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Hypoperfusion following the injection of epinephrine in human forearm skin can be measured by RGB analysis but not with laser speckle contrast imaging. Microvasc Res 2018; 121:7-13. [PMID: 30153456 DOI: 10.1016/j.mvr.2018.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 07/19/2018] [Accepted: 08/25/2018] [Indexed: 11/20/2022]
Abstract
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. The aim of this study was to test two methods of determining the time to maximum hypoperfusion. METHODS Laser speckle contrast imaging (LSCI) and red, green, blue (RGB) analysis of images obtained with a commercial digital camera, were used to monitor the effect of infiltration with commonly used local anesthetic preparations: lidocaine (20 mg/ml) + epinephrine (12.5 μg/ml), lidocaine (10 mg/ml) + epinephrine (5 μg/ml), and lidocaine (20 mg/ml) alone, in healthy subjects. RESULTS LSCI showed a paradoxical increase in signal after the injection of local anesthetics containing epinephrine, probably due to a change in the laser penetration depth resulting from blanching of the skin. However, RGB analysis of digital photographs gave more reliable results, showing skin blanching that corresponded to the expected effect of epinephrine in local anesthetics. The time to maximum effect was found to be 7 (range 5-10) minutes for 12.5 μg/ml epinephrine, and 9 (range 7-13) minutes for 5 μg/ml epinephrine in lidocaine. CONCLUSIONS RGB analysis of digital images proved to be a valid technique for monitoring the effect of local anesthetics with epinephrine in human skin. The technique requires only a commercial digital camera and constitutes a cheap, simple method. The optimal delay between epinephrine injection and incision, to minimize bleeding, was found to be 7 to 9 min, which is in good agreement with common surgical practice.
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Fazekas R, Molnár E, Nagy P, Mikecs B, Windisch P, Vág J. A Proposed Method for Assessing the Appropriate Timing of Early Implant Placements: A Case Report. J ORAL IMPLANTOL 2018; 44:378-383. [PMID: 29870305 DOI: 10.1563/aaid-joi-d-17-00295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Réka Fazekas
- 1 Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Eszter Molnár
- 1 Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Pál Nagy
- 2 Department of Periodontology, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Barbara Mikecs
- 1 Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Péter Windisch
- 2 Department of Periodontology, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - János Vág
- 1 Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
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Birkhoff W, de Vries J, Dent G, Verma A, Kerkhoffs J, van Meurs A, de Kam M, Moerland M, Burggraaf J. Retinal microcirculation imaging in sickle cell disease patients. Microvasc Res 2018; 116:1-5. [DOI: 10.1016/j.mvr.2017.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/05/2017] [Accepted: 09/05/2017] [Indexed: 01/24/2023]
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Tang YH, Thompson RW, Nathan C, Alexander JS, Lian T. Stem cells enhance reperfusion following ischemia: Validation using laser speckle imaging in predicting tissue repair. Laryngoscope 2018; 128:E198-E205. [DOI: 10.1002/lary.27110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Ya Hui Tang
- Department of Otolaryngology/HNSLSU Health Sciences CenterShreveport Louisiana U.S.A
| | - R. Will Thompson
- Department of Otolaryngology/HNSLSU Health Sciences CenterShreveport Louisiana U.S.A
| | - Cherie‐Ann Nathan
- Department of Otolaryngology/HNSLSU Health Sciences CenterShreveport Louisiana U.S.A
| | | | - Timothy Lian
- Department of Molecular and Cellular PhysiologyLSU Health Sciences CenterShreveport Louisiana U.S.A
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Loader J, Roustit M, Taylor F, MacIsaac RJ, Stewart S, Lorenzen C, Walther G. Assessing cutaneous microvascular function with iontophoresis: Avoiding non-specific vasodilation. Microvasc Res 2017; 113:29-39. [DOI: 10.1016/j.mvr.2017.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/26/2017] [Indexed: 10/19/2022]
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Tarantini S, Fulop GA, Kiss T, Farkas E, Zölei-Szénási D, Galvan V, Toth P, Csiszar A, Ungvari Z, Yabluchanskiy A. Demonstration of impaired neurovascular coupling responses in TG2576 mouse model of Alzheimer's disease using functional laser speckle contrast imaging. GeroScience 2017; 39:465-473. [PMID: 28578467 PMCID: PMC5636768 DOI: 10.1007/s11357-017-9980-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 05/23/2017] [Indexed: 01/28/2023] Open
Abstract
Increasing evidence from epidemiological, clinical, and experimental studies indicates that cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including both vascular cognitive impairment (VCI) and Alzheimer's disease. Vascular contributions to cognitive impairment and dementia (VCID) include impairment of neurovascular coupling responses/functional hyperemia ("neurovascular uncoupling"). Due to the growing interest in understanding and pharmacologically targeting pathophysiological mechanisms of VCID, there is an increasing need for sensitive, easy-to-establish methods to assess neurovascular coupling responses. Laser speckle contrast imaging (LSCI) is a technique that allows rapid and minimally invasive visualization of changes in regional cerebromicrovascular blood perfusion. This type of imaging technique combines high resolution and speed to provide great spatiotemporal accuracy to measure moment-to-moment changes in cerebral blood flow induced by neuronal activation. Here, we provide detailed protocols for the successful measurement in neurovascular coupling responses in anesthetized mice equipped with a thinned-skull cranial window using LSCI. This method can be used to evaluate the effects of anti-aging or anti-AD treatments on cerebromicrovascular health.
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Affiliation(s)
- Stefano Tarantini
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
| | - Gabor A Fulop
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
| | - Tamas Kiss
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
- Faculty of Medicine & Faculty of Science and Informatics, Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Faculty of Medicine & Faculty of Science and Informatics, Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Dániel Zölei-Szénási
- Faculty of Medicine & Faculty of Science and Informatics, Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Veronica Galvan
- Department of Cellular and Integrative Physiology, Barshop Institute for Longevity and Aging Studies University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Peter Toth
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
| | - Anna Csiszar
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
| | - Andriy Yabluchanskiy
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma, OK, 73104, USA.
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA.
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Laser speckle contrast imaging and Oxygen to See for assessing microcirculatory liver blood flow changes following different volumes of hepatectomy. Microvasc Res 2017; 110:14-23. [DOI: 10.1016/j.mvr.2016.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 12/14/2022]
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Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4042902. [PMID: 28232940 PMCID: PMC5292366 DOI: 10.1155/2017/4042902] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 01/04/2017] [Indexed: 01/25/2023]
Abstract
The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7–12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation.
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Milstein DM, Ince C, Gisbertz SS, Boateng KB, Geerts BF, Hollmann MW, van Berge Henegouwen MI, Veelo DP. Laser speckle contrast imaging identifies ischemic areas on gastric tube reconstructions following esophagectomy. Medicine (Baltimore) 2016; 95:e3875. [PMID: 27336874 PMCID: PMC4998312 DOI: 10.1097/md.0000000000003875] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Gastric tube reconstruction (GTR) is a high-risk surgical procedure with substantial perioperative morbidity. Compromised arterial blood supply and venous congestion are believed to be the main etiologic factors associated with early and late anastomotic complications. Identifying low blood perfusion areas may provide information on the risks of future anastomotic leakage and could be essential for improving surgical techniques. The aim of this study was to generate a method for gastric microvascular perfusion analysis using laser speckle contrast imaging (LSCI) and to test the hypothesis that LSCI is able to identify ischemic regions on GTRs.Patients requiring elective laparoscopy-assisted GTR participated in this single-center observational investigation. A method for intraoperative evaluation of blood perfusion and postoperative analysis was generated and validated for reproducibility. Laser speckle measurements were performed at 3 different time pointes, baseline (devascularized) stomach (T0), after GTR (T1), and GTR at 20° reverse Trendelenburg (T2).Blood perfusion analysis inter-rater reliability was high, with intraclass correlation coefficients for each time point approximating 1 (P < 0.0001). Baseline (T0) and GTR (T1) mean blood perfusion profiles were highest at the base of the stomach and then progressively declined towards significant ischemia at the most cranial point or anastomotic tip (P < 0.01). After GTR, a statistically significant improvement in mean blood perfusion was observed in the cranial gastric regions of interest (P < 0.05). A generalized significant decrease in mean blood perfusion was observed across all GTR regions of interest during 20° reverse Trendelenburg (P < 0.05).It was feasible to implement LSCI intraoperatively to produce blood perfusion assessments on intact and reconstructed whole stomachs. The analytical design presented in this study resulted in good reproducibility of gastric perfusion measurements between different investigators. LSCI provides spatial and temporal information on the location of adequate tissue perfusion and may thus be an important aid in optimizing surgical and anesthesiological procedures for strategically selecting anastomotic site in patients undergoing esophagectomy with GTR.
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Affiliation(s)
- Dan M.J. Milstein
- Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Can Ince
- Department of Translational Physiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Suzanne S. Gisbertz
- Department of Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Kofi B. Boateng
- Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Bart F. Geerts
- Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Markus W. Hollmann
- Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Denise P. Veelo
- Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Machado MV, Martins RL, Borges J, Antunes BR, Estato V, Vieira AB, Tibiriçá E. Exercise Training Reverses Structural Microvascular Rarefaction and Improves Endothelium-Dependent Microvascular Reactivity in Rats with Diabetes. Metab Syndr Relat Disord 2016; 14:298-304. [PMID: 27003580 DOI: 10.1089/met.2015.0146] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We evaluated structural microvascular alterations in the skeletal muscle and left ventricle, as well as endothelium-dependent microvascular reactivity in the skeletal muscle, of diabetic rats subjected to long-term aerobic exercise training. METHODS Diabetes was experimentally induced by a combination of a high-fat diet with a single low dose of streptozotocin (35 mg/kg, i.p.). Animals with diabetes were divided into sedentary (DM+SED) and training groups (DM+TR) and compared with rats without diabetes (CON). We then measured maximal exercise capacity, fasting glucose and insulin, endothelium-dependent microvascular reactivity in skeletal muscle, and structural alterations of microvasculature in the skeletal and cardiac muscles. RESULTS Diabetes induced microvascular rarefaction and reduced endothelium-dependent microvascular reactivity. Physical exercise completely reversed microvascular rarefaction in the skeletal muscle (1.85 ± 0.05 vs. 1.17 ± 0.03 capillary/fiber ratio, P < 0.05) and in the left ventricle (0.48 ± 0.66 vs. 0.25 ± 0.01 Vv[cap]/Vv[fib] ratio, P < 0.05) compared with the DM+SED group and normalized the microcirculatory responses to acetylcholine in skeletal muscle (CON 38.76 ± 5.60 vs. DM+TR 30.47% ± 5.77%). As expected, exercise training increased the maximal velocity and exercise tolerance compared with the DM+SED (P < 0.05) and CON (P < 0.05) groups. Exercise training also reduced fasting glucose (P < 0.05) compared with DM+SED and normalized insulin levels compared with CON. CONCLUSIONS Our results suggest that long-term physical exercise reverses skeletal and cardiac muscle microvascular rarefaction, as well as impaired endothelium-dependent microvascular reactivity, induced by diabetes in rats.
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Affiliation(s)
- Marcus V Machado
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
| | - Rômulo L Martins
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
| | - Juliana Borges
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
| | - Bárbara R Antunes
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
| | - Vanessa Estato
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
| | - Aline B Vieira
- 2 Laboratory of Inflammation, Oswaldo Cruz Institute, FIOCRUZ , Rio de Janeiro, Brazil
| | - Eduardo Tibiriçá
- 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil
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Tran BD, Chiu A, Tran C, Rogacion DR, Tfaye N, Ganesan G, Galassetti PR. Exercise and Repeated Testing Improves Accuracy of Laser Doppler Assessment of Microvascular Function Following Shortened (1-minute) Blood Flow Occlusion. Microcirculation 2016; 23:293-300. [PMID: 26998587 DOI: 10.1111/micc.12277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/14/2016] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To determine whether stability/accuracy of post-occlusive LDF following shortened, one-minute blood flow occlusion, increases in the post-exercise state or by averaging multiple measurements. METHODS Six healthy adults (3F) underwent LDF eight times at rest and following exercise, assessing post-occlusive (one-minute occlusion) reactive hyperemia in the cutaneous microcirculation of the forefinger. Measured variables included: pre- and post-occlusion steady-state perfusion (Plat1, Plat2), maximum post-occlusive perfusion (Max), PkT, and the ratio Max/Plat1. RESULTS Stability/accuracy of all variables improved performing measurements after exercise (p < 0.05 Plat 1, Plat 2, Max and Max/Plat1). PkT and Max/Plat 1 displayed the greatest accuracy at rest (26.6 ± 5.1% and 26.6 ± 4.4% average difference, %Diff, of single measurements from individual "true" means, respectively); for these variables, %Diff improved to 19.5 ± 5.3 and 17.6 ± 2.1, respectively, following exercise. Overall, averaging multiple measurements performed at rest also improved stability/accuracy in all variables. This improvement was comparable to that obtained with a single measurement following exercise. CONCLUSIONS A standardized exercise stimulus prior to testing significantly improves stability/accuracy of LDF following shortened, one-minute blood flow occlusion. Our results suggest the possibilities of broader applications of exercise to optimize measurements from a variety of skin perfusion methodologies.
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Affiliation(s)
- Brian D Tran
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Abraham Chiu
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Charlene Tran
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Danica Rose Rogacion
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Nicole Tfaye
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Goutham Ganesan
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Pietro R Galassetti
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
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Zötterman J, Bergkvist M, Iredahl F, Tesselaar E, Farnebo S. Monitoring of partial and full venous outflow obstruction in a porcine flap model using laser speckle contrast imaging. J Plast Reconstr Aesthet Surg 2016; 69:936-43. [PMID: 27026039 DOI: 10.1016/j.bjps.2016.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 01/28/2016] [Accepted: 02/28/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND In microsurgery, there is a demand for more reliable methods of post-operative monitoring of free flaps, especially with regard to tissue-threatening obstructions of the feeding arteries and draining veins. In this study, we evaluated laser speckle contrast imaging (LSCI) and laser Doppler flowmetry (LDF) to assess their possibilities to detect partial and full venous outflow obstruction, as well as full arterial occlusion, in a porcine flap model. METHODS Cranial gluteal artery perforator flaps (CGAPs) were raised, and arterial and venous blood flow to and from the flaps was monitored using ultrasonic flow probes. The venous flow was altered with an inflatable cuff to simulate partial and full (50% and 100%) venous obstruction, and arterial flow was completely obstructed using clamps. The flap microcirculation was monitored using LSCI and LDF. RESULTS Both LDF and the LSCI detected significant changes in flap perfusion. After partial (50%) venous occlusion, perfusion decreased from baseline, LSCI: 63.5 ± 12.9 PU (p = 0.01), LDF 31.3 ± 15.7 (p = 0.64). After 100% venous occlusion, a further decrease in perfusion was observed: LSCI 54.6 ± 14.2 PU (p < 0.001) and LDF 16.7 ± 12.8 PU (p < 0.001). After release of the venous cuff, LSCI detected a return of the perfusion to a level slightly, but not significantly, below the baseline level 70.1 ± 11.5 PU (p = 0.39), while the LDF signal returned to a level not significant from the baseline 36.1 ± 17.9 PU (p > 0.99). Perfusion during 100% arterial occlusion decreased significantly as measured with both methods, LSCI: 48.3 ± 7.7 (PU, p < 0.001) and LDF: 8.5 ± 4.0 PU (p < 0.001). During 50% and 100% venous occlusion, LSCI showed a 20% and 26% intersubject variability (CV%), respectively, compared to 50% and 77% for LDF. CONCLUSIONS LSCI offers sensitive and reproducible measurements of flap microcirculation and seems more reliable in detecting decreases in blood perfusion caused by venous obstruction. It also allows for perfusion measurements in a relatively large area of flap tissue. This may be useful in identifying areas of the flap with compromised microcirculation during and after surgery.
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Affiliation(s)
- Johan Zötterman
- Department of Hand and Plastic Surgery and Burns, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Max Bergkvist
- Department of Hand and Plastic Surgery and Burns, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Fredrik Iredahl
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Radiation Physics, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand and Plastic Surgery and Burns, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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Del Pozzi AT, Miller JT, Hodges GJ. The effect of heating rate on the cutaneous vasomotion responses of forearm and leg skin in humans. Microvasc Res 2016; 105:77-84. [PMID: 26808211 DOI: 10.1016/j.mvr.2016.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 11/19/2022]
Abstract
We examined skin blood flow (SkBF) and vasomotion in the forearm and leg using laser-Doppler fluxmetry (LDF) and spectral analysis to investigate endothelial, sympathetic, and myogenic activities in response to slow (0.1 °C·10 s(-1)) and fast (0.5 °C·10 s(-1)) local heating. At 33 °C (thermoneutral) endothelial activity was higher in the legs than the forearms (P ≤ 0.02). Fast-heating increased SkBF more than slow heating (P=0.037 forearm; P=0.002 leg). At onset of 42 °C, endothelial (P=0.043 forearm; P=0.48 leg) activity increased in both regions during the fast-heating protocol. Following prolonged heating (42 °C) endothelial activity was higher in both the forearm (P=0.002) and leg (P<0.001) following fast-heating. These results confirm regional differences in the response to local heating and suggest that the greater increase in SkBF in response to fast local heating is initially due to increased endothelial and sympathetic activity. Furthermore, with sustained local skin heating, greater vasodilatation was observed with fast heating compared to slow heating. These data indicate that this difference is due to greater endothelial activity following fast heating compared to slow heating, suggesting that the rate of skin heating may alter the mechanisms contributing to cutaneous vasodilatation.
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Affiliation(s)
- Andrew T Del Pozzi
- Integrative Exercise Physiology Laboratory, School of Kinesiology, Ball State University, Muncie, IN 47306, United States
| | - James T Miller
- Exercise Physiology Laboratory, Department of Kinesiology, The University of Alabama, Tuscaloosa, AL 35487, United States
| | - Gary J Hodges
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada.
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Ambrus R, Strandby RB, Svendsen LB, Achiam MP, Steffensen JF, Søndergaard Svendsen MB. Laser Speckle Contrast Imaging for Monitoring Changes in Microvascular Blood Flow. Eur Surg Res 2016; 56:87-96. [PMID: 26779925 DOI: 10.1159/000442790] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/13/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Microvascular blood flow is essential for healing and predicts surgical outcome. The aim of the current study was to investigate the relation between fluxes measured with the laser speckle contrast imaging (LSCI) technique and changes in absolute blood flow. In addition, we studied the reproducibility of the LSCI technique when assessing the intra-abdominal microcirculation of the pig. METHODS During trial 1, a fish gill arch was mechanically perfused with heparinized fish blood under controlled stepwise-altered flow rates alongside mechanically induced movement artefacts. The microcirculation of the fish gill was simultaneously assessed with the LSCI technique. In trial 2, microcirculation was measured in the stomach, liver, and small intestine of 10 pigs by two observers. RESULTS A linear correlation was observed between flux and volumetric flow. During conditions of no volumetric flow, the high recording speed with the LSCI technique registered the movement artefacts as flow signals. The LSCI measurements showed good correlation and agreement between the two observers when assessing microcirculation in the stomach, liver, and small intestine (r2 = 0.857, 0.956, and 0.946; coefficients of variation = 6.0, 3.2, and 6.4%, respectively). CONCLUSION Due to the non-contact and real-time assessment over large areas, LSCI is a promising technique for the intraoperative assessment of intra-abdominal microcirculation. A linear correlation between flux and volumetric flow was found, in accordance with previous experimental studies. However, movement artefacts affect flux measurements, and the choice of the sampling speed must be made with care, depending on the given setting.
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Affiliation(s)
- Rikard Ambrus
- Department of Surgical Gastroenterology C, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark
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Chen D, Ren J, Wang Y, Zhao H, Li B, Gu Y. Relationship between the blood perfusion values determined by laser speckle imaging and laser Doppler imaging in normal skin and port wine stains. Photodiagnosis Photodyn Ther 2015; 13:1-9. [PMID: 26592337 DOI: 10.1016/j.pdpdt.2015.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/02/2015] [Accepted: 11/18/2015] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Laser Doppler imaging (LDI) and laser speckle imaging (LSI) are two major optical techniques aiming at non-invasively imaging the skin blood perfusion. However, the relationship between perfusion values determined by LDI and LSI has not been fully explored. METHODS 8 healthy volunteers and 13 PWS patients were recruited. The perfusions in normal skin on the forearm of 8 healthy volunteers were simultaneously measured by both LDI and LSI during post-occlusive reactive hyperemia (PORH). Furthermore, the perfusions of port wine stains (PWS) lesions and contralateral normal skin of 10 PWS patients were also determined. In addition, the perfusions for PWS lesions from 3 PWS patients were successively monitored at 0, 10 and 20min during vascular-targeted photodynamic therapy (V-PDT). The average perfusion values determined by LSI were compared with those of LDI for each subject. RESULTS In the normal skin during PORH, power function provided better fits of perfusion values than linear function: powers for individual subjects go from 1.312 to 1.942 (R(2)=0.8967-0.9951). There was a linear relationship between perfusion values determined by LDI and LSI in PWS and contralateral normal skin (R(2)=0.7308-0.9623), and in PWS during V-PDT (R(2)=0.8037-0.9968). CONCLUSION The perfusion values determined by LDI and LSI correlate closely in normal skin and PWS over a broad range of skin perfusion. However, it still suggests that perfusion range and characteristics of the measured skin should be carefully considered if LDI and LSI measures are compared.
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Affiliation(s)
- Defu Chen
- School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Jie Ren
- Department of Laser Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Ying Wang
- Department of Laser Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Hongyou Zhao
- Department of Laser Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Buhong Li
- Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fujian 350007, China
| | - Ying Gu
- Department of Laser Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China.
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66
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Sun S, Hayes-Gill BR, He D, Zhu Y, Morgan SP. Multi-exposure laser speckle contrast imaging using a high frame rate CMOS sensor with a field programmable gate array. OPTICS LETTERS 2015; 40:4587-90. [PMID: 26469570 DOI: 10.1364/ol.40.004587] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A system has been developed in which multi-exposure laser speckle contrast imaging (LSCI) is implemented using a high frame rate CMOS imaging sensor chip. Processing is performed using a field programmable gate array (FPGA). The system allows different exposure times to be simulated by accumulating a number of short exposures. This has the advantage that the image acquisition time is limited by the maximum exposure time and that regulation of the illuminating light level is not required. This high frame rate camera has also been deployed to implement laser Doppler blood flow processing, enabling a direct comparison of multi-exposure laser speckle imaging and laser Doppler imaging (LDI) to be carried out using the same experimental data. Results from a rotating diffuser indicate that both multi-exposure LSCI and LDI provide a linear response to changes in velocity. This cannot be obtained using single-exposure LSCI, unless an appropriate model is used for correcting the response.
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67
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Detection of Site-Specific Blood Flow Variation in Humans during Running by a Wearable Laser Doppler Flowmeter. SENSORS 2015; 15:25507-19. [PMID: 26445047 PMCID: PMC4634506 DOI: 10.3390/s151025507] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/03/2015] [Accepted: 09/29/2015] [Indexed: 12/19/2022]
Abstract
Wearable wireless physiological sensors are helpful for monitoring and maintaining human health. Blood flow contains abundant physiological information but it is hard to measure blood flow during exercise using conventional blood flowmeters because of their size, weight, and use of optic fibers. To resolve these disadvantages, we previously developed a micro integrated laser Doppler blood flowmeter using microelectromechanical systems technology. This micro blood flowmeter is wearable and capable of stable measurement signals even during movement. Therefore, we attempted to measure skin blood flow at the forehead, fingertip, and earlobe of seven young men while running as a pilot experiment to extend the utility of the micro blood flowmeter. We measured blood flow in each subject at velocities of 6, 8, and 10 km/h. We succeeded in obtaining stable measurements of blood flow, with few motion artifacts, using the micro blood flowmeter, and the pulse wave signal and motion artifacts were clearly separated by conducting frequency analysis. Furthermore, the results showed that the extent of the changes in blood flow depended on the intensity of exercise as well as previous work with an ergometer. Thus, we demonstrated the capability of this wearable blood flow sensor for measurement during exercise.
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68
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Loader J, Montero D, Lorenzen C, Watts R, Méziat C, Reboul C, Stewart S, Walther G. Acute Hyperglycemia Impairs Vascular Function in Healthy and Cardiometabolic Diseased Subjects. Arterioscler Thromb Vasc Biol 2015; 35:2060-72. [DOI: 10.1161/atvbaha.115.305530] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/16/2015] [Indexed: 02/04/2023]
Abstract
Objectives—
Controversy exists over the effect of acute hyperglycemia on vascular function. In this systematic review, we compared the effect of acute hyperglycemia on endothelial and vascular smooth muscle functions across healthy and cardiometabolic diseased subjects.
Approach and Results—
A systematic search of MEDLINE, EMBASE, and Web of Science from inception until July 2014 identified articles evaluating endothelial or vascular smooth muscle function during acute hyperglycemia and normoglycemia. Meta-analyses compared the standardized mean difference (SMD) in endothelial and vascular smooth muscle functions between acute hyperglycemia and normoglycemia. Subgroup analyses and metaregression identified sources of heterogeneity. Thirty-nine articles (525 healthy and 540 cardiometabolic subjects) were analyzed. Endothelial function was decreased (39 studies; n=1065; SMD, −1.25; 95% confidence interval, −1.52 to −0.98;
P
<0.01), whereas vascular smooth muscle function was preserved (6 studies; n=144; SMD, −0.07; 95% confidence interval, −0.30 to 0.16;
P
=0.55) during acute hyperglycemia compared with normoglycemia. Significant heterogeneity was detected among endothelial function studies (
P
<0.01). A subgroup analysis revealed that endothelial function was decreased in the macrocirculation (30 studies; n=884; SMD, −1.40; 95% confidence interval, −1.68 to −1.12;
P
<0.01) but not in the microcirculation (9 studies; n=181; SMD, −0.63; 95% confidence interval, −1.36 to 0.11;
P
=0.09). Similar results were observed according to health status. Macrovascular endothelial function was inversely associated with age, blood pressure, and low-density lipoprotein cholesterol and was positively associated with the postocclusion interval of vascular assessment.
Conclusions—
To our knowledge, this is the first systematic review and meta-analysis of its kind. In healthy and diseased subjects, we found evidence for macrovascular but not microvascular endothelial dysfunction during acute hyperglycemia.
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Affiliation(s)
- Jordan Loader
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - David Montero
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Christian Lorenzen
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Rani Watts
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Cindy Méziat
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Cyril Reboul
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Simon Stewart
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
| | - Guillaume Walther
- From the Avignon University, LAPEC EA4278, Avignon, France (J.L., C.M., C.R., G.W.); School of Exercise Science (J.L., C.L., R.W., G.W.) and The Mary MacKillop Institute for Health Research (S.S.), Australian Catholic University, Melbourne, Victoria, Australia; and Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland (D.M.)
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69
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Wu CY, Yeh YC, Chien CT, Chao A, Sun WZ, Cheng YJ. Laser speckle contrast imaging for assessing microcirculatory changes in multiple splanchnic organs and the gracilis muscle during hemorrhagic shock and fluid resuscitation. Microvasc Res 2015; 101:55-61. [DOI: 10.1016/j.mvr.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 06/06/2015] [Accepted: 06/06/2015] [Indexed: 10/23/2022]
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70
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Hellmann M, Roustit M, Cracowski JL. Skin microvascular endothelial function as a biomarker in cardiovascular diseases? Pharmacol Rep 2015; 67:803-10. [DOI: 10.1016/j.pharep.2015.05.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 11/17/2022]
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71
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Barwick A, Lanting S, Chuter V. Intra-tester and inter-tester reliability of post-occlusive reactive hyperaemia measurement at the hallux. Microvasc Res 2015; 99:67-71. [DOI: 10.1016/j.mvr.2015.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/06/2015] [Accepted: 03/07/2015] [Indexed: 11/29/2022]
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72
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Verri V, Brandão A, Tibirica E. The evaluation of penile microvascular endothelial function using laser speckle contrast imaging in healthy volunteers. Microvasc Res 2015; 99:96-101. [DOI: 10.1016/j.mvr.2015.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/25/2015] [Accepted: 03/26/2015] [Indexed: 11/27/2022]
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73
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Bi R, Dong J, Poh CL, Lee K. Optical methods for blood perfusion measurement--theoretical comparison among four different modalities. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2015; 32:860-6. [PMID: 26366910 DOI: 10.1364/josaa.32.000860] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Blood perfusion in human tissue can be measured in vivo by means of various optical methods, which seem to be very different from one another. The most prominent examples of them are laser Doppler flowmetry, laser speckle contrast imaging, diffuse correlation spectroscopy, and the most recently developed diffuse speckle contrast analysis. In this paper, we claim that these four seemingly different modalities are examining different aspects of the same entity-the temporal autocorrelation function of scattered photons. We will show how the observables in each modality can be theoretically derived from the temporal autocorrelation function, and will discuss the merits and drawbacks of each modality in its practical use.
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74
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Del Pozzi AT, Hodges GJ. To reheat, or to not reheat: that is the question: The efficacy of a local reheating protocol on mechanisms of cutaneous vasodilatation. Microvasc Res 2015; 97:47-54. [DOI: 10.1016/j.mvr.2014.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/08/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
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75
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Cheung SS. Responses of the hands and feet to cold exposure. Temperature (Austin) 2015; 2:105-20. [PMID: 27227009 PMCID: PMC4843861 DOI: 10.1080/23328940.2015.1008890] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 11/19/2022] Open
Abstract
An initial response to whole-body or local exposure of the extremities to cold is a strong vasoconstriction, leading to a rapid decrease in hand and foot temperature. This impairs tactile sensitivity, manual dexterity, and muscle contractile characteristics while increasing pain and sympathetic drive, decreasing gross motor function, occupational performance, and survival. A paradoxical and cyclical vasodilatation often occurs in the fingers, toes, and face, and this has been termed the hunting response or cold-induced vasodilatation (CIVD). Despite being described almost a century ago, the mechanisms of CIVD are still disputed; research in this area has remained largely descriptive in nature. Recent research into CIVD has brought increased standardization of methodology along with new knowledge about the impact of mediating factors such as hypoxia and physical fitness. Increasing mechanistic analysis of CIVD has also emerged along with improved modeling and prediction of CIVD responses. The present review will survey work conducted during this century on CIVD, its potential mechanisms and modeling, and also the broader context of manual function in cold conditions.
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Affiliation(s)
- Stephen S Cheung
- Environmental Ergonomics Laboratory; Department of Kinesiology ; Brock University; St. Catharines , Canada
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76
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Eriksson S, Nilsson J, Sturesson C. Non-invasive imaging of microcirculation: a technology review. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2014; 7:445-52. [PMID: 25525397 PMCID: PMC4267586 DOI: 10.2147/mder.s51426] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Microcirculation plays a crucial role in physiological processes of tissue oxygenation and nutritional exchange. Measurement of microcirculation can be applied on many organs in various pathologies. In this paper we aim to review the technique of non-invasive methods for imaging of the microcirculation. Methods covered are: videomicroscopy techniques, laser Doppler perfusion imaging, and laser speckle contrast imaging. Videomicroscopy techniques, such as orthogonal polarization spectral imaging and sidestream dark-field imaging, provide a plentitude of information and offer direct visualization of the microcirculation but have the major drawback that they may give pressure artifacts. Both laser Doppler perfusion imaging and laser speckle contrast imaging allow non-contact measurements but have the disadvantage of their sensitivity to motion artifacts and that they are confined to relative measurement comparisons. Ideal would be a non-contact videomicroscopy method with fully automatic analysis software.
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Affiliation(s)
- Sam Eriksson
- Department of Surgery, Clinical Sciences Lund, Lund University, Lund, Sweden ; Skåne University Hospital, Lund, Sweden
| | - Jan Nilsson
- Department of Surgery, Clinical Sciences Lund, Lund University, Lund, Sweden ; Skåne University Hospital, Lund, Sweden
| | - Christian Sturesson
- Department of Surgery, Clinical Sciences Lund, Lund University, Lund, Sweden ; Skåne University Hospital, Lund, Sweden
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77
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Johnson JM, Minson CT, Kellogg DL. Cutaneous vasodilator and vasoconstrictor mechanisms in temperature regulation. Compr Physiol 2014; 4:33-89. [PMID: 24692134 DOI: 10.1002/cphy.c130015] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this review, we focus on significant developments in our understanding of the mechanisms that control the cutaneous vasculature in humans, with emphasis on the literature of the last half-century. To provide a background for subsequent sections, we review methods of measurement and techniques of importance in elucidating control mechanisms for studying skin blood flow. In addition, the anatomy of the skin relevant to its thermoregulatory function is outlined. The mechanisms by which sympathetic nerves mediate cutaneous active vasodilation during whole body heating and cutaneous vasoconstriction during whole body cooling are reviewed, including discussions of mechanisms involving cotransmission, NO, and other effectors. Current concepts for the mechanisms that effect local cutaneous vascular responses to local skin warming and cooling are examined, including the roles of temperature sensitive afferent neurons as well as NO and other mediators. Factors that can modulate control mechanisms of the cutaneous vasculature, such as gender, aging, and clinical conditions, are discussed, as are nonthermoregulatory reflex modifiers of thermoregulatory cutaneous vascular responses.
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Affiliation(s)
- John M Johnson
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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78
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Eriksson S, Nilsson J, Lindell G, Sturesson C. Laser speckle contrast imaging for intraoperative assessment of liver microcirculation: a clinical pilot study. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2014; 7:257-61. [PMID: 25114599 PMCID: PMC4122554 DOI: 10.2147/mder.s63393] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Liver microcirculation can be affected by a wide variety of causes relevant to liver transplantation and resectional surgery. Intraoperative assessment of the microcirculation could possibly predict postoperative outcome. The present pilot study introduces laser speckle contrast imaging (LSCI) as a new clinical method for assessing liver microcirculation. Methods LSCI measurements of liver microcirculation were performed on ten patients undergoing liver resection. Measurements were made during apnea with and without liver blood inflow occlusion. Hepatic blood flow was assessed by subtracting zero inflow signal from the total signal. Zero inflow signal was obtained after hepatic artery and portal vein occlusion. Perfusion was expressed in laser speckle perfusion units, and intraindividual and interindividual variability in liver perfusion was investigated using the coefficient of variability. Results Hepatic microcirculation measurements were successfully made in all patients resulting in analyzable speckle contrast images. Mean hepatic blood flow was 410±36 laser speckle perfusion units. Zero inflow signal amounted to 40%±4% of the total signal. Intraindividual and interindividual coefficients of variability in liver perfusion were 25% and 28%, respectively. Conclusion Under the conditions of this pilot study, LSCI allows rapid noncontact measurements of hepatic blood perfusion over wide areas. More studies are needed on methods of handling movement artifacts.
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Affiliation(s)
- Sam Eriksson
- Department of Surgery, Clinical Sciences Lund, Lund University, Sweden ; Skåne University Hospital, Lund, Sweden
| | - Jan Nilsson
- Department of Surgery, Clinical Sciences Lund, Lund University, Sweden ; Skåne University Hospital, Lund, Sweden
| | - Gert Lindell
- Department of Surgery, Clinical Sciences Lund, Lund University, Sweden ; Skåne University Hospital, Lund, Sweden
| | - Christian Sturesson
- Department of Surgery, Clinical Sciences Lund, Lund University, Sweden ; Skåne University Hospital, Lund, Sweden
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79
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Li CH, Wang HD, Hu JJ, Ge XL, Pan K, Zhang AQ, Dong JH. The monitoring of microvascular liver blood flow changes during ischemia and reperfusion using laser speckle contrast imaging. Microvasc Res 2014; 94:28-35. [DOI: 10.1016/j.mvr.2014.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 04/14/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
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80
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Allen J, Howell K. Microvascular imaging: techniques and opportunities for clinical physiological measurements. Physiol Meas 2014; 35:R91-R141. [DOI: 10.1088/0967-3334/35/7/r91] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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81
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Puissant C, Abraham P, Durand S, Humeau-Heurtier A, Faure S, Leftheriotis G, Mahé G. Assessment of endothelial function by acetylcholine iontophoresis: Impact of inter-electrode distance and electrical cutaneous resistance. Microvasc Res 2014; 93:114-8. [DOI: 10.1016/j.mvr.2014.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 11/25/2022]
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Abstract
Microvascular dysfunction in diabetes plays a crucial role in the development of diabetic complications. The skin, as one of the most accessible organs, serves as a model for the investigation of microvascular dysfunction. Several non-invasive, mostly laser-Doppler-based methods have been developed lately to assess microvascular function in the skin. Microvascular functional changes occur even in the prediabetic state and become more complex with overt diabetes, being exacerbated by the presence of peripheral and/or autonomic diabetic neuropathy. The present article aims at shedding light on the implication of endothelial and neurovascular dysfunction in microvascular changes in diabetes, highlighting the contribution of different forms of diabetic neuropathy.
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Affiliation(s)
- Alin Stirban
- Profil Institute for Metabolic Research, Hellersbergstr. 9, 41460, Neuss, Germany,
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83
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Humeau-Heurtier A, Abraham P, Mahe G. Linguistic Analysis of Laser Speckle Contrast Images Recorded at Rest and During Biological Zero: Comparison With Laser Doppler Flowmetry Data. IEEE TRANSACTIONS ON MEDICAL IMAGING 2013; 32:2311-2321. [PMID: 24058017 DOI: 10.1109/tmi.2013.2281620] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Laser speckle contrast imaging (LSCI) is a newly commercialized imaging modality to monitor microvascular blood flow. Contrary to the well-known laser Doppler flowmetry (LDF), LSCI has the advantage of giving a full-field image of surface blood flow using simple instrumentation. However, laser speckle contrast images are not fully understood yet and their link with LDF signals still has to be studied. To quantify the similarity between LSCI and LDF symbolic sequences, we propose to use, for the first time, the index adapted from linguistic analysis and information theory proposed by Yang For this purpose, LSCI and LDF data were recorded simultaneously on the forearm of healthy subjects, at rest and during a vascular occlusion (biological zero). We show that there are different dynamical patterns for LSCI and LDF data, and the distances between these patterns differ through the space scales explored. Moreover, our results suggest that these different dynamical patterns could be linked to blood flow. The quantitative metric used herein therefore provides new information on LSCI and brings knowledge on links between LSCI and LDF.
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84
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Del Pozzi AT, Carter SJ, Collins AB, Hodges GJ. The regional differences in the contribution of nitric oxide synthase to skin blood flow at forearm and lower leg sites in response to local skin warming. Microvasc Res 2013. [DOI: 10.1016/j.mvr.2013.10.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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85
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Petersen LJ. Direct comparison of laser Doppler flowmetry and laser Doppler imaging for assessment of experimentally-induced inflammation in human skin. Inflamm Res 2013; 62:1073-8. [DOI: 10.1007/s00011-013-0668-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 09/17/2013] [Indexed: 11/29/2022] Open
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86
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Nguyen-Tu MS, Begey AL, Decorps J, Boizot J, Sommer P, Fromy B, Sigaudo-Roussel D. Skin microvascular response to pressure load in obese mice. Microvasc Res 2013; 90:138-43. [PMID: 24120748 DOI: 10.1016/j.mvr.2013.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/06/2013] [Accepted: 10/02/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE The role of obesity in the appearance of skin pressure ulcers remains controversial. The aim of the present study was to evaluate blood perfusion and related lesions after skin compression in obese mice. METHODS Sixty C57BL6 male mice were randomly assigned to a control or hypercalorific diet (HCD) for 2, 4 and 12weeks. Skin compression was induced by a magnetic force of 11 kPa overlying a subcutaneous metal plate and applied for 4h. Skin perfusion was examined using laser Doppler imaging before skin compression, immediately after compression release and 24h later. 24h after magnet removal, skin injuries were determined by photography. RESULTS A heterogeneous distribution of blood perfusion was observed using the colour-coded map of the skin perfusion on the compressed area. At 24-h post-compression release, 60% to 75% of the compressed area was ischaemic in the 2-week HCD group and in all the control groups compared to 35% in the 4- and 15% in the 12-week HCD groups. The lowest occurrence of skin lesion seen as skin redness or pressure-sores was observed in the 12- week HCD group (4%) compared to about 12% in either the control or the 2- and 4-week HCD groups. CONCLUSIONS This study suggests that there was no clear relationship between the extent of ischaemia and skin lesion occurrence after skin compression in short-duration obese mice. In contrast, it appears that long-duration obesity could reduce both ischaemia and skin lesions in response to skin compression through changes in skin structure.
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Affiliation(s)
- Marie-Sophie Nguyen-Tu
- UMR 5305 CNRS, 69 367 Lyon cedex 07, France; University of Lyon 1, 69 367 Lyon cedex 07, France
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Roustit M, Cracowski JL. Assessment of endothelial and neurovascular function in human skin microcirculation. Trends Pharmacol Sci 2013; 34:373-84. [DOI: 10.1016/j.tips.2013.05.007] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/03/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
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Binzoni T, Humeau-Heurtier A, Abraham P, Mahe G. Blood Perfusion Values of Laser Speckle Contrast Imaging and Laser Doppler Flowmetry: Is a Direct Comparison Possible? IEEE Trans Biomed Eng 2013; 60:1259-65. [DOI: 10.1109/tbme.2012.2232294] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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89
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Puissant C, Abraham P, Durand S, Humeau-Heurtier A, Faure S, Lefthériotis G, Rousseau P, Mahé G. Reproducibility of non-invasive assessment of skin endothelial function using laser Doppler flowmetry and laser speckle contrast imaging. PLoS One 2013; 8:e61320. [PMID: 23620742 PMCID: PMC3631172 DOI: 10.1371/journal.pone.0061320] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 03/07/2013] [Indexed: 11/26/2022] Open
Abstract
Background Endothelial dysfunction precedes atherosclerosis. Vasodilation induced by acetylcholine (ACh) is a specific test of endothelial function. Reproducibility of laser techniques such as laser-Doppler-flowmetry (LDF) and Laser-speckle-contrast-imaging (LSCI) to detect ACh vasodilation is debated and results expressions lack standardization. We aimed to study at a 7-day interval (i) the inter-subject reproducibility, (ii) the intra-subjects reproducibility, and (iii) the effect of the results expressions over variability. Methods and Results Using LDF and LSCI simultaneously, we performed two different ACh-iontophoresis protocols. The maximal ACh vasodilation (peak-ACh) was expressed as absolute or normalized flow or conductance values. Inter-subject reproducibility was expressed as coefficient of variation (inter-CV,%). Intra-subject reproducibility was expressed as within subject coefficients of variation (intra-CV,%), and intra-class correlation coefficients (ICC). Fifteen healthy subjects were included. The inter-subject reproducibility of peak-ACh depended upon the expression of the results and ranged from 55% to 162% for LDF and from 17% to 83% for LSCI. The intra-subject reproducibility (intra-CV/ICC) of peak-ACh was reduced when assessed with LSCI compared to LDF no matter how the results were expressed and whatever the protocol used. The highest intra-subject reproducibility was found using LSCI. It was 18.7%/0.87 for a single current stimulation (expressed as cutaneous vascular conductance) and 11.4%/0.61 for multiple current stimulations (expressed as absolute value). Conclusion ACh-iontophoresis coupled with LSCI is a promising test to assess endothelial function because it is reproducible, safe, and non-invasive. N°: NCT01664572.
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Affiliation(s)
- Cyril Puissant
- Laboratory of Vascular Investigations, University Hospital, Angers, France
| | - Pierre Abraham
- Laboratory of Vascular Investigations, University Hospital, Angers, France
- Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI) - Unité mixte UMR CNRS 6214/INSERM U 1083, LUNAM University, Medicine Faculty, Angers, France
| | - Sylvain Durand
- EA 4334 Motricity, Interactions, and Performance, LUNAM University, University du Maine, Le Mans, France
| | - Anne Humeau-Heurtier
- LISA – Laboratoire d'Ingénierie des Systèmes Automatisés, LUNAM University, University of Angers, Angers, France
| | - Sébastien Faure
- INSERM U1063, Stress oxydant et pathologies métaboliques (SOPAM), LUNAM University, University of Angers, Angers, France
| | - Georges Lefthériotis
- Laboratory of Vascular Investigations, University Hospital, Angers, France
- Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI) - Unité mixte UMR CNRS 6214/INSERM U 1083, LUNAM University, Medicine Faculty, Angers, France
| | - Pascal Rousseau
- Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI) - Unité mixte UMR CNRS 6214/INSERM U 1083, LUNAM University, Medicine Faculty, Angers, France
- Department of Plastic Surgery, University Hospital, Angers, France
| | - Guillaume Mahé
- Laboratory of Vascular Investigations, University Hospital, Angers, France
- Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI) - Unité mixte UMR CNRS 6214/INSERM U 1083, LUNAM University, Medicine Faculty, Angers, France
- * E-mail:
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Humeau-Heurtier A, Guerreschi E, Abraham P, Mahe G. Relevance of Laser Doppler and Laser Speckle Techniques for Assessing Vascular Function: State of the Art and Future Trends. IEEE Trans Biomed Eng 2013; 60:659-66. [DOI: 10.1109/tbme.2013.2243449] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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91
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Laser speckle contrast imaging for assessment of liver microcirculation. Microvasc Res 2013; 87:34-40. [PMID: 23403398 DOI: 10.1016/j.mvr.2013.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/18/2012] [Accepted: 01/29/2013] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Laser speckle contrast imaging (LSCI) is a novel technique for microcirculation imaging not previously used in the liver. The aim of the present experimental study was to evaluate the use of LSCI for assessing liver microcirculation. MATERIALS AND METHODS In six male Wistar rats, the median liver lobe was exposed through a midline laparotomy. Liver blood perfusion was measured simultaneously with LSCI and sidestream dark-field (SDF) imaging at baseline and during sequential temporary occlusions of the portal vein, hepatic artery, and total blood inflow occlusion. Both the inter-individual variability associated with perfusion sampling area and comparisons in perfusion measurements between both imaging techniques were investigated and validated for the application of LSCI in the liver. RESULTS Occlusion of the hepatic artery, portal vein, and total inflow occlusion resulted in a significant decrease in LSCI signal to 74.7±6.4%, 15.0±2.3%, and 10.4±0.5% respectively (p<0.005 vs. baseline). The LSCI perfusion units correlated with sinusoidal blood flow velocity as measured with SDF imaging (Pearson's r=0.94, p<0.001). In a 10 mm diameter region of interest, as measured with LSCI, baseline inter-individual variability measured by the coefficient of variability was 13%. CONCLUSION Alterations in LSCI signal during sequential inflow occlusions were in accordance with previously published results on hepatic hemodynamics in the rat and correlated well with our SDF imaging-derived sinusoidal blood flow velocity measurements. We found that LSCI was able to produce reproducible real-time blood perfusion measurements of hepatic microcirculation. Compared to established techniques for liver blood perfusion measurements LSCI holds the advantages of non-contact measurements over large surfaces with a high speed of data acquisition.
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Mahe G, Abraham P, Le Faucheur A, Bruneau A, Humeau-Heurtier A, Durand S. Cutaneous microvascular functional assessment during exercise: a novel approach using laser speckle contrast imaging. Pflugers Arch 2013; 465:451-8. [PMID: 23328863 DOI: 10.1007/s00424-012-1215-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/31/2012] [Indexed: 10/27/2022]
Abstract
Cardiovascular diseases are often revealed during exercise and are associated with cutaneous blood flow (CBF) dysfunction. Studies of CBF during exercise are consequently of interest. Laser speckle contrast imaging (LSCI) allows for non-contact and real-time recording of CBF at rest. We tested whether LSCI could allow the study of CBF during a cycling exercise using a specific signal treatment procedure that removes movement-induced artefacts from the LSCI raw signal. We recorded the baseline CBF and peak post-occlusive reactive hyperaemia (PORH) from the cutaneous forearm using LSCI and the mean blood pressure before and during cycling (80 W at 70 rpm) in nine healthy subjects. We determined the cross-correlation coefficient r between LSCI traces obtained before and during cycling and before and after a specifically designed signal processing technique. The results are presented as the median (25th-75th centile) and expressed as the cutaneous vascular conductance (laser speckle perfusion units (LSPU) per millimetre of mercury). Cross-correlation r increased from 0.226 ± 0.140 before to 0.683 ± 0.170 after post-processing. After signal processing, the peak PORH during exercise was reduced [0.38 (0.30-0.52) LSPU/mmHg] compared with the peak PORH during the non-exercise phase [0.69 (0.63-0.74) LSPU/mmHg, p < 0.01], whereas no difference was found between the baseline values. With adequate signal processing, LSCI appears valuable for investigating CBF during exercise. During constant-load lower limb cycling exercise, the upper limb peak PORH is reduced compared with the peak PORH during non-exercise. The underlying mechanisms warrant further investigations in both healthy (trained) subjects and diseased (e.g., coronary heart disease) patients.
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Affiliation(s)
- G Mahe
- Laboratory of Vascular Investigations, University Hospital of Angers, Angers, France.
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MAHÉ GUILLAUME, DURAND SYLVAIN, HUMEAU-HEURTIER ANNE, LEFTHERIOTIS GEORGES, ABRAHAM PIERRE. Impact of Experimental Conditions on Noncontact Laser Recordings in Microvascular Studies. Microcirculation 2012; 19:669-75. [DOI: 10.1111/j.1549-8719.2012.00205.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Humeau-Heurtier A, Abraham P, Durand S, Leftheriotis G, Henrion D, Mahé G. Clinical use of laser speckle techniques: beyond the sole mapping. Med Biol Eng Comput 2012; 50:1001-2. [DOI: 10.1007/s11517-012-0942-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 07/05/2012] [Indexed: 11/30/2022]
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Petrofsky JS. Resting blood flow in the skin: does it exist, and what is the influence of temperature, aging, and diabetes? J Diabetes Sci Technol 2012; 6:674-85. [PMID: 22768900 PMCID: PMC3440047 DOI: 10.1177/193229681200600324] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Measurement of resting blood flow to the skin and other organs is an important indicator of health and disease and a way to assess the reaction to various stimuli and pharmaceutical interventions. However, unlike plasma ions such as sodium or potassium, it is difficult to determine what the proper value for resting blood flow really is. Part of the problem is in the measurement of blood flow; various techniques yield very different measures of skin blood flow even in the same area. Even if there were common techniques, resting blood flow to tissue, such as the skin, is determined by the interaction of a plurality of factors, including the sympathetic nervous system, temperature, pressure, shear forces on blood vessels, tissue osmolality, and a variety of other stimuli. Compounding this variability, the blood flow response to any stressor is reduced by free radicals in the blood and diminished by aging and diabetes. Race also has an effect on resting blood flow to the skin. All these factors interact to make the exact resting blood flow difficult to determine in any one individual and at any one time. This review examines the main techniques to assess blood flow, the factors that alter blood flow in the skin, and how aging and diabetes affect blood flow. Recommendations for the measurement of resting blood flow are presented.
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Affiliation(s)
- Jerrold Scott Petrofsky
- Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, California 92350, USA.
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Cordovil I, Huguenin G, Rosa G, Bello A, Köhler O, de Moraes R, Tibiriçá E. Evaluation of systemic microvascular endothelial function using laser speckle contrast imaging. Microvasc Res 2012; 83:376-9. [PMID: 22326551 DOI: 10.1016/j.mvr.2012.01.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/18/2012] [Accepted: 01/24/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The aim of this study was to compare cutaneous microvascular function in young healthy subjects (n=50) with that of cardiometabolic diseased patients (n=50) using laser speckle contrast imaging (LSCI) coupled with transdermal iontophoretic delivery of acetylcholine (ACh) and post-occlusive reactive hyperemia (PORH). METHODS Cutaneous blood flow was assessed in the forearm using LSCI at rest, during PORH and during iontophoresis of ACh with increasing anodal currents of 30, 60, 90, 120, 150 and 180 μA during 10-second intervals spaced 1 min apart. RESULTS Endothelium-dependent skin microvascular vasodilator responses induced by both ACh and PORH were significantly reduced in cardiometabolic diseased patients compared to healthy subjects. Vasodilator responses induced by ACh were significantly higher in young women than in young men. Iontophoresis charges up to 1.5 mC do not induce nonspecific effects on skin microvascular flux. CONCLUSION LSCI appears to be a promising noninvasive technique for evaluating systemic microvascular endothelial function.
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Affiliation(s)
- Ivan Cordovil
- National Institute of Cardiology (INC), Rio de Janeiro, Brazil
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Humeau-Heurtier A, Buard B, Mahe G, Abraham P. Laser speckle contrast imaging of the skin: interest in processing the perfusion data. Med Biol Eng Comput 2011; 50:103-5. [DOI: 10.1007/s11517-011-0856-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
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