I quite like the "Glandulae parathyreoideae von hinten gesehen", I feel it's particularly clear, has some colour, and is not cluttered with the surrounding structures. I'd support including this but hope we can still retain the first lead image. I particularly like the current lead image because I think it is simple, modern, colourful, and conveys an idea about where the glands are and is, I feel, quite engaging to lay readers.