3D Hybrid Imaging for Structural and Congenital Heart Interventions in the Cath Lab

Hybrid imaging (HI) during cardiovascular interventions enables the peri-procedural visualization of the organs and tissues by means of integrating different imaging modalities. HI can improve the procedural efficacy and safety. This review provides an overview of different systems, their possibilities and the current clinical use and benefits focused on structural and congenital heart diseases. We have performed a literature search and linked the software options to the clinical use in cardiology to gain insight into the clinical use of the systems. In this review, we focus on radiation and contrast exposure, complication rate and procedure time. We found that currently available studies are limited by small cohorts. Nevertheless, HI systems for valvular procedures result in a significant decrease of radiation and contrast exposure. The largest benefit hereof is observed when HI is used in combination with rotational angiography. Furthermore, automatically determined optimal implant angle for transcatheter aortic valve implantation decreases the complication rate significantly. Congenital heart disease interventions that require 2D/3D Transoesophageal echocardiography (TEE) such as septal defects show a significant decrease in radiation and contrast exposure and procedural time when using TEE-Mono- and bi-plane cine angiography and fluoroscopy (XRF) fusion software. MitraClip procedures using these HI systems, however, show only a trend in decrease of these effects. In conclusion, major interventional X-ray vendors offer HI software solutions which are safe and can aid the planning and image guidance of cardiovascular interventions. Even though current HI technologies have limitations, HI provides support in the increasingly complex cardiac interventional procedures to provide better patient care

3D Hybrid Imaging for Structural and Congenital Heart Interventions in the Cath Lab

Hybrid imaging (HI) during cardiovascular interventions enables the peri-procedural visualization of the organs and tissues by means of integrating different imaging modalities. HI can improve the procedural efficacy and safety. This review provides an overview of different systems, their possibilities and the current clinical use and benefits focused on structural and congenital heart diseases. We have performed a literature search and linked the software options to the clinical use in cardiology to gain insight into the clinical use of the systems. In this review, we focus on radiation and contrast exposure, complication rate and procedure time. We found that currently available studies are limited by small cohorts. Nevertheless, HI systems for valvular procedures result in a significant decrease of radiation and contrast exposure. The largest benefit hereof is observed when HI is used in combination with rotational angiography. Furthermore, automatically determined optimal implant angle for transcatheter aortic valve implantation decreases the complication rate significantly. Congenital heart disease interventions that require 2D/3D Transoesophageal echocardiography (TEE) such as septal defects show a significant decrease in radiation and contrast exposure and procedural time when using TEE-Mono- and bi-plane cine angiography and fluoroscopy (XRF) fusion software. MitraClip procedures using these HI systems, however, show only a trend in decrease of these effects. In conclusion, major interventional X-ray vendors offer HI software solutions which are safe and can aid the planning and image guidance of cardiovascular interventions. Even though current HI technologies have limitations, HI provides support in the increasingly complex cardiac interventional procedures to provide better patient care

Cardiac motion estimation using ultrafast ultrasound imaging tested in a finite element model of cardiac mechanics

Recent developments in ultrafast ultrasound imaging allow accurate assessment of 3D cardiac deformation in cardiac phases with high deformation rates. This paper investigates the performance of a multiple spherical wave (SW) ultrasound transmission scheme in combination with a motion estimation algorithm for cardiac deformation assessment at high frame rates. Ultrasound element data of a realistically deforming 3D cardiac finite element model were simulated for a phased array transducer, transmitting five SWs (PRF 2500 Hz). After delay-and-sum beamforming, coherent compounding of multiple SW transmissions was performed to generate radiofrequency data (frame rate 500 Hz). Axial and lateral displacements were determined using a normalized cross-correlation-based technique. Good agreement was obtained between estimated and ground truth displacements derived from the model over the cardiac cycle. This study indicates that high frame rate displacement estimation using multiple SWs is feasible and serves as an important step towards high frame rate 3D cardiac deformation imaging

A systematic comparison of cardiovascular magnetic resonance and high resolution histological fibrosis quantification in a chronic porcine infarct model

The noninvasive reference standard for myocardial fibrosis detection on cardiovascular magnetic resonance imaging (CMR) is late gadolinium enhancement (LGE). Currently there is no consensus on the preferred method for LGE quantification. Moreover myocardial wall thickening (WT) and strain are measures of regional deformation and function. The aim of this research was to systematically compare in vivo CMR parameters, such as LGE, WT and strain, with histological fibrosis quantification. Eight weeks after 90 min ischemia/reperfusion of the LAD artery, 16 pigs underwent in vivo Cine and LGE CMR. Histological sections from transverse heart slices were digitally analysed for fibrosis quantification. Mean fibrosis percentage of analysed sections was related to the different CMR techniques (using segmentation or feature tracking software) for each slice using a linear mixed model analysis. The full width at half maximum (FWHM) technique for quantification of LGE yielded the highest R2 of 60%. Cine derived myocardial WT explained 16–36% of the histological myocardial fibrosis. The peak circumferential and radial strain measured by feature tracking could explain 15 and 10% of the variance of myocardial fibrosis, respectively. The used method to systematically compare CMR image data with digital histological images is novel and feasible. Myocardial WT and strain were only modestly related with the amount of fibrosis. The fully automatic FWHM analysis technique is the preferred method to detect myocardial fibrosis

A fast pH-switchable and self-healing supramolecular hydrogel carrier for guided, local catheter-injection in the infarcted myocardium

Minimally invasive intervention strategies after myocardial infarction use state-of-the-art catheter systems that are able to combine mapping of the infarcted area with precise, local injection of drugs. To this end, catheter delivery of drugs that are not immediately pumped out of the heart is still challenging, and requires a carrier matrix that in the solution state can be injected through a long catheter, and instantaneously gelates at the site of injection. To address this unmet need, a pH-switchable supramolecular hydrogel is developed. The supramolecular hydrogel is switched into a liquid at pH > 8.5, with a viscosity low enough to enable passage through a 1-m long catheter while rapidly forming a hydrogel in contact with tissue. The hydrogel has self-healing properties taking care of adjustment to the injection site. Growth factors are delivered from the hydrogel thereby clearly showing a reduction of infarct scar in a pig myocardial infarction model