title: Automated detection and measurement of isolated retinal arterioles by a combination of edge enhancement and cost analysis.
abstract: Pressure myography studies have played a crucial role in our understanding of vascular physiology and pathophysiology. Such studies depend upon the reliable measurement of changes in the diameter of isolated vessel segments over time. Although several software packages are available to carry out such measurements on small arteries and veins, no such software exists to study smaller vessels (<50 µm in diameter). We provide here a new, freely available open-source algorithm, MyoTracker, to measure and track changes in the diameter of small isolated retinal arterioles. The program has been developed as an ImageJ plug-in and uses a combination of cost analysis and edge enhancement to detect the vessel walls. In tests performed on a dataset of 102 images, automatic measurements were found to be comparable to those of manual ones. The program was also able to track both fast and slow constrictions and dilations during intraluminal pressure changes and following application of several drugs. Variability in automated measurements during analysis of videos and processing times were also investigated and are reported. MyoTracker is a new software to assist during pressure myography experiments on small isolated retinal arterioles. It provides fast and accurate measurements with low levels of noise and works with both individual images and videos. Although the program was developed to work with small arterioles, it is also capable of tracking the walls of other types of microvessels, including venules and capillaries. It also works well with larger arteries, and therefore may provide an alternative to other packages developed for larger vessels when its features are considered advantageous.
authors.affiliation: Centre for Experimental Medicine, The Queen's University of Belfast, Belfast, United Kingdom.
authors.forename: José A
authors.initials: JA
authors.lastname: Fernández
authors.affiliation: Centre for Cancer Research and Cell Biology, The Queen's University of Belfast, Belfast, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Bankhead
authors.affiliation: School of Electronics, Electrical Engineering and Computer Science, The Queen's University of Belfast, Belfast, United Kingdom.
authors.forename: Huiyu
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Centre for Experimental Medicine, The Queen's University of Belfast, Belfast, United Kingdom.
authors.forename: J Graham
authors.initials: JG
authors.lastname: McGeown
authors.affiliation: Centre for Experimental Medicine, The Queen's University of Belfast, Belfast, United Kingdom.
authors.forename: Tim M
authors.initials: TM
authors.lastname: Curtis
mesh_terms: D001160:Arterioles / Q000502:physiology; D006801:Humans; D008833:Microcirculation; D009213:Myography / Q000379:methods*; D012160:Retina / Q000502:physiology*; D012171:Retinal Vessels / Q000502:physiology*; D012984:Software