Lvovsky Y.,General Electric |
Stautner E.W.,General Electric |
Zhang T.,General Electric |
Zhang T.,Alltech Medical Systems
Superconductor Science and Technology | Year: 2013
A review of non-traditional approaches and emerging trends in superconducting magnets for MRI is presented. Novel technologies and concepts have arisen in response to new clinical imaging needs, changes in market cost structure, and the realities of newly developing markets. Among key trends are an increasing emphasis on patient comfort and the need for 'greener' magnets with reduced helium usage. The paper starts with a brief overview of the well-optimized conventional MR magnet technology that presently firmly occupies the dominant position in the imaging market up to 9.4 T. Non-traditional magnet geometries, with an emphasis on openness, are reviewed. The prospects of MgB2 and high-temperature superconductors for MRI applications are discussed. In many cases the introduction of novel technologies into a cost-conscious commercial market will be stimulated by growing needs for advanced customized procedures, and specialty scanners such as orthopedic or head imagers can lead the way due to the intrinsic advantages in their design. A review of ultrahigh-field MR is presented, including the largest 11.7 T Iseult magnet. Advanced cryogenics approaches with an emphasis on low-volume helium systems, including hermetically sealed self-contained cryostats requiring no user intervention, as well as future non-traditional non-helium cryogenics, are presented. © 2013 IOP Publishing Ltd.
Wang Z.M.,Alltech Medical Systems
2013 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2013 | Year: 2013
The successfully commercial application of superconductivity is the superconducting magnet in the magnetic resonance imaging systems of $7 billion business global annually. Today over 35000 systems are used around the world and half millions medical imaging scanning are taken every day. As the most costly part of the system, superconducting magnet has many special requirements in order to perform the job, such as field of view(FOV), field strength, field uniformity, field persistence, stray field, shielding of external disturbance and boil-off rate of the Liquid Helium, etc. Some of these requirements are contradiction with each other, so a trade off is usually needed in the design and manufacturing. Alltech Medical Systems successfully developed 1.5 T superconducting magnet special for MRI system on Jan. 7, 2009 in Chengdu, China and more than over a hundred systems have been delivered to customs. Development of 3 T and 7 T (small bore) MRI systems are also in progress. © 2013 IEEE.
Wu Z.,Alltech Medical Systems |
Chen W.,University of California at Los Angeles |
Davidson Ward S.L.,University of California at Los Angeles |
Nayak K.S.,University of California at Los Angeles
Journal of Magnetic Resonance Imaging | Year: 2016
Purpose: To develop and demonstrate a real-time MRI method for assessing upper airway collapsibility in sleep apnea. Materials and Methods: Data were acquired on a clinical 3 Tesla scanner using a radial CAIPIRIHNA sequence with modified golden angle view ordering and reconstructed using parallel imaging and compressed sensing with temporal finite difference sparsity constraint. Segmented airway areas together with synchronized facemask pressure were used to calculate airway compliance and projected closing pressure, Pclose, at four axial locations along the upper airway. This technique was demonstrated in five adolescent obstructive sleep apnea (OSA) patients, three adult OSA patients and four healthy volunteers. Heart rate, oxygen saturation, facemask pressure, and abdominal/chest movements were monitored in real-time during the experiments to determine sleep/wakefulness. Results: Student's t-tests showed that both compliance and Pclose were significantly different between healthy controls and OSA patients (P<0.001). The results also suggested that a narrower airway site does not always correspond to higher collapsibility. Conclusion: With the proposed methods, both compliance and Pclose can be calculated and used to quantify airway collapsibility in OSA with an awake scan of 30min total scan room time. © 2015 Wiley Periodicals, Inc.
Alltech Medical Systems | Date: 2015-03-20
Alltech Medical Systems | Entity website
1.5T Alltechadmin2014-07-30 A A A 2014730 1 ...