Endovascular interventional magnetic resonance imaging

Abstract

Minimally invasive interventional radiological procedures, such as balloon angioplasty, stent placement or coiling of aneurysms, play an increasingly important role in the treatment of patients suffering from vascular disease. The non-destructive nature of magnetic resonance imaging (MRI), its ability to combine the acquisition of high quality anatomical images and functional information, such as blood flow velocities, perfusion and diffusion, together with its inherent three dimensionality and tomographic imaging capacities, have been advocated as advantages of using the MRI technique for guidance of endovascular radiological interventions. Within this light, endovascular interventional MRI has emerged as an interesting and promising new branch of interventional radiology. In this review article, the authors will give an overview of the most important issues related to this field. In this context, we will focus on the prerequisites for endovascular interventional MRI to come to maturity. In particular, the various approaches for device tracking that were proposed will be discussed and categorized. Furthermore, dedicated MRI systems, safety and compatibility issues and promising applications that could become clinical practice in the future will be discussed.

MR‐guided intravascular interventions: Techniques and applications

“…Despite the availability of fast MR acquisition techniques the visualization and tracking of interventional instruments is still technically demanding, because intravascular interventions simultaneously require a high spatial and temporal resolution for an adaequate visualization of the small catheters in the rapidly moving anatomy. In recent years a variety of methods have been developed to image and track flexible instruments such as catheters and guidewires in the MR environment (26,27) (Table 1).…”

Interventional and intraoperative MR: review and update of techniques and clinical experience

“…Even if X-ray fluoroscopy still is the imaging modality of choice to guide vascular interventions, MRI has been receiving increasing attention in the last years, in particular because of the perception that MR angiography (MRA) has grown to a serious alternative to digital subtraction angiography (DSA) for diagnostic vascular imaging [84,85]. A drawback of X-ray fluoroscopy is the potential radiation hazard for patients and operators, since some interventions can take up to several hours.…”

“…The ultimate solution, however, has not been found yet. It is likely that the use of nonconducting material, and in particular of fiber optic techniques, plays an important role as a safe mean of data transmission through endovascular devices [85] (Fig. 8).…”

Design of catheter radio frequency coils using coaxial transmission line resonators for interventional neurovascular MR imaging

“…The use of catheter-based radio frequency (RF) coils for interventional MRI application, while invasive, has significant advantages over using conventional external RF coils as the signal detector (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). An endovascular RF device offers improved detection sensitivity as a result of its proximity to the imaging target, providing high efficiency of the RF magnetic fields (i.e., B 1 fields) generated by the coil and improved filling factors.…”

“…The requirement for lumped capacitors, which are usually large in size, makes it challenging to incorporate such bulky structures into miniature endovascular devices. Additionally, the long, conductive leads of the coil are part of the coil resonant circuit and can dissipate MR signals, introduce noise, and also create a safety hazard by heating surrounding tissues (12). The long, unshielded leads can also make the coil resonance unstable and consequently degrade imaging performance.…”