TY - JOUR
T1 - Influence of magnetic field strength on t2* decay and phase effects in gradient echo mri of vertebral bone marrow
AU - Parizel, Paul M.
AU - Van Riet, Bavo
AU - Van Hasselt, Boudewijn A.A.M.
AU - Van Goethem, Johan W.
AU - Van Den Hauwe, Luc
AU - Dijkstra, Homme A.J.
AU - Van Wiechen, Peter J.
AU - De Schepper, Arthur M.
PY - 1995/1/1
Y1 - 1995/1/1
N2 - Objective: The goal of this study was twofold: First, to quantify the influence of magnetic field strength (fl0) on T2* and T2susceptibmty relaxation rates in vertebral bone marrow; and second, to determine the significance of in-phase/ out-of-phase phenomena in GE MRI as a function of TEs at different B0 values. Materials and Methods: Magnetic resonance imaging of the spine was performed at 1.5, 1.0, and 0.2 T using a GE sequence (2D-FLASH) with variable TE. Vertebral body signal intensities were measured and plotted against TE values. These curves were used to calculate T2* decay of bone marrow at different B0 values. Results: At all field strengths, we observed exponential signal decay, modulated by a cosine function, the periodicity of which was proportional to B0. The T2* values of vertebral bodies were 9.7 ± 1.8 ms at 1.5 T, 17.2 ± 2.4 ms at 1.0 T, and 53 ± 5 ms at 0.2 T. True T2 relaxation time (independent of field strength) was 62 ± 4 ms. The T2susccptibmty was 11.7 ms at 1.5 T, 24.8 ms at 1.0 T, and 585 ms at 0.2 T. Conclusion: We conclude that at low B0, susceptibility effects become less important and T2* approaches true T2 relaxation.
AB - Objective: The goal of this study was twofold: First, to quantify the influence of magnetic field strength (fl0) on T2* and T2susceptibmty relaxation rates in vertebral bone marrow; and second, to determine the significance of in-phase/ out-of-phase phenomena in GE MRI as a function of TEs at different B0 values. Materials and Methods: Magnetic resonance imaging of the spine was performed at 1.5, 1.0, and 0.2 T using a GE sequence (2D-FLASH) with variable TE. Vertebral body signal intensities were measured and plotted against TE values. These curves were used to calculate T2* decay of bone marrow at different B0 values. Results: At all field strengths, we observed exponential signal decay, modulated by a cosine function, the periodicity of which was proportional to B0. The T2* values of vertebral bodies were 9.7 ± 1.8 ms at 1.5 T, 17.2 ± 2.4 ms at 1.0 T, and 53 ± 5 ms at 0.2 T. True T2 relaxation time (independent of field strength) was 62 ± 4 ms. The T2susccptibmty was 11.7 ms at 1.5 T, 24.8 ms at 1.0 T, and 585 ms at 0.2 T. Conclusion: We conclude that at low B0, susceptibility effects become less important and T2* approaches true T2 relaxation.
KW - Magnetic resonance imaging
KW - Magnetic resonance imaging, physics
KW - Magnetic resonance imaging, techniques
UR - http://www.scopus.com/inward/record.url?scp=0029024598&partnerID=8YFLogxK
M3 - Article
C2 - 7790560
AN - SCOPUS:0029024598
SN - 0363-8715
VL - 19
SP - 465
EP - 467
JO - Journal of Computer Assisted Tomography
JF - Journal of Computer Assisted Tomography
IS - 3
ER -