Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Patent
1998-10-28
2000-11-14
Oda, Christine
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
324307, 600410, G01V 300
Patent
active
061474924
ABSTRACT:
A magnetic resonance imaging (MRI) method and apparatus is disclosed for quantitating water and fat content of tissues using nuclear magnetic resonance (NMR) image data of the tissues and for producing an images indicative of the fat and water fractions of the total water and fat content of the tissues. To reduce the overall scanning time, a quadruple field-echo imaging scan sequence is used to acquire the image data. Each imaging sequence comprises an initial slice-selective RF excitation pulse followed by four magnetic field read-out gradient pulses and the acquisition of four separate field-echoes. Each field-echo is generated through the controlled timing and polarity of an applied read gradient. The period of time between field-echoes (T) is selected according to the chemical-shift difference between water and fat signals so that the two signals develop between them an angular phase difference of .pi. radians (180.degree.) during the inter-echo time. Resulting field-echo signals acquired from two scans, one scan preferably having a sequence repetition period (TR) twice that of the other, are analyzed to determine the tissue fat and water fractions for each pixel and produce corresponding fraction images.
REFERENCES:
patent: 5256967 (1993-10-01), Foo et al.
patent: 5347216 (1994-09-01), Foo
patent: 5594336 (1997-01-01), Gullapalli et al.
J. Ma et al "A Single-Scan Imaging Technique for Measurement of the Relative Concentrations of Fat and Water Protons and Their Transverse Relaxation Times," Journal of Magnetic Resonance 125, 92-101 (1997), Article No. MN961086, pp. 92-101.
W. Zhang et al "Separation of Water and Fat MR Images in a Single Scan at .35 T Using `Sandwich` Echoes," JMRI Nov./Dec. 1996, vol. 6, No. 6, pp. 909-917.
Vogler III, et al "Bone Marrow Imaging," Radiology, vol. 168, No. 3 (1988) pp. 679-691.
Buxton et al "Quantitative Proton Chemical-Shift Imaging," Magnetic Resonance in Medicine 3, 881-900 (1986).
Rosen et al "Hematologic Bone Marrow Disorders: Quantitative Chemical Shift MR Imaging," Radiology, Dec. 1988, pp. 799-804.
Johnson et al "Quantitative Chemical Shift Imaging of Vertebral Bone Marrow in Patients with Gaucher Disease," Radiology, vol. 182, No. 2, Feb. 1992, pp. 451-455.
Jensen et al "Localized in Vivo Proton Spectroscopy of the Bone Marrow in Patients with Leukemia," Magnetic Resonance Imaging, vol. 8, pp. 779-789 (1990).
Carlson Joseph W.
Zhang Weiguo
Oda Christine
Shrivastav Brij B.
Toshiba America MRI Inc.
LandOfFree
Quantitative MR imaging of water and fat using a quadruple-echo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Quantitative MR imaging of water and fat using a quadruple-echo , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantitative MR imaging of water and fat using a quadruple-echo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2068401