scholarly journals Photoacoustic imaging for monitoring of local changes in oxygen saturation following adrenaline injection in human forearm skin

2021 ◽  
Author(s):  
Josefine Bunke ◽  
Aboma Merdasa ◽  
Rafi Sheikh ◽  
John Albinsson ◽  
Tobias Erlöv ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Photoacoustic Imaging ◽  
Human Forearm ◽  
Forearm Skin ◽  
Adrenaline Injection

scholarly journals Preclinical Ultrasound-Guided Photoacoustic Imaging of the Placenta in Normal and Pathologic Pregnancy

2018 ◽  
Vol 17 ◽  
pp. 153601211880272 ◽  
Author(s):  
Liliya M. Yamaleyeva ◽  
K. Bridget Brosnihan ◽  
Lane M. Smith ◽  
Yao Sun
Keyword(s):  
Oxygen Saturation ◽  
Early Identification ◽  
Photoacoustic Imaging ◽  
Three Dimensional ◽  
Normal Pregnancy ◽  
Preclinical Study ◽  
Ultrasound Guided ◽  
3 Dimensional ◽  
Sensitive Tool ◽  
Different Levels

Placental oxygenation varies throughout pregnancy. The detection of early changes in placental oxygenation as pregnancy progresses is important for early identification of preeclampsia or other complications. This invited commentary discusses a recent preclinical study on the application of 3-dimensional photoacoustic imaging (PAI) for assessment of regional variations in placental oxygenation and longitudinal analysis of differences in placental oxygenation throughout normal pregnancy and pregnancy associated with hypertension or placental insufficiency in mice. Three-dimensional PAI more accurately reflects oxygen saturation, hemoglobin concentrations, and changes in oxygen saturation in whole placenta compared to 2-dimensional imaging. These studies suggest that PAI is a sensitive tool to detect different levels of oxygen saturation in the placental and fetal vasculature in pathologic and normal pregnancy in mice.

Interactions between local and reflex influences on human forearm skin blood flow

1976 ◽  
Vol 41 (6) ◽  
pp. 826-831 ◽  
Author(s):  
J. M. Johnson ◽  
G. L. Brengelmann ◽  
L. B. Rowell
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Forearm Blood Flow ◽  
Lower Body Negative Pressure ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Vasoconstrictor Response ◽  
Human Forearm ◽  
Forearm Skin ◽  
Forearm Muscle

A three-part experiment was designed to examine interactions between local and reflex influences on forearm skin blood flow (SkBF). In part I locally increasing arm skin temperature (Tsk) to 42.5 degrees C was not associated with increases in underlying forearm muscle blood flow, esophageal temperature (Tes), or forearm blood flow in the contralateral cool arm. In part II whole-body Tsk was held at 38 or 40 degrees C and the surface temperature of one arm held at 38 or 42 degrees C for prolonged periods. SkBF in the heated arm rose rapidly with the elevation in body Tsk and arm Tsk continued to rise as Tes rose. SkBF in the arm kept at 32 degrees C paralleled rising Tes. In six studies, SkBF in the cool arm ultimately converged with SkBF in the heated arm. In eight other studies, heated arm SkBF maintained an offset above cool arm SkBF throughout the period of whole-body heating. In part III, local arm Tsk of 42.5 degrees C did not abolish skin vasoconstrictor response to lower body negative pressure. We conclude that local and reflex influences to skin interact so as to modify the degree but not the pattern of skin vasomotor response.

scholarly journals 4267 Noninvasive hybrid ultrasound and photoacoustic imaging for the assessment of liver fibrosis

2020 ◽  
Vol 4 (s1) ◽  
pp. 110-111
Author(s):  
Laith Riyadh Sultan ◽  
Mrigendra Karmacharya ◽  
Julia D’Souza ◽  
Brooke Kirkham ◽  
Angela K Brice ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Oxygen Saturation ◽  
Photoacoustic Imaging ◽  
Texture Features ◽  
Male Rats ◽  
Imaging Method ◽  
Sampling Errors ◽  
Tissue Heterogeneity ◽  
Time Points ◽  
Over Time

OBJECTIVES/GOALS: The detection of liver fibrotic changes at an early and reversible stage is essential to prevent its progression to end-stage cirrhosis and hepatocellular carcinoma. Liver biopsy, which is the current gold standard for fibrosis assessment, is accompanied by several complications due to its invasive nature in addition to sampling errors and reader variability. In this study, we evaluate the use of quantitative parameters extracted from hybrid ultrasound and photoacoustic imaging to detect and monitor fibrotic changes in a DEN rat model. METHODS/STUDY POPULATION: Liver fibrotic changes were induced in 34 Wistar male rats by oral administration of Diethylnitrosamine (DEN) for 12 weeks. 22 rats were imaged with B-mode ultrasound at 3 different time points (baseline, 10 weeks and 13 weeks) for monitoring liver texture changes. Texture features studied included tissue echointensity (liver brightness normalized to kidney brightness) and tissue heterogeneity. 12 rats were imaged with photoacoustic imaging at 4 time points (baseline, 5 wks, 10 wks, and 13 wks) to look at changes in tissue oxygenation. Hemoglobin oxygen saturation (sO2A) and hemoglobin concentration (HbT) in the right and left lobes of the liver were measured. 8 rats were used as controls. Liver tissue samples were obtained following 13 weeks from DEN start time for METAVIR histopathology staging of fibrosis. RESULTS/ANTICIPATED RESULTS: Texture features studied showed an increase with time in DEN rats. Normalized echointensity increased from 0.28 ± 0.06 at baseline to 0.46 ± 0.10 at 10 weeks (p < 0.0005) and 0.53 ± 0.15 at 13 weeks in DEN rats (p < 0.0005). In the control rats, echointensity remained at an average of 0.25 ± 0.05 (p = 0.31). Tissue heterogeneity increased over time in the DEN-exposed rats from a baseline of 208.7 ± 58.3 to 344.6 ± 52.9 at 10 weeks (p < 0.0005) and 376.8 ± 54.9 at 13 weeks (p = 0.06) however it stayed constant at 225.7 ± 37.6 in control rats (p = 0.58). The quantitative analyses of the photoacoustic signals showed that blood oxygen saturation significantly increased with time. At 5 weeks sO2AvT increased by 53.83 % (± 0.25), and HbT by 35.31 % (± 0.07). Following 10 weeks of DEN; sO2AvT by 92.04 % (± 0.29), and HbT by 55.24 % (± 0.1). All increases were significant p < 0.05. In the 13th week, however, the values of all of these parameters were lower than those in the 10th week, however, the decrease was statistically insignificant. DISCUSSION/SIGNIFICANCE OF IMPACT: Quantitative features from B-mode ultrasound and photoacoustic imaging consistently increased over time corresponding to hepatic damage, inflammation and fibrosis progressed. The use of this hybrid imaging method in clinical practice can help meet the significant need for noninvasive assessment of liver fibrosis.

scholarly journals Small reduction of capsaicin-induced neurogenic inflammation in human forearm skin by the glucocorticoid prednicarbate

1993 ◽  
Vol 38 (S2) ◽  
pp. C31-C34 ◽  
Author(s):  
R. Tafler ◽  
M. K. Herbert ◽  
R. F. Schmidt ◽  
K. H. Weis
Keyword(s):  
Neurogenic Inflammation ◽  
Small Reduction ◽  
Human Forearm ◽  
Forearm Skin
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