PPT-G16.4427 Practical MRI 1

Pulse Design for Parallel MR Transmission Outline Kspace analysis of small tipangle excitation RF shimming and Parallel MR Transmission B 1 mapping Accelerated MR excitations Homogeneity and SAR minimization. *Correspondingauthor.Tel.:+33-1-4427-6873;Fax:+33-1-4427-2481;E-mail:cj@ccr.jussieu.frEPSL542619-4-00EarthandPlanetaryScienceLetters178(2000)139^149 www.elsevier.com/locate/epsl perturbation,whichisse Transmit Arrays. Outline. Paper Review. RF . power amplifiers. Dual-tuned coils. Paper Review. Sidebar: Component coil combinations in arrays . ?. = * + * + * + *. Receive Arrays. Receive Arrays Are Critical in MRI. Advantages. SNR. Speed (parallel MRI). Volumetric coverage. Image quality. Simplicity. Disadvantages. Cost. Complexity. Data load. …. How many elements do we need?. Linjiong Zhou. 1,2. ,. . Minghua. Zhang. 1. , Steve . Goldhaber. 3. 1. . SoMAS. , Stony Brook University. 2. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences. 3. AMP, NCAR Earth System Laboratory. Basic pulse sequences. Gradient Echo (GRE). A class of pulse sequences that is primarily used for fast scanning. 3D volume imaging. Cardiac imaging. Gradient reversal on the frequency-encoded axis forms the echo. RF Coils’ Evaluation. Outline. Quality factor of an RF coil. Definition of SNR. Determinants of SNR in MRI. Methods to measure SNR in MRI. Ultimate intrinsic SNR. Coil performance maps. Quality Factor. Gary Hui Zhang, PhD. Microstructure Imaging Group. Centre for Medical Image Computing. Department of Computer Science. University College London. 26th of June, 2013. UCL Centre for Medical Image Computing. QUIZ. 3. : . Shoulder. Imaging. What is the . mean goal of . T1WS ?.  :. A : to analyze the . trophicity. and . /or the fatty . degeneration of the . muscles . of rotator cuff. Safety Background. The MRI scanner is a very large and powerful magnet. Most clinical scanners are 1.5 - 3 Tesla scanners. 3 Tesla = 30,000 gauss. Earths magnetic field ~ 0.5 gauss. MRI SAFETY. Magnetic Resonance Imaging (MRI) is one of the most powerful medical diagnostic technologies, combining strong magnetic fields with powerful computer image processing.. Safety Background. The MRI scanner is a very large and powerful magnet. Most clinical scanners are 1.5 - 3 Tesla scanners. 3 Tesla = 30,000 gauss. Earths magnetic field ~ 0.5 gauss. MRI SAFETY. Magnetic Resonance Imaging (MRI) is one of the most powerful medical diagnostic technologies, combining strong magnetic fields with powerful computer image processing.. Jenn Lacey, USGS (LSI-VC Co-Lead). 2017 CEOS Chair Initiative. SIT. -32 . Agenda Item. #10. ESA Headquarters – Paris, France. 25. th. -27. th. April 2017. Committee on Earth Observation Satellites. Magnetic Field. While MRI is considered to be a safe imaging technique, it is not without hazards. The magnet field will attract many ferromagnetic metals in an uncontrolled fashion and cause them to fly towards the magnets bore and turning them into high velocity projectiles. The bore of the magnet is where the fringe field is strongest, as all the lines of force are constricted and their relative strengths heightened. Various objects can be considered projectiles. Nassir F. Marrouche, MD. , Oussama . Wazni. , MD, Tom Greene, PhD, J Michael Dean, MD, Eugene . Kholmovski. , PhD, Moussa Mansour, MD, Hugh Calkins, MD, Francis . Marchlinski. , MD, David Wilber, MD, Gerhard . Magnetic Resonance Imaging (MRI) is a painless and harmless examination. This type of scan uses a powerful magnetic field and radio frequencies. It does not use Xrays. It isa technique that allows do