Figure 4.

In vivo imaging of the coronary artery with an implanted NIR fluorescent fibrin-labelled stent using the 4.5F/40MHz hybrid cNIRF-IVUS catheter. (A) Longitudinal cNIRF-IVUS fusion image of the artery. (B) Distance-corrected cNIRF signal measured in vivo through blood from the same artery shown in panel (a). (C) Intensity profile of NIRF concentration as function of NIRF catheter pullback position. (D) FRI of the resected coronary artery shown in panels (a) and (b). (E, F) Expanded view of the uncorrected and corrected NIRF image across the stented region, with (G) corresponding FM of the resected stent lumen surface after opening the stent longitudinally (red/orange pseudocolor = FTP11-Cy7 NIRF fibrin signal; green pseudocolor = FITC autofluorescence). Note that area 1 and 2 in (G) were not visible on the raw NIRF image (E), but were recovered as result of distance correction (F). Quantitative image analysis demonstrated good correlation between in vivo cNIRF (F) and resected stent FM (G) images (R= 0.74), that were improved compared to the raw NIRF and FM images (R= 0.68). (H) Representative cross-sectional cNIRF-IVUS images corresponding to pull back positions S1, S2, and S3 from panel (B). The cNIRF signal is fused on to the interior of the IVUS catheter and also the exterior boundary of the IVUS image (highlighted by red dotted lines). Scale bars, 1 mm.