Towards Subject-Specific Models of the Dynamic Heart for Image-Guided Mitral Valve Surgery

Abstract

Abstract. Surgeons need a robust interventional system capable of providing reliable, real-time information regarding the position and orientation of the surgical targets and tools to compensate for the lack of direct vision and to enhance manipulation of intracardiac targets during minimally-invasive, off-pump cardiac interventions. In this paper, we describe a novel method for creating dynamic, pre-operative, subjectspecific cardiac models containing the surgical targets and surrounding anatomy, and how they are used to augment the intra-operative virtual environment for guidance of valvular interventions. The accuracy of these pre-operative models was established by comparing the target registration error between the mitral valve annulus characterized in the pre-operative images and their equivalent structures manually extracted from 3D US data. On average, the mitral valve annulus was extracted with a 3.1 mm error across all cardiac phases. In addition, we also propose a method for registering the pre-operative models into the intra-operative virtual environment.

Inside the beating heart: an in vivo feasibility study on fusing pre- and intra-operative imaging for minimally invasive therapy

“…Using a registrationbased segmentation approach, the high-resolution average heart model has been used to segment cardiac MR images of human subjects that were not part of the database, generating segmented anatomical structures which were validated to be accurate within 5.0 ± 1.0, 4.7 ± 0.9, and 5.3 ± 1.3 mm for the LV, LA, and the right atrium and ventricle (RA/RV), respectively. While this technique has been applied and validated on human subject MR data [24], we are currently in the process of building a similar database from porcine images, and employ this technique to automatically generate the anatomical models as an alternative to manual segmentation. However, for the time being, we have to resort to the manual segmentation approach to generate the anatomical models for our animal studies.…”

Accuracy considerations in image-guided cardiac interventions: experience and lessons learned

“…Using similar techniques on human MRI data, subject-specific 3D cardiac models (Fig. 3) were generated by fitting an a priori heart model [18,19] to a mid-diastolic (MD) subject MR image [20,21]. The segmented anatomical structures were shown to be accurate within 5.0 ± 1.0 mm, 4.7 ± 0.9 mm, and 5.3 ± 1.3 mm for the left ventricle, left atrium, and the right atrium and ventricle, respectively compared to the gold-standard structures manually segmented under expert assistance.…”

Toward Patient-Specific Myocardial Models of the Heart

“…There is important literature on cardiac image analysis for the segmentation of the heart from medical images [11][12][13][14][15][16][17][18][19][20][21]. The idea is not to be exhaustive but to present a generic pipeline where most of the approaches can fit.…”