Real-Time Control of Active Catheter Signals for Better Visual Profiling During Cardiovascular Interventions Under MRI Guidance

Ali C Ozen,Constantin Von Zur Muhlen,Thomas Lottner,Timo Heidt,Simon Reiss,Michael Bock

doi:10.1109/access.2022.3151804

Ali C Ozen, Constantin Von Zur Muhlen + Show 4 more

Open Access

https://doi.org/10.1109/access.2022.3151804

Copy DOI

Abstract

In MR-guided interventional procedures, RF coils can be attached to the instruments to provide a positive MR signal for device tracking. The signal from these coils can vary strongly over the procedure and mask the surrounding anatomy. The purpose of this study is to introduce and demonstrate a low-cost, vendor- and device-independent interface circuit that allows the interventionalist to adjust the active device signal intensity. In this work a variable attenuator circuit was constructed to control the tip signal of an active coronary artery catheter in real-time from within the MR scanner room. Performance of the attenuator circuit and the active catheter was characterized on the test bench, in a phantom model, and in vivo. The system was used in a pig model at 3T during the introduction of the catheter into the left coronary artery. The circuit could attenuate the amplitude of the tracking coil signal by up to 20 dB. Without attenuation, the tracking coil signal intensity was masking anatomical details of the coronary ostium making it impossible to reliably introduce the catheter into the artery. After interactive adjustment, which was performed in a few seconds by the interventionalist, the improved visualization of the vascular anatomy enabled a rapid insertion of the catheter into the coronary ostium. The vendor-independent variable attenuator provides real-time control of the catheter signal without interrupting the image acquisition. Even though most MRI systems can control the individual signal levels from coils by software, the attenuator hardware is advantageous as it can be integrated into any MR-system, and it provides a direct interface for the interventionalist at the magnet.

Highlights

Magnetic resonance imaging (MRI) has been used for image guidance in diagnostic and therapeutic interventions including coronary catheterization [1]–[4], electrophysiological therapies [5], hepatic tumor ablation [6], [7] and prostate marker implantation [8]
MRI would offer several advantages over existing imaging techniques for interventional guidance : MRI does not use ionizing radiation such as X-ray-based imaging methods, MR images can be acquired in arbitrary slice orientations that can be adapted to the anatomy of the patient, MRI offers different image contrasts to differentiate soft tissues and lesions, and it VOLUME XX, 2017
We propose a dedicated interface circuit to manually attenuate the signal intensity of the active coil during the interventional procedure

Summary

Introduction

Magnetic resonance imaging (MRI) has been used for image guidance in diagnostic and therapeutic interventions including coronary catheterization [1]–[4], electrophysiological therapies [5], hepatic tumor ablation [6], [7] and prostate marker implantation [8]. Intravascular interventions such as catheterization or embolization are typically performed under real-time X-ray image guidance. Özen: Real-time control of active catheter signals for better visual profiling can be combined with functional imaging techniques such as flow measurements to assess the outcome of the intervention quantitatively. In MRI, passive markers with well-defined susceptibility artifacts [11] have been used for position detection, or inductively coupled RF resonators [12], which enhance the receive sensitivity in their vicinity

Objectives

Methods

Results

Conclusion