Can I use UK radiators in Belgium?

My question as a so and so DIYer, I have noticed in Brussels, and throughout Belgium, it quite difficult to get nice radiators for a reasonable price, on the other hand, UK has much more choice and better prices. I have found a couple of nice radiators I like for my new flat. However, I've been hearing conflicting info regarding pipes measurements used here and there lately, it would seem like, UK use the metric system while Continental Europe uses the royal system, therefore making it impossible to use those radiators bought in UK, in the rest of Europe. Could somebody with experience or knowledge in this matter clarify this to me? Seems a bit odd, but "tout à fait possible".