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Laser speckle contrast imaging

Robin Mirdell, Aukje Nienke Lemstra-Idsardi, Simon Farnebo, Erik Tesselaar
OBJECTIVES: Laser speckle contrast imaging (LSCI) has seen limited use in the study of perfusion dynamics such as vasomotion. The aim of this study was to investigate the effects of a prolonged seated position on perfusion dynamics in the nail bed using LSCI. METHODS: Perfusion was recorded in digits II to IV bilaterally for 20 min during two separate sessions in ten healthy volunteers. The acclimatization period was 5 min for the 1st session and 20 min for the 2nd...
October 12, 2018: Microvascular Research
Christoph R Behem, Michael F Graessler, Hans O Pinnschmidt, Anna Duprée, Harleen K Sandhu, E Sebastian Debus, Sabine H Wipper, Constantin J C Trepte
OBJECTIVES: In the presence of ischaemia/reperfusion (I/R) induced endothelial injury, volume administration may not correlate with increased microcirculation. The aim of this study was to evaluate intestinal microcirculation after standardised sequential volume loading in an animal model of I/R injury following supracoeliac aortic clamping. METHODS: This was a prospective exploratory pilot animal study. Intestinal I/R injury was induced in eight pigs during experimental thoraco-abdominal aortic repair...
October 8, 2018: European Journal of Vascular and Endovascular Surgery
Olga A Sindeeva, Olga I Gusliakova, Olga Inozemtseva, Arkady S Abdurashitov, Ekaterina P Brodovskaya, Meiyu Gai, Valery V Tuchin, Dmitry A Gorin, Gleb B Sukhorukov
This paper presents the synthesis of highly biocompatible and biodegradable poly-lactide-co-glycolide (PLGA) microchamber arrays sensitive to low-intensity therapeutic ultrasound (1 MHz, 1-2W, 1 min). A reliable method was elaborated that allowed the microchambers to be uniformly filled with epinephrine hydrochloride (EH), with the possibility of varying the cargo amount. The maximum load of EH was 4.5 μg per array of 5 mm x 5 mm (about 24 pg of EH per single microchamber). A gradual, spontaneous drug release was observed to start on the first day, which is especially important in the treatment of acute patients...
October 9, 2018: ACS Applied Materials & Interfaces
W G Xie, F Lei, J Wang, J Xu, J J Ruan, Z Li
Objective: To observe the clinical effects of sequential treatments of pulsed dye laser (PDL) and ablative fractional carbon dioxide laser on early stage hypertrophic burn scars. Methods: From January 2016 to December 2017, 221 patients with 228 hypertrophic scars in all parts of body within 6 months post healing, conforming to the study criteria and treated in our department, were included in this prospective study. They were first treated by PDL, repeated at an interval of one month until the vascularity score of scar fell below 2 points, and then treated by ablative fractional carbon dioxide laser, repeated at an interval of 3 months...
September 20, 2018: Zhonghua Shao Shang za Zhi, Zhonghua Shaoshang Zazhi, Chinese Journal of Burns
Bin Bo, Yao Li, Wanlu Li, Yongting Wang, Shanbao Tong
OBJECTIVE: Directly modulating targeted cortical function, brain stimulation provides promising techniques for stroke intervention. However, the cellular level mechanisms underlying preserved neurovascular function remains unclear. Optogenetics provides cell-specific approach to modulate neuronal activity. This study aims to investigate whether the exclusive excitation of sensorimotor neurons using optogenetics in acute stroke can protect neurovascular function and reduce infarct size...
October 1, 2018: IEEE Transactions on Bio-medical Engineering
Changhong Ren, Ning Li, Sijie Li, Rongrong Han, Qingjian Huang, Jiangnan Hu, Kunlin Jin, Xunming Ji
Intracranial and extracranial arterial stenosis, the primary cause of chronic cerebral hypoperfusion (CCH), is a critical reason for the pathogenesis of vascular dementia and Alzheimer's disease characterized by cognitive impairments. Our previous study demonstrated that limb remote ischemic conditioning (LRIC) improved cerebral perfusion in intracranial arterial stenosis patients. The current study aimed to test whether LRIC promotes angiogenesis and increases phosphorylated endothelial nitric oxide synthase (p-eNOS) activity in CCH rat model...
October 2018: Aging and Disease
Pei-Yu Chao, Wei-Wen Liu, Shih-Feng You, Pai-Chi Li
Shear wave elastography (SWE) has been widely adopted for clinical in vivo imaging of tissue elasticity for disease diagnosis, and this modality can be a valuable tool for in vitro mechanobiology studies but its full potential has yet to be explored. Here we present a laser speckle contrast SWE system for noncontact monitoring the spatiotemporal changes of the extracellular matrix (ECM) stiffness in three-dimensional cancer cell culture system while providing submillimeter spatial resolution and temporal resolution of 10 s...
September 27, 2018: Scientific Reports
X Wu, J Li, K Joypaul, W W Bao, D Wang, Y J Huang, P C Li, W Mei
BACKGROUND: Laser speckle contrast imaging allows real-time, non-invasive, quantitative measurements of regional blood flow. The objectives of this prospective observational study were to use laser speckle contrast imaging to evaluate blood flow changes after sciatic nerve block, and to determine whether this novel optical technique can evaluate block success. METHODS: This observational study included 63 adult patients undergoing elective lower limb surgery with sciatic nerve block...
October 2018: British Journal of Anaesthesia
Hari P Paudel, Clemens Alt, Judith Runnels, Charles P Lin
Differential interference contrast (DIC) microscopy is a powerful technique for imaging phase objects in transparent samples but does not work with scattering samples. This Letter, to the best of our knowledge, describes a new technique for obtaining DIC-like phase-gradient images in scattering media based on differential detection of forward-scattered light, using detectors arranged in a ring configuration around the microscope objective pupil or its conjugate pupil plane. This method, called pupil plane differential detection (P2D2) microscopy, does not need polarization optics or a confocal pinhole, yet produces images that are free of speckles and interference noises...
September 15, 2018: Optics Letters
Sae Uchida, Hiroshi Taniguchi, Yoshie Ito, Fusako Kagitani
We aimed to determine whether acupuncture to the auricular region increases cortical regional cerebral blood flow (rCBF). The rCBF was measured using laser speckle contrast imaging in urethane-anesthetized rats. Acupuncture stimulation was performed manually at the auricular concha or abdomen. The former's stimulation significantly increased the rCBF of the bilateral cerebral cortex in the frontal, parietal, and occipital lobes without altering the systemic arterial pressure. In contrast, abdominal stimulation affected neither rCBF nor systemic arterial pressure...
September 6, 2018: Journal of Physiological Sciences: JPS
O A Bragina, D A Lara, E M Nemoto, C W Shuttleworth, O V Semyachkina-Glushkovskaya, D E Bragin
Traumatic brain injury (TBI), causing neurological deficit in 70% of survivors, still lacks a clinically proven effective therapy. Transcranial direct current stimulation (tDCS) has emerged as a promising electroceutical therapeutic intervention possibly suitable for TBI; however, due to limited animal studies the mechanisms and optimal parameters are unknown. Using a mouse model of TBI we evaluated the acute effects of the anodal tDCS on cerebral blood flow (CBF) and tissue oxygenation, and assessed its efficacy in long-term neurologic recovery...
2018: Advances in Experimental Medicine and Biology
Rafi Sheikh, Josefine Bunke, Rannveig Linda Thorisdottir, Jenny Hult, Kajsa Tenland, Bodil Gesslein, Nina Reistad, Malin Malmsjö
BACKGROUND: The time taken for epinephrine to achieve its optimal effect during local anesthesia has recently become the subject of debate. The time from injection to commencement of surgery is traditionally quoted to be 7 to 10 min, while recent reports claim that it may take 30 min to achieve maximum hypoperfusion, which would prolong the time required for surgical procedures. The discrepancy may be related to difficulties associated with the techniques used to measure blood perfusion...
August 25, 2018: Microvascular Research
Shuo Hu, Tao Zheng, Yanchao Dong, Juan Du, Lanxiang Liu
Transcranial direct-current stimulation (DCS) offers a method for noninvasive neuromodulation usable in basic and clinical human neuroscience. Laser-speckle contrast imaging (LSCI), a powerful, low-cost method for obtaining images of dynamic systems, can detect regional blood-flow distributions with high spatial and temporal resolutions. Here, we used LSCI for measuring DCS-induced cerebral blood flow in real-time. Results showed that the change-rate of cerebral blood flow could reach approximately 10.1 ± 5...
2018: Frontiers in Neuroscience
Colin T Sullender, Andrew E Mark, Taylor A Clark, Tatiana V Esipova, Sergei A Vinogradov, Theresa A Jones, Andrew K Dunn
We present a dual-modality imaging system combining laser speckle contrast imaging and oxygen-dependent quenching of phosphorescence to simultaneously map cortical blood flow and oxygen tension ( <mml:math xmlns:mml=""> <mml:mrow> <mml:msub> <mml:mi>pO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ) in mice. Phosphorescence signal localization is achieved through the use of a digital micromirror device (DMD) that allows for selective excitation of arbitrary regions of interest...
July 2018: Neurophotonics
Marie-Pierre Cyr, Alexandra Pinard, Olivia Dubois, Mélanie Morin
BACKGROUND: Microvascular assessment has become increasingly used in gynecology to better understand the pathophysiology of various vulvar conditions and to study sexual function. Alteration in blood perfusion of the vulvar area has been observed using laser technologies in women with provoked vestibulodynia (PVD), the leading cause of vulvar pain. However, no studies have thus far investigated the reliability of and agreement between lasers for evaluating vulvar blood perfusion. OBJECTIVES: The main objective was to investigate the between-session reliability of the laser Doppler perfusion imaging (LDPI) and laser speckle contrast imaging (LSCI) for assessing blood perfusion of the vulvar vestibule in women with PVD...
August 16, 2018: Microvascular Research
Wei Feng, Rui Shi, Chao Zhang, Shaojun Liu, Tingting Yu, Dan Zhu
To realize visualization of the skin microvascular dysfunction of type 1 diabetic mice, we combined laser speckle contrast imaging and hyperspectral imaging to simultaneously monitor the noradrenaline (NE)-induced responses of vascular blood flow and blood oxygen with the development of diabetes through optical clearing skin window. The main results showed that venous and arterious blood flow decreased without recovery after injection of NE; furthermore, the decrease of arterious blood oxygen induced by NE greatly weakened, especially for 2- and 4-week diabetic mice...
August 2018: Journal of Biomedical Optics
Dong Wen, Yangyang Li, Xuan Zhu, Ming Chen, Jinling Lu, Pengcheng Li
Neural activity leads to alterations in cerebral blood flow (CBF), i.e., neurovascular regulation, which is implicated in brain physiology and pathology. Here a method for simultaneous imaging of CBF and spatially selective photoactivation of neural activity is proposed. CBF was obtained by laser speckle contrast imaging, and a liquid-crystal spatial light modulator (LC-SLM) was used to generate photoactivation patterns targeting designated locations in the cortex. Animal experiments stimulating defined cortical regions of VGAT-ChR2 and wild-type mice were conducted, and experiments with low-intensity stimulation were performed to investigate the influence of background light produced by the LC-SLM...
August 1, 2018: Optics Letters
Felix Jünger, Alexander Rohrbach
Cells change their shape within seconds, cellular protrusions even on subsecond timescales enabling various responses to stimuli of approaching bacteria, viruses or pharmaceutical drugs. Typical response patterns are governed by a complex reorganization of the actin cortex, where single filaments and molecules act on even faster timescales. These dynamics have remained mostly invisible due to a superposition of slow and fast motions, but also due to a lack of adequate imaging technology. Whereas fluorescence techniques require too long integration times, novel coherent techniques such as ROCS microscopy can achieve sufficiently high spatiotemporal resolution...
July 17, 2018: Cytoskeleton
Axel Neulen, Simon Meyer, Andreas Kramer, Tobias Pantel, Michael Kosterhon, Svenja Kunzelmann, Hermann Goetz, Serge C Thal
Clinical studies on subarachnoid hemorrhage (SAH) have shown discrepancies between large vessel vasospasm, cerebral perfusion, and clinical outcome. We set out to analyze the contribution of large vessel vasospasm to impaired cerebral perfusion and neurological impairment in a murine model of SAH. SAH was induced in C57BL/6 mice by endovascular filament perforation. Vasospasm was analyzed with microcomputed tomography, cortical perfusion by laser SPECKLE contrast imaging, and functional impairment with a quantitative neuroscore...
July 12, 2018: Translational Stroke Research
Wenzhi Lv, Yang Wang, Xiao Chen, Xiaoxi Fu, Jinling Lu, Pengcheng Li
Laser speckle contrast imaging (LSCI) is a full-field optical imaging method for monitoring blood flow and vascular morphology with high spatiotemporal resolution. However, due to the limited depth of field of optical system, it is difficult to capture a clear blood flow image with all blood vessels focused, especially for the non-planar biological tissues. In this paper, a multi-focus image fusion method based on contourlet transform is introduced to reduce the misfocus effects in LSCI. The experimental results suggest that this method can provide an all-in-focus blood flow image, which is convenient to observe the blood vessels...
June 28, 2018: Journal of Biophotonics
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