Leaflet Free Edge Detection for the Automatic Analysis of Prosthetic Heart Valve Opening and Closing Motion Patterns from High Speed Video Recordings

Improved Visualisation of Patient-Specific Heart Structure Using Three-Dimensional Printing Coupled with Image-Processing Techniques Inspired by Astrophysical Methods

“…This change-of-view also allowed for falsely-segmented areas from the axial view thresholding steps to be removed producing a clear picture of the tricuspid valve pattern in three-dimensions. The resulting segmented volume was then subsequently dilated 5 in preparation for thinning 5,11 during the design-fixing stage of processing. Dilation 5 of the image data extends any highlighted data point outward to its nearest neighbouring pixels in the axial, sagittal and coronal slices in accordance with the expression 5…”

“…Next, a higher threshold of [-600, 170] was applied in order to incorporate the brighter pixel platescale of the valve tissue into the model. Due to a large amount of calcification observed on the With the calcified region then highlighted to be included in the 3D rendering, it was then possible to observe the three aortic valve cusps and the tricuspid pattern where individual valve cusps partially overlap and occlude each other 11 . Using an axial view of the segmented valve, further enhancement of the tricuspid pattern was applied using Slicer 4.8.1's paint tool for a spherical brush of radius 1.400mm along the tricuspid lines of occlusion for a threshold range of [170,190] between the axial slices -977.768mm to -957.270mm.…”

“…Using the occlusion lines observed between axial slices -977.768mm to -957.270mm as a mask 11 , thresholding using Slicer 4.8.1's draw tool was selected for a threshold range [130,190] around areas where valve cusp outlines could be observed. In order to minimize error, and to provide a higher degree of clarity to the observed valve tissue, additional thresholding passes were applied to axial slices -977.768mm to -957.270mm for incrementally increasing thresholds of [190,200], [200,210] and [210,220].…”