Biomaterial Database

Prepolarized fast spin-echo pulse sequence for low-field MRI. 2007

C Kegler, and H C Seton, and J M S Hutchison

Department of Bio-Medical Physics and Bio-Engineering, University of Aberdeen, Aberdeen, Scotland, UK. c.kegler@biomed.abdn.ac.uk

Clinical MRI systems use magnetic fields of at least 0.5T to take advantage of the increase in signal-to-noise ratio (SNR) with B(0). Low-field MRI apparatus is less expensive and offers the potential benefit of improved T(1) contrast between tissues. The poor inherent SNR at low field can be offset by incorporating prepolarizing field pulses with the MRI pulse sequence. The prepolarizing field does not need to be as homogeneous as the detection field, so it can be generated by a relatively inexpensive electromagnet. Prepolarizing hardware for a 0.01T MRI system was developed together with a prepolarized MRI pulse sequence that incorporates fast imaging techniques to reduce acquisition times by a factor of 5 relative to standard methods. Comparison images of test objects show that most of the enhanced SNR is retained with the fast method. Low-field images of a human wrist acquired using the fast prepolarized method are also shown.

UI	MeSH Term	Description	Entries
D008279	Magnetic Resonance Imaging	Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.	Chemical Shift Imaging,MR Tomography,MRI Scans,MRI, Functional,Magnetic Resonance Image,Magnetic Resonance Imaging, Functional,Magnetization Transfer Contrast Imaging,NMR Imaging,NMR Tomography,Tomography, NMR,Tomography, Proton Spin,fMRI,Functional Magnetic Resonance Imaging,Imaging, Chemical Shift,Proton Spin Tomography,Spin Echo Imaging,Steady-State Free Precession MRI,Tomography, MR,Zeugmatography,Chemical Shift Imagings,Echo Imaging, Spin,Echo Imagings, Spin,Functional MRI,Functional MRIs,Image, Magnetic Resonance,Imaging, Magnetic Resonance,Imaging, NMR,Imaging, Spin Echo,Imagings, Chemical Shift,Imagings, Spin Echo,MRI Scan,MRIs, Functional,Magnetic Resonance Images,Resonance Image, Magnetic,Scan, MRI,Scans, MRI,Shift Imaging, Chemical,Shift Imagings, Chemical,Spin Echo Imagings,Steady State Free Precession MRI
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014953	Wrist	The region of the upper limb between the metacarpus and the FOREARM.	Wrists
D019047	Phantoms, Imaging	Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)	Phantoms, Radiographic,Phantoms, Radiologic,Radiographic Phantoms,Radiologic Phantoms,Phantom, Radiographic,Phantom, Radiologic,Radiographic Phantom,Radiologic Phantom,Imaging Phantom,Imaging Phantoms,Phantom, Imaging