title: Ex vivo detection of macrophages in atherosclerotic plaques using intravascular ultrasonic-photoacoustic imaging.
abstract: Macrophages are excellent imaging targets for detecting atherosclerotic plaques as they are involved in all the developmental stages of atherosclerosis. However, no imaging technique is currently capable of visualizing macrophages inside blood vessel walls. The current study develops an intravascular ultrasonic-photoacoustic (IVUP) imaging system combined with indocyanine green (ICG) as a contrast agent to provide morphological and compositional information about the targeted samples. Both tissue-mimicking vessel phantoms and atherosclerotic plaque-mimicking porcine arterial tissues are used to demonstrate the feasibility of mapping macrophages labeled with ICG by endoscopically applying the proposed hybrid technique. A delay pulse triggering technique is able to sequentially acquire photoacoustic (PA) and ultrasound (US) signals from a single scan without using any external devices. The acquired PA and US signals are used to reconstruct 2D cross-sectional and 3D volumetric images of the entire tissue with the ICG-loaded macrophages injected. Due to high imaging contrast and sensitivity, the IVUP imaging vividly reveals structural information and detects the spatial distribution of the ICG-labeled macrophages inside the samples. ICG-assisted IVUP imaging can be a feasible imaging modality for the endoscopic detection of atherosclerotic plaques.
authors.affiliation: Interdisciplinary Program of Biomedical Mechanical & Electrical Engineering, Pukyong National University, Busan 48513, Korea.
authors.forename: Nhat Quang
authors.initials: NQ
authors.lastname: Bui
authors.forename: Kyu Kyu
authors.initials: KK
authors.lastname: Hlaing
authors.forename: Yong Wook
authors.initials: YW
authors.lastname: Lee
authors.forename: Hyun Wook
authors.initials: HW
authors.lastname: Kang
authors.forename: Junghwan
authors.initials: J
authors.lastname: Oh
mesh_terms: D000792:Angiography; D000818:Animals; D001808:Blood Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D003430:Cross-Sectional Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D007208:Indocyanine Green; D008264:Macrophages / Q000473:pathology*; D033401:Microscopy, Acoustic / Q000295:instrumentation* / Q000379:methods; D064847:Multimodal Imaging / Q000379:methods; D019047:Phantoms, Imaging; D058226:Plaque, Atherosclerotic / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013552:Swine; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
chemical_list: D007208:Indocyanine Green