    Finlayson, Nonie J; Zhang, Xiaoli; Golomb, Julie D

    2017-02-15

    Visual information is initially represented as 2D images on the retina, but our brains are able to transform this input to perceive our rich 3D environment. While many studies have explored 2D spatial representations or depth perception in isolation, it remains unknown if or how these processes interact in human visual cortex. Here we used functional MRI and multi-voxel pattern analysis to investigate the relationship between 2D location and position-in-depth information. We stimulated different 3D locations in a blocked design: each location was defined by horizontal, vertical, and depth position. Participants remained fixated at the center of the screen while passively viewing the peripheral stimuli with red/green anaglyph glasses. Our results revealed a widespread, systematic transition throughout visual cortex. As expected, 2D location information (horizontal and vertical) could be strongly decoded in early visual areas, with reduced decoding higher along the visual hierarchy, consistent with known changes in receptive field sizes. Critically, we found that the decoding of position-in-depth information tracked inversely with the 2D location pattern, with the magnitude of depth decoding gradually increasing from intermediate to higher visual and category regions. Representations of 2D location information became increasingly location-tolerant in later areas, where depth information was also tolerant to changes in 2D location. We propose that spatial representations gradually transition from 2D-dominant to balanced 3D (2D and depth) along the visual hierarchy.

  15. 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.

  16. 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)....

  17. MRI of the Prostate

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Prostate Magnetic resonance imaging (MRI) of the prostate ... limitations of MRI of the Prostate? What is MRI of the Prostate? Magnetic resonance imaging (MRI) is ...

  18. 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

  19. 多层螺旋CT小肠造影对克罗恩病活动度的评估价值%Evaluation of Crohn's disease activity with multi-slice CT enterography

    Institute of Scientific and Technical Information of China (English)

    亓昌珍; 章士正; 刘义涛; 胡鹏

    2015-01-01

    Objective To discuss the diagnostic value of Crohn's disease activity with multi-slice CT enterography.Methods MSCTE examination data of 88 cases of CD patients by clinical,endoscopy,pathology confirmed in Sir Run Run Shaw Hospital from January 2013 to June 2014 were analysed.According to the Harvey-Bradshaw index,all of CD patients were divided into the active phase group and remission phase group.Imaging findings of two groups were compared.To explore the relationship between MSCTE findings and CRP/ESR of CD patients.Results The wall thickness (8.2 ± 2.6)mm and enhancement degree(112 ± 16)HU in active phase group were higher than the wall thickness(5.4 ± 1.6)mm and enhancement degree(93 ± 17)HU in the remission phase group(P < 0.01).The incidences of intestinal wall stratification enhancement,comb sign,swollen lymph nodes,phlegmon,intestinal fistula,intestinal stenosis in active phase group (88.5%,72.1%,77%,45.9%,26.2%,65.6%) were significantly higher than those in remission phase group (29.6%,18.5%,25.9%,0,3.7%,37%) (P <0.05).The incidences of intestinal wall homogeneous enhancement in remission phase group(70.4%) were higher than those in active phase group(11.5%) (P < 0.01).There was no significant difference in the incidences of abscesse in two groups (P > 0.05).CRP was correlated with the wall thickness and enhancement degree,abnornlal mesentery vascularity,lymph node enlargement,phlegmon,intestinal fistula (r > 0.2,P < 0.05).ESR was correlated with the wall enhancement degree,abnormal mesentery vascularity,lymph node enlargement and phlegmon (r > 0.2,P < 0.05).Conclusion CT enterography can adequately demonstrate mural abnormalities and assess the presence of extramural complications,which are helpful in evaluating the activity of Crohn's disease.%目的 探讨多层螺旋CT小肠造影(MSCTE)在克罗恩病活动度中的评估价值.方法 收集2013年1月至2014年6月在浙江大学附属邵逸夫医院经

  20. Investigation on the prospects of multi-slice computed tomography enterography in diagnosing small intestine tumor%CT小肠造影在诊断小肠肿瘤中的应用价值

    Institute of Scientific and Technical Information of China (English)

    徐莹; 陈业媛; 舒虹; 肖香佐

    2015-01-01

    目的:探讨多层螺旋CT小肠造影(MSCTE)在小肠肿瘤诊断中的应用价值。方法回顾性分析经手术病理证实的45例小肠肿瘤的MSCTE影像表现,总结其影像学表现特点。结果45例小肠肿瘤中,良性肿瘤9例,其中脂肪瘤6例,影像表现为腔内含脂肪低密度肿块影;腺瘤2例,表现为腔内均质的软组织肿块;回肠系膜淋巴管瘤1例,表现为不规则囊性病灶。常见的恶性肿瘤34例,其中腺癌14例,表现为肠壁局限不规则的环形增厚,中度不均匀强化;间质瘤11例,表现为较大的软组织肿块,以腔外生长为主,密度不均匀,中度或明显强化,常伴有囊变、坏死;淋巴瘤9例,肠壁不规则增厚或形成软组织肿块,累及肠段较长,均匀轻中度强化,常伴有肠系膜、腹膜后淋巴结肿大。少见的恶性肿瘤2例,转移瘤1例,表现为多发肠壁不规则增厚,明显强化,腹壁出现转移性结节;类癌1例,右下腹不规则肿块影。结论 MSCTE在小肠肿瘤诊断与鉴别诊断中有较好的临床应用价值。%Objective To investigate application prospects of Multi-slice computed tomography Enterography(MSCTE) in diag-nosing small intestine tumor (SIT). Methods MSCTE findings were retrospectively analyzed in 45 cases of SIT diagnosed patho-logically after surgery and were summarized in terms of imaging features. Results Of all 45 cases of SIT,9 were benign ones and 6 were lipoma,characterized by low-density mass shadow in intestinal cavity;2 were adenoma,characterized by homogeneous soft tissue mass in intestinal cavity;1 belonged to ileac mesentery lymphangioma,characterized by irregular cyst-like focus;34 were the most common type of malignancies,14 of which were adenocarcinoma,characterized by localized ring-formed thickening of in-testinal wall with moderate heterogeneous enhancement;11 were mesenchymoma,characterized by soft tissue mass relatively big in

  1. 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

  2. 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

  3. Diagnostic Value of Non-segmental Misty Mesentery on Multi-slice CT%多层螺旋CT弥漫性肠系膜混浊征的诊断价值

    Institute of Scientific and Technical Information of China (English)

    符熙; 靳仓正; 姚吕祥; 李春芳; 谭婉嫦

    2013-01-01

    Purpose To investigate the value of non-segmental misty mesentery (NMM) in the diagnosis of different diseases on the multi-slice CT (MSCT),and to improve the diagnostic level.Materials and Methods Eighty patients displayed as NMM on CT and proved by pathology or follow-up were selected,including 25 cases of portal hypertension (PH),20 cases of non tuberculous peritonitis,15 cases of tuberculous peritonitis (TBP)and 20 cases of carcinomatous peritonitis (CP).The characteristics of NMM caused by different diseases were compared.Results Of 80 patients with NMM caused by different diseases,PH was easily displayed as grade Ⅰ NMM,acute pancreatitis often had prerenal fascial thickening,and TBP easily lead to high density (>20 Hu) MM.CP was more vulnerable to show grade Ⅲ NMM,parietal peritoneum mass and abdominal mass.There were 21 patients of PH with grade Ⅰ NMM,18 patients (85.71%) were more likely to occur in the mesenteric root.Intestinal wall thickening was seen at the ascending colon in 2patients with PH.There were 11 patients of CP displayed as perietal peritoneum tumor,7 patients (7/11,63.64%) in the right lower abdomen,2 (2/11,18.18%) in the anterior peritoneum and 2 (2/11,18.18%) around the parietal peritoneum.There were 9 patients of CP showed abdominal mass,5 (5/9,55.56%) were found in the right lower abdomen,2(2/9,22.22%) in the anterior lower abdomen,and 2 (2/9,22.22%) showed multiple lesions in the peritoneal cavity.Conclusion NMM can be caused by different reasons.Combined with other CT findings and clinical history would be helpful to make the correct diagnosis.%目的 探讨不同性质病变所致弥漫性肠系膜混浊征(NMM)的多层螺旋CT (MSCT)诊断价值,提高疾病的诊断水平.资料与方法 80例经手术病理或随访证实的非创伤、代谢类疾病患者,CT均表现为NMM,其中门脉高压症(PH)25例,非结核性腹膜炎20例,结核性腹膜炎(TBP) 15例,癌性腹膜炎(CP) 20例.观察不同性

  4. 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

  5. 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....... MRI was done using a Philips Achieva 1.5 T system and CT was performed using a Siemens Somatom system. Axial and sagittal slices were acquired using standard T1w and T2w MRI sequences, and visualization was made using the Mistar software (Apollo Imaging Technology, Melbourne, Australia). Images were...

  6. 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.

  7. 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...

  8. Knee MRI

    Science.gov (United States)

    ... air-conditioned and well-lit. Some scanners have music to help you pass the time. When the ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  9. 2D/3D switchable displays

    Science.gov (United States)

    Dekker, T.; de Zwart, S. T.; Willemsen, O. H.; Hiddink, M. G. H.; IJzerman, W. L.

    2006-02-01

    A prerequisite for a wide market acceptance of 3D displays is the ability to switch between 3D and full resolution 2D. In this paper we present a robust and cost effective concept for an auto-stereoscopic switchable 2D/3D display. The display is based on an LCD panel, equipped with switchable LC-filled lenticular lenses. We will discuss 3D image quality, with the focus on display uniformity. We show that slanting the lenticulars in combination with a good lens design can minimize non-uniformities in our 20" 2D/3D monitors. Furthermore, we introduce fractional viewing systems as a very robust concept to further improve uniformity in the case slanting the lenticulars and optimizing the lens design are not sufficient. We will discuss measurements and numerical simulations of the key optical characteristics of this display. Finally, we discuss 2D image quality, the switching characteristics and the residual lens effect.

  10. Matrix models of 2d gravity

    Energy Technology Data Exchange (ETDEWEB)

    Ginsparg, P.

    1991-01-01

    These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date.

  11. Matrix models of 2d gravity

    Energy Technology Data Exchange (ETDEWEB)

    Ginsparg, P.

    1991-12-31

    These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date.

  12. Applications of 2D helical vortex dynamics

    DEFF Research Database (Denmark)

    Okulov, Valery; Sørensen, Jens Nørkær

    2010-01-01

    In the paper, we show how the assumption of helical symmetry in the context of 2D helical vortices can be exploited to analyse and to model various cases of rotating flows. From theory, examples of three basic applications of 2D dynamics of helical vortices embedded in flows with helical symmetry...... of the vorticity field are addressed. These included some of the problems related to vortex breakdown, instability of far wakes behind rotors and vortex theory of ideal rotors....

  13. 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.

  14. Image processing of 2D crystal images.

    Science.gov (United States)

    Arheit, Marcel; Castaño-Díez, Daniel; Thierry, Raphaël; Gipson, Bryant R; Zeng, Xiangyan; Stahlberg, Henning

    2013-01-01

    Electron crystallography of membrane proteins uses cryo-transmission electron microscopy to image frozen-hydrated 2D crystals. The processing of recorded images exploits the periodic arrangement of the structures in the images to extract the amplitudes and phases of diffraction spots in Fourier space. However, image imperfections require a crystal unbending procedure to be applied to the image before evaluation in Fourier space. We here describe the process of 2D crystal image unbending, using the 2dx software system.

  15. 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.

  16. 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.

  17. 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。

  18. Fast, accurate 2D-MR relaxation exchange spectroscopy (REXSY): Beyond compressed sensing

    Science.gov (United States)

    Bai, Ruiliang; Benjamini, Dan; Cheng, Jian; Basser, Peter J.

    2016-10-01

    Previously, we showed that compressive or compressed sensing (CS) can be used to reduce significantly the data required to obtain 2D-NMR relaxation and diffusion spectra when they are sparse or well localized. In some cases, an order of magnitude fewer uniformly sampled data were required to reconstruct 2D-MR spectra of comparable quality. Nonetheless, this acceleration may still not be sufficient to make 2D-MR spectroscopy practicable for many important applications, such as studying time-varying exchange processes in swelling gels or drying paints, in living tissue in response to various biological or biochemical challenges, and particularly for in vivo MRI applications. A recently introduced framework, marginal distributions constrained optimization (MADCO), tremendously accelerates such 2D acquisitions by using a priori obtained 1D marginal distribution as powerful constraints when 2D spectra are reconstructed. Here we exploit one important intrinsic property of the 2D-MR relaxation exchange spectra: the fact that the 1D marginal distributions of each 2D-MR relaxation exchange spectrum in both dimensions are equal and can be rapidly estimated from a single Carr-Purcell-Meiboom-Gill (CPMG) or inversion recovery prepared CPMG measurement. We extend the MADCO framework by further proposing to use the 1D marginal distributions to inform the subsequent 2D data-sampling scheme, concentrating measurements where spectral peaks are present and reducing them where they are not. In this way we achieve compression or acceleration that is an order of magnitude greater than that in our previous CS method while providing data in reconstructed 2D-MR spectral maps of comparable quality, demonstrated using several simulated and real 2D T2 - T2 experimental data. This method, which can be called "informed compressed sensing," is extendable to other 2D- and even ND-MR exchange spectroscopy.

  19. 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。

  20. 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%.

  1. 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...

  2. 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.

  3. 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  

  4. Reconstruction and measurement of optic nerve sheath imaging in normal population with multi-slice spiral CT%正常人眶内段视神经的CT重建和参数测量

    Institute of Scientific and Technical Information of China (English)

    游勇; 成洪波; 樊宁; 王宁利; 杨洁; 刘璐; 刘旭阳

    2015-01-01

    Background Optical nerve damage of glaucomatous eyes is associated with intracranial pressure.Conventional method of evaluating intracranial pressure is to measure cerebrospinal pressure by lumber puncture.However,the measurement of intraorbital optical nerve parameters,a novel method of evaluating intracranial pressure,is introduced in this field.Objective This study was to measure and analyze the intraorbital optic nerve sheath diameter (ONSD) and cross sectional area (ONSA) in normal population using multi-slice spiral CT.Methods This study protocol was approved by Clinical Ethic Committee of Shenzhen Chinese Traditional Medical Hospital and followed Hersinki Declaration.Informed consent was obtained from each individual prior to any medical examination.One hundred and five eyes of 105 normal persons with normal cerebral CT image were enrolled in Shenzhen Chinese Traditional Medical Hospital from January 2012 to September 2013.Cerebral volume was scanned in all the individuals by 64 slice spiral CT.The brain images were obtained for the curve planar rebuilding of intraorbital optical nerve on image post-processing workstation.The maximum and minimum of ONSD and the ONSA in axial sections at 3,6,9,12 and 15 mm far away from globe wall were measured using a standardized technique to analyze the change of optical nerve parameters at different point locations.These parameters were compared in different gender or eyes.The correlation among age and the optical nerve parameters at 3 mm far away from globe wall was evaluated by multivariate regression analysis.Results The average maximal ONSDs were (6.24±0.47), (5.56±0.44),(5.18±0.43),(4.82±0.41) and (4.69±0.41) mm;the average minimal ONSDs were (5.56±0.50),(4.97± 0.41) ,(4.55±0.35),(4.26±0.39) and (4.10±0.40) mm;the average ONSAs were (27.68±4.40),(22.02±3.35) , (18.74± 2.75) , (16.34±2.72) , (15.40±2.68) mm2 at 3,6,9,12 and 15 mm far away from posterior eyeball wall,respectively, showing significant

  5. Characteristics and diagnosis of multi-slice computed tomography examination of portal vein diseases%门静脉病变的多排螺旋CT检查特征与诊断

    Institute of Scientific and Technical Information of China (English)

    任小军; 潘高争; 王霞; 杨如武

    2015-01-01

    恶性肿瘤引起胆管梗阻17例,肝硬化门静脉海绵样变伴肝内胆管扩张(门静脉高压性胆管病)2例.结论 门静脉病变多排螺旋CT检查主要表现为门静脉狭窄、闭塞或扩张、积气,其继发病变表现为门-腔静脉侧支循环形成及门静脉海绵样变、肠缺血以及门静脉高压性胆病;其原发病变多样,以肝硬化和恶性肿瘤为主.多排螺旋CT检查可清楚显示门静脉病变,对其原发病变与继发病变可进行准确诊断.%Objective To summarize the characteristics of multi-slice computed tomography (MSCT) of portal vein diseases and investigate the CT diagnosis of its primary and secondary diseases.Methods The imaging data of 62 patients from Xi'an Xidian Group Hospital,28 patients from Nuclear Industry 215 Hospital of Shanxi Province and 16 patients from Xi'an Gaoxin Hospital with portal vein diseases from January 2012 to March 2015 were retrospectively analyzed.The CT findings,primary and secondary diseases of portal vein lesions were recorded through plain scan and enhanced scan of MSCT.Results Changes in the width of portal vein:among 106 patients,dilation of main portal vein was detected in 45 cases,stenosis of stem or branches of portal vein in 39 cases,portal vein obstruction in 49 cases (21 patients accompanied with enlargement in stem of portal vein and 6 patients with normal width).The diameters of dilated portal vein were 1.4-2.2 cm with a mean diameter of 1.8 cm.The diameters of portal vein with stenosis and occlusion caused by carcinomas were 1.8-4.0 cm with a mean diameter of 2.3cm.Portal vein fistula and pneumatosis:hepatic artery-portal vein fistulas were detected in 12 patients,posterior right branches of portal vein-inferior vena cava fistulas in 2 patients,inferior vena cavaportal vein fistulas and portal-hepatic vein fistulas in 2 patients,pneumatosis in 2 patients.Lesions of portal vein occlusions:occlusions located at main portal veins were detected in 4 cases

  6. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... radiologist) see some areas more clearly. During the MRI, the person who operates the machine will watch ...

  7. 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 ...

  8. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... and Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... usually given through an IV in the arm. MRI Research Programs at FDA Magnetic Resonance Imaging (MRI) ...

  9. 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.

  10. 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.

  11. Orthotropic Piezoelectricity in 2D Nanocellulose

    Science.gov (United States)

    García, Y.; Ruiz-Blanco, Yasser B.; Marrero-Ponce, Yovani; Sotomayor-Torres, C. M.

    2016-10-01

    The control of electromechanical responses within bonding regions is essential to face frontier challenges in nanotechnologies, such as molecular electronics and biotechnology. Here, we present Iβ-nanocellulose as a potentially new orthotropic 2D piezoelectric crystal. The predicted in-layer piezoelectricity is originated on a sui-generis hydrogen bonds pattern. Upon this fact and by using a combination of ab-initio and ad-hoc models, we introduce a description of electrical profiles along chemical bonds. Such developments lead to obtain a rationale for modelling the extended piezoelectric effect originated within bond scales. The order of magnitude estimated for the 2D Iβ-nanocellulose piezoelectric response, ~pm V‑1, ranks this material at the level of currently used piezoelectric energy generators and new artificial 2D designs. Such finding would be crucial for developing alternative materials to drive emerging nanotechnologies.

  12. 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.

  13. Assessing 2D electrophoretic mobility spectroscopy (2D MOSY) for analytical applications.

    Science.gov (United States)

    Fang, Yuan; Yushmanov, Pavel V; Furó, István

    2016-12-08

    Electrophoretic displacement of charged entity phase modulates the spectrum acquired in electrophoretic NMR experiments, and this modulation can be presented via 2D FT as 2D mobility spectroscopy (MOSY) spectra. We compare in various mixed solutions the chemical selectivity provided by 2D MOSY spectra with that provided by 2D diffusion-ordered spectroscopy (DOSY) spectra and demonstrate, under the conditions explored, a superior performance of the former method. 2D MOSY compares also favourably with closely related LC-NMR methods. The shape of 2D MOSY spectra in complex mixtures is strongly modulated by the pH of the sample, a feature that has potential for areas such as in drug discovery and metabolomics. Copyright © 2016 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd. StartCopTextCopyright © 2016 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.

  14. 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...

  15. 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 wavegui...

  16. Canonical structure of 2D black holes

    CERN Document Server

    Navarro-Salas, J; Talavera, C F

    1994-01-01

    We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.

  17. 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.

  18. 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 nonrig...

  19. 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

  20. Clinical application value of multi slice spiral CT in the variation of sinus and nasal complex and sinusitis diagnosis%多层螺旋CT对窦口鼻道复合体解剖变异及鼻窦炎诊断的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    张爱军

    2016-01-01

    目的研究多层螺旋CT对窦口-鼻道复合体(OMC)变异及鼻窦炎诊断的临床应用价值。方法选取2014年5月~2015年4月我院收治的192例慢性鼻窦炎患者,其中40例行鼻内镜手术。经多层螺旋CT观察OMC的解剖变异、鼻窦炎症及鼻内镜技术在手术中的应用。结果192例慢性鼻窦炎症患者中,有164例(85.4%)为OMC解剖变异,其中泡状鼻甲30.21%(58/192),反常中鼻甲9.38%(18/192),钩突肥厚13.54%(25/192),钩突内侧偏移11.64%(22/192),钩突外侧偏移4.17%(8/192),钩突气化3.13%(6/192),Haller气房8.33%(16/192),鼻丘气房9.38%(18/192),鼻中隔偏曲25%(48/192)。鼻及鼻窦炎发病部位分布:前组筛窦168例,后组筛窦72例,上颌筛窦134例,上颌窦126例,额隐窝38例,额窦28例,碟窦16例。行鼻内镜手术患者术中所见和CT显示一致。结论慢性鼻窦炎患者OMC变异及解剖结构采取多层螺旋CT进行观察具有重要的价值,尤其是对功能性内镜鼻窦手术具有重要作用。%Objective To study the clinical applica-tion value of multi slice spiral CT in the variation of sinus and nasal complex(OMC)and sinusitis diagnosis.Methods From May 2014 to April 2015,192 cases with chronic sinusitis,including 40 cases underwent nasal endoscopic surgery were included in this study. OMC anatomical variations and sinusitis were observed by multi-slice spiral CT. Nasal sinus endoscope was used in the surgery. Results Of the 192 cases,164 cases(85.4%)were proved with OMC anatomical variations,including 30.21% concha bullosa, 9.38% abnormal middle turbinate,13.53% uncinate process hypertrophy,11.64% uncinate medial offset,4.17% lateral deviation of uncinate process,3.13%cuncinate gasification, 8.33% Haller cell and 9.38% agger nasi cell,and 25% nasal septum deviation. The nasal sinusitis distribution:168 cases of anterior ethmoid sinus,72 cases of ethmoid sinus,134 cases of

  1. 多层螺旋CT骨三维重建在肋骨及肋软骨骨折的诊断价值%The Diagnostic Value of Multi-slice Spiral CT 3D Bone Reconstruction on Rib and Rib Cartilage Fractures

    Institute of Scientific and Technical Information of China (English)

    苏杨; 刘静; 王江玥

    2016-01-01

    Objective To explore the application value of multi-slice spiral CT (MSCT) three-dimensional (3D) bone reconstruction on the diagnosis of rib and rib cartilage fractures.Methods Forty-three cases of patients with chest injury were treated as the study objects. All of them underwent multi-slice spiral CT scanning. Volume rendering (VR), maximum intensity projection (MIP) and multi planar reconstruction (MPR) were used for 3D reconstruction of ribs and rib cartilage. Compared with routine CT scan, the diagnostic advantages of MSCT 3D reconstruction were analyzed.Results Forty-three cases had rib fractures, a total of 122 ribs. Single fractures accounted for 30.23% and multiple fractures accounted for 69.77%; The axillary segment of rib fracture was common, accounting for 95.65%, 15 cases had rib cartilage fractures, a total of 23, 24 cases were detected with complications by MSCT. The accuracy rate of MSCT 3D reconstruction in the diagnosis of rib and rib cartilage fractures (98.36%, 95.65%) were significantly higher than those of CT scan (72.95%, 13.04%) (P<0.05).Conclusion The accuracy of MSCT in the diagnosis of rib and cartilage fractures is high. It can be used as an ideal imaging method for the diagnosis of the disease.%目的:探讨多层螺旋CT(multi-slice spiral computed tomography, MSCT)骨三维重建在诊断肋骨及肋软骨骨折中的应用价值。方法选取43例胸部外伤患者为研究对象,均行多层螺旋CT扫描,运用容积重建(volume rendering, VR)、最大密度投影(maximum intensity projection, MIP)、多平面重建(multi planar reconstruction, MPR)三维重建肋骨及肋软骨,并与常规CT平扫对比,分析MSCT三维重建的诊断优势。结果43例肋骨骨折,共122根;其中单发骨折占30.23%,多发骨折占69.77%;肋骨骨折腋段较为常见,占95.65%;15例肋软骨骨折,共23根;MSCT检出24例外伤后并发症。MSCT三维重建技术诊断肋骨及肋软骨骨折的准确率为98

  2. 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

  3. 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.

  4. Schottky diodes from 2D germanane

    Science.gov (United States)

    Sahoo, Nanda Gopal; Esteves, Richard J.; Punetha, Vinay Deep; Pestov, Dmitry; Arachchige, Indika U.; McLeskey, James T.

    2016-07-01

    We report on the fabrication and characterization of a Schottky diode made using 2D germanane (hydrogenated germanene). When compared to germanium, the 2D structure has higher electron mobility, an optimal band-gap, and exceptional stability making germanane an outstanding candidate for a variety of opto-electronic devices. One-atom-thick sheets of hydrogenated puckered germanium atoms have been synthesized from a CaGe2 framework via intercalation and characterized by XRD, Raman, and FTIR techniques. The material was then used to fabricate Schottky diodes by suspending the germanane in benzonitrile and drop-casting it onto interdigitated metal electrodes. The devices demonstrate significant rectifying behavior and the outstanding potential of this material.

  5. 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

  6. SLIMMER: SLIce MRI motion estimation and reconstruction tool for studies of fetal anatomy

    Science.gov (United States)

    Kim, Kio; Habas, Piotr A.; Rajagopalan, Vidya; Scott, Julia; Rousseau, Francois; Barkovich, A. James; Glenn, Orit A.; Studholme, Colin

    2011-03-01

    We describe a free software tool which combines a set of algorithms that provide a framework for building 3D volumetric images of regions of moving anatomy using multiple fast multi-slice MRI studies. It is specifically motivated by the clinical application of unsedated fetal brain imaging, which has emerged as an important area for image analysis. The tool reads multiple DICOM image stacks acquired in any angulation into a consistent patient coordinate frame and allows the user to select regions to be locally motion corrected. It combines algorithms for slice motion estimation, bias field inconsistency correction and 3D volume reconstruction from multiple scattered slice stacks. The tool is built onto the RView (http://rview.colin-studholme.net) medical image display software and allows the user to inspect slice stacks, and apply both stack and slice level motion estimation that incorporates temporal constraints based on slice timing and interleave information read from the DICOM data. Following motion estimation an algorithm for bias field inconsistency correction provides the user with the ability to remove artifacts arising from the motion of the local anatomy relative to the imaging coils. Full 3D visualization of the slice stacks and individual slice orientations is provided to assist in evaluating the quality of the motion correction and final image reconstruction. The tool has been evaluated on a range of clinical data acquired on GE, Siemens and Philips MRI scanners.

  7. 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

  8. 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...

  9. Quasiparticle interference in unconventional 2D systems

    Science.gov (United States)

    Chen, Lan; Cheng, Peng; Wu, Kehui

    2017-03-01

    At present, research of 2D systems mainly focuses on two kinds of materials: graphene-like materials and transition-metal dichalcogenides (TMDs). Both of them host unconventional 2D electronic properties: pseudospin and the associated chirality of electrons in graphene-like materials, and spin-valley-coupled electronic structures in the TMDs. These exotic electronic properties have attracted tremendous interest for possible applications in nanodevices in the future. Investigation on the quasiparticle interference (QPI) in 2D systems is an effective way to uncover these properties. In this review, we will begin with a brief introduction to 2D systems, including their atomic structures and electronic bands. Then, we will discuss the formation of Friedel oscillation due to QPI in constant energy contours of electron bands, and show the basic concept of Fourier-transform scanning tunneling microscopy/spectroscopy (FT-STM/STS), which can resolve Friedel oscillation patterns in real space and consequently obtain the QPI patterns in reciprocal space. In the next two parts, we will summarize some pivotal results in the investigation of QPI in graphene and silicene, in which systems the low-energy quasiparticles are described by the massless Dirac equation. The FT-STM experiments show there are two different interference channels (intervalley and intravalley scattering) and backscattering suppression, which associate with the Dirac cones and the chirality of quasiparticles. The monolayer and bilayer graphene on different substrates (SiC and metal surfaces), and the monolayer and multilayer silicene on a Ag(1 1 1) surface will be addressed. The fifth part will introduce the FT-STM research on QPI in TMDs (monolayer and bilayer of WSe2), which allow us to infer the spin texture of both conduction and valence bands, and present spin-valley coupling by tracking allowed and forbidden scattering channels.

  10. 2D Metals by Repeated Size Reduction.

    Science.gov (United States)

    Liu, Hanwen; Tang, Hao; Fang, Minghao; Si, Wenjie; Zhang, Qinghua; Huang, Zhaohui; Gu, Lin; Pan, Wei; Yao, Jie; Nan, Cewen; Wu, Hui

    2016-10-01

    A general and convenient strategy for manufacturing freestanding metal nanolayers is developed on large scale. By the simple process of repeatedly folding and calendering stacked metal sheets followed by chemical etching, free-standing 2D metal (e.g., Ag, Au, Fe, Cu, and Ni) nanosheets are obtained with thicknesses as small as 1 nm and with sizes of the order of several micrometers.

  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. Irreversibility-inversions in 2D turbulence

    Science.gov (United States)

    Bragg, Andrew; de Lillo, Filippo; Boffetta, Guido

    2016-11-01

    We consider a recent theoretical prediction that for inertial particles in 2D turbulence, the nature of the irreversibility of their pair dispersion inverts when the particle inertia exceeds a certain value. In particular, when the particle Stokes number, St , is below a certain value, the forward-in-time (FIT) dispersion should be faster than the backward-in-time (BIT) dispersion, but for St above this value, this should invert so that BIT becomes faster than FIT dispersion. This non-trivial behavior arises because of the competition between two physically distinct irreversibility mechanisms that operate in different regimes of St . In 3D turbulence, both mechanisms act to produce faster BIT than FIT dispersion, but in 2D, the two mechanisms have opposite effects because of the inverse energy cascade in the turbulent velocity field. We supplement the qualitative argument given by Bragg et al. by deriving quantitative predictions of this effect in the short-time dispersion limit. These predictions are then confirmed by results of inertial particle dispersion in a direct numerical simulation of 2D turbulence.

  13. 多层螺旋CT血管成像在脑动静脉畸形诊断及治疗中的价值%Value of multi-slice spiral CT angiography in diagnosis and treatment of cerebral arteriovenous malformations

    Institute of Scientific and Technical Information of China (English)

    余海浪; 庹秀均; 李战辉; 张应和

    2013-01-01

    目的 探讨脑动静脉畸形(CAVM)在多层螺旋CT血管造影(MSCTA)中的表现及MSCTA的临床价值.方法 收集36例行MSCTA检查的CAVM患者的资料,采用容积再现重组(VR)血管生长技术(AV)进行血管重建,分析供血动脉、引流静脉的表现.结果 36例CAVM患者中,病变累及枕叶10例,颞叶9例,额叶2例,顶叶3例,枕叶、小脑半球7例,颞、枕叶3例,额、顶叶2例,均清楚显示畸形血管团、供血动脉及引流静脉;4例合并血管畸形内动脉瘤,2例合并血管畸形外动脉瘤,3例蛛网膜下腔出血,6例脑出血.结论 MSCTA能清楚显示CAVM的畸形血管团、供血动脉、引流静脉及合并的动脉瘤.%Objective To evaluate the manifestation of cerebral arteriovenous malformations (CAVM) on multi-slice spiral CT (MSCT) angiography and the clinical value of this examinaion.Methods The data on 36 patients with CAVM undergoing MSCT angiography were collected.Vascular reconstruction were performed by volume rendering and AV.The manifestations of feeding arteries and draining veins were then analyzed.Results Among these 36 patients with cerebral arteriovenous malformations,ten patients had the lesion in occipital lobe,nine in temporal lobe,two in frontal lobe,three in parietal lobe,seven in occipital lobe and cerebellar hemisphere,three in occipital and temporal lobe,and two in frontal and parietal lobe,with a clear display of masses of deformed vessels,feeding arteries and draining veins; 4 patients were complicated by intra-aneurysm of CAVM,2 were complicated by extra-aneurysm of CAVM,3 concurred with subarachnoid hemorrhage,and 6 concurred with cerebral hemorrhage.Conclusions Multi-slice spiral angiography can clearly detect masses of deformed vessels,feeding arteries,draining veins,and coexisting aneurysms.

  14. Clinical Value of Multi-slice Spiral CT in the Staging of Sacroiliac Arthropathy in Ankylosing Spondylitis%多层螺旋CT在强直性脊柱炎骶髂关节病变分期中的应用价值

    Institute of Scientific and Technical Information of China (English)

    王辉; 徐春生; 汪四海; 张金山; 杨佳; 刘健

    2011-01-01

    目的 探讨多层螺旋CT(multi-slice spiral CT,MSCT)在强直性脊柱炎(ankylosing spondylitis,AS)骶髂关节病变的诊断及分期中的应用价值.方法 回顾性分析82例AS患者骶髂关节的MSCT表现,对其进行分期.结果 82例中,双侧骶髂关节正常9例,单侧受累6例,双侧均受累67例;164个骶髂关节中,0级24个(构成比0.146),Ⅰ级42个(构成比0.256),Ⅱ级36个(构成比0.220),Ⅲ级54个(构成比0.329),Ⅳ级8个(构成比0.049).结论 MSCT分期为AS骶髂关节病变提供了半定量分析方法,更客观、准确地反映了患者的病情及骶髂关节受累程度,为长期随访患者的病情和疗效判断提供了客观依据.%Objective To evaluate the clinical values of multi-slice spiral CT (MSCT) in the diagnosis and staging of sacroiliac arthropathy in patients with ankylosing spondylitis(AS). Methods The MSCT features of sacroiliac arthropathy in 82 patients with AS were analyzed retrospectively, and the staging of sacroiliac arthropathy were determined by MSCT. Results Of 82 patients, there were normal bilateral sacroiliac joints in 9, unilateral involvement in 6, and bilateral involvement in 67. Of 164 sacroiliac joints, 24 (accounting for 0. 146) were classified into grade 0, 42 (accounting for 0. 256) into grade Ⅰ, 36 (accounting for 0. 220) into grade Ⅱ, 54 (accounting for 0. 329) into grade Ⅲ , and 8 (accounting for 0. 049) into grade Ⅳ. The CT features included cartilage calcification, joint space narrowing or widening, articular surface and undersurface erosion, and ligament calcification. Conclusion MSCT staging of sacroiliac arthropathy provides a method of semi-quantitative analysis on AS. It can reflect the clinical state of AS more objectively and accurately, and can provide an objective basis for judgement on the disease conditions and curative effects in patients with long-term follow-up.

  15. 2D superconductivity by ionic gating

    Science.gov (United States)

    Iwasa, Yoshi

    2D superconductivity is attracting a renewed interest due to the discoveries of new highly crystalline 2D superconductors in the past decade. Superconductivity at the oxide interfaces triggered by LaAlO3/SrTiO3 has become one of the promising routes for creation of new 2D superconductors. Also, the MBE grown metallic monolayers including FeSe are also offering a new platform of 2D superconductors. In the last two years, there appear a variety of monolayer/bilayer superconductors fabricated by CVD or mechanical exfoliation. Among these, electric field induced superconductivity by electric double layer transistor (EDLT) is a unique platform of 2D superconductivity, because of its ability of high density charge accumulation, and also because of the versatility in terms of materials, stemming from oxides to organics and layered chalcogenides. In this presentation, the following issues of electric filed induced superconductivity will be addressed; (1) Tunable carrier density, (2) Weak pinning, (3) Absence of inversion symmetry. (1) Since the sheet carrier density is quasi-continuously tunable from 0 to the order of 1014 cm-2, one is able to establish an electronic phase diagram of superconductivity, which will be compared with that of bulk superconductors. (2) The thickness of superconductivity can be estimated as 2 - 10 nm, dependent on materials, and is much smaller than the in-plane coherence length. Such a thin but low resistance at normal state results in extremely weak pinning beyond the dirty Boson model in the amorphous metallic films. (3) Due to the electric filed, the inversion symmetry is inherently broken in EDLT. This feature appears in the enhancement of Pauli limit of the upper critical field for the in-plane magnetic fields. In transition metal dichalcogenide with a substantial spin-orbit interactions, we were able to confirm the stabilization of Cooper pair due to its spin-valley locking. This work has been supported by Grant-in-Aid for Specially

  16. MRI of the Chest

    Medline Plus

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

  17. GBL-2D Version 1.0: a 2D geometry boolean library.

    Energy Technology Data Exchange (ETDEWEB)

    McBride, Cory L. (Elemental Technologies, American Fort, UT); Schmidt, Rodney Cannon; Yarberry, Victor R.; Meyers, Ray J. (Elemental Technologies, American Fort, UT)

    2006-11-01

    This report describes version 1.0 of GBL-2D, a geometric Boolean library for 2D objects. The library is written in C++ and consists of a set of classes and routines. The classes primarily represent geometric data and relationships. Classes are provided for 2D points, lines, arcs, edge uses, loops, surfaces and mask sets. The routines contain algorithms for geometric Boolean operations and utility functions. Routines are provided that incorporate the Boolean operations: Union(OR), XOR, Intersection and Difference. A variety of additional analytical geometry routines and routines for importing and exporting the data in various file formats are also provided. The GBL-2D library was originally developed as a geometric modeling engine for use with a separate software tool, called SummitView [1], that manipulates the 2D mask sets created by designers of Micro-Electro-Mechanical Systems (MEMS). However, many other practical applications for this type of software can be envisioned because the need to perform 2D Boolean operations can arise in many contexts.

  18. Another solution of 2D Ising model

    Science.gov (United States)

    Vergeles, S. N.

    2009-04-01

    The partition function of the Ising model on a two-dimensional regular lattice is calculated by using the matrix representation of a Clifford algebra (the Dirac algebra), with number of generators equal to the number of lattice sites. It is shown that the partition function over all loops in a 2D lattice including self-intersecting ones is the trace of a polynomial in terms of Dirac matrices. The polynomial is an element of the rotation group in the spinor representation. Thus, the partition function is a function of a character on an orthogonal group of a high degree in the spinor representation.

  19. 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

  20. Robust and resistant 2D shape alignment

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Eiriksson, Hrafnkell

    2001-01-01

    \\_\\$\\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......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...

  1. 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.

  2. Knee MRI scan

    Science.gov (United States)

    MRI - knee ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ... less anxious. Your provider may suggest an "open" MRI, in which the machine is not as close ...

  3. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the chest is performed ...

  4. 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...

  5. Remarks on thermalization in 2D CFT

    Science.gov (United States)

    de Boer, Jan; Engelhardt, Dalit

    2016-12-01

    We revisit certain aspects of thermalization in 2D conformal field theory (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 Banados-Teitelboim-Zanelli black hole. The extra conserved charges, while rendering c <1 theories essentially integrable, therefore seem to have little effect on large-c conformal field theories.

  6. 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.

  7. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  8. SU-F-303-13: Initial Evaluation of Four Dimensional Diffusion- Weighted MRI (4D-DWI) and Its Effect On Apparent Diffusion Coefficient (ADC) Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y [Duke University Medical Physics Program (United States); Yin, F; Czito, B; Bashir, M; Palta, M; Cai, J [Duke University Medical Center, Durham, NC (United States); Zhong, X; Dale, B [Siemens Healthcare, Durham, NC (United States)

    2015-06-15

    Purpose: Diffusion-weighted imaging(DWI) has been shown to have superior tumor-to-tissue contrast for cancer detection.This study aims at developing and evaluating a four dimensional DWI(4D-DWI) technique using retrospective sorting method for imaging respiratory motion for radiotherapy planning,and evaluate its effect on Apparent Diffusion Coefficient(ADC) measurement. Materials/Methods: Image acquisition was performed by repeatedly imaging a volume of interest using a multi-slice single-shot 2D-DWI sequence in the axial planes and cine MRI(served as reference) using FIESTA sequence.Each 2D-DWI image were acquired in xyz-diffusion-directions with a high b-value(b=500s/mm2).The respiratory motion was simultaneously recorded using bellows.Retrospective sorting was applied in each direction to reconstruct 4D-DWI.The technique was evaluated using a computer simulated 4D-digital human phantom(XCAT),a motion phantom and a healthy volunteer under an IRB-approved study.Motion trajectories of regions-of-interests(ROI) were extracted from 4D-DWI and compared with reference.The mean motion trajectory amplitude differences(D) between the two was calculated.To quantitatively analyze the motion artifacts,XCAT were controlled to simulate regular motion and the motions of 10 liver cancer patients.4D-DWI,free-breathing DWI(FB- DWI) were reconstructed.Tumor volume difference(VD) of each phase of 4D-DWI and FB-DWI from the input static tumor were calculated.Furthermore, ADC was measured for each phase of 4D-DWI and FB-DWI data,and mean tumor ADC values(M-ADC) were calculated.Mean M-ADC over all 4D-DWI phases was compared with M-ADC calculated from FB-DWI. Results: 4D-DWI of XCAT,the motion phantom and the healthy volunteer demonstrated the respiratory motion clearly.ROI D values were 1.9mm,1.7mm and 2.0mm,respectively.For motion artifacts analysis,XCAT 4D-DWI images show much less motion artifacts compare to FB-DWI.Mean VD for 4D-WDI and FB-DWI were 8.5±1.4% and 108±15

  9. 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 it ... and MRI Breast-feeding and MRI What is MRI and how does it work? Magnetic resonance imaging, ...

  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. 2D Electrostatic Actuation of Microshutter Arrays

    Science.gov (United States)

    Burns, Devin E.; Oh, Lance H.; Li, Mary J.; Jones, Justin S.; Kelly, Daniel P.; Zheng, Yun; Kutyrev, Alexander S.; Moseley, Samuel H.

    2015-01-01

    An electrostatically actuated microshutter array consisting of rotational microshutters (shutters that rotate about a torsion bar) were designed and fabricated through the use of models and experiments. Design iterations focused on minimizing the torsional stiffness of the microshutters, while maintaining their structural integrity. Mechanical and electromechanical test systems were constructed to measure the static and dynamic behavior of the microshutters. The torsional stiffness was reduced by a factor of four over initial designs without sacrificing durability. Analysis of the resonant behavior of the microshutter arrays demonstrates that the first resonant mode is a torsional mode occurring around 3000 Hz. At low vacuum pressures, this resonant mode can be used to significantly reduce the drive voltage necessary for actuation requiring as little as 25V. 2D electrostatic latching and addressing was demonstrated using both a resonant and pulsed addressing scheme.

  12. 2-d Simulations of Test Methods

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2004-01-01

    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......One of the main obstacles for the further development of self-compacting concrete is to relate the fresh concrete properties to the form filling ability. Therefore, simulation of the form filling ability will provide a powerful tool in obtaining this goal. In this paper, a continuum mechanical...... 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...

  13. 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.

  14. Lie symmetries and 2D Material Physics

    CERN Document Server

    Belhaj, Adil

    2014-01-01

    Inspired from Lie symmetry classification, we establish a correspondence between rank two Lie symmetries and 2D material physics. The material unit cell is accordingly interpreted as the geometry of a root system. The hexagonal cells, appearing in graphene like models, are analyzed in some details and are found to be associated with A_2 and G_2 Lie symmetries. This approach can be applied to Lie supersymmetries associated with fermionic degrees of freedom. It has been suggested that these extended symmetries can offer a new way to deal with doping material geometries. Motivated by Lie symmetry applications in high energy physics, we speculate on a possible connection with (p,q) brane networks used in the string theory compactification on singular Calabi-Yau manifolds.

  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. Analysis of the IEA 2D test. 2D, 3D, steady or unsteady airflow?

    DEFF Research Database (Denmark)

    Cortes, Ines Olmedo; Nielsen, Peter V.

    The “IEA Annex 20 two-dimensional test case” was defined by proffesor Peter V. Nielsen (1990) and was originally considered two-dimensional and steady flow. However, some recent works considering the case as three dimensional have shown different solutions from the 2D case as well as different so...

  17. 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

  18. 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

  19. 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).

  20. 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.

  1. Competing coexisting phases in 2D water

    Science.gov (United States)

    Zanotti, Jean-Marc; Judeinstein, Patrick; Dalla-Bernardina, Simona; Creff, Gaëlle; Brubach, Jean-Blaise; Roy, Pascale; Bonetti, Marco; Ollivier, Jacques; Sakellariou, Dimitrios; Bellissent-Funel, Marie-Claire

    2016-05-01

    The properties of bulk water come from a delicate balance of interactions on length scales encompassing several orders of magnitudes: i) the Hydrogen Bond (HBond) at the molecular scale and ii) the extension of this HBond network up to the macroscopic level. Here, we address the physics of water when the three dimensional extension of the HBond network is frustrated, so that the water molecules are forced to organize in only two dimensions. We account for the large scale fluctuating HBond network by an analytical mean-field percolation model. This approach provides a coherent interpretation of the different events experimentally (calorimetry, neutron, NMR, near and far infra-red spectroscopies) detected in interfacial water at 160, 220 and 250 K. Starting from an amorphous state of water at low temperature, these transitions are respectively interpreted as the onset of creation of transient low density patches of 4-HBonded molecules at 160 K, the percolation of these domains at 220 K and finally the total invasion of the surface by them at 250 K. The source of this surprising behaviour in 2D is the frustration of the natural bulk tetrahedral local geometry and the underlying very significant increase in entropy of the interfacial water molecules.

  2. 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...

  3. 多排螺旋CT在快速扩弓器联合前方牵引矫治替牙期骨性反的应用效果%Application Effect of Multi-slice Spiral CT in Orthodontic Treatment of Skeletal Crossbite during Mixed Dentition by Rapid Maxillary Expansion Device Combined with Anterior Traction

    Institute of Scientific and Technical Information of China (English)

    李洪; 朱光恒; 黄文英

    2016-01-01

    目的:探讨多排螺旋CT在快速扩弓器联合前方牵引矫治替牙期骨性反的应用效果。方法:36例儿童替牙期骨性安氏Ⅲ类错患儿均接受快速扩弓器联合前方牵引矫治治疗,均同时接受拍摄X线片及MSCT片,测量上下颌骨各项参数。结果:X线片与MSCT的SNA角、SNB角、ANB角、U1-NA角、颌凸角、U1-NA距、ANS-Ptm距、L1-MP角及U1-SN角比较,差异均有统计学意义(P<0.05)。X线片各角的CV值均高于MSCT,差异均有统计学意义(P<0.05)。结论:多排螺旋CT在替牙期骨性反儿童快速扩弓器联合前方牵引矫治中上颌骨相关指标测量的精确度更高,离散程度小,重复测量结果好,通过较准确的测量数据分析来探讨快速扩弓器联合前方牵引矫治替牙期骨性反诱导上颌骨生长量的变化,对该技术作出更为准确的疗效评价并指导临床治疗等方面具有较高的应用价值。%Objective:To investigate the application effect of multi-slice spiral CT in orthodontic treatment of skeletal crossbite during mixed dentition by rapid maxillary expansion device combined with anterior traction. Method:36 children with mixed dentition skeletal class III malocclusion were treated with rapid palatal expansion and protraction treatment,were also being filmed X-ray and MSCT sheet,measuring the parameters of the upper and lower jaw.Result:X-ray and MSCT SNA angle,SNB angle,ANB angle,U1-NA angle,angle of convexity, U1-NA distance,ANS-Ptm distance,L1-MP angle and U1-SN angle of comparison,the differences were statistically significant(P<0.05).X-ray of the CV were higher than MSCT,the differences were statistically significant(P<0.05).Conclusion:The accuracy of multi slice spiral CT measurement of related indexes in skeletal malocclusion in mixed dentition children rapid palatal expansion combined with maxillary protraction in the higher dispersion degree of small, repeated measurement results, through the

  4. Diagnostic value of combination of 99mTc-MIBI imaging,multi-slice spiral CT and tumor marker measurements for lung cancer%99mTc-MIBI肺显像、多排螺旋CT和肿瘤标志物检测对肺癌的诊断价值

    Institute of Scientific and Technical Information of China (English)

    党国际

    2009-01-01

    目的 探讨99Tc-甲氧基异丁基乙腈(99Tc-MIBI)亲肿瘤显像、多排螺旋CT、血清肿瘤标志物[癌胚抗原(CEA)、细胞角蛋白19片断(CYFRA21-1)、神经元特异性烯醇化酶(NSE)]检测联合应用对肺癌的诊断价值.方法 对350例临床怀疑为肺癌患者的99mTc-MIBI亲肿瘤显像、多排螺旋CT、血清肿瘤标志物榆测资料进行回顾性分析,总结每种方法及三种方法联合应用诊断肺癌的灵敏度、特异度及正确度.350例患者分别经纤维支气管镜检查、手术治疗及穿刺活组织枪查、病理最后证实200例为肺癌患者.结果 三种检查方法诊断肺癌的灵敏度、特异度及正确度分别为74.5%(149/200)、68.7%(103/150)、72.0%(252/350),97.5%(195/200)、42.7%(64/150)、74.0%(259/350)及62.5%(125/200)、28.7%(43/150)、48.0%(168/350).三法联合应用为99.5%(199/200)、82.0%(123/150)、92.0%(322/350).结论 上述三种检查方法对肺癌诊断各有其独特的重要的临床价值,三种方法联合应用诊断价值更大.%Objective To explore the clinical value of the combination of three methods including 99mTc-MIBI imaging, multi-slice spiral CT and tumor markers [carcinoembryonic antigen(CEA),cytokeretin19 fragment(CYFRA21-1), neuron-specific enolase(NSE)] measurement for diagnosis of lung cancer. Methods 350 patients were performed 99mTc-MIBl imaging, multi-slice spiral CT and measurements of tumor markers apart within one week. 200 patients were proved by pathology lung cancer in all 350 patients. Results The sensitivity, specificity and accuracy obtained with the three methods and combination of three methods were 74.5 %(149/200), 68.7 %(103/150), 72.0 %(252/350);97.5 %(195/200), 42.7 %(64/150), 74.0 %(259/350);62.5 %(125/200), 28.7 %(43/150), 48.0 %(168/350) and 99.5 %(199/200), 82.0 %(123/150), 92.0 %(322/350),respectively. Conclusion The results imply that three methods has its distinct important clinical value in diagnosis of lung cancer respectively

  5. 总结多层螺旋CT在创伤性上颈椎隐形损伤患者诊断中的应用体会%Summary of Multi-Slice Spiral CT in traumatic Upper Cervical Injury Patients Contact Experience Application in Diagnosis

    Institute of Scientific and Technical Information of China (English)

    魏波

    2015-01-01

    Objective: To explore the focus of traumatic upper cervical contact diagnosis value of multi-slice spiral CT in injury patients.Methods: the research object selected is 2011 02 Feb 01 to 2014 02 months 01 days in our hospital underwent multislice spiral CT examination of 56 patients with suspected in patients with upper cervical injury, detailed analysis of the results of image.Results: the display for the contact damage in a total of 45 patients, 4 patients belonged to the ring gear joint, 2 patients belonged to the vertebral rotation dislocation, 9 cases belong to C1 lateral mass fracture, 2 cases belong to the simple transverse ligament injury, atlas lateral mass fracture on the right side of a total of 3 cases of C1 fracture dislocation;accompanied by vertebral attachment a total of 2 cases of fracture of vertebral arch fracture C1, a total of 6 cases of vertebral fracture and dislocation; C2 with a total of 3 cases of accessory fracture, fracture C2 of vertebral arch of a total of 5 cases;C2 vertebral fracture accompanied by accessory fracture has a total of 3 cases, C2 a total of 6 cases of vertebral fracture, tooth styloid fractures with a total of 11 cases.Conclusion: multi slice spiral CT in the diagnosis of traumatic upper cervical application invisible injury high accuracy, can provide valuable references for clinical treatment.%目的:重点探索在创伤性上颈椎隐形损伤患者中应用多层螺旋CT的诊断价值。方法挑选的研究对象是2011年02月01日—2014年02月01日在我院行多层螺旋CT检查的56例疑似上颈椎损伤患者,细致的分析影像学结果。结果显示为隐形损伤的总共有45例,4例患者属于环齿关节,2例患者属于椎体旋转脱位,9例属于C1侧块骨折,2例属于单纯横韧带损伤,环椎右侧侧块骨折的总共有3例;C1骨折脱位并伴随椎体附件骨折的总共有2例,C1椎弓骨折的总共有6例;C2椎体骨折脱位并伴随附件骨折的总共有3

  6. 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.

  7. 多层螺旋 CT 口服小肠造影与胶囊内镜对不明原因腹痛患者诊断价值的对比研究%Comparison of diagnostic value of multi-slice computer tomography enterography versus capsule endoscopy for unexplained abdominal pain

    Institute of Scientific and Technical Information of China (English)

    梁晓燕; 伦伟健; 黄鹤; 贾柳萍

    2016-01-01

    Objective To compare and evaluate the diagnositic value of multi-slice computer tomography enterography (MSCTE)versus capsule endoscopy for patients with unexplained abdominal pain.Methods twenty-nine cases of unknown abdominal pain were collected.8 cases of 29 cases received MSCTE examination,24 cases received the capsule endoscopy and 3 cases received both of the examinations.Results The detection rate for lesions was 62.5% by MSCTE and 75.0% by capsule endoscopy.There was no statistical difference between the two methods(P >0.05).The detection rate in cases undergoing both examinations was 1 00%. Conclusions MSCTE and capsule endoscopy have high diagnostic value in patients with unexplained abdominal pain.The detection rate can be increased if the two methods are combined to conduct examination.%目的:对比多层螺旋 CT 口服小肠造影(MSCTE)与胶囊内镜对不明原因腹痛患者的诊断价值。方法收集29例不明原因腹痛患者,其中 MSCTE 检查8例,胶囊内镜检查24例,同时接受两种方法检查3例。结果 MSCTE 病变检出率为62.5%,胶囊内镜为75.0%,两者差别无统计学意义(P >0.05),联合两者病变检出率为100%。结论 MSCTE 与胶囊内镜检查对不明原因腹痛患者具有较高的诊断价值,二者联合诊断意义更高。

  8. 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.

  9. 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

  10. 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.

  11. 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

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

    Science.gov (United States)

    Viallon, Magalie; Cuvinciuc, Victor; Delattre, Benedicte; Merlini, Laura; Barnaure-Nachbar, Isabelle; Toso-Patel, Seema; Becker, Minerva; Lovblad, Karl-Olof; Haller, Sven

    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.

  13. 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.)

  14. Cine-MRI versus two-dimensional echocardiography to measure in vivo left ventricular function in rat heart.

    Science.gov (United States)

    Stuckey, Daniel J; Carr, Carolyn A; Tyler, Damian J; Clarke, Kieran

    2008-08-01

    Two-dimensional echocardiography is the most commonly used non-invasive method for measuring in vivo cardiac function in experimental animals. In humans, measurements of cardiac function made using cine-MRI compare favourably with those made using echocardiography. However, no rigorous comparison has been made in small animals. Here, standard short-axis two-dimensional (2D) echocardiography (2D-echo) and cine-MRI measurements were made in the same rats, both control and after chronic myocardial infarction. Correlations between the two techniques were found for end diastolic area, stroke area and ejection fraction, but cine-MRI measurements of ejection fraction were 12+/-6% higher than those made using 2D-echo, because of the 1.8-fold higher temporal resolution of the MRI technique (4.6 ms vs 8.3 ms). Repeated measurements on the same group of rats over several days showed that the cine-MRI technique was more reproducible than 2D-echo, in that 2D-echo would require five times more animals to find a statistically significant difference. In summary, caution should be exercised when comparing functional results acquired using short-axis 2D-echo vs cine-MRI. The accuracy of cine-MRI allows identification of alterations in heart function that may be missed when using 2D-echo.

  15. 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 ...

  16. 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.

  17. Pharm GKB: CYP2D6 [PharmGKB

    Lifescience Database Archive (English)

    Full Text Available el for vortioxetine and CYP2D6 FDA Label for acetaminophen,tramadol and CYP2D6 FDA Label for dextromethorphan... Label for vortioxetine and CYP2D6 European Medicines Agency (EMA) Label for dextromethorphan,quinidine and ...ore of this label. Read more. last updated 10/25/2013 FDA Label for dextromethorphan, quinidine and CYP2D6 O...of NUEDEXTA is a CYP2D6 inhibitor used to increase the plasma availability of dextromethorphan, which is met... 05/02/2014 European Medicines Agency (EMA) Label for dextromethorphan, quinidine

  18. 3D/2D Registration of medical images

    OpenAIRE

    Tomaževič, D.

    2008-01-01

    The topic of this doctoral dissertation is registration of 3D medical images to corresponding projective 2D images, referred to as 3D/2D registration. There are numerous possible applications of 3D/2D registration in image-aided diagnosis and treatment. In most of the applications, 3D/2D registration provides the location and orientation of the structures in a preoperative 3D CT or MR image with respect to intraoperative 2D X-ray images. The proposed doctoral dissertation tries to find origin...

  19. 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

  20. 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…

  1. Backscattering in a 2D topological insulator and the conductivity of a 2D strip

    Science.gov (United States)

    Magarill, L. I.; Entin, M. V.

    2015-01-01

    A strip of the 2D HgTe topological insulator is studied. The same-spin edge states in an ideal system propagate in opposite directions on different sides of the strip and do not mix by tunneling. Impurities, edge irregularities, and phonons produce transitions between the counterpropagating edge states on different edges. This backscattering determines the conductivity of an infinitely long strip. The conductivity at finite temperature is determined in the framework of the kinetic equation. It is found that the conductivity exponentially grows with the strip width. In the same approximation the nonlocal resistance coefficients of a four-terminal strip are found.

  2. MRI of the Chest

    Medline Plus

    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of cardiovascular conditions. MRI has proven valuable in ...

  3. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ...

  4. Abdominal MRI scan

    Science.gov (United States)

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ...

  5. MRI of the Chest

    Medline Plus

    Full Text Available ... have this exam in the first trimester of pregnancy unless the potential benefit from the MRI exam ... See the Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of ...

  6. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  7. 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 ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  8. Residual lens effects in 2D mode of auto-stereoscopic lenticular-based switchable 2D/3D displays

    Science.gov (United States)

    Sluijter, M.; IJzerman, W. L.; de Boer, D. K. G.; de Zwart, S. T.

    2006-04-01

    We discuss residual lens effects in multi-view switchable auto-stereoscopic lenticular-based 2D/3D displays. With the introduction of a switchable lenticular, it is possible to switch between a 2D mode and a 3D mode. The 2D mode displays conventional content, whereas the 3D mode provides the sensation of depth to the viewer. The uniformity of a display in the 2D mode is quantified by the quality parameter modulation depth. In order to reduce the modulation depth in the 2D mode, birefringent lens plates are investigated analytically and numerically, by ray tracing. We can conclude that the modulation depth in the 2D mode can be substantially decreased by using birefringent lens plates with a perfect index match between lens material and lens plate. Birefringent lens plates do not disturb the 3D performance of a switchable 2D/3D display.

  9. 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...

  10. 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.

  11. 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.

  12. The value of multi-slice spiral CT enterography and double-balloon enteroscopy in the diagnosis of unexplained abdominal pains%多层螺旋CT小肠造影与双气囊小肠镜在不明原因腹痛诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    周建伟; 潘杰; 侯俊良

    2012-01-01

    Objective To assess the value of multi-slice spiral CT enterography (MSCTE) and double-balloon enteroscopy (DBE) in the diagnosis of unexplained abdominal pains. Methods 41 patients with unexplained abdominal pains were selected and received MSCTE and DBE examination. With combining the results of endoscopy and/or surgical pathology, clinical follow-ups, the differences in pathological detection rate and diagnostic accuracy between these two measures were compared. Results The detection rates of MSCTE and DBE were 63.41% (26/41) and 87.80% (36/41), and the diagnostic accuracies were 70.73% (29/41) and 92.68% (38/41), respectively. Conclusion The detection rate and diagnostic accuracy of DBE were both higher than those of MSCTE. MSCTE could facilitate the diagnosis of small bowel tumor and Crohn's disease, with positioning and qualitative value. MSCTE could be a pre-test to help decide the appropriate way of DBE insertion.%目的:评价多层螺旋CT小肠造影(MSCTE)与双气囊小肠镜(DBE)在不明原因腹痛患者诊断中的价值.方法:41例不明原因腹痛患者,同时行MSCTE和DBE检查,结合内镜和(或)手术病理、临床随访等,比较两者对不明原因腹痛病因的检出率、诊断准确率.结果:MSCTE和DBE的病变检出率分别为63.41%(26/41)和87.80%(36/41);诊断准确率分别为70.73%(29/41)和92.68%(38/41).结论:DBE对不明原因腹痛患者的病变检出率、诊断准确率均高于MSCTE; MSCTE对小肠肿瘤、克罗恩病有一定的定位、定性诊断价值;MSCTE可作为DBE检查前筛选性检查,对DBE进镜方式选择提供有效的帮助.

  13. 多层螺旋CT扫描及重建技术在腹股沟疝分类中的应用%Application of multi-slice spiral CT and three-dimensional reconstruction techniques in the classification of inguinal hernia

    Institute of Scientific and Technical Information of China (English)

    皇旭辉; 卢跃忠; 葛宇曦

    2013-01-01

    Objective To assess the contribution of multi-slice spiral CT and three-dimensional reconstruction techniques in the accurate diagnosis of direct and indirect inguinal hernias. Methods Fifty-four patients, who had undergone both a multi-section CT and a hernioplasty, were identied in order to evaluate the display of inguinal hernia on axial, coronary and sagittal planes and to distinguish the direct and indirect inguinal hernias. Then, we compared the classification of inguinal hernia with the result of surgery. Results Inguinal hernias were clearly demonstrable using multi-section CT and reconstructions and were accurately classified in direct and indirect inguinal hernias. On coronal CT reconstructions, the anatomy of inguinal hernias was clearly demonstrated than others and the accuracy of inguinal hernias classification was 100% , following by sagittal planes with the accuracy of 94% , the axial was poor for the identication of the inguinal hernias with the accuracy rate of 87%. Conclusion The high-resolution coronal and sagittal images available from multisection CT now permit the accurate diagnosis of groin hernias. Using simple anatomical criteria, direct and indirect inguinal hernias can be reliably distinguished.%目的 评估多层螺旋CT扫描及三维重建技术在区别腹股沟直疝及斜疝的应用.方法 收集54例同时行CT扫描及外科疝修补术的腹股沟疝病例资料,分别观察CT轴位、冠状位及矢状位对腹股沟疝的显示情况并区分腹股沟斜疝及直疝,并与手术结果对照.结果 MSCT及重建可以清晰直观地显示腹股沟疝并区分直疝及斜疝.其中冠状位对腹股沟结构显示最清楚,对腹股沟疝分类诊断正确率100%;矢状位次之,诊断正确率94%;横断位诊断正确率87%.结论 MSCT及高分辨率冠状位及矢状位重建可以精确地显示以及辨别腹股沟直疝、斜疝.

  14. 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。

  15. 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.

  16. 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

  17. Diagnostic study of multi-slice spiral CT 3D reconstruction and virtual endoscope technology on diagnosing ear temporal diseases%多层螺旋CT三维重建及仿真内镜技术对耳颞部疾病的诊断研究

    Institute of Scientific and Technical Information of China (English)

    张金玲; 李延皎; 陈鹏; 王海波; 李金平; 刘白鹭

    2012-01-01

    Objective To investigate the diagnostic value of multi-slice spiral CT (MSCT) 3D reconstruction and virtual endoscope technology on ear temporal diseases.Methods One hundred and forty patients suspected with ear temporal diseases were examined with MSCT,and all the scanned images were 3D reconstructed and processed by virtual endoscopy.Results In 140 patients,97 cases were detected with ear temporal disease,including 58 cases with acute and chronic otitis media,20 cases with artificially cochlear placement evaluation,2 cases with concha and middle ear malformations and 17 cases with temporal bone injury.MSCT 3D reconstruction and virtual endoscope technology could clearly show the location,scope and form of the lesions and structure relationships with nearby tissues.Conclusions MSCT 3D reconstruction and virtual endoscope technology have important value on diagnosing ear temporal diseases.%目的 探讨多层螺旋CT (MSCT)三维重建及仿真内镜技术对耳颞部疾病的诊断价值.方法 对140例怀疑有耳颞部疾病患者行颞骨MSCT检查,对所有扫描图像进行三维重建及仿真内镜处理.结果 140例患者中97例检出耳颞部疾病,其中58例急、慢性中耳炎,20例人工耳蜗植入术前进行评价,2例外中耳部发育畸形,17例颞骨外伤.MSCT三维重建及仿真内镜技术能够清晰显示病变的位置、范围、形态及与周围组织结构的关系.结论 MSCT三维重建及仿真内镜技术对耳颞部疾病的诊断具有重要价值.

  18. MSCT多平面重组结合分型在十二指肠乳头旁憩室综合征的临床应用%Clinical application of multi-slice CT and multi-planar reconstruction in Lemmel’ s syndrome combined with its types

    Institute of Scientific and Technical Information of China (English)

    阚宏; 邓克学; 张朝强; 马友章; 田娜

    2014-01-01

    Objective To investigate the clinical application value of multi-slice CT (MSCT) and multi-planar reconstruction ( MPR) in Lemmel’ s syndrome combined with its types. Methods MSCT and MPR manifestations of 32 patients who were diagnosed as Lem-mel’ s syndrome by clinicians were retrospectively analysed. The anatomical relationship among nipples, diverticulitis and bile duct was analysed combined with endoscopic characteristic. Results There were 32 cases of Lemmel’ s syndrome, of which the central type was in 23 cases and peripheral type in 9 cases;in the 32 cases, biliary dilatation occurred in 30 cases, bile duct stones in 13 cases, acute and chronic cholecystitis in 8 cases, gallstones in 7 cases, gallbladder polyps in 2 cases, acute pancreatitis in 2 cases, and cholangiocarcinoma in 1 case. Conclusion MSCT and MPR can effectively display the anatomical relationship among nipple, diverticulitis and bile duct, and provide the basis for the etio-logical diagnosis and treatment in periampullary diverticula with pancreaticobiliary diseases.%目的:探讨MSCT多平面重组并结合分型在十二指肠乳头旁憩室综合征的临床应用价值。方法利用MPR回顾性分析32例临床确诊为十二指肠乳头旁憩室综合征的CT征象,观察憩室与乳头及胆、胰管的解剖关系,结合内镜治疗特点进行分型。结果32例乳头旁憩室综合征中中心型23例,周围型9例。32例中合并胆总管扩张30例,胆管结石13例,急慢性胆囊炎8例,胆囊结石7例,胆囊息肉2例,急性胰腺炎2例,胆管细胞癌1例。结论 MSCT多平面重组可有效显示乳头、憩室及胆、胰管的解剖关系,为合并的胆胰疾病提供病因诊断及治疗依据。

  19. 多层螺旋CT门静脉成像对门静脉高压症的诊断及分类价值%Evaluation of the Diagnosis and Classification of Portal Hypertension on Multi-slice Spiral CT Portal Venography

    Institute of Scientific and Technical Information of China (English)

    梁萍; 方华盛; 陈更瑞

    2015-01-01

    Objective Discussion on classification and diagnostic value of multi-slice spiral CT portography (CTPV) on portal hypertension (PHT). Methods A total of 42 patients with PHT, 26 cases of intrahepatic PHT, both in patients with liver cirrhosis, and hepatocellular carcinoma in 7 cases,3 cases of intrahepatic portal vein tumor thrombosis;before the liver of PHT13patients, including 3 cases of portal vein thro mbosis in 4 cases of outer segment, portal vein tumor thrombus in 6 cases of outer segment,cavernous transformation, liver after PHT Budd Chiari syndrome in 3 cases; underwent imaging of 64 slice spiral CT portal, MIP, VR,MPR or CPR reconstruction using volume data, observation of portal vein branches, collateral circulation, characteristics of imaging. Results CTPV can clearly show the initial distribution, evaluating collateral circulation of portal hypertension degree and position classification. Conclusion CTPV can accurately diagnose PHT and differential classification, have important significance to establish prediction of its complications, operation scheme.%目的:探讨多层螺旋CT门静脉成像(CTPV)对门静脉高压症(PHT)的诊断及分类价值。方法收集42例PHT,肝内性PHT 26例,均为肝硬化患者,合并肝癌7例,门静脉肝内分支癌栓形成3例;肝前性PHT13例,其中门静脉肝外段血栓3例,门静脉肝外段癌栓4例,海绵样变6例;肝后性PHT3例,为布加综合征患者;均行64层螺旋CT门静脉成像检查,容积数据采用MIP、VR、MPR或CPR重建,观察门静脉、属支及侧支循环的影像学特征。结果 CTPV能清楚显示侧支循环的分布范围、初步评估门静脉高压程度及部位分类。结论 CTPV能准确诊断PHT及鉴别分类,对预测其并发症、手术方案的制定具有重要的指导意义。

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

    OpenAIRE

    Queiroz Júnior,Luiz H. K.; Antonio G. Ferreira; Patrick Giraudeau

    2013-01-01

    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...

  1. CYP2D6 polymorphism in relation to tramadol metabolism

    DEFF Research Database (Denmark)

    Halling, Jónrit; Weihe, Pál; Brosen, Kim

    2008-01-01

    to investigate whether the previously observed frequency of CYP2D6 poor metabolizers (PMs) in the Faroese, which was shown to be double that of other Europeans, was evident in a patient group medicated with a CYP2D6 substrate. The patients were CYP2D6-phenotyped by the intake of sparteine, followed by urine...... European populations (7%-10%). The concentrations of (+)-M1 when corrected for dose (nM/mg) and the (+)-M1/(+)-tramadol ratio were approximately 14-fold higher in the extensive metabolizers (EMs) than in the PMs. In conclusion, the impact of the CYP2D6 polymorphism on the pharmacokinetics of tramadol...

  2. 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...

  3. WE-G-BRD-06: Volumetric Cine MRI (VC-MRI) Estimated Based On Prior Knowledge for On-Board Target Localization

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W; Yin, F; Cai, J; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: To develop a technique to generate on-board VC-MRI using patient prior 4D-MRI, motion modeling and on-board 2D-cine MRI for real-time 3D target verification of liver and lung radiotherapy. Methods: The end-expiration phase images of a 4D-MRI acquired during patient simulation are used as patient prior images. Principal component analysis (PCA) is used to extract 3 major respiratory deformation patterns from the Deformation Field Maps (DFMs) generated between end-expiration phase and all other phases. On-board 2D-cine MRI images are acquired in the axial view. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI at the end-expiration phase. The DFM is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by matching the corresponding 2D slice of the estimated VC-MRI with the acquired single 2D-cine MRI. The method was evaluated using both XCAT (a computerized patient model) simulation of lung cancer patients and MRI data from a real liver cancer patient. The 3D-MRI at every phase except end-expiration phase was used to simulate the ground-truth on-board VC-MRI at different instances, and the center-tumor slice was selected to simulate the on-board 2D-cine images. Results: Image subtraction of ground truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground truth with prior image. Excellent agreement between profiles was achieved. The normalized cross correlation coefficients between the estimated and ground-truth in the axial, coronal and sagittal views for each time step were >= 0.982, 0.905, 0.961 for XCAT data and >= 0.998, 0.911, 0.9541 for patient data. For XCAT data, the maximum-Volume-Percent-Difference between ground-truth and estimated tumor volumes was 1.6% and the maximum-Center-of-Mass-Shift was 0.9 mm. Conclusion: Preliminary studies demonstrated the feasibility to estimate real-time VC-MRI for on

  4. 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...

  5. 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.

  6. Energy Efficiency of D2D Multi-User Cooperation.

    Science.gov (United States)

    Zhang, Zufan; Wang, Lu; Zhang, Jie

    2017-03-28

    The Device-to-Device (D2D) communication system is an important part of heterogeneous networks. It has great potential to improve spectrum efficiency, throughput and energy efficiency cooperation of multiple D2D users with the advantage of direct communication. When cooperating, D2D users expend extraordinary energy to relay data to other D2D users. Hence, the remaining energy of D2D users determines the life of the system. This paper proposes a cooperation scheme for multiple D2D users who reuse the orthogonal spectrum and are interested in the same data by aiming to solve the energy problem of D2D users. Considering both energy availability and the Signal to Noise Ratio (SNR) of each D2D user, the Kuhn-Munkres algorithm is introduced in the cooperation scheme to solve relay selection problems. Thus, the cooperation issue is transformed into a maximum weighted matching (MWM) problem. In order to enhance energy efficiency without the deterioration of Quality of Service (QoS), the link outage probability is derived according to the Shannon Equation by considering the data rate and delay. The simulation studies the relationships among the number of cooperative users, the length of shared data, the number of data packets and energy efficiency.

  7. 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

  8. 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....

  9. Animación 2D: curriculum vitae animado

    OpenAIRE

    CANTOS BELMONTE, CONSUELO

    2015-01-01

    Trabajo Fin de Grado de animación 2D donde un personaje (alter ego de la animadora) expone, mediante la interación con una Voz en Off y su sombra, el curriclum vitae de la animadora. Cantos Belmonte, C. (2014). Animación 2D: curriculum vitae animado. http://hdl.handle.net/10251/45910. Archivo delegado

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

    CERN Document Server

    Cruz, J; Navarro-Salas, J; Talavera, C F

    1997-01-01

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

  11. 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.

  12. 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

  13. 2D materials and van der Waals heterostructures.

    Science.gov (United States)

    Novoselov, K S; Mishchenko, A; Carvalho, A; Castro Neto, A H

    2016-07-29

    The physics of two-dimensional (2D) materials and heterostructures based on such crystals has been developing extremely fast. With these new materials, truly 2D physics has begun to appear (for instance, the absence of long-range order, 2D excitons, commensurate-incommensurate transition, etc.). Novel heterostructure devices--such as tunneling transistors, resonant tunneling diodes, and light-emitting diodes--are also starting to emerge. Composed from individual 2D crystals, such devices use the properties of those materials to create functionalities that are not accessible in other heterostructures. Here we review the properties of novel 2D crystals and examine how their properties are used in new heterostructure devices.

  14. 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

  15. Changes in T2-weighted MRI of supinator muscle, pronator teres muscle, and extensor indicis muscle with manual muscle testing

    Science.gov (United States)

    Yoshida, Kazuya; Akiyama, Sumikazu; Takamori, Masayoshi; Otsuka, D. Eng, Hiroshi; Seo, Yoshiteru

    2017-01-01

    [Purpose] In order to detect muscle activity with manual muscle testing, T2-weighted magnetic resonance (T2w-MR) images were detected by a 0.2 T compact MRI system. [Subjects and Methods] The subjects were 3 adult males. Transverse T2-weighted multi-slice spin-echo images of the left forearm were measured by a 39 ms echo-time with a 2,000 ms repetition time, a 9.5 mm slice thickness, 1 accumulation and a total image acquisition time of 4 min 16 s. First, T2w-MR images in the resting condition were measured. Then, manipulative isometric contraction exercise (5 sec duration) to the supinator muscle, the pronator teres muscle or the extensor indicis muscle was performed using Borg’s rating of perceived exertion (RPE) scale of 15–17. The T2w-MR images were measured immediately after the exercise. [Results] T2w-MR image intensities increased significantly in the supinator muscle, the pronator teres muscle and the extensor indicis muscle after the exercise. However, the image intensities in the rest of the muscle did not change. [Conclusion] Using T2w-MR images, we could detect muscle activity in a deep muscle, the supinator muscle, and a small muscle, the extensor indicis muscle. These results also support the reliability of the manual muscle testing method. PMID:28356621

  16. 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.

  17. 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.)

  18. Three-dimensional liver motion tracking using real-time two-dimensional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Brix, Lau, E-mail: lau.brix@stab.rm.dk [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Ringgaard, Steffen [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Poulsen, Per Rugaard [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)

    2014-04-15

    Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

  19. 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 ...

  20. 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.

  1. Postretinal Structure and Function in Severe Congenital Photoreceptor Blindness Caused by Mutations in the GUCY2D Gene

    Science.gov (United States)

    Aguirre, Geoffrey K.; Butt, Omar H.; Datta, Ritobrato; Roman, Alejandro J.; Sumaroka, Alexander; Schwartz, Sharon B.; Cideciyan, Artur V.; Jacobson, Samuel G.

    2017-01-01

    Purpose To examine how severe congenital blindness resulting from mutations of the GUCY2D gene alters brain structure and function, and to relate these findings to the notable preservation of retinal architecture in this form of Leber congenital amaurosis (LCA). Methods Six GUCY2D-LCA patients (ages 20–46) were studied with optical coherence tomography of the retina and multimodal magnetic resonance imaging (MRI) of the brain. Measurements from this group were compared to those obtained from populations of normally sighted controls and people with congenital blindness of a variety of causes. Results Patients with GUCY2D-LCA had preservation of the photoreceptors, ganglion cells, and nerve fiber layer. Despite this, visual function in these patients ranged from 20/160 acuity to no light perception, and functional MRI responses to light stimulation were attenuated and restricted. This severe visual impairment was reflected in substantial thickening of the gray matter layer of area V1, accompanied by an alteration of resting-state correlations within the occipital lobe, similar to a comparison group of congenitally blind people with structural damage to the retina. In contrast to the comparison blind population, however, the GUCY2D-LCA group had preservation of the size of the optic chiasm, and the fractional anisotropy of the optic radiations as measured with diffusion tensor imaging was also normal. Conclusions These results identify dissociable effects of blindness upon the visual pathway. Further, the relatively intact postgeniculate white matter pathway in GUCY2D-LCA is encouraging for the prospect of recovery of visual function with gene augmentation therapy.

  2. 2D vs. 3D mammography observer study

    Science.gov (United States)

    Fernandez, James Reza F.; Hovanessian-Larsen, Linda; Liu, Brent

    2011-03-01

    Breast cancer is the most common type of non-skin cancer in women. 2D mammography is a screening tool to aid in the early detection of breast cancer, but has diagnostic limitations of overlapping tissues, especially in dense breasts. 3D mammography has the potential to improve detection outcomes by increasing specificity, and a new 3D screening tool with a 3D display for mammography aims to improve performance and efficiency as compared to 2D mammography. An observer study using a mammography phantom was performed to compare traditional 2D mammography with this ne 3D mammography technique. In comparing 3D and 2D mammography there was no difference in calcification detection, and mass detection was better in 2D as compared to 3D. There was a significant decrease in reading time for masses, calcifications, and normals in 3D compared to 2D, however, as well as more favorable confidence levels in reading normal cases. Given the limitations of the mammography phantom used, however, a clearer picture in comparing 3D and 2D mammography may be better acquired with the incorporation of human studies in the future.

  3. An automated pipeline to screen membrane protein 2D crystallization.

    Science.gov (United States)

    Kim, Changki; Vink, Martin; Hu, Minghui; Love, James; Stokes, David L; Ubarretxena-Belandia, Iban

    2010-06-01

    Electron crystallography relies on electron cryomicroscopy of two-dimensional (2D) crystals and is particularly well suited for studying the structure of membrane proteins in their native lipid bilayer environment. To obtain 2D crystals from purified membrane proteins, the detergent in a protein-lipid-detergent ternary mixture must be removed, generally by dialysis, under conditions favoring reconstitution into proteoliposomes and formation of well-ordered lattices. To identify these conditions a wide range of parameters such as pH, lipid composition, lipid-to-protein ratio, ionic strength and ligands must be screened in a procedure involving four steps: crystallization, specimen preparation for electron microscopy, image acquisition, and evaluation. Traditionally, these steps have been carried out manually and, as a result, the scope of 2D crystallization trials has been limited. We have therefore developed an automated pipeline to screen the formation of 2D crystals. We employed a 96-well dialysis block for reconstitution of the target protein over a wide range of conditions designed to promote crystallization. A 96-position magnetic platform and a liquid handling robot were used to prepare negatively stained specimens in parallel. Robotic grid insertion into the electron microscope and computerized image acquisition ensures rapid evaluation of the crystallization screen. To date, 38 2D crystallization screens have been conducted for 15 different membrane proteins, totaling over 3000 individual crystallization experiments. Three of these proteins have yielded diffracting 2D crystals. Our automated pipeline outperforms traditional 2D crystallization methods in terms of throughput and reproducibility.

  4. 2-D Versus 3-D Magnetotelluric Data Interpretation

    Science.gov (United States)

    Ledo, Juanjo

    2005-09-01

    In recent years, the number of publications dealing with the mathematical and physical 3-D aspects of the magnetotelluric method has increased drastically. However, field experiments on a grid are often impractical and surveys are frequently restricted to single or widely separated profiles. So, in many cases we find ourselves with the following question: is the applicability of the 2-D hypothesis valid to extract geoelectric and geological information from real 3-D environments? The aim of this paper is to explore a few instructive but general situations to understand the basics of a 2-D interpretation of 3-D magnetotelluric data and to determine which data subset (TE-mode or TM-mode) is best for obtaining the electrical conductivity distribution of the subsurface using 2-D techniques. A review of the mathematical and physical fundamentals of the electromagnetic fields generated by a simple 3-D structure allows us to prioritise the choice of modes in a 2-D interpretation of responses influenced by 3-D structures. This analysis is corroborated by numerical results from synthetic models and by real data acquired by other authors. One important result of this analysis is that the mode most unaffected by 3-D effects depends on the position of the 3-D structure with respect to the regional 2-D strike direction. When the 3-D body is normal to the regional strike, the TE-mode is affected mainly by galvanic effects, while the TM-mode is affected by galvanic and inductive effects. In this case, a 2-D interpretation of the TM-mode is prone to error. When the 3-D body is parallel to the regional 2-D strike the TE-mode is affected by galvanic and inductive effects and the TM-mode is affected mainly by galvanic effects, making it more suitable for 2-D interpretation. In general, a wise 2-D interpretation of 3-D magnetotelluric data can be a guide to a reasonable geological interpretation.

  5. 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.

  6. Harvest Survive : Game Mechanics of Unity 2D Game

    OpenAIRE

    2014-01-01

    The purpose of this project was to learn how to create Games in Unity 2D, to see the work-flow and to test if the new Unity 2D feature of the Unity engine was a good alternative for developing 2D games. A further aspect was to learn the different steps and mechanics of the Unity environment. The goal was to create a survival game, in which the player would have to grow plants in order to get food and money to stay alive in a hostile environment. The player has to survive in six different...

  7. 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)

  8. Spin Waves in 2D ferromagnetic square lattice stripe

    OpenAIRE

    Ahmed, Maher Z.

    2011-01-01

    In this work, the area and edges spin wave calculations were carried out using the Heisenberg Hamiltonian and the tridiagonal method for the 2D ferromagnetic square lattice stripe, where the SW modes are characterized by a 1D in-plane wave vector $q_x$. The results show a general and an unexpected feature that the area and edge spin waves only exist as optic modes. This behavior is also seen in 2D Heisenberg antiferromagnetic square lattice. This absence of the acoustic modes in the 2D square...

  9. 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.

  10. 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

  11. 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.

  12. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

    2010-02-15

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  13. 多层螺旋 CT 小肠造影在诊断肠结核与克罗恩病中的价值研究%Diagnostic value of multi-slice CT enterography in Crohn’s disease and intestinal tuberculosis

    Institute of Scientific and Technical Information of China (English)

    徐莹; 余晨; 陈业媛; 肖香佐; 龚洪翰

    2015-01-01

    Objective To investigate the application value of multi-slice CT enterography (MSCTE)in diagnosing intestinal tuberculosis (ITB)and Crohn’s disease (CD).Methods MSCTE findings were retrospectively analyzed in 25 patients with ITB and in other 25 patients with CD diagnosed through endoscopy,pathologic examination and clinical follow-up.Statistical analysis was performed to find out the difference in CT findings between the ITB and CD.Results 25 patients with CD included the involved ileum in 23,involved duode-num and jejunum in 8,multiple segmental lesions in 20,asymmetrically thickened intestinal wall in 20,hierarchical reinforcement in 1 9,mesenteric vascular hyperplasia in 20,fibrofatty hyperplasia in 18,peritoneal abscess or fistula in 8,anal fistula in 1,and pseu-do-diverticulum formation in the intestinal wall on the opposite side of the mesentery in 2.Meanwhile,the other 25 patients with ITB included the involved terminal ileum in 25,symmetrically thickened intestinal wall in 23,annular enhancement of lymph nodes in 11,thickened peritoneum and omentum together with distinct enhancement,or intestinal adhesion,or ascites appeared in 15.The CD was more likely to represent multiple segmental lesions,asymmetrically thickened intestinal wall,hierarchical reinforcement,mesenteric vascular hyperplasia,fibrofatty hyperplasia,and peritoneal abscess or fistula formation (P <0.05).Meanwhile,the ITB was more likely to represent the lesion only in ileum,symmetrically thickened intestinal wall,and annular enhancement of lymph nodes (P <0.05).Conclusion MSCTE shows promising clinical application in diagnosis and differential diagnosis of CD and ITB.%目的:探讨多层螺旋 CT 小肠造影(MSCTE)在肠结核(ITB)、克罗恩病(CD)诊断中的应用价值。方法回顾性分析经内镜、病理或临床随访证实的 ITB、CD 各25例的 MSCTE 影像表现,并对两者间的差异进行统计学分析。结果25例 CD 中,病变累及回肠23

  14. 多层CT小肠造影与单气囊小肠镜对小肠梗阻的诊断价值%Diagnostic value of multi-slice computed tomography enterography before single balloon enteroscopy for small bowel obstruction

    Institute of Scientific and Technical Information of China (English)

    李娜; 赵晓军; 王海红; 王昕; 李爱琴; 谢惠; 余东亮; 韩英; 盛剑秋

    2013-01-01

    目的 探讨多层CT小肠造影(MSCTE)与单气囊小肠镜(SBE)在小肠梗阻性病变的诊断价值.方法 收集2009年6月-2013年2月临床和/或腹部X线平片疑为小肠梗阻的患者30例.所有患者先行MSCTE检查,根据检查结果选择经口或经肛SBE检查.分析两种检查方法对小肠梗阻性病变的诊断率.结果 ①MSCTE检查诊断小肠梗阻的灵敏度为85.19%,特异度为66.67%,阳性预测值为95.83%,阴性预测值为33.33%.SBE检查分别为81.48%、100%、100%和37.50%.②MSCTE和SBE检出病变一致性为53.33% (16/30).③根据MSCTE检查结果选择经口或经肛SBE检查,MSCTE检查阳性指导SBE选择进镜方式正确率高于MSCTE检查阴性(95.83% vs 33.33%,P<0.05).结论 MSCTE和SBE对小肠梗阻的诊断率相当,二者联合应用可提高对小肠梗阻性病变的诊断率.MSCTE检查结果可以指导SBE选择进镜方式.%Objective To evaluate the diagnostic value of multi-slice CT enterography (MSCTE) before single balloon enteroscopy (SBE) for patients with small bowel obstruction (SBO).Methods 30 patients with MSCTE before SBE for SBO were collected prospectively from Jun.2009 to Feb.2013.The clinical impact of MSCTE on the subsequent SBE examinations and the diagnostic yields of both MSCTE and SBE were evaluated respectively.Results ① In detecting SBO,MSCTE had a sensitivity of 85.19%,a specificity of 66.67%,a positive predictive value of 95.83%,and a negative predictive value of 33.33%.SBE had a sensitivity of 81.48%,a specificity of 100%,a positive predictive value of 100%,and a negative predictive value of 37.5%.② The consistency was 53.33%.③ The choice of initial route of SBE was correct in those with a positive MSCTE vs negative MSCTE (95.83% vs 33.33 %,P <0.05).Conclusion MSCTE and SBE are nearly equal in their ability to detect SBO.The combined application of two methods can improve the diagnosis rate of SBO.This study suggests MSCTE

  15. 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

  16. The clinical value of transthoracic echocardiography and Multi-slice spiral CT for evaluation of fistula diameter in patients with coronary artery fistula%经胸超声心动图及多层螺旋CT对诊断冠状动脉瘘患者的临床价值

    Institute of Scientific and Technical Information of China (English)

    李晓明; 牛宝荣; 吴山; 杨娅; 张纯

    2015-01-01

    目的:以血管造影为“金标准”,评价经胸超声心动图( transthoracic echocardiography,TTE)和多层螺旋CT( multi-slice spiral CT,MSCT)筛查冠状动脉瘘及估算瘘口直径的能力,并分析其各自的影响因素。方法回顾性分析北京安贞医院接受封堵术治疗并经血管造影确诊为冠状动脉瘘的患者,所有患者均于术前1个月内接受TTE及MSCT辅助检查。结果以血管造影结果为金标准,MSCT及TTE对冠状动脉瘘患者的明确诊断准确度为96.7%及90.0%。针对瘘口直径的测定,血管造影对瘘口直径的平均测定值为(8.70±3.50)mm,MSCT及TTE的平均估算值分别为(8.86±3.71)mm及(7.50±5.90)mm,经配对t检验,P值均>0.05。但MSCT估测值较TTE的估算值与血管造影结果的相关性更好( r值分别为0.913及0.778,P值均10.5mm时,TTE高估瘘口直径;MSCT估测结果则与血管造影间的吻合性良好。结论 TTE和MSCT对冠状动脉瘘患者的筛查准确度均较高。但是,对于瘘口直径的判断,MSCT的稳定性较TTE更佳,其术前应用可以进一步提高诊断的准确性。%Objective Angiography as a reference to evaluate the clinical value of transthoracic echocardiography ( TTE) and multi – slice apiral CT ( MSCT) for evaluation of fistula diameters in patients with coronary artery fis-tula( CAF) ,and to investigate their influencing factors. Method Thirty consecutive patients who had coronary artery fistula were revealed by angiography through the interventional operation in Anzhen Hospital. Result Accuracy of MSCT and TTE for diagnosis of CAF are 96. 7% and 90. 0% ,with angiography as reference. For CAF patients, di-ameter of fistula determined by MSCT ,TTE and Angiography were (8. 86 ± 3. 71) mm,(7. 50 ± 5. 90) mm and (8. 70 ± 3. 50)mm (all P>0. 05). But, fistula diameter revealed by MSCT was better related with angiography re-sult than that revealed by TTE (r=0. 913 and 0. 778,P<0. 001). And through Bland-Altman analyze

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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,

  3. 多层螺旋CT多模式重组在复杂髋臼骨折术前检查中的应用%The preoperative application of multi slice CT with three-dimensional reconstruction in complex acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    陈木养; 黄伟坚; 余洪希; 王东

    2016-01-01

    Objective To evaluate the value of volume scanning method, multiplanar reconstruction (MPR), surface shaded display (SSD), and volume reconstruction (VR) techniques in the preoperative examination of complex acetabular fractures. Methods Fifty-eight cases with ancetabular fractures were all accepted CT volume scanning , and MPR were done in all cases. In addition, case-control analysis were done with conventional acetabular CT imagings. Results Coronal plane of MPR, surface shaded display (SSD) combined with VR imaging, could display the acetabular fractures clearly, in accordance with the operations, and its diagnostic accuracy was significantly higher than conventional CT scan. The two sets of data had significances difference (P<0.05) in displaying fracture type, the length of the fracture lines, the shapes and direction of the fracture, the sizes of fracture pieces, the spatial location, the degree of fracture displacement and the joint dislocation classification. Conclusion Multi slice CT (MSCT) volume scanning, MPR, SSD and VR techniques have good display abilities of acetabular fractures , their performance are close to the pathological anatomy. They are considered to be the ideal imaging methods to know about the complex acetabular fractures and its microscopic structures.%目的:利用多层螺旋CT的容积扫描方法和多平面重建(MPR)、表面遮盖法(SSD)及容积再现(VR)技术,评价其在复杂性髋臼骨折术前检查中的应用价值。方法选取58例患者的损伤髋臼进行多层螺旋CT容积扫描,所得原始数据做数字化三维重组处理,并与常规髋臼CT平扫图像进行对照分析。结果 MPR冠状面、SSD重建结合VR成像,能清晰显示58例髋臼骨折情况,与手术相符,诊断正确率明显高于常规CT平扫。在显示骨折分型、骨折线的长短、形态、走向,骨折片大小、空间位置以及骨折移位程度和关节脱位分类征象方面,2组

  4. 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

  5. The usefulness of 3D quantitative analysis with using MRI for measuring osteonecrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Young; Lee, Sun Wha [Ewha Womans University College of Medicine, Seoul (Korea, Republic of); Park, Youn Soo [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2006-11-15

    We wanted to evaluate the usefulness of MRI 3D quantitative analysis for measuring osteonecrosis of the femoral head in comparison with MRI 2D quantitative analysis and quantitative analysis of the specimen. For 3 months at our hospital, 14 femoral head specimens with osteonecrosis were obtained after total hip arthroplasty. The patients preoperative MRIs were retrospectively reviewed for quantitative analysis of the size of the necrosis. Each necrotic fraction of the femoral head was measured by 2D quantitative analysis with using mid-coronal and mid-sagittal MRIs, and by 3D quantitative analysis with using serial continuous coronal MRIs and 3D reconstruction software. The necrotic fraction of the specimen was physically measured by the fluid displacement method. The necrotic fraction according to MRI 2D or 3D quantitative analysis was compared with that of the specimen by using Spearman's correlation test. On the correlative analysis, the necrotic fraction by MRI 2D quantitative analysis and quantitative analysis of the specimen showed moderate correlation (r = 0.657); on the other hand, the necrotic fraction by MRI 3D quantitative analysis and quantitative analysis of the specimen demonstrated a strong correlation (r = 0.952) ({rho} < 0.05). MRI 3D quantitative analysis was more accurate than 2D quantitative analysis using MRI for measuring osteonecrosis of the femoral head. Therefore, it may be useful for predicting the clinical outcome and deciding the proper treatment option.

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  8. 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.

  9. First Principles Calculations of Electronic Excitations in 2D Materials

    DEFF Research Database (Denmark)

    Rasmussen, Filip Anselm

    -thin electronics and high efficiency solar cells. Contrary to many other nano-materials, methods for large scale fabrication and patterning have already been demonstrated and the first real technological applications have already be showcased. Still the technology is very young and the number of well-studied 2D...... materials are few. However as the list of 2D materials is growing it is necessary to investigate their fundamental structural, electronic and optical properties. These are determined by the atomic and electronic structure of the materials that can quite accurately predicted by computational quantum...... as if it is being screened by the electrons in the material. This method has been very successful for calculating quasiparticle energies of bulk materials but results have been more varying for 2D materials. The reason is that the 2D confined electrons are less able to screen the added charge and some...

  10. 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.

  11. 2-D electromagnetic simulation of passive microstrip circuits

    CERN Document Server

    Dueñas Jiménez, Alejandro

    2009-01-01

    A reference for circuit design engineers and microwave engineers. It uses a simple 2-D electromagnetic simulation procedure to provide basic knowledge and practical insight into quotidian problems of microstrip passive circuits applied to microwave systems and digital technologies.

  12. 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

    ) 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......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...

  13. 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.

  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. Generating a 2D Representation of a Complex Data Structure

    Science.gov (United States)

    James, Mark

    2006-01-01

    A computer program, designed to assist in the development and debugging of other software, generates a two-dimensional (2D) representation of a possibly complex n-dimensional (where n is an integer >2) data structure or abstract rank-n object in that other software. The nature of the 2D representation is such that it can be displayed on a non-graphical output device and distributed by non-graphical means.

  16. Maximizing the Optical Band Gap in 2D Photonic Crystals

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Sigmund, Ole

    Topology optimization is used to find the 2D photonic crystal designs with the largest relative photonic band gaps. Starting points for the topology optimization are found with an exhaustive binary search on a low resolution grid.......Topology optimization is used to find the 2D photonic crystal designs with the largest relative photonic band gaps. Starting points for the topology optimization are found with an exhaustive binary search on a low resolution grid....

  17. New design of 2-D photonic crystal waveguide couplers

    Institute of Scientific and Technical Information of China (English)

    ZHONG Zhi-rong; ZHANG Li-hua; YANG Hong-qin; JIANG Yun-kun

    2006-01-01

    @@ Based on couple wave equation and finite-difference time-domain (FDTD) algorithm,the strong couple characteristic of 2-D photonic crystal couplers is calculated.Theoretical analysis and numerical simulated results indicate that the energy in a 2-D photonic crystal coupler can not be totally transferred between two wave-guides.Compared with the result of weak coupling theory,our result is more accurate.

  18. QSAR Models for P-450 (2D6) Substrate Activity

    DEFF Research Database (Denmark)

    Ringsted, Tine; Nikolov, Nikolai Georgiev; Jensen, Gunde Egeskov;

    2009-01-01

    activity relationship (QSAR) modelling systems. They cross validated (leave-groups-out) with concordances of 71%, 81% and 82%, respectively. Discrete organic European Inventory of Existing Commercial Chemical Substances (EINECS) chemicals were screened to predict an approximate percentage of CYP 2D6...... substrates. These chemicals are potentially present in the environment. The biological importance of the CYP 2D6 and the use of the software mentioned above were discussed....

  19. 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.

  20. A simultaneous 2D/3D autostereo workstation

    Science.gov (United States)

    Chau, Dennis; McGinnis, Bradley; Talandis, Jonas; Leigh, Jason; Peterka, Tom; Knoll, Aaron; Sumer, Aslihan; Papka, Michael; Jellinek, Julius

    2012-03-01

    We present a novel immersive workstation environment that scientists can use for 3D data exploration and as their everyday 2D computer monitor. Our implementation is based on an autostereoscopic dynamic parallax barrier 2D/3D display, interactive input devices, and a software infrastructure that allows client/server software modules to couple the workstation to scientists' visualization applications. This paper describes the hardware construction and calibration, software components, and a demonstration of our system in nanoscale materials science exploration.

  1. 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.

  2. CYP2D6 variability in populations from Venezuela.

    Science.gov (United States)

    Moreno, Nancy; Flores-Angulo, Carlos; Villegas, Cecilia; Mora, Yuselin

    2016-12-01

    CYP2D6 is an important cytochrome P450 enzyme that plays an important role in the metabolism of about 25% of currently prescribed drugs. The presence of polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatments. The most prevalent diseases in the admixed population from Venezuela are cardiovascular and cancer, whereas viral, bacterial and parasitic diseases, particularly malaria, are prevalent in Amerindian populations; in the treatment of these diseases, several drugs that are metabolized by CYP2D6 are used. In this work, we reviewed the data on CYP2D6 variability and predicted metabolizer phenotypes, in healthy volunteers of two admixed and five Amerindian populations from Venezuela. The Venezuelan population is very heterogeneous as a result of the genetic admixture of three major ethnical components: Europeans, Africans and Amerindians. There are noticeable inter-regional and inter-population differences in the process of mixing of this population. Hitherto, there are few published studies in Venezuela on CYP2D6; therefore, it is necessary to increase research in this regard, in particular to develop studies with a larger sample size. There is a considerable amount of work remaining before CYP2D6 is integrated into clinical practice in Venezuela.

  3. A 2-D simulation of hydrocephalus in the Foramens of Monro of the human ventricular system

    Energy Technology Data Exchange (ETDEWEB)

    Ammourah, S.; Aroussi, A. [Univ. of Nottingham, School of Mechanical, Materials, Manufacturing and Management, University Park, Nottingham (United Kingdom)]. E-mail: eaxsaka@nottingham.ac.uk; Vloeberghs, M. [Queen' s Medical Centre, Dept. of Child Health, Nottingham (United Kingdom)

    2004-07-01

    This study investigates the Cerebrospinal fluid (CSF) flow behavior in a two-dimensional plane (2-D) of the human ventricular system when the hydrocephalus in the Foramens of Monro (F.O.M) occurs. In order to understand the CSF behaviour when the hydrocephalus occurs, it is essential to comprehend its normal flow dynamics i.e. the healthy case with no hydrocephalus. This had been done numerically by reconstructing the ventricular system geometry from the MRI scans and then made a 15{sup o} degree cut in the surgical line to obtain the outlines of the 2-D plane. The healthy cases were solved for the CSF actual flow rate, which is between 100-500 ml/day in 100 incremental steps. The unhealthy cases were studied for the average flow rate, which is 300 ml/day but for blockage ratios of the Foramen diameter of 20%, 50% and 75%. These obstructions are designed to simulate the hydrocephalus. The results show that as the flow rate increases the pressure and the velocity values increases, but no changes in the flow pattern occurs. The maximum pressure on the normal cases occurred in the lateral ventricles and the maximum velocity occurred in the aqueduct neck. The results of the hydrocephalus cases show that as the obstruction degree increases the pressure in the lateral ventricle increases accompanied with a velocity increase in the obstructed Foramen, which may cause unwanted stress on the neighboring tissues. (author)

  4. Ultrasound- and MRI-Guided Prostate Biopsy

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Ultrasound- and MRI-Guided Prostate Biopsy Ultrasound- and MRI-guided prostate ... MRI-guided Prostate Biopsy? What is Ultrasound- and MRI-guided Prostate Biopsy? Ultrasound- and MRI-guided prostate ...

  5. Ultrasound- and MRI-Guided Prostate Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound- and MRI-Guided Prostate Biopsy Ultrasound- and MRI- ... Ultrasound-and MRI-guided Prostate Biopsy? What is Ultrasound- and MRI-guided Prostate Biopsy? Ultrasound- and MRI- ...

  6. 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...

  7. 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.

  8. Twin characterisation using 2D and 3D EBSD

    Institute of Scientific and Technical Information of China (English)

    M. D. NAVE; J. J. L. MULDERS; A. GHOLINIA

    2005-01-01

    Electron backscatter diffraction (EBSD) is a superior technique for twin characterisation due to its ability to provide highly detailed classification (by generation, system and variant) of a significant number of twins in a relatively short time. 2D EBSD is now widely used for twin characterisation and provides quite good estimates of twin volume fractions under many conditions. Nevertheless, its accuracy is limited by assumptions that have to be made due to the 2D nature of the technique. With 3D EBSD, two key assumptions are no longer required, as additional information can be derived from the 3D map. This paper compares the benefits and limitations of 2D and 3D EBSD for twin characterisation. 2D EBSD enables a larger number of twins to be mapped in a given space of time, giving better statistics. 3D EBSD provides more comprehensive twin characterisation and will be a valuable tool for validation of 2D stereological methods and microstructural models of twinning during deformation.

  9. New Reductions and Nonlinear Systems for 2D Schrodinger Operators

    CERN Document Server

    Mironov, A

    2010-01-01

    New Completely Integrable (2+1)-System is studied. It is based on the so-called L-A-B-triples $L_t=[H,L]-fL$ where L is a 2D Schrodinger Operator. This approach was invented by S.Manakov and B.Dubrovin, I.Krichever, S.Novikov(DKN) in the works published in 1976. A nonstandard reduction for the 2D Schrodinger Operator (completely different from the one found by S.Novikov and A.Veselov in 1984) compatible with time dynamics of the new Nonlinear System, is studied here. It can be naturally treated as a 2D extension of the famous Burgers System. The Algebro-Geometric (AG) Periodic Solutions here are very specific and unusual (for general and reduced cases). The reduced system is linearizable like Burgers. However, the general one (and probably the reduced one also) certainly lead in the stationary AG case to the nonstandard examples of algebraic curves $\\Gamma\\subset W$ in the full complex 2D manifold of Bloch-Floquet functions W for the periodic elliptic 2D operator H where $H\\psi(x,y,P)=\\lambda(P)\\psi(x,y,P),P\\...

  10. 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...

  11. 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.

  12. Three-Dimensional Volume-Rendered Series Complements 2D Orthogonal Multidetector Computed Tomography in the Evaluation of Abnormal Spinal Curvature in Patients at a Major Cancer Center: A Retrospective Review

    OpenAIRE

    2012-01-01

    Background. Abnormal spinal curvature is routinely assessed with plain radiographs, MDCT, and MRI. MDCT can provide two-dimensional (2-D) orthogonal as well as reconstructed three-dimensional volume-rendered (3-D VR) images of the spine, including the translucent display: a computer-generated image set that enables the visualization of surgical instrumentation through bony structures. We hypothesized that the 3-D VR series provides additional information beyond that of 2-D orthogonal MDCT in ...

  13. Joint 2-D DOA and Noncircularity Phase Estimation Method

    Directory of Open Access Journals (Sweden)

    Wang Ling

    2012-03-01

    Full Text Available Classical joint estimation methods need large calculation quantity and multidimensional search. In order to avoid these shortcoming, a novel joint two-Dimension (2-D Direction Of Arrival (DOA and noncircularity phase estimation method based on three orthogonal linear arrays is proposed. The problem of 3-D parameter estimation can be transformed to three parallel 2-D parameter estimation according to the characteristic of three orthogonal linear arrays. Further more, the problem of 2-D parameter estimation can be transformed to 1-D parameter estimation by using the rotational invariance property among signal subspace and orthogonal property of noise subspace at the same time in every subarray. Ultimately, the algorithm can realize joint estimation and pairing parameters by one eigen-decomposition of extended covariance matrix. The proposed algorithm can be applicable for low SNR and small snapshot scenarios, and can estiame 2(M −1 signals. Simulation results verify that the proposed algorithm is effective.

  14. Genetics, genomics, and evolutionary biology of NKG2D ligands.

    Science.gov (United States)

    Carapito, Raphael; Bahram, Seiamak

    2015-09-01

    Human and mouse NKG2D ligands (NKG2DLs) are absent or only poorly expressed by most normal cells but are upregulated by cell stress, hence, alerting the immune system in case of malignancy or infection. Although these ligands are numerous and highly variable (at genetic, genomic, structural, and biochemical levels), they all belong to the major histocompatibility complex class I gene superfamily and bind to a single, invariant, receptor: NKG2D. NKG2D (CD314) is an activating receptor expressed on NK cells and subsets of T cells that have a key role in the recognition and lysis of infected and tumor cells. Here, we review the molecular diversity of NKG2DLs, discuss the increasing appreciation of their roles in a variety of medical conditions, and propose several explanations for the evolutionary force(s) that seem to drive the multiplicity and diversity of NKG2DLs while maintaining their interaction with a single invariant receptor.

  15. 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.

  16. 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.

  17. 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.  

  18. Applications of Doppler Tomography in 2D and 3D

    Science.gov (United States)

    Richards, M.; Budaj, J.; Agafonov, M.; Sharova, O.

    2010-12-01

    Over the past few years, the applications of Doppler tomography have been extended beyond the usual calculation of 2D velocity images of circumstellar gas flows. This technique has now been used with the new Shellspec spectrum synthesis code to demonstrate the effective modeling of the accretion disk and gas stream in the TT Hya Algol binary. The 2D tomography procedure projects all sources of emission onto a single central (Vx, Vy) velocity plane even though the gas is expected to flow beyond that plane. So, new 3D velocity images were derived with the Radioastronomical Approach method by assuming a grid of Vz values transverse to the central 2D plane. The 3D approach has been applied to the U CrB and RS Vul Algol-type binaries to reveal substantial flow structures beyond the central velocity plane.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 2D fluid simulations of interchange turbulence with ion dynamics

    DEFF Research Database (Denmark)

    Nielsen, Anders Henry; Madsen, Jens; Xu, G. S.

    2013-01-01

    In this paper we present a first principle global two-dimensional fluid model. The HESEL (Hot Edge SOL Electrostatic) model is a 2D numerical fluid code, based on interchange dynamics and includes besides electron also the ion pressure dynamic. In the limit of cold ions the model almost reduces......B vorticity as well as the ion diamagnetic vorticity. The 2D domain includes both open and closed field lines and is located on the out-board midplane of a tokamak. On open field field lines the parallel dynamics are parametrized as sink terms depending on the dynamic quantities; density, electron and ion...

  4. Recording 2-D Nutation NQR Spectra by Random Sampling Method.

    Science.gov (United States)

    Glotova, Olga; Sinyavsky, Nikolaj; Jadzyn, Maciej; Ostafin, Michal; Nogaj, Boleslaw

    2010-10-01

    The method of random sampling was introduced for the first time in the nutation nuclear quadrupole resonance (NQR) spectroscopy where the nutation spectra show characteristic singularities in the form of shoulders. The analytic formulae for complex two-dimensional (2-D) nutation NQR spectra (I = 3/2) were obtained and the condition for resolving the spectral singularities for small values of an asymmetry parameter η was determined. Our results show that the method of random sampling of a nutation interferogram allows significant reduction of time required to perform a 2-D nutation experiment and does not worsen the spectral resolution.

  5. Exact computation of scalar 2D aerial imagery

    Science.gov (United States)

    Gordon, Ronald L.

    2002-07-01

    An exact formulation of the problem of imaging a 2D object through a Koehler illumination system is presented; the accurate simulation of a real layout is then not time- limited but memory-limited. The main idea behind the algorithm is that the boundary of the region that comprise a typical TCC Is made up of circular arcs, and therefore the area - which determines the value of the TCC - should be exactly computable in terms of elementary analytical functions. A change to integration around the boundary leads to an expression with minimal dependence on expensive functions such as arctangents and square roots. Numerical comparisons are made for a simple 2D structure.

  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. 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.

  8. On the Nonrelativistic 2D Purely Magnetic Supersymmetric Pauli Operator

    OpenAIRE

    Grinevich, P.; Mironov, A.(Lebedev Physics Institute; ITEP, Moscow, Russia); Novikov, S.

    2011-01-01

    The Complete Manifold of Ground State Eigenfunctions for the Purely Magnetic 2D Pauli Operator is considered as a by-product of the new reduction found by the present authors few years ago for the Algebrogeometric Inverse Spectral Data (i.e. Riemann Surfaces and Divisors). This reduction is associated with the (2+1) Soliton Hierarhy containing a 2D analog of the famous "Burgers System". This article contains also exposition of the previous works made since 1980 including the first topological...

  9. MRI of the Chest

    Medline Plus

    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... in diagnosing a broad range of conditions, including cancer, heart and vascular disease, heart valve abnormalities, bone ...

  10. MRI of the Chest

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    Full Text Available ... provides movie-like sequential imaging of the cardiovascular system that is important to assess the health and ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  11. MRI of the Chest

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    Full Text Available ... magnetic field is produced by passing an electric current through wire coils in most MRI units. Other ... that are detected by the coils. The electric current does not come in contact with the patient. ...

  12. MRI of the Chest

    Science.gov (United States)

    ... surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  13. MRI of the Breast

    Science.gov (United States)

    ... surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  14. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D. L.; Pichler, B. J.; Gückel, B.;

    2015-01-01

    This paper summarises key themes and discussions from the 4th international workshop dedicated to the advancement of the technical, scientific and clinical applications of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) systems that was held in Tübingen, Germany, from...... February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology......, neurology and multi-parametric imaging, the latter of which was suggested as a key promoting factor for the wider adoption of integrated PET/MRI. Discussions throughout the workshop and a poll taken on the final day demonstrated that attendees felt more strongly that PET/MRI has further advanced in both...

  15. MRI of the Chest

    Medline Plus

    Full Text Available ... and should not enter the MRI scanning area: cochlear (ear) implant some types of clips used for ... follow-up exam is done because a potential abnormality needs further evaluation with additional views or a ...

  16. MRI of the Chest

    Medline Plus

    Full Text Available ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  17. Extradural spinal meningioma: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Sato, N. [Department of Diagnostic Radiology, Yale University School of Medicine, P. O. Box 20 8042, New Haven, CT 06520-8042 (United States); Sze, G. [Department of Diagnostic Radiology, Yale University School of Medicine, P. O. Box 20 8042, New Haven, CT 06520-8042 (United States)

    1997-06-01

    We report a case of extradural spinal meningioma with pathologically proven features of malignant transformation. The MRI findings of extradural spinal meningioma and differences in the findings from intradural meningiomas are discussed. (orig.). With 1 fig.

  18. MRI of the Chest

    Medline Plus

    Full Text Available ... of the chest uses a powerful magnetic field, radio waves and a computer to produce detailed pictures ... medical conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed ...

  19. MRI of the Chest

    Medline Plus

    Full Text Available ... any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast ... an MRI. If you have a history of kidney disease or liver transplant, it will be necessary to ...

  20. MRI of the Chest

    Medline Plus

    Full Text Available ... intercom. Many MRI centers allow a friend or parent to stay in the room as long as they are also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ...

  1. MRI of the Chest

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  2. MRI of the Chest

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    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

  3. MRI of the Chest

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    Full Text Available ... it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should ... or if you have asthma. The contrast material most commonly used for an MRI exam contains a ...

  4. MRI of the Chest

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    Full Text Available ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  5. MRI of the Chest

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

  6. MRI of the Chest

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    Full Text Available ... Unless you are told otherwise, take your regular medications as usual. Leave jewelry at home and wear ... your regular daily routine and take food and medications as usual. Some MRI examinations may require you ...

  7. 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.

  8. 多层螺旋CT小肠造影在结肠受累克罗恩病患者诊断中的价值%The clinical value of multi-slice CT enterography in diagnosis of Crohn disease involving colon

    Institute of Scientific and Technical Information of China (English)

    丰萍璐; 程建美; 吴兴旺; 胡乃中

    2015-01-01

    Objective To analyze the clinical,endoscopic,histological and multi-slice CT enterography(MSCTE)characteristics of Crohn disease(CD),and to explore the value of MSCTE in the diagnosis of CD involving the colon. Methods Clinical,endoscopic,histo-logical and MSCTE data of 71 patients with CD attending in our hospital from January 2009 to September 2013 were analyzed,and the data of 28 patients with ITB as a control at the same period were studied. The parameters for diagnosis of CD were screened by logistic regression a-nalysis. Results The incidence rates of diarrhea,perianal disease and C-reaction protein elevated in CD were higher than those in intestinal tuberculosis(ITB);the occurrence rate of history of abenteric tuberculosis,and the positive rates of PPD and T-SPOT were lesser than those of ITB(P0. 05). The pathological analysis showed that non-caseous granulomas,fissure-like ulcers,crypt abscess and caseous granulomas between the two groups had no statistically significant difference (P>0. 05 ). The analysis of MSCTE imaging showed that mural stratification enhancement,thickening obviously of the membrane margin and comb sign occurred more frequently in CD than in ITB and that Lymph node calcification or central necrosis was more frequently found in ITB than in CD. The results of logistic regression anal-ysis showed that thickening obviously of the membrane margin(OR=5. 140,95%CI:1. 053~25. 087)was an independent predictor for the diagnosis of CD. Conclusion CD has clinical,colonoscopic and pathological characteristics,but the diagnostic value of these characteristics is limited,and the comprehensive judgment can not meet the demand of clinical diagnosis. Application of MSCTE is helpful to improve the level of diagnosis of CD.%目的:分析结肠受累克罗恩病(CD)的临床、内镜、病理及多层螺旋CT小肠造影(MSCTE)特征,探讨MSCTE在CD诊断中的临床价值。方法选择结肠受累CD住院患者71例,选取同期28

  9. 大小肠双充盈法多层螺旋CT肠道成像对炎症性肠病的诊断价值%Multi-slice CT Enterography with Double-iflling Method in Diagnosis of Inlfammatory Bowel Diseases

    Institute of Scientific and Technical Information of China (English)

    刘克昌; 项微微; 张胜兰; 项光涨; 殷焱; 杨国平

    2015-01-01

    Purpose To summarize the imaging features of inflammatory bowel diseases (IBD) with double-filling method using multi-slice CT enterography (MSCTE), and to evaluate the clinical significance of MSCTE in diagnosis of IBD. Materials and Methods MSCTE data with double-filling method of 52 patients with IBD were retrospectively analyzed. 52 IBD patients included 42 cases of Crohn's disease (CD) and 10 cases of ulcerative colitis (UC). Bowel dilatation and lesions display were evaluated. Results Among 52 patients, ileum dilated optimal in 10 cases (19.23%) and good in 42 cases (80.77%); jejunum dilated good in 21 cases (40.38%) and poor in 31cases (59.62%). Exhaustive evaluation for large bowel diseases were good in 50 cases (96.15%). The ileocecal junction displayed well in 52 cases (100.00%). Among the 42 cases of CD, 20 cases (47.62%) had lesions limited in the small intestine, 22 cases (52.38%) had lesions involved both small intestine and colon. Among 10 cases of UC, 9 cases had lesions limited in the colon, and 1 case with the terminal ileum and the colon involved simultaneously. The MSCTE findings of 52 patients included bowel wall thickening and abnormal enhancement in 52 cases, stenosis in 28 cases, increased mesenteric vascularity in 46 cases, enlarged mesenteric lymph nodes in 27 cases, phlegmon in 10 cases, incomplete intestinal obstruction in 4 cases, abscess or inflammatory masses in 7 cases, fistulas in 3 cases, perianal lesion in 12 cases, serous cavity effusion in 15 cases, sacroiliitis in 13 cases, the urinary and biliary stones in 18 cases, and hepatosplenomegaly in 9 cases. Conclusion MSCTE with double-filling method can delineate the wall lesions of small bowels and colons very well, and can also display extraintestinal lesions and complications. It obviously improves the accuracy of localization and qualitative diagnosis on IBD.%目的:总结炎症性肠病(IBD)在大小肠双充盈法多层螺旋CT(MSCT)肠道成像中的影像表现,

  10. Application of multi-slice CT in measurement of morphological parameters of waist muscle and its clinical significance%多排螺旋 CT 在腰部肌群形态学参数测量中的应用及其临床意义

    Institute of Scientific and Technical Information of China (English)

    付卫光; 刘硕; 丁军; 安俐莹

    2015-01-01

    -69 years old group,and 70-79 years old group were set up.The lumbar transverse psoas muscle,lumbar side muscle,erector spinae cross-sectional areas (CSA)and mean CT values were measured at different levels.Scanning equipment:Toshiba Activion 16-slice spiral CT scanners, acquisition range from the waist 1 to S1.Results ①Compared between the measurement results of the same age groups (except 70-79 years old group),the average CSA of the male at the same level waist was higher than the female (P 0.05).Compared between the same level groups of 50-59 years,60-69 years and 70-79 years,there was no significant difference (P >0.05).③Compared the CSA of man’s erector spinae muscle between 40-49 years group and 50-59 years group,there were significant differences (P 0.05).⑤The same level average density of erector spinae muscle was lowest compared with the psoas major muscle and quadratus lumborum muscle,and falling faster,the psoas major muscle was relatively higher.The same level average density of female’s erector spinae muscle was lower than man’s,specially in 70-79 years group.Conclusion Multi-slice spiral CT can be used to diagnose the lumbar degenerative conditions.

  11. 多层螺旋 CT 多平面重组在诊断先天感音神经性耳聋儿童内耳畸形中的应用%The diagnostic value of multiplanar reconstruction of multi-slice spiral CT in pediatric sensorineural hearing loss children induced by inner ear malformation

    Institute of Scientific and Technical Information of China (English)

    胡辉军; 李国照; 王东烨; 张翔; 沈君

    2015-01-01

    Objective To investigate the diagnostic value of multiplanar reconstruction (MPR) of multi-slice spiral CT (MSCT) in inner ear malformation of children. Methods Retrospective analysis of 223 children in Sun Yat-Sen Memorial Hospital suspected sensorineural hearing loss (SNHL) clinically was performed between September 2010 and March 2014. All the patients received MSCT scan and 68 patients of inner ear malformation were detected. Deformed bony labyrinths of 68 patients and two cases of normal inner ear were reconstructed with the method of MPR on basis of raw data of MSCT images by one radiologist. In 68 patients of inner ear malformation, there were 33 males and 35 females (aged from 9 days to 16 years). Two senior radiologists evaluated the MSCT manifestations of 68 patients and than statistics analysis of classification for inner ear malformation were performed. Results Sixty-eight patients (5 patients with single ear malformation, 63 patients with bilateral ear malformation, 131 ears in total) with SNHL were clearly shown by MPR images. There were 33 ears of cochlear malformation, 39 ears of vestibular malformation, 42 ears of semicircular canal malformation, 18 ears of internal auditory canal malformation and 86 ears of vestibular aqueduct malformation. In 68 patients (131 ears), single constructive malformation was detected in 8 ears (6. 1% ), two or more kinds of combined malformations were detected in 123 ears (93. 9% ). Conclusions Most of these patients suffered from two or more kinds of combined malformations. MPR images can display the structures of cochlear, vestibule, semicircular canal, internal auditory canal and vestibular aqueduct. The application of this kind of post-processing technology is expected to improve the detection rate of inner ear malformation, especially the various structural malformations, which is conducive to the treatment decisions making and surgical planning.%目的:探讨多层螺旋 CT(MSCT)多平面重组(MPR)技术在

  12. 多层螺旋CT门静脉血管成像在胰源性门脉高压症诊断中的应用%The application of multi-slice spiral CT portography in pancreatic portal hypertension disease

    Institute of Scientific and Technical Information of China (English)

    靳勇; 林晓珠; 吴云林; 朱晖; 吴志远; 瞿晴; 徐学勤; 陈克敏

    2008-01-01

    Objective To study the application of multi-slice spiral CT(MSCT) portography in diagnonsis of pancreatic portal hypertension. Methods Forty-seven patients with lesion in body or tail of pancrease,47 normal subjects and 126 patients with portal hypertension underwent MSCT portography with LightSpeed 16 CT scanner. The inner diameter of portal system and the main collateral veins were measured in maximun intensity projection (MIP) image. The volume of liver and spleen were also measured in volume rendering (VR) image. The liver parenchyma and main portal vein enhancement in portal vein phase were also taken. The endoscopy examination was made in 57 patiens with portal hypertension. Results In 47 patiens with lesion in body or tail of pancreas , stenosis or occlusion of spleen vein were found in 38 patients(pancreatic portal hypertension in 27 patients, chronic and acute pancreatitis in 11 patients). In 38 patients with pancreatic portal hypertension, esophageal varices was found in 5 patients(13.2%), gastric fundus varix in 25 patients (65.8%), gastric body variees in 22 patients (57.9%), short-gastric vein/post-gastric vein(SGV/PGV) in 26 patients (68.4%), coronal gastric vein in 26 patients (68.4%),dilated gasto-omenta vein in 24 patients(63.2%), mesenterica varicesin 1 patient, splenic vein occlusion in 14 patients (36.8%), splenic vein stenosis in 23 patinets(63.2%). Conclusions The patients with pancreatic portal hypertension were demonstrate characteristic changes in MSCT portography. The MSCT portography is helpful in etiological diagnosis of pancreatic portal hypertension by supplying images in vessel morphology.%目的 研究多层螺旋CT门静脉血管成像在胰源性门静脉高压患者诊断中的应用.方法 应用16排多层螺旋CT门静脉血管成像,对47例临床怀疑胰腺体尾部病变的患者的门静脉系统形态改变与126例肝源性门脉高压患者和47例正常对照组进行形态学对比观察,并测量胃

  13. 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

  14. 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

  15. Diagnostic value of multi-slice spiral CT post-processing technique on sacroiliac joint lesions in patients with ankylosing spondylitis%多层螺旋CT后处理技术在强直性脊柱炎骶髂关节病变中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    亓立勇

    2012-01-01

    Objective To investigate the diagnostic value of multi-slice spiral CT(MSCT) and its multi-planar reconstruction(MPR) and curved planar reconstruction(CPR) on sacroiliac joint with ankylosing spondylitis(AS).Methods Fifty-six patients with AS proved clinically were examined and analyzed with MSCT and reconstruction.Then the CT manifestations of sacroiliace joints were analyzed.And choose a sagittal image respectively in the margin of the sacrum one-four,one-second and two-four.Then went down the sacrum line trace for CPR technique get double sided sacroiliac joint imaging.The images,MPR transect images and CPR image were analyed.Results Early CT findings included coarsearticular surface,interrupted jiont cortex,vague articular face,subcortical microcysts and sclerotic articular surface,while jiont space was normal.CT findings in progressive stage were uneven articular surface,damaged bony cortex,subcartilaginous bone microcyats,obviously sclerotic articular surface,extended jiontspace.In stable stage,CT findings included joint ankylosis,articular space dsiappearance,and sacroiliac ligament calcification.Fifty-six cases of AS patients,bilateral simultaneous involvement in 47 cases,unilateral involvement in 9 cases,axial image diagnosis,Ⅰ-Ⅱ grade 16 cases,Ⅲ-Ⅳ grade 26 cases.MPR image diagnosis of Ⅰ-Ⅱ grade 24 cases,Ⅲ-Ⅳ Grade 26 cases,CPR class Ⅰ diagnostic images-Ⅱ grade 29 cases,Ⅲ-Ⅳ grade in 26 cases,early diagnosis of axial images and reconstruction images were significantly different (P < 0.05),the late diagnosis rates were not significantly different (P > 0.05).Conclusions It is valuable to use MPR and CPR images to diagnosis sacroiliac joint lesions in patients with ankylosing spondylitis.Especially CPR image can be used to comprehensively observe sacroiliac joint,and it is more meaningful in early diagnosis of sacroiliac joint lesions in patients with AS.%目的 探讨多层螺旋CT(MSCT)多平面重组(MPR)技术和曲面重组(CPR

  16. Multi-slice CT diagnosis of anomaly of ostiomeatal complex and chronic sinusitis%多螺旋 CT检测在窦口-鼻道复合体解剖变异与慢性鼻窦炎中的应用

    Institute of Scientific and Technical Information of China (English)

    刘景旺; 蒋守芳

    2014-01-01

    Objective To study the incidence of anomaly of ostiomeatal complex ( OMC) and its relation to chronic sinusi-tis.Methods CT images of 933 cases who received health examination were retrospectively analyzed .The anatomical variants of OMC were clearly displayed by MPR .Variants of middle turbinate recurvation/gasification , ethmoidal bulla excessive gasi-fication,uncinate process diviation/hypertrophy/gasification,agger excessive gasification,and Haller cell were observed and compared in order to search the relation between anomaly and sinusitis .Results In the 933 cases,the incidence of chronic si-nusitis was 30.12%,with chronic genyantritis being the highest .The incidences of OMC anomaly were 1.7%,13.8%,5.8%, 6.8%,5.1%,1.1%,0.4%,and 2.7%respectively.OMC anomaly in chronic genyantritis ,ethmoidal sinusitis and frontal si-nusitis showed significant differences (P<0.01).The incidence of nasosinusitis in the mixed anomaly group was remarkably higher than the single anomaly group .In 457 cases of non-smokers,OMC anomaly was significantly related to the incidence differences of chronic genyantritis ,ethmoidal sinusitis and frontal sinusitis (P<0.05).In terms of single anomaly factors,mid-dle turbinate recurvation ,uncinate process gasification/diviation/hypertrophy were closely related to the incidence of chronic genyantritis;ethmoidal bulla excessive gasification was closely related to chronic ethmoidal sinusitis ;uncinate process diviation was closely related to chronic frontal sinusitis .Conclusion 1.Multi-slice CT can clearly show the anomaly of OMC .2.Differ-ent anomalies of OMC play different roles in the development of chronic sinusitis .%目的:应用多螺旋CT检测窦口-鼻道复合体( OMC)解剖变异发生率及探讨其与慢性鼻窦炎发生的关系。方法回顾性分析本院933例健康查体者鼻窦扫描图像,薄层横断图像重建冠状面图像,观察OMC解剖变异情况:中鼻甲(反曲、气化)、筛泡过度气化、

  17. Measurement of coronary artery calcification with multi-slice spiral computed tomography and the associated factors in maintenance hemodialysis patients%维持性血液透析患者冠状动脉钙化的评价及影响因素分析

    Institute of Scientific and Technical Information of China (English)

    郑淑蓓; 金领微; 李占园; 周志宏

    2015-01-01

    Objective To investigate the factors correlated to coronary artery calcification (CAC) in maintenance hemodialysis (MHD) patients.Methods This study included 132 patients(54 females,78 males),aged 26-94 years,who were on hemodialysis for 10-204 months(median dialysis duration 51.00 months).The parameters including calcium,phosphorus,parathyroid hormone,total cholesterol,low density lipoprotein,triglycerides,C-reactive protein (CRP),klotho,and so on were assessed.Quantification of CAC was determined by multi-slice spiral computed tomography (MSCT),known as the coronary artery calcification score (CACs).Results Ninety-two patients (69.70%) had CAC,with CACs ranging from 0 to 13 450.20.More than 30% patients experienced one even a variety of cardiovascular and cerebrovascular diseases.A positive correlation was observed between the degree of CAC and the incidence of cardiovascular and cerebrovascular diseases.Whereas a positive correlation existed between CACs and age (r=0.347,P=0.000),duration of hemodialysis (r=0.245,P=0.005),systolic blood pressure (r=0.184,P=0.034),diabetes history (r=0.211,P=0.015),phosphorus (r=0.262,P=0.002),calcium-phosphorus product (r=0.247,P=0.004);and a negative correlation between CACs and klotho level (r=-0.294,P=0.001).Multivariate logistic regression analysis showed that the main factor influencing the degree of CAC in MHD patients was age.Conclusions CAC is common and widespread in hemodialysis patients,who are often accompanied by cardiovascular and cerebrovascular diseases.The prevalence rate of cardiovascular and cerebrovascular diseases increases with the aggravation of CAC degree.Age,duration of hemodialysis,systolic blood pressure,diabetes history,disturbance of calcium and phosphorus metabolism and klotho are correlated with the severity of CAC.Age is an independent risk factor of CAC degree.%目的 探讨影响维持性血液透析(MHD)患者冠状动脉钙化(CAC)的相关因素.方法 收集2012年12月至2014年8月在

  18. Values of multi-slice spiral computed tomography on predicting hypovolemic shock in patients with severe multiple trauma%多层螺旋CT对严重多发伤患者低血容量性休克的预测价值

    Institute of Scientific and Technical Information of China (English)

    李阳; 张连阳; 王毅; 张伟国

    2013-01-01

    Objective To investigate the value of multi-slice spiral computed tomography (MSCT) on predicting hypovolemic shock in patients with severe multiple trauma. Methods The clinical and MSCT data of 63 patients with severe multiple trauma admitted to the Trauma Center from Jan. 2008 to Dec. 2011 were retrospectively reviewed. According to the occurrence of hypovolemic shock in 24 hours after CT scan, the patients were divided into shock group (n=34) and stable group (n=29). Blood pressure, heart rate, shock index and injury severity score (ISS) on admission were collected and analyzed. Transverse (T) and anteroposterior (AP) diameter of inferior vena cava (IVC), diameter of abdominal aorta, CT values of enhanced CT of abdominal organs both in early and late phase were measured. The differences of aforementioned parameters between the two groups were compared by Student's t test. The values of above indexes showing significant difference between the two groups on predicting hypovolemic shock were analyzed by using receiver operating characteristic (ROC) curve and logistic regression analysis. Results The shock index, ISS and collapsibility index (T/AP) of IVC in 4 abdominal levels were significantly greater in shock group than in stable group (I'<0.05). In early phase of enhanced CT, the mean CT value of spleen was significantly lower in shock group (93 ± 16HU) than in stable group (112 ± 24HU, P<0.0l), while the mean CT value of adrenal gland was higher in shock group (153 ± 35HU) than in stable group (131 ± 24HU, P<0.0l). In delayed phase, the mean CT value of renal medulla was significantly lower in shock group (193 ± 57HU) than in stable group (228 ± S3HU, P<0.05). The diagnostic cutoff value of ROC curve of shock index, ISS, collapsibility index (T/AP) of IVC, CT value of spleen and adrenal gland in early phase, CT value of renal medulla in delayed phase were 1.19, 19.5, 3.02, 115HU, 150HU and 184HU, respectively. Logistic regression analysis showed that ISS

  19. Posttraumatic pseudolipoma: MRI appearances

    Energy Technology Data Exchange (ETDEWEB)

    Theumann, N.; Abdelmoumene, A.; Wintermark, M.; Schnyder, P.; Gailloud, M.C.; Resnick, D. [CHUV, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland)

    2005-09-01

    The goal of this study was to describe the MRI characteristics of posttraumatic pseudolipomas. Ten patients with previous history of blunt trauma or local surgery were investigated with MRI at the level of their deformity. The etiology was blunt trauma in eight patients and postoperative trauma in two. For all patients medical documentation, in the form of clinical history and physical examination, confirmed that a visible hematoma was present acutely at the same location following the injury and that the contour deformity subsequently appeared. All patients underwent liposuction. Preoperative bilateral MRI examinations were performed on all patients. The mean clinical follow-up was 17.8 months. MRI examinations were interpreted in consensus by two experienced musculoskeletal radiologists with attention to fatty extension (subcutaneous fatty thickness and anatomical extension), asymmetry compared with the asymptomatic side, the presence or absence of fibrous septae or nonfatty components, and patterns of contrast enhancement. Ten posttraumatic pseudolipomas were identified. Clinically, they showed as subcutaneous masses with the consistency of normal adipose tissue. Their locations were the abdomen (n=1), hip (n=1), the upper thigh (n=6), the knee (n=1), and the ankle (n=1). On MRI examinations, using the contralateral side as a control, pseudolipomas appeared as focal fatty masses without a capsule or contrast enhancement. Posttraumatic pseudolipomas may develop at a site of blunt trauma or surgical procedures often antedated by a soft tissue hematoma. Characteristic MRI findings are unencapsulated subcutaneous fatty masses without contrast enhancement. (orig.)

  20. Implementation of 2D Discrete Wavelet Transform by Number Theoretic Transform and 2D Overlap-Save Method

    Directory of Open Access Journals (Sweden)

    Lina Yang

    2014-01-01

    Full Text Available To reduce the computation complexity of wavelet transform, this paper presents a novel approach to be implemented. It consists of two key techniques: (1 fast number theoretic transform(FNTT In the FNTT, linear convolution is replaced by the circular one. It can speed up the computation of 2D discrete wavelet transform. (2 In two-dimensional overlap-save method directly calculating the FNTT to the whole input sequence may meet two difficulties; namely, a big modulo obstructs the effective implementation of the FNTT and a long input sequence slows the computation of the FNTT down. To fight with such deficiencies, a new technique which is referred to as 2D overlap-save method is developed. Experiments have been conducted. The fast number theoretic transform and 2D overlap-method have been used to implement the dyadic wavelet transform and applied to contour extraction in pattern recognition.

  1. 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.

  2. 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.

  3. Fast 2D-DCT implementations for VLIW processors

    OpenAIRE

    Sohm, OP; Canagarajah, CN; Bull, DR

    1999-01-01

    This paper analyzes various fast 2D-DCT algorithms regarding their suitability for VLIW processors. Operations for truncation or rounding which are usually neglected in proposals for fast algorithms have also been taken into consideration. Loeffler's algorithm with parallel multiplications was found to be most suitable due to its parallel structure

  4. 2D nanomaterials based electrochemical biosensors for cancer diagnosis.

    Science.gov (United States)

    Wang, Lu; Xiong, Qirong; Xiao, Fei; Duan, Hongwei

    2017-03-15

    Cancer is a leading cause of death in the world. Increasing evidence has demonstrated that early diagnosis holds the key towards effective treatment outcome. Cancer biomarkers are extensively used in oncology for cancer diagnosis and prognosis. Electrochemical sensors play key roles in current laboratory and clinical analysis of diverse chemical and biological targets. Recent development of functional nanomaterials offers new possibilities of improving the performance of electrochemical sensors. In particular, 2D nanomaterials have stimulated intense research due to their unique array of structural and chemical properties. The 2D materials of interest cover broadly across graphene, graphene derivatives (i.e., graphene oxide and reduced graphene oxide), and graphene-like nanomaterials (i.e., 2D layered transition metal dichalcogenides, graphite carbon nitride and boron nitride nanomaterials). In this review, we summarize recent advances in the synthesis of 2D nanomaterials and their applications in electrochemical biosensing of cancer biomarkers (nucleic acids, proteins and some small molecules), and present a personal perspective on the future direction of this area.

  5. The partition function of 2d string theory

    CERN Document Server

    Dijkgraaf, R; Plesser, R

    1993-01-01

    We derive a compact and explicit expression for the generating functional of all correlation functions of tachyon operators in 2D string theory. This expression makes manifest relations of the $c=1$ system to KP flow and $W_{1+\\infty}$ constraints. Moreover we derive a Kontsevich-Penner integral representation of this generating functional.

  6. 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 dimension...

  7. Validation of minor species of the MIPAS2D database

    Directory of Open Access Journals (Sweden)

    Enzo Papandrea

    2014-01-01

    Full Text Available The MIPAS2D [Dinelli et al., 2010] database has been developed applying the tomographic analysis technique GMTR [Carlotti et al., 2001] to measurements acquired in the nominal observation mode of the complete MIPAS (Michelson Interferometer for Passive Atmosphere Sounding [Fischer et al., 2008] mission. […

  8. The 2D Boussinesq equations with logarithmically supercritical velocities

    CERN Document Server

    Chae, Dongho

    2011-01-01

    This paper investigates the global (in time) regularity of solutions to a system of equations that generalize the vorticity formulation of the 2D Boussinesq-Navier-Stokes equations. The velocity $u$ in this system is related to the vorticity $\\omega$ through the relations $u=\

  9. Dynamic and approximate pattern matching in 2D

    DEFF Research Database (Denmark)

    Clifford, Raphaël; Fontaine, Allyx; Starikovskaya, Tatiana

    2016-01-01

    updates can be performed in O(log2 n) time and queries in O(log2 m) time. - We then consider a model where an update is a new 2D pattern and a query is a location in the text. For this setting we show that Hamming distance queries can be answered in O(log m + H) time, where H is the relevant Hamming...... distance. - Extending this work to allow approximation, we give an efficient algorithm which returns a (1+ε) approximation of the Hamming distance at a given location in O(ε−2 log2 m log log n) time. Finally, we consider a different setting inspired by previous work on locality sensitive hashing (LSH......). Given a threshold k and after building the 2D text index and receiving a 2D query pattern, we must output a location where the Hamming distance is at most (1 + ε)k as long as there exists a location where the Hamming distance is at most k. - For our LSH inspired 2D indexing problem, the text can...

  10. 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

  11. The Analytical Approximate Solution of the 2D Thermal Displacement

    Institute of Scientific and Technical Information of China (English)

    Chu-QuanGuan; Zeng-YuanGuo; 等

    1996-01-01

    The 2D plane gas flow under heating (with nonentity boundary condition)has been discussed by the analytical approach in this paper.The approximate analytical solutions have been obtained for the flow passing various kinds of heat sources.Solutions demonstrate the thermal displacement phenomena are strongly depend on the heating intensity.

  12. Band Alignment of 2D Transition Metal Dichalcogenide Heterojunctions

    KAUST Repository

    Chiu, Ming Hui

    2016-09-20

    It is critically important to characterize the band alignment in semiconductor heterojunctions (HJs) because it controls the electronic and optical properties. However, the well-known Anderson\\'s model usually fails to predict the band alignment in bulk HJ systems due to the presence of charge transfer at the interfacial bonding. Atomically thin 2D transition metal dichalcogenide materials have attracted much attention recently since the ultrathin HJs and devices can be easily built and they are promising for future electronics. The vertical HJs based on 2D materials can be constructed via van der Waals stacking regardless of the lattice mismatch between two materials. Despite the defect-free characteristics of the junction interface, experimental evidence is still lacking on whether the simple Anderson rule can predict the band alignment of HJs. Here, the validity of Anderson\\'s model is verified for the 2D heterojunction systems and the success of Anderson\\'s model is attributed to the absence of dangling bonds (i.e., interface dipoles) at the van der Waal interface. The results from the work set a foundation allowing the use of powerful Anderson\\'s rule to determine the band alignments of 2D HJs, which is beneficial to future electronic, photonic, and optoelectronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Rheological Properties of Quasi-2D Fluids in Microgravity

    Science.gov (United States)

    Stannarius, Ralf; Trittel, Torsten; Eremin, Alexey; Harth, Kirsten; Clark, Noel; Maclennan, Joseph; Glaser, Matthew; Park, Cheol; Hall, Nancy; Tin, Padetha

    2015-01-01

    In recent years, research on complex fluids and fluids in restricted geometries has attracted much attention in the scientific community. This can be attributed not only to the development of novel materials based on complex fluids but also to a variety of important physical phenomena which have barely been explored. One example is the behavior of membranes and thin fluid films, which can be described by two-dimensional (2D) rheology behavior that is quite different from 3D fluids. In this study, we have investigated the rheological properties of freely suspended films of a thermotropic liquid crystal in microgravity experiments. This model system mimics isotropic and anisotropic quasi 2D fluids [46]. We use inkjet printing technology to dispense small droplets (inclusions) onto the film surface. The motion of these inclusions provides information on the rheological properties of the films and allows the study of a variety of flow instabilities. Flat films have been investigated on a sub-orbital rocket flight and curved films (bubbles) have been studied in the ISS project OASIS. Microgravity is essential when the films are curved in order to avoid sedimentation. The experiments yield the mobility of the droplets in the films as well as the mutual mobility of pairs of particles. Experimental results will be presented for 2D-isotropic (smectic-A) and 2D-nematic (smectic-C) phases.

  14. Research Synthesis and Characterization of 2D Conjugated Polymers

    Science.gov (United States)

    2007-07-13

    polythiophene chain on the Scheme should necessarily result in a continuous brick wall 2D structure). Furthermore, the design should eliminate any...Photoelectron Spectroscopy and Ultraviolet Photoelectron Spectroscopy are under way. We have also conducted preliminary experiments on the two other low

  15. 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 Nav...

  16. BPS black holes in N=2 D=4 gauged supergravities

    NARCIS (Netherlands)

    Hristov, K.; Looyestijn, H.T.; Vandoren, S.J.G.

    2010-01-01

    We construct and analyze BPS black hole solutions in gauged N=2, D=4 supergravity with charged hypermultiplets. A class of solutions can be found through spontaneous symmetry breaking in vacua that preserve maximal supersymmetry. The resulting black holes do not carry any hair for the scalars. We de

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    £ 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...... of the Markov random field defined by the 2-D constraint is estimated to be (upper bounded by) 0.8570 bits/symbol using the iterative technique of Belief Propagation on 2 £ 2 finite lattices. Based on combinatorial bounding techniques the maximum entropy for the constraint was determined to be 0.848.......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...

  18. The Anglo-Australian Observatory's 2dF Facility

    CERN Document Server

    Lewis, I J; Taylor, K; Glazebrook, K; Bailey, J A; Baldry, I K; Barton, J R; Bridges, T J; Dalton, G B; Farrell, T J; Gray, P M; Lankshear, A; McCowage, C; Parry, I R; Sharples, R M; Shortridge, K; Smith, G A; Stevenson, J; Straede, J O; Waller, L G; Whittard, J D; Wilcox, J K; Willis, K C

    2002-01-01

    The 2dF (Two-degree Field) facility at the prime focus of the Anglo-Australian Telescope provides multiple object spectroscopy over a 2 degree field of view. Up to 400 target fibres can be independently positioned by a complex robot. Two spectrographs provide spectra with resolutions of between 500 and 2000, over wavelength ranges of 440nm and 110nm respectively. The 2dF facility began routine observations in 1997. 2dF was designed primarily for galaxy redshift surveys and has a number of innovative features. The large corrector lens incorporates an atmospheric dispersion compensator, essential for wide wavelength coverage with small diameter fibres. The instrument has two full sets of fibres on separate field plates, so that re-configuring can be done in parallel with observing. The robot positioner places one fibre every 6 seconds, to a precision of 0.3 arcsec (20micron) over the full field. All components of 2dF, including the spectrographs, are mounted on a 5-m diameter telescope top-end ring for ease of ...

  19. Nonlinear excursions of particles in ideal 2D flows

    DEFF Research Database (Denmark)

    Aref, Hassan; Pedersen, Johan Rønby; Stremler, Mark A.;

    2010-01-01

    A number of problems related to particle trajectories in ideal 2D flows are discussed. Both regular particle paths, corresponding to integrable dynamics, and irregular or chaotic paths may arise. Examples of both types are shown. Sometimes, in the same flow, certain particles will follow regular ...

  20. Approximate 2D inversion of airborne TEM data

    DEFF Research Database (Denmark)

    Christensen, N.B.; Wolfgram, Peter

    2006-01-01

    We propose an approximate two-dimensional inversion procedure for transient electromagnetic data. The method is a two-stage procedure, where data are first inverted with 1D multi-layer models. The 1D model section is then considered as data for the next inversion stage that produces the 2D model ....... Application to GEOTEM data over the Harmony nickel sulphide deposit recovered the three dipping conductors in the 2D section despite their complex structure and high conductivity contrast.......We propose an approximate two-dimensional inversion procedure for transient electromagnetic data. The method is a two-stage procedure, where data are first inverted with 1D multi-layer models. The 1D model section is then considered as data for the next inversion stage that produces the 2D model...... section. For moving platform data there is translational invariance and the second part of the inversion becomes a deconvolution. The convolution kernels are computed by perturbing one model element in an otherwise homogeneous 2D section and calculating full nonlinear responses. These responses...

  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. Discrepant Results in a 2-D Marble Collision

    Science.gov (United States)

    Kalajian, Peter

    2013-01-01

    Video analysis of 2-D collisions is an excellent way to investigate conservation of linear momentum. The often-desired experimental design goal is to minimize the momentum loss in order to demonstrate the conservation law. An air table with colliding pucks is an ideal medium for this experiment, but such equipment is beyond the budget of many…

  3. 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.

  4. 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.

  5. 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

  6. 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...

  7. 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

  8. Cytochrome P-450 2D6 (CYP2D6) Genotype and Breast Cancer Recurrence in Tamoxifen-Treated Patients

    DEFF Research Database (Denmark)

    Ahern, Thomas P; Hertz, Daniel L; Damkier, Per;

    2017-01-01

    -infiltrated tissues, all of which showed excellent CYP2D6 genotype agreement. We applied these concordance data to a quantitative bias analysis of the subset of the 31 studies that were based on genotypes from tumor-infiltrated tissue to examine whether genotyping errors substantially biased estimates of association....... The bias analysis showed negligible bias by discordant genotypes. Summary estimates of association, with or without bias adjustment, indicated no clinically important association between CYP2D6 genotype and breast cancer survival in tamoxifen-treated women....

  9. WE-AB-BRA-07: Quantitative Evaluation of 2D-2D and 2D-3D Image Guided Radiation Therapy for Clinical Trial Credentialing, NRG Oncology/RTOG

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, T; Yu, J; Xiao, Y [Thomas Jefferson University, Philadelphia, PA (United States); Jacobs, P [MIM Software, Inc, Cleavland, Ohio (United States); Manfredi, D; Linnemann, N [IROC Philadelphia, RTQA Center, Philadelphia, PA (United States)

    2015-06-15

    Purpose: 2D-2D kV image guided radiation therapy (IGRT) credentialing evaluation for clinical trial qualification was historically qualitative through submitting screen captures of the fusion process. However, as quantitative DICOM 2D-2D and 2D-3D image registration tools are implemented in clinical practice for better precision, especially in centers that treat patients with protons, better IGRT credentialing techniques are needed. The aim of this work is to establish methodologies for quantitatively reviewing IGRT submissions based on DICOM 2D-2D and 2D-3D image registration and to test the methodologies in reviewing 2D-2D and 2D-3D IGRT submissions for RTOG/NRG Oncology clinical trials qualifications. Methods: DICOM 2D-2D and 2D-3D automated and manual image registration have been tested using the Harmony tool in MIM software. 2D kV orthogonal portal images are fused with the reference digital reconstructed radiographs (DRR) in the 2D-2D registration while the 2D portal images are fused with DICOM planning CT image in the 2D-3D registration. The Harmony tool allows alignment of the two images used in the registration process and also calculates the required shifts. Shifts calculated using MIM are compared with those submitted by institutions for IGRT credentialing. Reported shifts are considered to be acceptable if differences are less than 3mm. Results: Several tests have been performed on the 2D-2D and 2D-3D registration. The results indicated good agreement between submitted and calculated shifts. A workflow for reviewing these IGRT submissions has been developed and will eventually be used to review IGRT submissions. Conclusion: The IROC Philadelphia RTQA center has developed and tested a new workflow for reviewing DICOM 2D-2D and 2D-3D IGRT credentialing submissions made by different cancer clinical centers, especially proton centers. NRG Center for Innovation in Radiation Oncology (CIRO) and IROC RTQA center continue their collaborative efforts to enhance

  10. 2d-LCA - an alternative to x-wires

    Science.gov (United States)

    Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

    2014-11-01

    The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150 kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

  11. 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.

  12. Two Dimensional Spatial Independent Component Analysis and Its Application in fMRI Data Process

    Institute of Scientific and Technical Information of China (English)

    CHEN Hua-fu; YAO De-zhong

    2005-01-01

    One important application of independent component analysis (ICA) is in image processing. A two dimensional (2-D) composite ICA algorithm framework for 2-D image independent component analysis (2-D ICA) is proposed. The 2-D nature of the algorithm provides it an advantage of circumventing the roundabout transforming procedures between two dimensional (2-D) image data and one-dimensional (1-D) signal. Moreover the combination of the Newton (fixed-point algorithm) and natural gradient algorithms in this composite algorithm increases its efficiency and robustness. The convincing results of a successful example in functional magnetic resonance imaging (fMRI) show the potential application of composite 2-D ICA in the brain activity detection.

  13. 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 ...

  14. Joint Compression-Segmentation of functional MRI Data

    DEFF Research Database (Denmark)

    Zhang, N.; Wu, Mo; Forchhammer, Søren

    2005-01-01

    Functional Magnetic Resonance Imaging (fMRI) data sets are four dimensional (4D) and very large in size. Compression can enhance system performance in terms of storage and transmission capacities. Two approaches are investigated: adaptive DPCM and integer wavelets. In the DPCM approach, each voxel...... information. Each voxel time sequence is DPCM coded using a quantized autoregressive model. The prediction residuals are coded by simple Rice coding for high decoder throughput. In the wavelet approach, the 4D fMRI data set is mapped to a 3D data set, with the 3D volume at each time instance being laid out...... into a 2D plane as a slice mosaic. 3D integer wavelet packets are used for lossless compression of fMRI data. The wavelet coefficients are compressed by 3D context-based adaptive arithmetic coding. An object-oriented compression mode is also introduced in the wavelet codec. An elliptic mask combined...

  15. 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.

  16. Instantons in 2D U(1) Higgs model and 2D CP(N-1) sigma models

    Science.gov (United States)

    Lian, Yaogang

    2007-12-01

    In this thesis I present the results of a study of the topological structures of 2D U(1) Higgs model and 2D CP N-1 sigma models. Both models have been studied using the overlap Dirac operator construction of topological charge density. The overlap operator provides a more incisive probe into the local topological structure of gauge field configurations than the traditional plaquette-based operator. In the 2D U(1) Higgs model, we show that classical instantons with finite sizes violate the negativity of topological charge correlator by giving a positive contribution to the correlator at non-zero separation. We argue that instantons in 2D U(1) Higgs model must be accompanied by large quantum fluctuations in order to solve this contradiction. In 2D CPN-1 sigma models, we observe the anomalous scaling behavior of the topological susceptibility chi t for N ≤ 3. The divergence of chi t in these models is traced to the presence of small instantons with a radius of order a (= lattice spacing), which are directly observed on the lattice. The observation of these small instantons provides detailed confirmation of Luscher's argument that such short-distance excitations, with quantized topological charge, should be the dominant topological fluctuations in CP1 and CP 2, leading to a divergent topological susceptibility in the continuum limit. For the CPN-1 models with N > 3 the topological susceptibility is observed to scale properly with the mass gap. Another topic presented in this thesis is an implementation of the Zolotarev optimal rational approximation for the overlap Dirac operator. This new implementation has reduced the time complexity of the overlap routine from O(N3 ) to O(N), where N is the total number of sites on the lattice. This opens up a door to more accurate lattice measurements in the future.

  17. Anatomical evaluation of CT-MRI combined femoral model

    Directory of Open Access Journals (Sweden)

    Kim Gyu-Ha

    2008-01-01

    Full Text Available Abstract Background Both CT and MRI are complementary to each other in that CT can produce a distinct contour of bones, and MRI can show the shape of both ligaments and bones. It will be ideal to build a CT-MRI combined model to take advantage of complementary information of each modality. This study evaluated the accuracy of the combined femoral model in terms of anatomical inspection. Methods Six normal porcine femora (180 ± 10 days, 3 lefts and 3 rights with ball markers were scanned by CT and MRI. The 3D/3D registration was performed by two methods, i.e. the landmark-based 3 points-to-3 points and the surface matching using the iterative closest point (ICP algorithm. The matching accuracy of the combined model was evaluated with statistical global deviation and locally measure anatomical contour-based deviation. Statistical analysis to assess any significant difference between accuracies of those two methods was performed using univariate repeated measures ANOVA with the Turkey post hoc test. Results This study revealed that the local 2D contour-based measurement of matching deviation was 0.5 ± 0.3 mm in the femoral condyle, and in the middle femoral shaft. The global 3D contour matching deviation of the landmark-based matching was 1.1 ± 0.3 mm, but local 2D contour deviation through anatomical inspection was much larger as much as 3.0 ± 1.8 mm. Conclusion Even with human-factor derived errors accumulated from segmentation of MRI images, and limited image quality, the matching accuracy of CT-&-MRI combined 3D models was 0.5 ± 0.3 mm in terms of local anatomical inspection.

  18. Multidimensional diffusion MRI

    Science.gov (United States)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  19. MRI of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, Hans-Ulrich (ed.) [University Clinic Heidelberg (Germany). Diagnostic and Interventional Radiology

    2009-07-01

    For a long time, only chest X-ray and CT were used to image lung structure, while nuclear medicine was employed to assess lung function. During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation. (orig.)

  20. 多排螺旋CT在胆源性胆囊-十二指肠瘘诊断中的临床价值%Clinical value of multi-slice computed tomography in the diagnosis of biliary gallbladder-duodenal fistula

    Institute of Scientific and Technical Information of China (English)

    王均庆; 郑庆华; 陆风旗; 张雷; 张追阳; 丁忠; 余迅

    2015-01-01

    Objective To summarize the characteristics and clinical value of multi-slice spiral computed tomography (MSCT) examination in the biliary gallbladder-duodenal fistula.Methods The imaging data of 28 patients with gallbladder-duodenal fistula who were admitted to the Wuxi No.2 Hospital