Myocardial perfusion and viability after percutaneous recanalization of coronary chronic total occlusions: a cardiovascular magnetic resonance study by Gatehouse Peter, Symmonds Karen, Wright Christine, Del Furia Francesca, O'Hanlon Rory, Grasso Agata, Petryka Joanna, Ferrante Giuseppe, Locca Didier, Bucciarelli-Ducci Chiara, Prasa Sanjay, Di Mario Carlo, Pennell Dudley