Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS): study protocol for a randomised controlled trial

Mathilde M H Pauls, Natasha Clarke, Sarah Trippier, Shai Betteridge, Franklyn A Howe, Usman Khan, Christina Kruuse, Jeremy B Madigan, Barry Moynihan, Anthony C Pereira, Debbie Rolfe, Egill Rostrup, Caroline E Haig, Thomas R Barrick, Jeremy D Isaacs, Atticus H Hainsworth