Susceptibility artifacts from metallic markers and cardiac catheterization devices on a high-performance 0.55 T MRI system

Abstract

Introduction: Visualization of passive devices during MRI-guided catheterizations often relies on a susceptibility artifact from the device itself or added susceptibility markers that impart a unique imaging signature. High-performance low field MRI systems offer reduced RF-induced heating of metallic devices during MRI-guided invasive procedures, but susceptibility artifacts are expected to diminish with field strength, reducing device visualization. In this study, field strength and orientation dependence of artifacts from susceptibility markers and metallic guidewires were evaluated using a prototype high-performance 0.55 T MRI system. Materials and methods:Artifact volume from nitinol and stainless steel passive susceptibility markers was quantified using histogram analysis of pixel intensities from three-dimensional gradient echo images at 0.55 T, 1.5 T and 3 T. In addition, visibility of commercially available clinical catheterization devices was compared between 0.55 T and 1.5 T using real-time bSSFP in phantoms and in vivo. Results:A low-tensile strength stainless-steel marker produced field strength-and orientationdependent artifact size (1.7 cm 3 , 1.95 cm 3 , 2.21 cm 3 at 0.55 T, 1.5 T, 3 T, respectively). Whereas, a high-tensile strength steel marker, of the same alloy, produced field strength-and orientationindependent artifact size (3.35 cm 3 , 3.41 cm 3 , 3.42 cm 3 at 0.55 T, 1.5 T, 3 T, respectively). Visibility of commercially available nitinol guidewires was reduced at 0.55 T, but imaging signature could be maintained using high-susceptibility stainless steel markers.

Current State of MRI‐Guided Endovascular Arterial Interventions: A Systematic Review of Preclinical and Clinical Studies

“…Furthermore, diagnostic outcomes, such as pulmonary vascular resistance, cardiac output, and hemodynamic measurements, can be accurately determined using MRI‐guided catheterization 81 . Contrary to diagnostic procedures, MRI‐guided cardiac interventions such as balloon angioplasty, valvuloplasty, or ablation of atrial flutter are sparse, partly due to the lack of procedure‐specific MRI‐compatible devices 81,82 . Notwithstanding advancements in MRI and image processing techniques, an increased availability of MRI‐compatible endovascular devices will be required to enable wider clinical adoption.…”

Sustainable low-field cardiovascular magnetic resonance in changing healthcare systems

“…Moreover, in a swine model, artefacts from high-susceptibility materials like stainless steel were indistinguishable across 0.55 T, 1.5 T, and 3 T, meaning device visibility is maintained at LFs with reduced heating for some metals. 114 LF CMR pre-procedural planning and post-procedural assessment are demonstrated in a swine model when Kolandaivelu et al 136 used LF (0.55 T) native T1-weighted contrast CMR to assess and characterize tissue necrosis from cardiac ablation, especially with acetic acid chemoablation. This work indicates the potential of using LF CMR for accurately delineating myocardial lesions and necrosis to guide cardiac ablation.…”

Low-Field Magnetic Resonance Imaging

“…The degradation of image quality associated with the effect of magnetic susceptibility is generally reduced at a lower static magnetic field strength. 51 , 52 At the boundary between tissues with significantly different magnetic susceptibilities (eg, soft tissue, bone, and air), signal degradation is observed, but it is mitigated when the static magnetic field strength is low. 51 Therefore, it may be possible to evaluate clinically lung lesions that are difficult to image at 1.5 T or 3 T with a low-field MRI system (this is discussed in more detail later).…”