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OBJECTIVES:: After presenting in part I the protocol and the methodology of the Tetrafigap Survey, this article is aimed at investigating demographic characteristics, initial cause of trauma and spinal injury in the French tetraplegic spinal cord injured (TSCI) population. STUDY DESIGN:: The Tetrafigap Survey is a multicentre epidemiological survey on the outcome of TSCI people following their first admission to a rehabilitation department or centre. SETTING:: The survey was conducted with the participation of 35 French-speaking collaborating centres. METHOD:: A self-administered questionnaire was carried out among consenting TSCI patients followed by the centres. 1668 questionnaires fulfilled all the required criteria for data analysis. RESULTS:: The socio-demographic variables (gender, current age and age at the time of accident, duration of disability), circumstances of accident as well as initial spinal cord lesions are reviewed in the body of the text. CONCLUSION:: The results from this survey form the first detailed description of the French TSCI population. Whereas demographic data show many similarities with those of previous studies in other countries, some specific differences are highlighted, in particular relating to the type of accident.Spinal Cord (2000) 38, 164–172. [ABSTRACT FROM AUTHOR]

The Tetrafigap Survey, a multicentre epidemiological survey on the outcome of tetraplegic spinal cord injured (TSCI) people from their first admission to a Rehabilitation Department or Centre is currently being undertaken in France. The general objective of this survey is to evaluate the situation of the TSCI people and their conditions of life in its medical, psychological and social aspects. This first article is aimed at presenting the protocol and the methodology of this survey. In a second part, yet to be submitted for publication, the preliminary results will be presented. It was first necessary to create a database of the population of TSCI people known to the centres and medical rehabilitation services, removing double entries. The criteria used for inclusion in the study were: a complete or incomplete traumatic cervical cord lesion, including post-surgical complications; age 16 or over at the time of the accident which must have occurred before December 31, 1992. The enquiry consisted of a self-administered questionnaire carried out with surviving tetraplegic people who had given their informed consent for their participation. The questionnaire consecutively covered the following topics: the situation at the time of the accident, the medical evolution between the accident and the end of stay in a rehabilitation unit, their evolution after discharge and the current situation (medical, social, professional and personal). During this first phase, 6082 TSCI people were identified by the collaborating centres. The 603 files of those who had died and 769 double entries were removed. Thus, 4710 questionnaires were sent out. The results of the participation show that 2251 people gave their consent and received questionnaires (340 additional deaths were acknowledged at this step), 163 refused, 869 were lost for follow-up, and 67 were excluded. There was no reply from 1020 people. We received 1830 questionnaires of which 1669 fulfilled all the necessary criteria... [ABSTRACT FROM AUTHOR]

Introduction: Interventional cardiac MRI in the context of the treatment of cardiac arrhythmia requires submillimeter image resolution to precisely characterize the cardiac substrate and guide the catheter-based ablation procedure in real-time. Conventional MRI receiver coils positioned on the thorax provide insufficient signal-to-noise ratio (SNR) and spatial selectivity to satisfy these constraints., Methods: A small circular MRI receiver coil was developed and evaluated under different experimental conditions, including high-resolution MRI anatomical and thermometric imaging at 1.5 T. From the perspective of developing a therapeutic MR-compatible catheter equipped with a receiver coil, we also propose alternative remote active detuning techniques of the receiver coil using one or two cables. Theoretical details are presented, as well as simulations and experimental validation., Results: Anatomical images of the left ventricle at 170 µm in-plane resolution are provided on ex vivo beating heart from swine using a 2 cm circular receiver coil. Taking advantage of the increase of SNR at its vicinity (up to 35 fold compared to conventional receiver coils), real-time MR-temperature imaging can reach an uncertainty below 0.1°C at the submillimetric spatial resolution. Remote active detuning using two cables has similar decoupling efficiency to conventional on-site decoupling, at the cost of an acceptable decrease in the resulting SNR., Discussion: This study shows the potential of small dimension surface coils for minimally invasive therapy of cardiac arrhythmia intraoperatively guided by MRI. The proposed remote decoupling approaches may simplify the construction process and reduce the cost of such single-use devices., Competing Interests: MD did part of her Ph.D as an employee of Siemens Healthineers. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Marhabaie, Delcey, El Hamrani, Vaillant, Ginefri, Ozenne, Abell, Poirier-Quinot and Quesson.)

The complexity of the MRI protocol is one of the factors limiting the clinical adoption of MR temperature mapping for real-time monitoring of cardiac ablation procedures and a push-button solution would ease its use. Continuous gradient echo golden angle radial acquisition combined with intra-scan motion correction and undersampled temperature determination could be a robust and more user-friendly alternative than the ultrafast GRE-EPI sequence which suffers from sensitivity to magnetic field susceptibility artifacts and requires ECG-gating. The goal of this proof-of-concept work is to establish the temperature uncertainty as well as the spatial and temporal resolutions achievable in an Agar-gel phantom and in vivo using this method. GRE radial golden angle acquisitions were used to monitor RF ablations in a phantom and in vivo in two sheep hearts with different slice orientations. In each case, 2D rigid motion correction based on catheter micro-coil signal, tracking its motion, was performed and its impact on the temperature imaging was assessed. The temperature uncertainty was determined for three spatial resolutions (1 × 1 × 3 mm 3 , 2 × 2 × 3 mm 3 , and 3 × 3 × 3 mm 3 ) and three temporal resolutions (0.48, 0.72, and 0.97 s) with undersampling acceleration factors ranging from 2 to 17. The combination of radial golden angle GRE acquisition, simultaneous catheter tracking, intra-scan 2D motion correction, and undersampled thermometry enabled temperature monitoring in the myocardium in vivo during RF ablations with high temporal (< 1 s) and high spatial resolution. The temperature uncertainty ranged from 0.2 ± 0.1 to 1.8 ± 0.2 °C for the various temporal and spatial resolutions and, on average, remained superior to the uncertainty of an EPI acquisition while still allowing clinical monitoring of the RF ablation process. The proposed method is a robust and promising alternative to EPI acquisition to monitor in vivo RF cardiac ablations. Further studies remain required to improve the temperature uncertainty and establish its clinical applicability., (© 2022. The Author(s).)

Purpose: To propose a MR-thermometry method and associated data processing technique to predict the maximal RF-induced temperature increase near an implanted wire for any other MRI sequence., Methods: A dynamic single shot echo planar imaging sequence was implemented that interleaves acquisition of several slices every second and an energy deposition module with adjustable parameters. Temperature images were processed in real time and compared to invasive fiber-optic measurements to assess accuracy of the method. The standard deviation of temperature was measured in gel and in vivo in the human brain of a volunteer. Temperature increases were measured for different RF exposure levels in a phantom containing an inserted wire and then a MR-conditional pacemaker lead. These calibration data set were fitted to a semi-empirical model allowing estimation of temperature increase of other acquisition sequences., Results: The precision of the measurement obtained after filtering with a 1.6x1.6 mm2 in plane resolution was 0.2°C in gel, as well as in the human brain. A high correspondence was observed with invasive temperature measurements during RF-induced heating (0.5°C RMSE for a 11.5°C temperature increase). Temperature rises of 32.4°C and 6.5°C were reached at the tip of a wire and of a pacemaker lead, respectively. After successful fitting of temperature curves of the calibration data set, temperature rise predicted by the model was in good agreement (around 5% difference) with measured temperature by a fiber optic probe, for three other MRI sequences., Conclusion: This method proposes a rapid and reliable quantification of the temperature rise near an implanted wire. Calibration data set and resulting fitting coefficients can be used to estimate temperature increase for any MRI sequence as function of its power and duration., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: Marylene Delcey and Wadie Ben Hassen are employees of Siemens Healthcare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

The non-equilibrium dynamics of electrons and nuclei govern the function of photoactive materials. Disentangling these dynamics remains a critical goal for understanding photoactive materials. Here we investigate the photoinduced dynamics of the [Fe(bmip) 2 ] 2+ photosensitizer, where bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)-pyridine, with simultaneous femtosecond-resolution Fe Kα and Kβ X-ray emission spectroscopy (XES) and X-ray solution scattering (XSS). This measurement shows temporal oscillations in the XES and XSS difference signals with the same 278 fs period oscillation. These oscillations originate from an Fe-ligand stretching vibrational wavepacket on a triplet metal-centered ( 3 MC) excited state surface. This 3 MC state is populated with a 110 fs time constant by 40% of the excited molecules while the rest relax to a 3 MLCT excited state. The sensitivity of the Kα XES to molecular structure results from a 0.7% average Fe-ligand bond length shift between the 1 s and 2p core-ionized states surfaces.