CMR-guidance of passively tracked endomyocardial biopsy in an in vivo porcine model

Abstract

Endomyocardial biopsy (EMB) is considered to be the diagnostic gold-standard in detection of myocardial-inflammation. EMB is usually conducted under fluoroscopy without any specific target information. Specific target-information provided by cardiovascular magnetic resonance (CMR) may improve specificity of EMB. The aim was to investigate feasibility and safety of CMR-guided and targeted EMB in a preclinical-model using passively-tracked devices. Procedures were performed on a MRI-System equipped with an Interventional Software-Platform for real-time imaging. Ex vivo experiments were conducted to optimize visibility of the guide-sheath. In vivo experiments were conducted in 2 pigs for technical feasibility assessment and in 4 pigs after acute myocardial infarction to test feasibility of guided and lesion targeted EMB. For anatomical real-time imaging a single-shot-balanced-SSFP-sequence was applied. Myocardial targets were identified under real-time imaging (single-shot-T2 (sshT2) and single-shot Late-Gadolinium-Enhancement (sshLGE) sequences). Ex vivo experiments demonstrated best visibility of continuously labelled guide-sheath. CMR-guided EMB was feasible in all cases without major complications. Likewise, lesion-targeting endomyocardial biopsy was feasible in two cases. Biopsies exhibited appropriate sizes and qualities. Real-time lesion sequences revealed comparable CNR values to clinical-protocols. Real-time imaging of lesions showed following signal- and contrast-to-noise ratios (SNR/CNR): SNR of sshT2- and sshLGE was 124 ± 35 and 67 ± 51 respectively, whereas CNR was 81 ± 30 and 57 ± 44. This study demonstrates feasibility and safety of CMR-guided and basically targeted EMB with passively-tracked devices. Signal-to-noise ratios of real-time sequences is non-inferior to standard sequences for lesion detection. CMR-guidance may improve diagnostic accuracy of EMB since CMR can detect myocardial-targets under real-time-imaging.

Cardiovascular imaging 2018 in the International Journal of Cardiovascular Imaging

“…The feasibility of CMR guidance for endomyocardial biopsy was demonstrated in an in vivo porcine model [84]. The same group also demonstrated the feasibility of MRI guided renal denervation using active tracking in a porcine model [84].…”

Introduction of a CMR-conditional cardiac phantom simulating cardiac anatomy and function and enabling training of interventional CMR procedures

“…CMR studies were performed on a 1.5-T Philips scanner with cardiac-dedicated surface coils (Ingenia, Best, The Netherlands). As outlined elsewhere 7 , the MR scanner was equipped with a dedicated intervention/navigation software platform called iSuite from Philips Research (Hamburg, Germany) enabling real-time imaging (RTI). The interventional operator is located in the scanner room, while the CMR operator is located outside in the control room.…”

“…A number of interventional CMR procedures have already been successfully performed in smaller human studies such as right heart catheterization 1–3 or electrophysiological CMR-guided radiofrequency (RF) ablation of atrial flutter 4–6 . In addition, RT-CMR-guided endomyocardial biopsy has only been tested ex vivo or in animal models so far 7–10 .…”

Micro-biopsy for detection of gene expression changes in ischemic swine myocardium: A pilot study

“…As mentioned, when using basic fluoroscopic guidance, the ability to detect and target an ischemic lesion is limited. Sampling accuracy may improve with the use of other guidance techniques, such as cardiac magnetic resonance (CMR) imaging or an electroanatomical mapping system [18][19][20]. We did not have access to these techniques when the study was performed.…”