Development and application of a structured preclinical protocol for MRI-guided endomyocardial biopsy: a multimodal imaging approach using a hybrid vessel phantom and porcine in vivo models.

BACKGROUND

MRI-guided cardiovascular procedures provide high-resolution, radiation-free imaging, but clinical translation is limited due to the lack of MR Conditional medical devices. This study presents a structured preclinical evaluation protocol for MRI-guided endomyocardial biopsy (EMB) interventions, demonstrating its feasibility for both instrument performance and procedural workflow.

METHODS

An MR-compatible prototype EMB forceps was evaluated using the three-stage preclinical protocol. First, device visibility was assessed using fluoroscopy and two MRI systems (Magnetom Sola 1.5T and a Biograph 3.0T, both Siemens Healthineers). Tissue samples retrieved from the left ventricle of a fresh porcine heart using MR-compatible (n = 5) and standard Cordis biopsy forceps (n = 5) were subjected to histological analysis. In the second stage, the device and workflow were tested using a developed hybrid vessel phantom, combining a human CT-based silicone aortic model and a Thiel-embalmed porcine heart. Handling performance was assessed by experienced cardiac interventionists (n = 4). Finally, in vivo testing was performed in a porcine model (n = 4), following ethics committee approval.

RESULTS

Visibility of the EMB forceps was confirmed in all MRI systems and fluoroscopy. Handling was rated medium or higher by all operators. No significant difference in histological tissue quality and tissue sampling times (p > 0.05) was observed between MR-compatible and standard EMB forceps. In vivo, five tissue samples of equivalent quality were successfully harvested from six attempts, with the MR-compatible EMB forceps exhibiting smaller MRI artifact sizes in vivo compared to in vitro measurements.

CONCLUSIONS

The developed preclinical testing protocol effectively evaluated key device characteristics (reliable visibility, handling, and accurate tissue sampling) of the MR-compatible EMB forceps, providing valuable insights in the early stages of in vivo trials.