I have seen some classic Apple product placements but there are also names of some medical equipment manufacturers shown, e.g. on CT Machines.
Are there product placements of medical equipment in House?
I say probably because I haven't yet found a source specifically for House.
But, a similar show in the UK called Casualty, which is a long-running medical drama, also uses a range of medical equipment. A BBC blog describes how:
Much of the medical equipment and props used in the show are donated from former hospitals. Other items have to be bought in, and others are made on site for specific episodes.
It's likely that once the sets were constructed for House, which would be kept until production ended, specific medical equipment needed for an episode was hired on an episode-by-episode basis.
I know from experience on a short film that you can hire medical props for a day or longer quite easily. For example, in the UK, you can hire an MRI from https://www.medicalhire.co.uk/:
And in the US you could hire your very own ultrasound machine from https://medicalmovieprops.com/inventory: