Tsang-Wei Tu1,2, Matthew D. Budde3,
James D. Quirk2, Sheng-Kwei Song2
1Mechanical, Aerospace and Structural
Engineering, Washington University in St. Louis, Saint Louis, MO, United
States; 2Radiology, Washington University in St. Louis, Saint
Louis, MO, United States; 3Radiology and Imaging Science, National
Institutes of Health Clinical Center, Bethesda, MD, United States
Diffusion-weighted
multiple spin echo (DW-MSE) sequences have been introduced to improve DTI
quality without increasing scan time by combining the images of multiple
echoes. Since complex image combination can cause artifacts due to phase
variations between echoes, magnitude images are often employed. But this
results in a noise distribution change from Gaussian to Rician leading to a
SNR decline and biased tensor estimation. Our results demonstrate that
absorption-mode addition of multiple echoes obtained using the DW-MSE
sequence improves SNR by nearly 50% compared to a conventional DW-SE sequence
and also overcomes the problem of phase variations without Rician noise
complications.
Keywords