 The study will be conducted at a single center, Herzzentrum Leipzig University Hospital, in Germany, and a maximum of 30 subjects meeting inclusionexclusion criteria will participate in the study. This study requires the use of investigational products from two independent manufacturers: Imricor and Philips. Imricor has developed the ablation catheter with related accessories, introducers, and recording system. Philips has developed an image guidance and mapping system that is compatible with the Imricor products. The Vision Ablation Catheter will be used in conjunction with the following investigational products: Vision Ablation Catheter Cable Set accessory sterile cable, Vision Hemostasis Introducer, Vision Dual-Deflect Sheath, Horizon recording system, and the interventional MRI Suite iSuite image guidance and mapping system. With the exception of iSuite, which is manufactured by Philips, Imricor will provide all investigational devices used in the study. Each procedure will utilize the following two single-use products: two Vision Ablation Catheters and an accessory Catheter Cable set. At the discretion of the investigator, Vision Hemostasis Introducers may be used for femoral access and a Vision Dual- Deflect Sheath and may be used in conjunction with the Vision Ablation Catheter Cable Set. Ablation for the treatment of arrhythmia is an inherently complex procedure. Use of the investigational products listed above under magnetic resonance guidance is a new approach to performing the interventional electrophysiology procedure. The study population will consist of adult patients requiring ablation for type I atrial flutter. 