9,614 research outputs found
A multispeaker dataset of raw and reconstructed speech production real-time MRI video and 3D volumetric images
Real-time magnetic resonance imaging (RT-MRI) of human speech production is
enabling significant advances in speech science, linguistics, bio-inspired
speech technology development, and clinical applications. Easy access to RT-MRI
is however limited, and comprehensive datasets with broad access are needed to
catalyze research across numerous domains. The imaging of the rapidly moving
articulators and dynamic airway shaping during speech demands high
spatio-temporal resolution and robust reconstruction methods. Further, while
reconstructed images have been published, to-date there is no open dataset
providing raw multi-coil RT-MRI data from an optimized speech production
experimental setup. Such datasets could enable new and improved methods for
dynamic image reconstruction, artifact correction, feature extraction, and
direct extraction of linguistically-relevant biomarkers. The present dataset
offers a unique corpus of 2D sagittal-view RT-MRI videos along with
synchronized audio for 75 subjects performing linguistically motivated speech
tasks, alongside the corresponding first-ever public domain raw RT-MRI data.
The dataset also includes 3D volumetric vocal tract MRI during sustained speech
sounds and high-resolution static anatomical T2-weighted upper airway MRI for
each subject.Comment: 27 pages, 6 figures, 5 tables, submitted to Nature Scientific Dat
Comparison of Cartesian and Non-Cartesian Real-Time MRI Sequences at 1.5T to Assess Velar Motion and Velopharyngeal Closure during Speech
This project is funded by CLEFT (CLEFT-2013-1) and an Institute of Physics and Engineering in Medicine (IPEM) Innovation and Research Award for computer equipment. MEM is partly (20%) funded by the National Institute for Health Research Cardiovascular Biomedical Research Unit at Barts. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript
Real-Time Magnetic Resonance Imaging
Realâtime magnetic resonance imaging (RTâMRI) allows for imaging dynamic processes as they occur, without relying on any repetition or synchronization. This is made possible by modern MRI technology such as fastâswitching gradients and parallel imaging. It is compatible with many (but not all) MRI sequences, including spoiled gradient echo, balanced steadyâstate free precession, and singleâshot rapid acquisition with relaxation enhancement. RTâMRI has earned an important role in both diagnostic imaging and image guidance of invasive procedures. Its unique diagnostic value is prominent in areas of the body that undergo substantial and often irregular motion, such as the heart, gastrointestinal system, upper airway vocal tract, and joints. Its value in interventional procedure guidance is prominent for procedures that require multiple forms of softâtissue contrast, as well as flow information. In this review, we discuss the history of RTâMRI, fundamental tradeoffs, enabling technology, established applications, and current trends
Cardiac magnetic resonance assessment of central and peripheral vascular function in patients undergoing renal sympathetic denervation as predictor for blood pressure response
Background:
Most trials regarding catheter-based renal sympathetic denervation (RDN) describe a proportion of patients without blood pressure response. Recently, we were able to show arterial stiffness, measured by invasive pulse wave velocity (IPWV), seems to be an excellent predictor for blood pressure response. However, given the invasiveness, IPWV is less suitable as a selection criterion for patients undergoing RDN. Consequently, we aimed to investigate the value of cardiac magnetic resonance (CMR) based measures of arterial stiffness in predicting the outcome of RDN compared to IPWV as reference.
Methods:
Patients underwent CMR prior to RDN to assess ascending aortic distensibility (AAD), total arterial compliance (TAC), and systemic vascular resistance (SVR). In a second step, central aortic blood pressure was estimated from ascending aortic area change and flow sequences and used to re-calculate total arterial compliance (cTAC). Additionally, IPWV was acquired.
Results:
Thirty-two patients (24 responders and 8 non-responders) were available for analysis. AAD, TAC and cTAC were higher in responders, IPWV was higher in non-responders. SVR was not different between the groups. Patients with AAD, cTAC or TAC above median and IPWV below median had significantly better BP response. Receiver operating characteristic (ROC) curves predicting blood pressure response for IPWV, AAD, cTAC and TAC revealed areas under the curve of 0.849, 0.828, 0.776 and 0.753 (pâ=â0.004, 0.006, 0.021 and 0.035).
Conclusions:
Beyond IPWV, AAD, cTAC and TAC appear as useful outcome predictors for RDN in patients with hypertension. CMR-derived markers of arterial stiffness might serve as non-invasive selection criteria for RDN
Accurate glottal model parametrization by integrating audio and high-speed endoscopic video data
The aim of this paper is to evaluate the effectiveness of using video data for voice source parametrization in the representation of voice production through physical modeling. Laryngeal imaging techniques can be effectively used to obtain vocal fold video sequences and to derive time patterns of relevant glottal cues, such as folds edge position or glottal area. In many physically based numerical models of the vocal folds, these parameters are estimated from the inverse filtered glottal flow waveform, obtained from audio recordings of the sound pressure at lips. However, this model inversion process is often problematic and affected by accuracy and robustness issues. It is here discussed how video analysis of the fold vibration might be effectively coupled to the parametric estimation algorithms based on voice recordings, to improve accuracy and robustness of model inversio
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