The upcoming new perspective of the high redshift Universe in the 21 cm line of atomic hydrogen opens possibilities to explore topics of spiral disk evolution, hitherto reserved for the optical regime.

The growth of spiral gas disks over Cosmic time can be explored with the new generation of radio telescopes, notably the SKA, as accurately as with the Hubble Space Telescope for stellar disks. Since the atomic hydrogen gas is the building block of these disks, it should trace their formation accurately.

Morphology of HI disks can now equally be quantified over Cosmic time. In studies of HST deep fields, the optical or UV morphology of high-redshift objects have been characterised using a few quantities: concentration (C), asymmetry (A), smoothness (S), second-order-moment (M20), the GINI coefficient (G), and Ellipticity (E). I will discuss the applicability of such quantifiers on future HI fields of high-redshift objects and their use to identify interacting, disturbed, star-forming and quiescent spiral disks.