Cardiovascular MR-Examination. Patients are examined in a clinical 1.5-T whole-body MR-scanner Achieva system (Philips Medical Systems, Best, The Netherlands) using a 5-element cardiac phased-array receiver coil. Cardiovascular MR-images were acquired at rest and during a standardized high-dose dobutamine/atropine protocol involving short breath holds, and using a vector electrocardiogram for R-wave triggering11. Electrocardiographic rhythm and symptoms were monitored continuously, and blood pressure was measured every 3 minutes.