High field MR carotid vessel wall imaging: reproducibility of five different MR-weightings by Bax Jeroen J, de Roos Albert, Kooi Eline, Schuijf Joanne D, Doornbos Joost, van der Geest Rob J, Westenberg Jos J, Kroner Eleanore S, Lamb Hildo J, Siebelink Hans-Marc