# Non-Cartesian trajectories

k-space covered by rotating the readout rather than by displacing it. The
sampling is no longer on a lattice, so how densely it is covered and how
long the traversal takes are both measured rather than prescribed.

| Page | What it establishes |
| --- | --- |
| {doc}`/generated/gallery/04-non-cartesian/01_radial` | Spokes in place of phase encodes: the azimuthal gap they leave at the edge of k-space, and what golden-angle ordering changes. |
| {doc}`/generated/gallery/04-non-cartesian/02_spiral` | Which of the amplitude, slew-rate and receiver limits determines the duration of a spiral arm, read off the waveform each design produces. |

```{toctree}
:hidden:

/generated/gallery/04-non-cartesian/01_radial
/generated/gallery/04-non-cartesian/02_spiral
```