Contrast-Free Blood Flow Velocity Profile Measurement With Ultrasound in Real-Time

2011 ◽  
Author(s):  
G. G. Koutsouridis ◽  
N. Bijnens ◽  
S. van Geldermalsen ◽  
P. J. Brands ◽  
F. N. van de Vosse ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Velocity ◽  
Profile Measurement ◽  
Doppler Measurement ◽  
Non Invasive ◽  
Hemodynamic Variables ◽  
Vascular Impedance ◽  
Velocity Profile Measurement ◽  
Invasive Method ◽  
Flow Velocity Profile

In clinical practice, ultrasound is frequently used as a non-invasive method to estimate geometric properties of large arteries such as diameter and intima-media wall thickness and in a separate Doppler measurement hemodynamic variables such as blood velocity. For the purpose of deducing biomechanical parameters and hemodynamic variables that are related to the development of Cardiovascular Disease, such as compliance and vascular impedance, the assessment of only geometry and blood velocity is not sufficient. A simultaneous and non-invasive assessment of blood flow and blood pressure is required. This can only be obtained by an accurate and simultaneous measurement of the blood velocity distribution and wall motion, which is not feasible with the commonly used Doppler technique.

Abstract P225: Non-invasive Measurement of Renal Blood Flow (RBF) in Different Rat Models by Magnetic Resonance Imaging (MRI)

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Cesar A Romero ◽  
Robert Knight ◽  
Glauber Cabral ◽  
Oscar A Carretero
Keyword(s):  
Blood Flow ◽  
Sham Group ◽  
Motion Artifacts ◽  
Arterial Stenosis ◽  
7 Tesla ◽  
Hypertensive Rats ◽  
Rat Models ◽  
Non Invasive ◽  
Sd Rats ◽  
Invasive Method

Quantitative measure of RBF provides important information regarding renal physiology and pathology, in different animal’s models. Arterial Spin Labelling-MRI (ASL-MRI) is a non-invasive method to measure blood flow without exogenous contrast media, using arterial water protons labeled by radiofrequency as an endogenous tracer. However, the low signal/noise radio, and the motion artifacts are a challenge for the acquisition of RBF in small animals. Our objective is evaluated the feasibility and reproducibility of the RBF measure by ASL-MRI in different hypertensive rats models. ASL-MRI images were obtained in Sprague-Dawley (SD) rats (200-300g) under inhalation anesthesia using a 7 Tesla Varian MRI system with a spin echo imaging sequence. After 4 days the MRI studies was repeated to evaluate reproducibility, using paired sample T-test and the test-retest reliability (TR) equation. RBF was also measured in in Dahl SS rats on regular chow and spontaneous hypertensive rats (SHR). Additionally we measure the RBF in a set of animals under unilateral nephrectomy (UNx) and renal arterial stenosis (RS) before and after the surgery. Table 1 shows the mean cortical RBF in different rat strains and models. Re-test analysis showed no relevant differences, being the means of differences 9.4±35 ml/min/100g tissue (p=0.58) in SD rats. The TR was 92.4±6%. UNx increase the RBF in 69.1% in comparison with sham group. (p<0.01). After the RS the blood pressure increased and the RBF decrease 56% (p<0.01) in comparison with sham group. ASL-MRI performed with navigator correction and respiratory gating is a feasible and reproducible non-invasive method to measure RBF in several rat models.

scholarly journals Cross-Modal Effect of Presenting Food Images on Taste Appetite

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6615
Author(s):  
Keisuke Tomono ◽  
Akira Tomono
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Salivary Secretion ◽  
Digital Signage ◽  
Non Invasive ◽  
Saliva Secretion ◽  
Sense Of Presence ◽  
Invasive Method ◽  
Food Images ◽  
The Relationship

We researched a method to objectively evaluate the presence of food images, for the purpose of applying it to digital signage. In this paper, we defined the presence of food images as a sensation that makes us recognize that food is there, and investigated the relationship between that recognition and the salivary secretion reaction. If saliva secretion can be detected by a non-invasive method, it may be possible to objectively estimate the presence of the viewer from the outside. Two kinds of experiments were conducted. STUDY 1 included presentations of popular cooking images, which portrayed a sense of deliciousness, and evaluated changes in the volume of saliva secretions and cerebral blood flow near the temples. STUDY 2 included comparisons of changes between presenting images only and images with corresponded smells. The images included scenes that introduced foods (i.e., almond pudding cake/bergamot orange) that were relatively simple, so that they did not induce the subjects themselves. As a result, we clarified the cross-modal effects that were closely related to sense of presence and salivation. Moreover, we clarified presentation of images with smells to improve one’s sense of presence, even though the images were relatively simple.

Evaluation of angiogenesis in chronic inflammation by laser-Doppler flowmetry

1988 ◽  
Vol 74 (2) ◽  
pp. 119-121 ◽  
Author(s):  
C. Orlandi ◽  
C. J. Dunn ◽  
L. G. Cutshaw
Keyword(s):  
Blood Flow ◽  
Chronic Inflammation ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Angiogenic Response ◽  
Non Invasive ◽  
Granulomatous Lesions ◽  
Invasive Method ◽  
Control Skin

1. A non-invasive method is described for the assessment of angiogenesis in chronic inflammation using laser-Doppler flowmetry. 2. Significant increases in capillary blood flow were seen on days 5 and 7 after induction of subcutaneous granulomatous lesions, as compared with control skin. 3. Changes in blood flow were accompanied by changes in pulsatile flow pattern and by an intense angiogenic response observed by light microscopy. 4. The potential application of laser-Doppler flowmetry to quantitative and qualitative studies of evolving angiogenesis in pathological responses is discussed.

A novel non-invasive method for estimating the local wave speed at a single site in the internal carotid artery

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Asma Ayadi ◽  
Wassila Sahtout ◽  
Olivier Baledent
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Wave Speed ◽  
Internal Carotid ◽  
Blood Velocity ◽  
Non Invasive ◽  
Velocity Waveform ◽  
Local Wave ◽  
Invasive Method

AbstractObjectivesLocal wave speed is a biomarker which provides an objective analysis of the cardiovascular function. The aim of this study was to determine the local wave speed in the internal carotid artery by a new non-invasive method that measures blood velocity waveform at only one site.MethodsFor this purpose, the cepstral analysis was employed to determine the arrival time of the reflection wave and the wave speed in the carotid artery. To validate our model, we applied it experimentally in vivo on young and old healthy subjects. The blood velocity waveform was measured by using phase-contrast magnetic resonance for 22 subjects.ResultsOur experimental results correlated with reference values reported in previous studies conducted on the internal arterial carotid usually adopting the invasive method. They also correlated with those obtained by using the foot-to-foot method (R2=0.72). The wave speed obtained by the method developed in this study and that of the foot-to-foot method increased with age (p<0.001).ConclusionsThe method developed in this study can be applied in the other arteries and it can also be used with other techniques such as ultrasound imaging.

New perspectives of hyperspectral imaging for clinical research

NIR news ◽  
2021 ◽  
Vol 32 (3-4) ◽  
pp. 5-13
Author(s):  
Johannes D Pallua ◽  
Andrea Brunner ◽  
Bernhard Zelger ◽  
Christian W Huck ◽  
Michael Schirmer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Data Analysis ◽  
Clinical Research ◽  
Hyperspectral Imaging ◽  
Tissue Blood Flow ◽  
Clinical Use ◽  
New Developments ◽  
Non Invasive ◽  
Invasive Method

New developments in instrumentation and data analysis have further improved the perspectives of hyperspectral imaging in clinical use. Thus, hyperspectral imaging can be considered as “Next Generation Imaging” for future clinical research. As a contactless, non-invasive method with short process times of just a few seconds, it quantifies predefined substance classes. Results of hyperspectral imaging may support the detection of carcinomas and the classification of different tissue structures as well as the assessment of tissue blood flow. Taken together, this method combines the principle of spectroscopy with imaging using conventional visual cameras. Compared to other optical imaging methods, hyperspectral imaging also analyses deeper layers of tissue.

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