Magnetic Resonance–Guided Cardiac Interventions Using Magnetic Resonance–Compatible Devices

Abstract

Background-Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results-In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions-The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution. (Circ Cardiovasc Interv. 2010;3:585-592.)

Circulation: Cardiovascular Imaging Editors' Picks

“…Although attractive, many challenges remain before certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance. 23 …”

White Paper: Interventional MRI: Current Status and Potential for Development Considering Economic Perspectives, Part 1: General Application

“…This increases the necessity to reduce the radiation exposure due to diagnosis and interventions to a minimum. However, after initial studies first on animal models and later on patients that were able to show feasibility and advantages [1,61,62], the use of endovascular MRI for this indication has barely been pursued in recent years due to a lack of availability of instruments and the effort and cost of adapting currently available units to endovascular interventions. To still be able to profit from the advantages of MRI, MRI datasets are increasingly being superimposed on angiography images used for interventions [63,64].…”

“…The use of hybrid systems in the form of MRI scanners that are connected to angiography units so that the patient is examined on the same examination table for both units allows the use of MRI datasets acquired immediately prior to the intervention for planning and performing angiography-guided interventions as well as the continuation of MR-guided interventions under fluoroscopy guidance as a backup method if necessary [1,58,59]. Such systems allow interventional MRI to be further included in the clinical routine.…”

Interventional Cardiac Magnetic Resonance Imaging in Electrophysiology

“…Passive guidewires have been applied successfully during cardiac interventions and are being investigated in larger trials. 37 The major limitation of using active guidewires is the potential of radio-frequency coupling because of the substantial length of these devices. This restriction has been addressed recently by the development of an active guidewire with embedded fiberoptic temperature probe.…”