Phase-contrast CT images of polystyrene spheres (8 µm diameter) pasted on a glass fiber (5 µm diameter). (a) 3D rendered view, (b) virtual cross-sectional CT image in the horizontal plane perpendicular to the rotation axis and (c) virtual cross-sectional CT image in the vertical direction parallel to the rotation axis. Voxel size is 175 nm × 175 nm (H) × 172 nm (V). Horizontal translation scan pitch is 175 nm, exposure time is 30 ms and dwell time is 33.3 ms. Number of projections is 501 for 180° rotation. Total measurement time for a tomographic scan is approximately 200 min.