Interventional Cardiovascular Magnetic Resonance Imaging

Abstract

Magnetic resonance imaging (MRI) provides structural and functional cardiovascular information with excellent soft tissue contrast. Real-time MRI can guide transcatheter cardiovascular interventions in large animal models, and may prove superior to x-ray and adjunct modalities for peripheral vascular, structural heart and cardiac electrophysiology applications. We describe technical considerations, pre-clinical work and early clinical studies in this emerging field.

MRI-Guided Electrophysiology Intervention

“…Though MRI-unsafe objects, such as ferromagnetic scissors and needle drivers, may be needed during the preparatory phase of a procedure, until MRI-compatible alternatives are available a system must be in place to methodically track and remove such objects before approaching the scanner. The electric current associated with defibrillation can also lead to strong displacement forces in high magnetic fields and should be performed with the defibrillator pads maintained a safe distance from the scanner bore 90. Similar attention is needed to address the ferromagnetic properties and MRI electromagnetic interference compatibility of other equipment associated with electrophysiology procedures including physiology monitoring equipment, ablation and pacing sources, and anesthesia apparatus.…”

“…A promising heating suppression technique for position tracking and intravascular imaging coils that need to pass differential mode signals at the same frequencies as unwanted common mode induced currents is to place thin transmission line transformers in the signal-carrying cables 77,97,98. Other strategies such as detuning and decoupling of circuits prone to heating,78,99 fiber-optic transmission of signals,100 and use of inductively coupled resonators for wireless device tracking101 are also considerations for new device design 25,90. Using surface coils instead of the higher-power body coil for RF transmission has also been proposed as a way to reduce RF current induction in devices 102.…”

Correction for the Article “MRI-Guided Electrophysiology Intervention” by Henry R. Halperin and Aravindan Kolandaivelu

“…The electric current associated with defibrillation can also lead to strong displacement forces in high magnetic fields and should be performed with the defibrillator pads maintained a safe distance from the scanner bore. 90 Similar attention is needed to address the ferromagnetic properties and MRI electromagnetic interference compatibility of other equipment associated with electrophysiology procedures including physiology monitoring equipment, ablation and pacing sources, and anesthesia apparatus. Clear marking of high-field areas and secure placement of objects that may experience magnetic forces is mandatory so that appropriate pieces of equipment are kept at a safe distance.…”

“…77,97,98 Other strategies such as detuning and decoupling of circuits prone to heating, 78,99 fiberoptic transmission of signals, 100 and use of inductively coupled resonators for wireless device tracking 101 are also considerations for new device design. 25,90 Using surface coils instead of the higher-power body coil for RF transmission has also been proposed as a way to reduce RF current induction in devices. 102 Now that academic sites and imaging companies are focusing on heating-safe device development, more rapid progress in this area is expected.…”

Motion Estimation Applied to Reconstruct Undersampled Dynamic MRI

“…Over the last years, Magnetic Resonance Imaging (MRI) has become an important tool for dynamic clinical studies. Applications are wide ranging, including cardiac MRI [1]- [2], real-time interventional imaging [3] and kinematics of joints [4]. The long time involved in the acquisition of an image sequence is still a challenge in dynamic MRI.…”