Magnetic Resonance Imaging–Guided Balloon Angioplasty of Coarctation of the Aorta

Abstract

Background-MRI guidance of percutaneous transluminal balloon angioplasty (PTA) of aortic coarctation (CoA) would be desirable for continuous visualization of anatomy and to eliminate x-ray exposure. The aim of this study was (1) to determine the suitability of MRI-controlled PTA using the iron oxide-based contrast medium Resovist (ferucarbotran) for catheter visualization and (2) to subsequently apply this technique in a pilot study with patients with CoA. Methods and Results-The MRI contrast-to-noise ratio and artifact behavior of Resovist-treated balloon catheters was optimized in in vitro and animal experiments (pigs). In 5 patients, anatomy of the CoA was evaluated before and after intervention with high-resolution respiratory-navigated 3D MRI and multiphase cine MRI. Position monitoring of Resovist-treated catheters was realized with interactive real-time MRI. Aortic pressures were continuously recorded.Conventional catheterization was performed before and after MRI to confirm interventional success. During MRI, catheters filled with 25 mol of iron particles per milliliter of Resovist produced good signal contrast between catheters and their background anatomy but no image distortion due to susceptibility artifacts. All MRI procedures were performed successfully in the patient study. There was excellent agreement between the diameters of CoA and pressure gradients as measured during MRI and conventional catheterization. In 4 patients, PTA resulted in substantial widening of the CoA and a decrease in pressure gradients. In 1 patient, PTA was ineffective. Conclusions-The MRI method described represents a potential alternative to conventional x-ray fluoroscopy for catheter-based treatment of patients with CoA. (Circulation. 2006;113:1093-1100.)

An isolated perfused pig heart model for the development, validation and translation of novel cardiovascular magnetic resonance techniques

“…In vivo imaging in pig models has previously been used to study coronary blood-flow using coloured microspheres [22], microvascular function using computer tomography (CT) [23], and to validate novel perfusion tracers for positron emission tomography (PET) [24]. Other applications include validation of MR-guided real time coronary catheterization or percutaneous transluminal balloon angioplasty in aortic coarctation [25,26]. …”

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

“…34 Translation of the animal MR-guided interventions in humans had not been made possible to date because of the lack of fully MR-compatible equipment. An MR-safe guide wire fulfilling all prerequisites to become a clinical device has been recently developed.…”

Magnetic Resonance Imaging-Guided Catheter Interventions in Congenital Heart Disease

“…After the intervention, high-resolution imaging of the nature and extent of aortic wall injury can be helpful in guiding the decision about further intervention. Notably, such information was not obtained in the study of Krueger et al 7 In this and in other diagnostic and interventional procedures, the ability to measure blood flow, to image changes to soft tissues (eg, radiofrequency or thermal damage during electrophysiological procedures), and to guide transcatheter delivery of stem cells and other therapeutic agents adds to the list of potential advantages of MRI in the interventional arena. 14 The road ahead to successful integration of MRI and diagnostic and interventional cardiac catheterization is long and challenging.…”

“…14 The road ahead to successful integration of MRI and diagnostic and interventional cardiac catheterization is long and challenging. To progress from the successful proof of concept demonstrated by Razavi et al 6 and Krueger et al 7 to safe and effective clinical application, the diagnostic and interventional cardiac suite of the future must be designed from the ground up. To supplant x-ray angiography, MRI will need not only to provide excellent real-time imaging but also to do so in a way that does not diminish the ability of the catheterizer and anesthesiologist to respond appropriately to unpredicted or adverse events.…”