scholarly journals Reproducibility and normalization of reactive hyperemia using laser speckle contrast imaging

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244795
Author(s):  
Behnia Rezazadeh Shirazi ◽  
Rudy J. Valentine ◽  
James A. Lang
Keyword(s):  
Reactive Hyperemia ◽  
Intraclass Correlation ◽  
Microvascular Dysfunction ◽  
Microvascular Function ◽  
Rate Of Change ◽  
Laser Speckle ◽  
Maximal Flow ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast

Background Impaired perfusion indices signal potential microvascular dysfunction preceding atherosclerosis and other cardiometabolic pathologies. Post-occlusive reactive hyperemia (PORH), a vasodilatory response following a mechanically induced ischemia, is a transient increase in perfusion and can assess microvascular function. The greatest blood flow change corresponding to the first minute of hyperemia (represented by time-to-peak, hyperemic velocity, AUC within 1st min) has been shown to indicate microvascular dysfunction. However, the reproducibility of these temporal kinetic indices of the PORH response is unknown. Our aim was to examine the inter- and intra-day reproducibility and standardization of reactive hyperemia, with emphasis on the kinetic indices of PORH, using laser speckle contrast imaging (LSCI) technique. Methods and results Seventeen healthy adults (age = 24 ± 3 years) completed three PORH bouts over two lab visits. LSCI region of interest was a standardized 10 cm region on the dominant ventral forearm. A 5-min brachial artery occlusion period induced by inflating an arm cuff to 200 mmHg, preceded a 4-min hyperemic period. Inter- and intra-day reliability and reproducibility of cutaneous vascular conductance (LSCI flux / mean arterial pressure) were determined using intraclass correlation (ICC) and coefficient of variation (CV%). Maximal flow and area under the curve standardized to zero perfusion showed intra- and inter-day reliability (ICC > 0.70). Time to maximal flow (TMF) was not reproducible (inter-day CV = 18%). However, alternative kinetic indices such as 1-min AUC and overshoot rate-of-change (ORC), represented as a piecewise function (at 5s, 10s, 15s, and 20s into hyperemia), were reproducible (CV< 11%). Biological zero was a reliable normalization point. Conclusion PORH measured with LSCI is a reliable assessment of microvascular function. However, TMF or its derived hyperemic velocity are not recommended for longitudinal assessment. Piecewise ORC and 1-min AUC are reliable alternatives to assess the kinetic response of PORH.

scholarly journals Use of Laser Speckle Contrast Imaging to Assess Digital Microvascular Function in Primary Raynaud Phenomenon and Systemic Sclerosis: A Comparison Using the Raynaud Condition Score Diary

2015 ◽  
Vol 42 (7) ◽  
pp. 1163-1168 ◽  
Author(s):  
John D. Pauling ◽  
Jacqueline A. Shipley ◽  
Darren J. Hart ◽  
Anita McGrogan ◽  
Neil J. McHugh
Keyword(s):  
Systemic Sclerosis ◽  
Objective Assessment ◽  
Microvascular Function ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Raynaud Phenomenon ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Condition Score ◽  
Cold Challenge

Objective.Evaluate objective assessment of digital microvascular function using laser speckle contrast imaging (LSCI) in a cross-sectional study of patients with primary Raynaud phenomenon (RP) and systemic sclerosis (SSc), comparing LSCI with both infrared thermography (IRT) and subjective assessment using the Raynaud Condition Score (RCS) diary.Methods.Patients with SSc (n = 25) and primary RP (n = 18) underwent simultaneous assessment of digital perfusion using LSCI and IRT with a cold challenge on 2 occasions, 2 weeks apart. The RCS diary was completed between assessments. The relationship between objective and subjective assessments of RP was evaluated. Reproducibility of LSCI/IRT was assessed, along with differences between primary RP and SSc, and the effect of sex.Results.There was moderate-to-good correlation between LSCI and IRT (Spearman rho 0.58–0.84, p < 0.01), but poor correlation between objective assessments and the RCS diary (p > 0.05 for all analyses). Reproducibility of IRT and LSCI was moderate at baseline (ICC 0.51–0.63) and immediately following cold challenge (ICC 0.56–0.86), but lower during reperfusion (ICC 0.3–0.7). Neither subjective nor objective assessments differentiated between primary RP and SSc. Men reported lower median daily frequency of RP attacks (0.82 vs 1.93, p = 0.03). Perfusion using LSCI/IRT was higher in men for the majority of assessments.Conclusion.Objective and subjective methods provide differing information on microvascular function in RP. There is good convergent validity of LSCI with IRT and acceptable reproducibility of both modalities. Neither subjective nor objective assessments could differentiate between primary RP and SSc. Influence of sex on subjective and objective assessment of RP warrants further evaluation.

scholarly journals Semi-Automatic Tracking of Laser Speckle Contrast Images of Microcirculation in Diabetic Foot Ulcers

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1054
Author(s):  
Onno A. Mennes ◽  
Mark Selles ◽  
Jaap J. van Netten ◽  
Jeff G. van Baal ◽  
Wiendelt Steenbergen ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Reactive Hyperemia ◽  
Intraclass Correlation ◽  
Laser Speckle ◽  
Tracking Algorithm ◽  
Foot Ulcers ◽  
Diabetic Foot Ulcers ◽  
Contrast Imaging ◽  
Speckle Contrast ◽  
Diagnosis And Prognosis

Foot ulcers are a severe complication of diabetes mellitus. Assessment of the vascular status of diabetic foot ulcers with Laser Speckle Contrast Imaging (LSCI) is a promising approach for diagnosis and prognosis. However, manual assessment during analysis of LSCI limits clinical applicability. Our aim was to develop and validate a fast and robust tracking algorithm for semi-automatic analysis of LSCI data. The feet of 33 participants with diabetic foot ulcers were recorded with LSCI, including at baseline, during the Post-Occlusive Reactive Hyperemia (PORH) test, and during the Buerger’s test. Different regions of interest (ROIs) were used to measure microcirculation in different areas of the foot. A tracking algorithm was developed in MATLAB to reposition the ROIs in the LSCI scans. Manual- and algorithm-tracking of all recordings were compared by calculating the Intraclass Correlation Coefficient (ICC). The algorithm was faster in comparison with the manual approach (90 s vs. 15 min). Agreement between manual- and algorithm-tracking was good to excellent during baseline (ICC = 0.896–0.984; p < 0.001), the PORH test (ICC = 0.790–0.960; p < 0.001), and the Buerger’s test (ICC = 0.851–0.978; p < 0.001), resulting in a tracking algorithm that delivers assessment of LSCI in diabetic foot ulcers with results comparable to a labor-intensive manual approach, but with a 10-fold workload reduction.

scholarly journals Assessment of Skin Microvascular Function and Dysfunction With Laser Speckle Contrast Imaging

2012 ◽  
Vol 5 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Guillaume Mahé ◽  
Anne Humeau-Heurtier ◽  
Sylvain Durand ◽  
Georges Leftheriotis ◽  
Pierre Abraham
Keyword(s):  
Microvascular Function ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast

Laser Speckle Contrast Imaging for Intraoperative Quantitative Assessment of Intestinal Blood Perfusion During Colorectal Surgery: A Prospective Pilot Study

2019 ◽  
Vol 26 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Shigehiro Kojima ◽  
Tsuguo Sakamoto ◽  
Yuko Nagai ◽  
Yutaka Matsui ◽  
Kyojiro Nambu ◽  
...  
Keyword(s):  
Pilot Study ◽  
Colorectal Surgery ◽  
Intraclass Correlation ◽  
Laser Speckle ◽  
Fluorescence Angiography ◽  
Contrast Imaging ◽  
Flow Measurements ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Perfusion Assessment

Background. The main limitation of perfusion assessment with indocyanine green fluorescence angiography during colorectal surgery is that the surgeon assesses the quality of perfusion subjectively. The ideal intestinal viability test must be minimally invasive, objective, and reproducible. We evaluated the quantitativity and reproducibility of laser speckle contrast imaging for perfusion assessment during colorectal surgery. Methods. This was a prospective, nonrandomized, pilot study of 8 consecutive patients who underwent elective left-sided colorectal resection. Laser speckle perfusion images at the site of proximal transection of the bowel were obtained intraoperatively. We tested the hypothesis that laser speckle contrast imaging was able to quantitatively identify areas of diminished intestinal perfusion after devascularization and assessed the reproducibility of this method. Results. All surgical procedures were uneventful and blood flow measurements were successfully made in all patients. None of the patients developed postoperative complications related to the anastomosis and stoma. Data analyses were successfully optimized to perform quantitative regional perfusion assessments in all cases. The bowel tissue blood flows of the anal side region adjacent to the transection line were significantly lower than those of the oral side region adjacent to the transection line after ligation of marginal vessels ( P = .012). Interrater reliability was high (intraclass correlation coefficients = 0.989), and a Bland-Altman plot showed few differences of mean flux data between 2 investigators. Conclusion. Laser speckle contrast imaging is feasible for real-time assessment of bowel perfusion with quantitativity and excellent reproducibility during colorectal surgery without administration of any contrast agents.

scholarly journals Comparison of laser speckle contrast imaging with laser Doppler for assessing microvascular function

2011 ◽  
Vol 82 (3) ◽  
pp. 326-332 ◽  
Author(s):  
Garry A. Tew ◽  
Markos Klonizakis ◽  
Helen Crank ◽  
J. David Briers ◽  
Gary J. Hodges
Keyword(s):  
Microvascular Function ◽  
Laser Speckle ◽  
Laser Doppler ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast
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