MRI—3D ultrasound—X-ray image fusion with electromagnetic tracking for transendocardial therapeutic injections: In-vitro validation and in-vivo feasibility

Abstract

Myocardial infarction (MI) is one of the leading causes of death in the world. Small animal studies have shown that stem-cell therapy offers dramatic functional improvement post-MI. An endomyocardial catheter injection approach to therapeutic agent delivery has been proposed to improve efficacy through increased cell retention. Accurate targeting is critical for reaching areas of greatest therapeutic potential while avoiding a life-threatening myocardial perforation. Multimodal image fusion has been proposed as a way to improve these procedures by augmenting traditional intra-operative imaging modalities with high resolution pre-procedural images. Previous approaches have suffered from a lack of real-time tissue imaging and dependence on X-ray imaging to track devices, leading to increased ionizing radiation dose. In this paper, we present a new image fusion system for catheter-based targeted delivery of therapeutic agents. The system registers real-time 3D echocardiography, magnetic resonance, X-ray, and electromagnetic sensor tracking within a single flexible framework. All system calibrations and registrations were validated and found to have target registration errors less than 5 mm in the worst case. Injection accuracy was validated in a motion enabled cardiac injection phantom, where targeting accuracy ranged from 0.57 to 3.81 mm. Clinical feasibility was demonstrated with in-vivo swine experiments, where injections were successfully made into targeted regions of the heart.

Noninvasive cardiac arrhythmia ablation with particle beams

“…Matching to the linac coordinate system and thus the reference CT data is achieved by optical tracking of IR‐markers attached to the ultrasound probe. Transesophageal Echocardiography (TEE) can also be fused with CT data . The potential of US imaging is greater than compensation of interfractional motion components.…”

“…Transesophageal Echocardiography (TEE) can also be fused with CT data. 43 The potential of US imaging is greater than compensation of interfractional motion components. Due to the high imaging rate, the technique further allows real-time imaging for motion monitoring including applications in ion beam therapy.…”

Improving the cardiac cath-lab interventional imaging eco-system

“…We are not limited to fusion of only two modalities. There are examples of successful fusion of MRI, 3D US, and XRF for guidance of transendocardial injections in swine models (16). We hope one day to have a better interventional imaging eco-system where interventionalists are presented with sensible displays that reliably show devices and their 3D relationship to anatomic structures, where radiation and contrast dose is kept to a minimum and where physiologic consequences of the intervention is rapidly apparent.…”

“…We hope one day to have a better interventional imaging eco-system where interventionalists are presented with sensible displays that reliably show devices and their 3D relationship to anatomic structures, where radiation and contrast dose is kept to a minimum and where physiologic consequences of the intervention is rapidly apparent. Aortic aneurysm repair (10); transcatheter aortic valve replacement, paravalvular leak closure; pulmonary vein stenting (11) MRI-XRF Aortic coarctation stenting (7); pulmonary artery stenting (12) Graft coronary arteriography, right ventricular free-wall biopsy, and iliac and femoral artery recanalization and stenting (8); transendocardial stem cell injection* (13) 3DUS-XRF ASD closure, Fontan fenestration closure, and transcatheter tricuspid valve replacement (14) Mitral valve repair, left atrial appendage, ASD and paravalvular leak closure (15) 3DUS-MRI-XRF* -Transendocardial stem cell injection* (16) CT-EM -Afib ablation (17) MRI-EM -Afib ablation (18) US-EM Ablation for intra-atrial re-entry tachycardia, Wolff-Parkinson-White syndrome, ventricular ectopic tachycardia and atrioventricular node re-entrant tachycardia (19) Afib ablation (20); atrial tachycardia and ventricular tachycardia ablation (21) *, indicates pre-clinical study. MRI, magnetic resonance imaging; 3DUS, three-dimensional ultrasound; CT, computed tomography; XRF, X-ray fluoroscopy; EM, electromagnetic tracking; ASD, atrial septal defect.…”

A Real‐time Color Doppler Marker for Echocardiographic Guidance of an Acoustically Active Extracorporeal Membrane Oxygenation Cannula

“…Practical examples of minimally invasive cardiovascular interventions include transcatheter treatment of valvular heart disease 1,2 and myocardial cellular therapy delivered by transendocardial injections. 3 However, image noise and artifacts in grayscale (B-mode) scans make navigation of minimally invasive imaging tools difficult. In addition, the echogenicity of cardiovascular tissue and minimally invasive tools are often similar in B-mode scans.…”