Fluorescent angioscopic imaging of calcium phosphate tribasic: precursor of hydroxyapatite, the major calcium deposit in human coronary plaques

Figures

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  Fig. 1. Schematic representation of experimental procedures BPF band-pass filter, BAF band-absorption filter

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  Fig. 2. Fluorescence color of calcium phosphate tribasic (CPT) and a mixture of CPT and collagen I elicited by Lac dye (LD) CPT does not autofluoresce (arrow in A) but exhibited red fluorescence in the presence of LD (arrow in A1). A mixture of collagen I and CPT does not autofluoresce (arrow in B), but exhibits purple fluorescence in the presence of LD (arrow in B1)

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  Fig. 3. Color fluorescent angioscopic (CFA) and microscopic (CFM) observation of calcium phosphate tribasic (CPT) in a yellow plaque with a necrotic core (NC) The yellow plaque (arrow in A) exhibited diffuse green autofluorescence (arrow in B), indicating deposition of β-carotene with collagen I, lipids and/ or calcium compounds, which then exhibited purple fluorescence (arrow in B1) after the administration of Lac dye (LD), indicating the presence of CPT. Purple fluorescence was observed in luminal surface by CFM (arrow in C). The transected surface scan revealed that the CPT covered the plate-like structure that exhibited white fluorescence (arrows in D). The plate-like structure was stained dark brown by histology, strongly suggesting hydroxyapatite deposits (arrow in E). L, I and M indicate lumen, intima and media, respectively. Bar 100 µm

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  Fig. 4. Color fluorescent angioscopic (CFA) and microscopic (CFM) visualization of calcium phosphate tribasic (CPT) in a yellow plaque. a yellow plaque (arrow in A) exhibited light-yellow autofluorescence, indicating the presence of collagen I and lipids (arrow in B) [7]. Plaque exhibited a light-purple fluorescence (arrow in B1) in the presence of Lac dye (LD), indicating the presence of CPT. Luminal and transected surface scanning by CFM revealed amorphous light-purple material (arrows in D and D1). The amorphous deposits corresponded to amorphous purple deposits visualized by histology (arrow in D2), indicating the presence of CPT. L, I and M indicate lumen, intima and media, respectively. Bar 100 µm

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  Fig. 5. The relationship between the percentage (%) incidence of calcium phosphate tribasic (CPT) and plaque morphology. The incidence of CPT increased in the order of normal segments, white plaques, yellow plaques without necrotic core (NC) and yellow plaques with NC. n number of preparations examined