title: Effects of temperature on multiparametric evaluation of hindlimb ischemia with dynamic fluorescence imaging.
abstract: Quantitative evaluation of hindlimb ischemia is essential for early diagnosis and therapy of peripheral arterial disease (PAD). Dynamic imaging using near-infrared (NIR) fluorophore indocyanine green (ICG) is a noninvasive and effective tool to monitor multiple vascular parameters including perfusion rate (PR), perfusion vascular density (PVD) and hemodynamics. It has been previously demonstrated that temperature changes could lead to significant variations of blood flow rate and vascular perfusion. In this paper, multiparametric evaluation of hindlimb ischemia was performed at different temperatures. Five different parameters were extracted from dynamic fluorescence imaging, including PR, PVD, rising time (Trise), blood flow index (BFI) and mean fluorescence intensity (MFI). Temperatures varied from 15 °C to 40 °C were set on a mouse model of hindlimb ischemia. The aforementioned five parameters were obtained at each temperature. The results suggest that PVD, BFI and MFI could be effective indicators to distinguish ischemic tissues from normal tissues in mouse hindlimb at different temperatures. In contrast, PR is effective only when the temperature is higher than 25 °C, while Triseis effective only when the temperature is lower than 35 °C. The parameters of PVD, BFI and MFI could provide quantitative and comprehensive evaluation for PAD at different temperatures. (A) Bright-field image of the normal (left) and ischemic (right) hindlimbs. (B-D) Parametric images of perfusion vascular density, blood flow index and mean fluorescence intensity.
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Cai
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China.
authors.forename: Huizhi
authors.initials: H
authors.lastname: Guang
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China.
authors.forename: Chuangjian
authors.initials: C
authors.lastname: Cai
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China.|Center for Biomedical Imaging Research, Tsinghua University, Beijing, 100084, China.
authors.forename: Jianwen
authors.initials: J
authors.lastname: Luo
mesh_terms: D000818:Animals; D005260:Female; D005456:Fluorescent Dyes; D006614:Hindlimb / Q000473:pathology*; D007208:Indocyanine Green; D007511:Ischemia / Q000000981:diagnostic imaging*; D051379:Mice; D008807:Mice, Inbred BALB C; D061848:Optical Imaging; D013696:Temperature
chemical_list: D005456:Fluorescent Dyes; D007208:Indocyanine Green
keywords: dynamic fluorescence imaging; hemodynamics; hindlimb ischemia; perfusion; temperature