is there a way to convert Garmin img files to qct memory map files? I’m trying to get a topo map for NW Italy (that I can use on Memory Map)

C

Can memory map open any other format? You may be able to go via a open street map format to something it will opne.

Its not really possible, they are very different formats. Garmin img files are a vector format, Memory Map qct are a bitmap. Memory Map can open a few other bitmap formats (eg TIFF), but no vector formats.
You could manually convert them, eg by taking screenshots of the Garmin maps, then georeferencing them to load into Memory Map. But that would be rather time consuming. Also they would need much more memory than the Garmin img files.

Depends on what you want to do. Probably easiest just to load the maps in Garmin BaseCamp (or maybe QMapShack). It has mostly similar features to Memory Map.

Any particular reason why it has to be used with Memory Map?

Have you had a look at the area on Open Cycle Map? If that’s sufficent, there are more options available (In fact, in some versions of Memory Map, you can get Open Cycle Map data direct off the Memory Map Digital Map Shop…)