MRI in patients with cardiac devices

Cardiovascular diseases can be diagnosed by assessing abnormal flow behavior in the heart. We introduce, for the first time, a magnetic resonance imaging-based diagnostic that produces sectional flow maps of cardiac chambers, and presents cardiac analysis based on the flow information. Using steady-state free precession magnetic resonance images of blood, we demonstrate intensity contrast between asynchronous and synchronous proton spins. Turbulent blood flow in cardiac chambers contains asynchronous blood proton spins whose concentration affects the signal intensities that are registered onto the magnetic resonance images. Application of intensity flow tracking based on their non-uniform signal concentrations provides a flow field map of the blood motion. We verify this theory in a patient with an atrial septal defect whose chamber blood flow vortices vary in speed of rotation before and after septal occlusion. Based on the measurement of cardiac flow vorticity in our implementation, we establish a relationship between atrial vorticity and septal defect. The developed system has the potential to be used as a prognostic and investigative tool for assessment of cardiac abnormalities, and can be exploited in parallel to examining myocardial defects using steady-state free precession magnetic resonance images of the heart.

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“…It can also measure blood flow through artificial cardiac devices in vivo at a magnetic strength of not more than 3 Tesla [22].…”

Section: Discussionmentioning

confidence: 99%

Noninvasive Cardiac Flow Assessment Using High Speed Magnetic Resonance Fluid Motion Tracking

et al. 2009

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“…Over the years, these safety concerns have been substantiated by at least 17 supposed MRI-associated deaths among patients with pacemakers 28. This number is probably an underestimation of the real number of fatalities, since there are several cases of patients with a cardiac pacemaker who died after exposure to MRI that have never been reported in the medical literature but have come to light via the general press or the legal system 29.…”

Section: Mri In Patients With Conventional Pacemakers: Feasible?mentioning

confidence: 99%

“…This number is probably an underestimation of the real number of fatalities, since there are several cases of patients with a cardiac pacemaker who died after exposure to MRI that have never been reported in the medical literature but have come to light via the general press or the legal system 29. However, it should also be noted that a firm causal relationship has seldom been established, and that most of these deaths occurred in patients with older pacemaker models undergoing MRI without appropriate programming or physician-supervised monitoring 28,30…”

Section: Mri In Patients With Conventional Pacemakers: Feasible?mentioning

confidence: 99%

MRI-conditional pacemakers: current perspectives

Ferreira¹,

Costa²,

Tralhão³

et al. 2014

MDER

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Use of both magnetic resonance imaging (MRI) and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radio frequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitations prompted a series of modifications in generator and lead engineering, designed to minimize interactions that could compromise device function and patient safety. The resulting MRI-conditional pacemakers were first introduced in 2008 and the clinical experience gathered so far supports their safety in the MRI environment if certain conditions are fulfilled. With this technology, new questions and controversies arise regarding patient selection, clinical impact, and cost-effectiveness. In this review, we discuss the potential risks of MRI in patients with electronic cardiac devices and present updated information regarding the features of MRI-conditional pacemakers and the clinical experience with currently available models. Finally, we provide some guidance on how to scan patients who have these devices and discuss future directions in the field.

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“…The study is performed within 10–15 minutes with free breathing and without any contrast or radiation burden. However, the spatial resolution (typically 0.5 to 1 mm) is not quite as good as with CCT, and the study cannot be routinely performed in patients with implanted cardiac devices 51 .…”

Section: Cardiac Magnetic Resonance Imagingmentioning

confidence: 99%