  Progressive acquisition of slowly-scanned images is desirable for drift
correction and real-time visualization. Interlacing methods are common
approaches to storing and transmitting data on rectilinear grids, and here we
propose using them for acquisition in scanning-mode image modalities.
Especially in these cases, it is essential to make optimal use of sample points
to speed up the scan and reduce damage to the subject. It has long been known
that optimal sampling of band-limited signals is achieved using hexagonal
scanning grids. In this note, we demonstrate two new methods for interlacing
hexagonal grids, which enable early full field-of-view imaging with optimal
sampling and resolution doubling.
