Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Reexamination Certificate
2007-08-28
2007-08-28
Shrivastav, Brij B. (Department: 2859)
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
C324S318000
Reexamination Certificate
active
11451605
ABSTRACT:
The invention relates to the obtainment of magnetic resonance measurement data for the reproduction of an image of an object volume, illustrating the contrast between volume elements (voxels) which differ from one another in the parameter vectors Piof the magnetic resonance property of the respective inherent substance i. The object volume which is to be imaged is subjected within a stationary magnetic field to a sequence of repetitive blocks of effects, each containing an RF-pulse with a flip angle α<90° and magnetic field gradients, in order to obtain in each block N≧1 location-coded measurement signals and to achieve sufficient intravoxel dephasing, wherein the phase φ(k) of the RF-pulse is changed from block to block in accordance with the rulein-line-formulae description="In-line Formulae" end="lead"?φk−φk-1=φ+k*Φ,in-line-formulae description="In-line Formulae" end="tail"?where k is the running index of the blocks within the sequence and φ is a randomly selected phase angle. In accordance with the invention, for the sequence parameter Φ a value Φcis selected, in which the set {Sij} of the difference valuesSij=∑n=1N[Sn(Φ,Q,Pi)-Sn(Φ,Q,Pj)]is optimized in accordance with a selected criterion K ({Sij}), where n with1≦n≦N is the running index of the measurement signals detected within a respective block, Sn(Φ,Q,Pi) or Sn(Φ,Q,Pj) is the value of the transversal magnetization of the voxels, which contain the substance i or j, in the condition of dynamic equilibrium at the point in time of the maximum of the nth measurement signal, Q stands for the values of the remaining sequence parameters, and {Sij} includes all desired pairs of substances i and j.
REFERENCES:
patent: 5408180 (1995-04-01), Mistretta et al.
patent: 5602477 (1997-02-01), McCarthy et al.
patent: 6912415 (2005-06-01), Kruger et al.
patent: 2005/0270026 (2005-12-01), Guthausen et al.
patent: 2007/0035299 (2007-02-01), Deimling
Ganter, Steady State of Gradient Echo Sequences with Radiofrequency Phase Cycling: Analytical Solution, Contrast Enhancement with Partial Spoiling, 2006, Magnetic Resonance in Medicine 55:98-107, pp. 98-107.
Denolin et al, On the Calculation and Interpretation of Signal Intensity in Echo-Shifted Sequences, 2004, Magnetic Resonance in Medicine 41:123, pp. 123-134.
Nitz, “Magnetresonanztomographie”, Siemens AG etc., 2003, pp. 745-766.
Zur et al, Spoiling of Transverse Magentization in Steady-State Sequences, 1991, Magnetic Resonance in Medicine 21, pp. 251-263.
Dennison, Schultz & MacDonald
Shrivastav Brij B.
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