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Image guided left ventricular lead-implantation for cardiac resynchronization therapy : assessment of the left phrenic nerve and coronary sinus.

Nieuwenhuis, E.R. (2016) Image guided left ventricular lead-implantation for cardiac resynchronization therapy : assessment of the left phrenic nerve and coronary sinus.

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Abstract:Objective. Visualization and implementation of the left phrenic nerve (LPN) and the coronary sinus ostium in CARTBox3 to support left ventricular lead placement in cardiac resynchronization therapy. Introduction. Cardiac resynchronization therapy can be used to resynchronize a dyssynchronous ventricle contraction in patients with heart failure. The response rate of the therapy needs to be improved, since 30% of treated patients do not benefit from the therapy. One of the factors that can improve the response rate is optimal left ventricular lead position. CARTBox3 software was developed to determine an optimal lead position and provides image guided placement of the left ventricular lead to the optimal position during cardiac resynchronization therapy. To complete the CARTBox3 functionality, a way to visualize and segment the LPN course and coronary sinus ostium is developed. Method. A feasibility study of LPN visualization using MRI was performed. Based on the time planning and the availability of CT data it was chosen to develop and validate a method for LPN segmentation using contrast and non-contrast cardiac CTs. The LPN segmentation was implemented into CB3. Also from CT data, the ostium was determined by finding intersection points of segmented right atrium and coronary sinus volumes. Two segmentation methods were tested on contrast and non-contrast cardiac CTs. Results. Current clinically available MRI technology was proven to be unsuitable to visualize the LPN. The LPN segmentation based on contrast CT data was in accordance to mapping data of patients who underwent epicardial ablation (n=7). The intraobserver variability study shows acceptable limits (<5mm), in 8/9 (89%) subjects and 6/7 (86%) subjects of contrast and non-contrast CTs respectively. In the interobserver variability study it shows 6/9 (67%) subjects and 5/7 (71%) subjects respectively. The LPNFuse software allowed incorporation of the LPN course in CARTBox3. For the segmentation of right atrium and coronary sinus, the fast growing cut edge method was found to be better than the robust statistic segmenter. Though these segmentations were made in scans with non-optimal contrast distribution. Conclusion. In this study current clinical MRI technology was unsuitable to visualize the LPN. The developed segmentation method in CT is reproducible and had no preference for contrast or non-contrast CT images. Based on the same CTs, a method to define the coronary sinus ostium was developed. The next step is a proof-of-principle study to evaluate the clinical value of the implemented LPN and ostium in CB3 to guide the LV lead implantation during CRT.
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:44 medicine
Programme:Technical Medicine MSc (60033)
Link to this item:http://purl.utwente.nl/essays/74347
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