  We present a flyscan compatible acquisition scheme for three-modal X-Ray
Computed Tomography (CT) with two-dimensional phase sensitivity. Our approach
is demonstrated using a "beam tracking" setup, through which a sample's
attenuation, phase (refraction) and scattering properties can be measured from
a single frame, providing three complementary contrast channels. Up to now,
such setups required the sample to be stepped at each rotation angle to sample
signals at an adequate rate, to prevent resolution losses, anisotropic
resolution, and under-sampling artefacts. However, the need for stepping
necessitated a step-and-shoot implementation, which is affected by motors
overheads and increases the total scan time. By contrast, our proposed scheme,
by which continuous horizontal and vertical translations of the sample are
integrated with its rotation (leading to a "cycloidal-spiral" trajectory), is
fully compatible with continuous scanning (flyscans). This leads to greatly
reduced scan times while largely preserving image quality and isotropic
resolution.
