View clinical trials related to MRI.
Filter by:Introduction: The incidence of occult cervical lymph node metastases (OCLNM) is reported to be 20%-30% in early-stage oral cancer and oropharyngeal cancer. There is a lack of an accurate diagnostic method to predict occult lymph node metastasis and to help surgeons make precise treatment decisions. Aim: To construct and evaluate a preoperative diagnostic method to predict occult lymph node metastasis (OCLNM) in early-stage oral and oropharyngeal squamous cell carcinoma (OC and OP SCC) based on deep learning features (DLFs) and radiomics features. Methods: A total of 319 patients diagnosed with early-stage OC or OP SCC were retrospectively enrolled and divided into training, test and external validation sets. Traditional radiomics features and DLFs were extracted from their MRI images. The least absolute shrinkage and selection operator (LASSO) analysis was employed to identify the most valuable features. Prediction models for OCLNM were developed using radiomics features and DLFs. The effectiveness of the models and their clinical applicability were evaluated using the area under the curve (AUC), decision curve analysis (DCA) and survival analysis.
Since January 2010, a new magnetic resonance imaging scanner (Philips 3T, Achieva) is installed on the Baudot Building in Toulouse hospital. This tool, is completely dedicated to the research. It was installed with sequences RMN supplied by the manufacturer. Imagers also contain an instrumentation susceptible to evolution and/or to adjustment (antennas radio frequency, sheath of gradients, elements of physiological monitoring (for example control of the breath), regulation of the homogeneity of the magnetic field). This MRI scanner and this instrumentation are used for anatomical examinations or for paradigms of cognitiveresearch (for example of detection of intellectual activations following simple stimuli of fingers movement, visual tasks, or of mental processes). The developpement of this equipment is going to favor the emergence of numerous projects and new themes, up to there adressed by other techniques (psychophysics, EEG). To obtain good quality signals and know the practical limits of this imager, it is thus necessary that the researchers doctors, physicists and engineers, can finalize on volunteers' significant number, all the sequences RMN necessary for the use of these tools for the research. These developments are going to get organized around four main axes: 1 the control of the geometrical distortions (generated by the introduction of an object within the magnetic field) 2 Optimization of the parameters of sequences to improve the contrast and the spatial resolution of the obtained images 3 the development of new sequences 4 the feasibility study of the protocols of functional MRI
3 d scan sequence can realize continuous thin layer scanning, the thinnest layer thickness of 0.5 mm, to reduce the effects of partial volume effect and improve the spatial resolution image, the other 3 d sequence can according to need to multiplanar reconstruction based on the original image, the image of the watch is no longer limited to a fixed plane, and can avoid repeated scanning, reducing overall inspection time. Initially, 3D MRI uses gradient echo sequences (3D-GRE). Although the scan time of 3D-GRE is acceptable and has a high spatial resolution, the contrast between tissues is poor. In recent years, is voxel 3D fast spin-echo sequence (3D-FSE) has become an alternative 3D scanning sequence. Compared with the 3D-GRE sequence, 3D-FSE has better-intertissued contrast. However, there are still some problems in the application of 3D sequence in clinical practice. On the one hand, although 3D sequence reduces the overall scanning time, it increases the single scanning time, so it is easy to produce motion artifacts. On the other hand, although many studies have demonstrated the diagnostic efficacy of 3D sequences in the diagnosis of common intraarticular structural injuries, especially in the diagnosis of knee cartilage injuries, the diagnostic value of 3D sequences is comparable to that of conventional 2D-FSE sequences, but the evidence on whether 3D sequences can replace 2D sequences is still insufficient. Recently, a new fast signal acquisition technology -- Compressed Sensing (Compressed Sensing) technology has been gradually applied to many kinds of MRI sequences, and its application in 3D sequences can greatly shorten the single scan time. In this study, Modulated Flip Angle Technique in Refocused Imaging with Extended Echo was applied by United Imaging Co., Ltd. (Compressed Sensing) Train, 3D-Matrix), which is a fast self-selected echo sequence based on variable turn Angle technology, and its single scan time can be shortened to 5 minutes. 3 d sequence to more systematic evaluation on sports injury of knee joint application value, the investigators will study from within the bony structure of knee joint injury, joint structure damage and injury of the surrounding support structure aspects to discuss the diagnosis effect, and with arthroscopy for the gold standard to evaluate the accuracy of the 3 d structure within the sequence in the diagnosis of knee joint injury.
Patients who have agreed to participate in the study will complete the MRI protocol as part of routine care, to which two additional sequences of 6 minutes duration will be added. The MRI of routine care includes at least the following sequences: - 3D T1 TFE 1.0 isotropic (2 minutes) - T2 TSE (2 minutes) - 3D FLAIR pre-injection (opt) (3 minutes) - 3D FLAIR post-injection (3 minutes) As part of the research, the following sequences will be acquired: - FABIR pre-injection (3 minutes) - FABIR post-injection (3 minutes) Patients hospitalized for a foreseeable duration of at least 24 hours will be offered participation in the longitudinal tab of the study, for which four non-injected MRI examinations will be performed. The examinations will be carried out remotely from the injected MRI (1h, 2h, 12h-15h, 24h-36h). These exams dedicated to research will include the following sequences for a maximum of 8 minutes: - 3D T1 TFE 1.0 isotropic (2 minutes) - 3D FLAIR (3 minutes) - FABIR (3 minutes)
An increasing number of studies have reported the use of dexmedetomidine in clinical practice. However, few studies have reported on the intranasal use of dexmedetomidine in radiological procedures The aim of this work is to compare the efficacy and safety of intranasal dexmedetomidine and intranasal midazolam in pediatrics undergoing MRI.
To explore whether there is a difference in the rate of tendon tear after hyperlipemia in tennis elbow patients and those with normal blood lipids after closed treatment, which provides clues for further exploration of its mechanism. 1. Collect data from 108 cases of tennis elbow patients treated at the Institute of Sports Medicine, Peking University Third Hospital from January 2010 to December 2018 at the Institute of Sports Medicine, Peking University Third Hospital. Statistics included the sex, age, BMI, number of closures, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein. 2. Retrieve the MRI imaging data of the above-mentioned patients, and use the extensor tendon at the humerus to see if there is a tear as an observation indicator. Analyze the difference of tendon tear after closed treatment in patients with high blood fat and normal blood fat.
The study's purpose is to validate STAGE images and, when applicable, their equivalence to conventional MRI through an assessment by a trained certified neuroradiologist in a clinical setting. For STAGE images without conventional equivalent, the neuroradiologist will determine if their contrasts, intensities, and quality are sufficient and meet expectations for images used in radiological reads of the brain. The study is a multi-center study in which STAGE can be assessed at sites with different MRI manufacturers and field strengths. Site names will be made available to the collaborators and participants. The sponsor is based out of Michigan, while participating sites may be located in other states. Any funding for the study will come from an industry source, SpinTech, Inc.
Diffusion tensor imaging (DTI) is a non-invasive MRI technique offering a functional approach that provides morphological information about the microstructures of the nerve roots. DTI is a widely used neuroimaging technique and is a current topic of research in the field of peripheral nerve imaging. The aim of this work is therefore to improve DTI sequences by specifically evaluating the contribution of the multiband technique in healthy volunteers.
Assess the reproductibility of PC-MRI for cerebrospinal fluid movements through the interventricular foramina on volunteer subjects.
Cricoid pressure is still considered as a standard of care in order to prevent the gastric regurgitation in full stomach surgery1. However, this attitude has been challenged in several case reports as oesophageal rupture, difficult intubation, and even failing to occlude the oesophagus. Moreover, in a large prospective randomized study , this maneuver has failed to show a definite benefit2. The lateral deviation to the left of the oeso deviate to the left side3,4 has led to the description of a new maneuver to compress directly the oesophagus at the low left paratracheal level. This maneuver has been shown to prevent gastric air insuflation during the ventilation. In the present study, the investigators aim to asses with an magnetic resonance imaging the compressibility of the oesophagus.