This dataset contains imaging files of the manuscript "Ascending aortic aneurysm in angiotensin II- infused mice: formation, progression and the role of focal dissections", published in ATVB in 2016. All published files are to be opened in Mimics (Materialise, Leuven, Belgium). All files are named as follows: "technique_id_timepoint_asc.mcs". The technique can be either in vivo micro-CT, or ex-vivo synchrotron-based PCXTM. The mouse ID corresponds to the ID that was used during the experiments. Mice were distributed at random into 2 groups (G1 and G2) and sacrificed after 1 of 4 possible timepoints. TP0 corresponds to baseline (prior to Ang II infusion), TP1 corresponds to 3 days of Ang II infusion, TP2 corresponds to 10 days of Ang II infusion, TP3 corresponds to 18 days of Ang II infusion and TP4 corresponds to 28 days of Ang II infusion. Image files from PCXTM are ex vivo and always correspond to the latest timepoint available with micro-CT.