Computational techniques for the simulation and evaluation of hydrogen NMR imaging methods

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6793683

Hylton, N M

Nuclear Magnetic Resonance Imaging of protons has become an imaging modality of proven diagnostic utility. The efficacy of the technique lies in the dependence of the NMR signal intensity on multiple parameters. The signal will depend on the intrinsic properties of the tissue, i.e., hydrogen density N(H), and the parameters characterizing relaxation, T1 and T2 and acquisition parameters, i.e., the interval between excitations, TR, and the delay between excitation and signal readout, TE. These multiple dependences provide the flexibility and therefore the potential of NMR imaging as well as the complexity involved in understanding and optimizing imaging methods. This dissertation describes techniques for evaluating the impact of these variables on image signal intensity and contrast. The NMR signal intensity is modeled for spin echo and inversion recovery imaging protocols by finding the solution to the Bloch equations under the boundary conditions imposed by the sequence. These equations describe the motion of the bulk magnetization in response to magnetic stimulations. The models are used to generate contour maps which illustrate the functional behavior of the response as two or more parameters change. These maps can be used to predict the useful imaging regime for best contrast between the tissue of interest and its surrounding background tissue. With an acquired set of data sufficient to extract hydrogen density and relaxation information, it is possible to calculate images at new acquisition parameters.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6793683
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
BARYONS
BLOCH EQUATIONS
CALCULATION METHODS
DIAGNOSTIC TECHNIQUES
ELEMENTARY PARTICLES
EQUATIONS
EVALUATION
FERMIONS
HADRONS
MAGNETIC RESONANCE
NMR IMAGING
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
PROTONS
RESONANCE
SIGNAL CONDITIONING
SIMULATION
SPIN ECHO