Real-time MRI-guided right heart catheterization in adults using passive catheters

Abstract

Aims: Real-time MRI creates images with superb tissue contrast that may enable radiation-free catheterization. Simple procedures are the first step towards novel interventional procedures. We aim to perform comprehensive transfemoral diagnostic right heart catheterization in an unselected cohort of patients entirely using MRI guidance.

Methods and results: We performed X-ray and MRI-guided transfemoral right heart catheterization in consecutive patients undergoing clinical cardiac catheterization. We sampled both cavae and both pulmonary arteries. We compared success rate, time to perform key steps, and catheter visibility among X-ray and MRI procedures using air-filled or gadolinium-filled balloon-tipped catheters. Sixteen subjects (four with shunt, nine with coronary artery disease, three with other) underwent paired X-ray and MRI catheterization. Complete guidewire-free catheterization was possible in 15 of 16 under both. MRI using gadolinium-filled balloons was at least as successful as X-ray in all procedure steps, more successful than MRI using air-filled balloons, and better than both in entering the left pulmonary artery. Total catheterization time and individual procedure steps required approximately the same amount of time irrespective of image guidance modality. Catheter conspicuity was best under X-ray and next-best using gadolinium-filled MRI balloons.

Conclusion: In this early experience, comprehensive transfemoral right heart catheterization appears feasible using only MRI for imaging guidance. Gadolinium-filled balloon catheters were more conspicuous than air-filled ones. Further workflow and device enhancement are necessary for clinical adoption.

Figure 1

A combined X-ray and magnetic resonance imaging intervention suite. Adjoining independent X-ray and magnetic resonance imaging systems are separated by radiofrequency- and X-ray-shielded doors. The X-ray system table is mounted on motorized rails. When the doors are opened and the X-ray gantries parked, the X-ray and magnetic resonance imaging tables can dock, and the patient can be transferred smoothly and rapidly between systems. Inset: the magnetic resonance imaging system is configured like an X-ray interventional system. Multiple LCD projectors display real-time magnetic resonance imaging, scanner control, and the same haemodynamic recording system as X-ray.

Figure 2

Magnetic resonance imaging catheterization using an air-filled balloon catheter. White arrows indicate catheter tips. Panels depict different chambers. (A and B) Superior vena cava. (C and D) Entering the main pulmonary artery from the right ventricle. (E) Main pulmonary artery bifurcation. (F) Right pulmonary artery.

Figure 3

Magnetic resonance imaging catheterization using a gadolinium-filled balloon catheter and interactive saturation-preparation imaging. Interactive application of saturation-preparation real-time magnetic resonance imaging mode helped to highlight the appearance of the gadolinium-filled balloon. The top row indicates the normal mode, and the bottom row indicates the saturation-preparation mode. White arrows indicate catheter tips. (A and B) Superior vena cava. (C and D) Entering the main pulmonary artery from the right ventricle. (E and F) Right pulmonary artery.

Figure 4

Ambiguity using air-filled balloon catheters. The black signal void created by air-filled balloon catheters (dashed arrow) was occasionally indistinguishable from signal voids created by other imaging artefacts (solid arrow).