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Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

Nam KH, Kim J, Ra G, Lee CH, Paeng DG - PLoS ONE (2015)

Bottom Line: The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results.In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images.The CAM artery model with the spectral analysis method is a useful in vivo experimental model for studying pulsatile variation in arterial geometry.

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Postgraduate Program in Biomedical Engineering, Jeju National University, Jeju, South Korea.

ABSTRACT
Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM) allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with the spectral analysis method is a useful in vivo experimental model for studying pulsatile variation in arterial geometry.

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Microscopic CAM artery images and vessel boundaries at systole and diastole.(A) CAM artery images and (B) corresponding vessel boundaries detected at peak systole and late diastole. Artery images were obtained from three ex ovo samples (#1: HH 35; #2: HH 34; #3; HH 37). Microscope magnification was ×40. Image size was 1,200 pixels × 1,200 pixels.
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pone.0145969.g003: Microscopic CAM artery images and vessel boundaries at systole and diastole.(A) CAM artery images and (B) corresponding vessel boundaries detected at peak systole and late diastole. Artery images were obtained from three ex ovo samples (#1: HH 35; #2: HH 34; #3; HH 37). Microscope magnification was ×40. Image size was 1,200 pixels × 1,200 pixels.

Mentions: Fig 2E presents a representative result of the boundary detection of the artery and vein captured in the same image. By superimposing the vessel boundaries at peak systole and late diastole on a single frame, the pattern of wall motion during a pulsatile cycle, such as the local variation of the wall movement direction and wall displacement amplitude, was well recognized visually. The zoomed-in images of the vessel boundaries in the artery (ROI 1) and vein (ROI 2) show that the artery had remarkable wall motion, but the wall displacement of the venous vessel was negligible. Fig 3 shows typical examples of microscopic CAM artery images obtained from three different ex ovo samples and the corresponding vessel boundaries observed at peak systole and late diastole. In case #1, the artery showed translational vessel movement in the up and down direction, whereas the arterial wall motion in case #2 was extremely weak and nearly unobservable. In the case of a curved artery (case #3), the analysis result showed large regional variations in wall displacement amplitude and direction, depending on the blood flow direction and curvature geometry.


Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

Nam KH, Kim J, Ra G, Lee CH, Paeng DG - PLoS ONE (2015)

Microscopic CAM artery images and vessel boundaries at systole and diastole.(A) CAM artery images and (B) corresponding vessel boundaries detected at peak systole and late diastole. Artery images were obtained from three ex ovo samples (#1: HH 35; #2: HH 34; #3; HH 37). Microscope magnification was ×40. Image size was 1,200 pixels × 1,200 pixels.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4696805&req=5

pone.0145969.g003: Microscopic CAM artery images and vessel boundaries at systole and diastole.(A) CAM artery images and (B) corresponding vessel boundaries detected at peak systole and late diastole. Artery images were obtained from three ex ovo samples (#1: HH 35; #2: HH 34; #3; HH 37). Microscope magnification was ×40. Image size was 1,200 pixels × 1,200 pixels.
Mentions: Fig 2E presents a representative result of the boundary detection of the artery and vein captured in the same image. By superimposing the vessel boundaries at peak systole and late diastole on a single frame, the pattern of wall motion during a pulsatile cycle, such as the local variation of the wall movement direction and wall displacement amplitude, was well recognized visually. The zoomed-in images of the vessel boundaries in the artery (ROI 1) and vein (ROI 2) show that the artery had remarkable wall motion, but the wall displacement of the venous vessel was negligible. Fig 3 shows typical examples of microscopic CAM artery images obtained from three different ex ovo samples and the corresponding vessel boundaries observed at peak systole and late diastole. In case #1, the artery showed translational vessel movement in the up and down direction, whereas the arterial wall motion in case #2 was extremely weak and nearly unobservable. In the case of a curved artery (case #3), the analysis result showed large regional variations in wall displacement amplitude and direction, depending on the blood flow direction and curvature geometry.

Bottom Line: The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results.In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images.The CAM artery model with the spectral analysis method is a useful in vivo experimental model for studying pulsatile variation in arterial geometry.

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Postgraduate Program in Biomedical Engineering, Jeju National University, Jeju, South Korea.

ABSTRACT
Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM) allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with the spectral analysis method is a useful in vivo experimental model for studying pulsatile variation in arterial geometry.

Show MeSH
Related in: MedlinePlus