Fig 1.
Photo of a chick embryo CAM at HH stage 36 (10 days of incubation).
Transparent CAM with well developed vascular network over the yolk sac. An artery marked with arrows appears darker than vein marked with an asterisk.
Fig 2.
Schematic of vessel boundary detection.
Vessel image was obtained from the CAM of an ex ovo sample at HH stage 37 (11 days). Arrow and asterisk in (A) indicate artery and vein, respectively. Bottom panel in (B) shows the time domain plot of image brightness variation at marked position (1 mm in vertical length). (E) Systolic and diastolic geometries were superimposed on a single image. Zoomed-in images of ROIs 1 and 2 are displayed in left and right panels, respectively.
Fig 3.
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.
Fig 4.
RMS amplitude maps and waveform analysis.
(A) Local variations of RMS amplitude corresponding to artery images in Fig 3 are presented in false color maps. (B) Time-amplitude plots and frequency spectra obtained from FFT analysis at selected points in RMS amplitude maps are displayed.
Fig 5.
Harmonic amplitude maps of arterial wall motion.
Local variations of magnitude of (A) fundamental and (B) second harmonic components corresponding to artery images in Fig 3 are presented in false color maps. (C) Maps for fundamental to second harmonic magnitude ratio obtained from (A) and (B). Color bars in (C) indicate percentage of ratio.
Fig 6.
Phase angle maps of arterial wall motion.
Local variations in phase angle of fundamental component corresponding to Fig 5A are displayed in (A) continuous phase maps and (B) histograms.
Fig 7.
Microscopic CAM artery images and vessel boundaries at systole and diastole (bifurcated arteries).
(A) Arterial bifurcation images in CAMs and (B) corresponding vessel boundaries detected at peak systole and late diastole. Artery images were obtained from four ex ovo samples (#1: HH 36; #2: HH 37; #3; HH 36; #4: HH 36). Microscope magnification was ×40. Image size was 1,200 pixels × 1,200 pixels.
Fig 8.
RMS and harmonic amplitude maps of arterial wall motion (bifurcated arteries).
FFT analysis results of arterial wall dynamics corresponding to arterial bifurcation images in Fig 7. (A) Local variations in RMS amplitude, and magnitude of (B) fundamental and (C) second harmonic components are displayed in false color maps. (D) Maps for fundamental to second harmonic magnitude ratio obtained from (B) and (C). Color bars in (D) indicate percentage of ratio.
Fig 9.
Phase angle maps of arterial wall motion (bifurcated arteries).
Local variations in phase angle of fundamental component corresponding to Fig 8A are displayed in (A) continuous phase maps and (B) histograms.
Fig 10.
Representative results of wavelet transform analysis.
(A) Arterial bifurcation of case #3 is presented as a gray scale image. Pixel brightness waveforms and FFT frequency spectra at points of interests, p1 and p2, are presented in (B) and (C), respectively. (D) Wavelet scalograms at corresponding points are shown. Pseudo-frequencies for fundamental and second harmonic frequencies (3.2 and 6.4 Hz) in the FFT spectra correspond to 30.5 and 15.2 in scale in wavelet scalograms, respectively.