Oh, and while I'm at it, here is one more Hydrogen Alpha image of NGC 4945, at a different scaling;
This image, which was taken with the Magellan Baade telescope and MMTF in 2006, shows H-alpha emission from the massive UV-luminous stars that trace some of the spiral arms. Also, it looks like this image (probably) does show the cone of H-alpha emission near to the nucleus, which marks an outflow of gas from the active central region of this galaxy.