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21.
Functional magnetic resonance imaging (fMRI) based on the selection of intermolecular double-quantum coherences (iDQC) was performed with a standard birdcage coil at 3 T in a group of normal human volunteers. Suppression of spurious signal contributions from unwanted coherence-transfer pathways was achieved by combining a two-step phase cycle and a long repetition time of 5 s. A gradient-recalled echo iDQC sequence (echo time, T(E) = 80 ms) yielded robust activation with a visual paradigm. Maximum z-scores were about half of those observed with conventional blood-oxygen level dependent fMRI, whereas the functional signal change increased by more than a factor of 5. No activation was obtained with a spin-echo iDQC sequence (T(E) = 160 ms), in which dephasing accumulated during the evolution period was fully rephased by an appropriate delay time. It is hypothesized that substantial inherent diffusion weighting of the iDQC technique efficiently suppresses intravascular contributions to the functional contrast. A consistent quantitative explanation of the observed amount of signal change currently remains speculative.  相似文献   
22.
Normal and diseased isolated lungs: high-resolution CT   总被引:8,自引:0,他引:8  
  相似文献   
23.

Background

Up to 40% of patients diagnosed with lumbar spinal stenosis (LSS) show evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). The etiology of RNR is still unclear. Preoperative evidence of RNR is associated with a worse postsurgical outcome. Consequently, potential predictors of RNR could have a prognostic value. The aim was to test whether patient demographics and MRI-based measurements can predict RNR in LSS patients.

Methods

In a retrospective database-based cohort study the preoperative data of 300 patients, 150 with (RNR+) and 150 without (RNR-) evidence of RNR on their MRI were analyzed. Three independent researchers performed the MRI reads. Potential predictors were age, gender, body height (BH), length of lumbar spine (LLS), segmental length of lumbar spine (SLLS), lumbar spine alignment deviation (LSAD), relative LLS (rLLS), relative SLLS (rSLLS), number of stenotic levels (LSS-level), and grade of LSS severity (LLS-grade, increasing from A to D). Binomial logistic regression models were performed.

Results

RNR+ patients were 2.6?years older (p?=?0.01). Weak RNR+ predictors were a two-years age increase (OR 1.06; p?=?0.02), 3?cm BH decrease (OR 1.09; p?=?0.01) and a 5?mm SLLS decrease (OR 1.34; p?<?0.001). Strong RNR+ predictors were a 1% rLLS decrease (OR 2.17; p?<?0.001), LSS-level?≥?2 (OR 2.59; p?=?0.001), LLS-grade C (OR 5.86; p?=?0.02) and LLS-grade D (OR 18.4; p?<?0.001). The mean rSLLS of RNR+ patients was 0.6% shorter (p?<?0.001; 95% C.I. 0.4 to 0.8) indicating a disproportionate shorter lumbar spine.

Conclusions

We identified LSS severity grade and LSS levels as the strongest predictors of RNR. In addition to previous studies, we conclude that a shortened lumbar spine by degeneration is involved in the development of RNR.
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The European Trauma Course (ETC) was officially launched during the international conference of the European Resuscitation Council (ERC) in 2008. The ETC was developed on behalf of ESTES (European Society of Trauma and Emergency Surgery), EuSEM (European Society of Emergency Medicine), the ESA (European Society of Anaesthesiology) and the ERC. The objective of the ETC is to provide an internationally recognised and certified life support course, and to teach healthcare professionals the key principles of the initial care of severely injured patients. Its core elements, that differentiates it from other trauma courses, are a strong focus on team training and a novel modular design that is adaptable to the differing regional European requirements.This article describes the lessons learnt during the European Trauma Course development and provides an outline of the planned future development.  相似文献   
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27.
Summary Hearts with one underdeveloped and one dominant ventricle form a spectrum of anomalies extending from the heart with two clearly adequate chambers to those with a true single ventricle. An angiographic concept of grouping such hearts is presented. 129 patients with unequal ventricles underwent catheterization and cineangiography between 1974 and 1983. The age at first catheterization ranged from one day to 24 years (mean 3.9 years). Male-female ratio was 2:1. Five groups of hearts (with their relative frequencies in the spectrum) were established: (1) dominant left ventricle (53%); (2) dominant right ventricle (20%), each with normally related chambers; (3) dominant left ventricle (20%); (4) dominant right ventricle (3%), each with ventricular inversion; (5) true single ventricle (5%). The incidence of atrial anatomy, venous return, intracardiac connections and associated lesions within each group was assessed. From the standpoint of deranged physiology as well as surgical implications there are more similarities than differences among these hearts. The fact that one ventricle will not generate an adequate stroke volume after repair is overwhelmingly more important than most other considerations. For the diagnostic and surgical approach, we believe that the system offers many advantages.  相似文献   
28.
The past 30 years have witnessed a major paradigm shift in brain tumor research with the development of a wide variety of molecular  相似文献   
29.
Magnetic resonance imaging of benign mediastinal masses   总被引:1,自引:0,他引:1  
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30.
Tidwell  T; Guzman  G; Vogler  WR 《Blood》1981,57(4):794-797
The action of an alkyl-lysophospholipid (ALP), ET180CH3, on clonogenicity, 3H-TdR uptake, and cell numbers was tested in two human leukemic cell lines, HL60 and K562, and short-term human leukemic bone marrow cultures. ALP eliminated clonogenicity in HL60 but not in K562 cultures; 3H-TdR uptake and cell numbers were depressed at low concentrations of ET180CH3 in HL60, but not K562 cultures. The action of the lysophospholipid analog on human leukemic bone marrow short-term cultures at low concentrations was similar to its action on HL60 cultures; clonogenicity and 3H-TdR uptake were depressed, but cell numbers were not significantly affected. The demonstration of differential action of ALP on two cell lines should significantly simplify the investigation of the mechanism of the reported differential action of ET180CH3 on normal and leukemic cell membranes.  相似文献   
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