Novel Spherical Phantoms for Q-Ball Imaging Under In Vivo Conditions

作者：Moussavi Biugui Amir; Stieltjes Bram; Fritzsche Klaus; Semmler Wolfhard; Laun Frederik B^*

来源：Magnetic Resonance in Medicine, 2011, 65(1): 190-194.

DOI：10.1002/mrm.22602

• Q-ball imaging
• phantom
• diffusion weighted imaging

For the validation of complex diffusion imaging techniques like q-ball imaging that aim to resolve multiple fiber directions, appropriate phantoms are highly desirable. However, previous q-ball imaging phantoms had diffusion anisotropies well below those of in vivo white matter. In this work, fiber phantoms of well-defined geometry are presented. The fibers are wound on a spherical spindle yielding high packing densities and consequently high diffusion anisotropies (fractional anisotropy 0.93 +/- 0.02 at b = 500 s/mm(2)). Phantoms with 90 degrees and 45 degrees crossing angle were constructed both with two crossing types. In the "stacked" crossing, two fiber strings were wound consecutively to simulate two touching fibers, in the "interleaved" crossing, fibers were wound alternately. The stacked crossing allows the alteration of partial volumes, whereas the interleaved crossing provides constant partial volumes, allowing e.g. the easy alteration of the SNR by varying the slice thickness. Exemplary q-ball imaging validation measurements using different b-values and slice thicknesses are presented. Magn Reson Med 65:190-194, 2011.

• 出版日期2011-1