Design and performance of a joint transform correlator (JTC) system for measuring blood flow and tissue motion

1995 ◽  
Author(s):  
Natalie Clark ◽  
Michael K. Giles
Keyword(s):  
Blood Flow ◽  
Joint Transform Correlator ◽  
And Performance ◽  
Tissue Motion

Tracking blood flow and tissue motion using optical correlation

1993 ◽  
Author(s):  
Natalie Clark ◽  
Michael K. Giles ◽  
Sarah H. Harrison ◽  
Chris P. Hofer
Keyword(s):  
Blood Flow ◽  
Optical Correlation ◽  
Tissue Motion

Capillary growth in relation to blood flow and performance in overloaded rat skeletal muscle

1998 ◽  
Vol 85 (6) ◽  
pp. 2025-2032 ◽  
Author(s):  
S. Egginton ◽  
O. Hudlická ◽  
M. D. Brown ◽  
H. Walter ◽  
J. B. Weiss ◽  
...  
Keyword(s):  
Blood Flow ◽  
Muscle Blood Flow ◽  
Tibialis Anterior Muscle ◽  
Mechanical Stimulus ◽  
Angiogenic Factor ◽  
Protein Distribution ◽  
Blood Flows ◽  
Capillary Growth ◽  
Capillary Bed ◽  
And Performance

Rat extensor digitorum longus muscles were overloaded by stretch after removal of the synergist tibialis anterior muscle to determine the relationship between capillary growth, muscle blood flow, and presence of growth factors. After 2 wk, sarcomere length increased from 2.4 to 2.9 μm. Capillary-to-fiber ratio, estimated from alkaline phosphatase-stained frozen sections, was increased by 33% ( P < 0.0001) and 60% ( P < 0.01), compared with control muscles (1.44 ± 0.06) after 2 and 8 wk, respectively. At 2 wk, the increased capillary-to-fiber ratio was not associated with any changes in mRNA for basic fibroblast growth factor (FGF-2) or its protein distribution. FGF-2 immunoreactivity was present in nerves and large blood vessels but was negative in capillaries, whereas the activity of low-molecular endothelial-cell-stimulating angiogenic factor (ESAF) was 50% higher in stretched muscles. Muscle blood flows measured by radiolabeled microspheres during contractions were not significantly different after 2 or 8 wk (132 ± 37 and 177 ± 22 ml ⋅ min−1 ⋅ 100 g−1, respectively) from weight-matched controls (156 ± 12 and 150 ± 10 ml ⋅ min−1 ⋅ 100 g−1, respectively). Resistance to fatigue during 5-min isometric contractions (final/peak tension × 100) was similar in 2-wk overloaded and contralateral muscles (85 vs. 80%) and enhanced after 8 wk to 92%, compared with 77% in contralateral muscles and 67% in controls. We conclude that increased blood flow cannot be responsible for initiating expansion of the capillary bed, nor does it explain the reduced fatigue within overloaded muscles. However, stretch can present a mechanical stimulus to capillary growth, acting either directly on the capillary abluminal surface or by upregulating ESAF, but not FGF-2, in the extracellular matrix.

scholarly journals Left Ventricular Oxygen Consumption, Blood Flow, and Performance in Mitral Stenosis

Circulation ◽  
1965 ◽  
Vol 31 (6) ◽  
pp. 824-833 ◽  
Author(s):  
MARTIN J. FRANK ◽  
GILBERT E. LEVINSON ◽  
HARPER K. HELLEMS ◽  
Harold Stevelman ◽  
Angelo J. Migliori
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Mitral Stenosis ◽  
Left Ventricular ◽  
And Performance

scholarly journals A review of the clinical applications and performance of laser speckle contrast imaging

2020 ◽  
Vol 6 (2) ◽  
pp. 77
Author(s):  
Muhsin Billah Bin Khashru ◽  
Zeng Tao Wang ◽  
Bilkis Akthar ◽  
Md Faisal Talukder
Keyword(s):  
Blood Flow ◽  
Speckle Pattern ◽  
Clinical Applications ◽  
Laser Speckle ◽  
Coherent Light ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Full Field ◽  
Speckle Contrast ◽  
And Performance

<p class="abstract">Laser speckle contrast imaging (LSCI) is a useful tool for visualizing full-field blood flow images. Speckle pattern is formed when a coherent light illuminates a rough object, and the backscattered radiation is transformed into images and be shown on a screen. Movement within the object results in the fluctuation of patterns over time. The same data can be obtained by employing the Doppler effect, yet producing a two-dimensional Doppler map needs scanning; speckle imaging renders the same information without the requirement to scan. Nowadays, LSCI has gained expanded consideration, in part because of its accelerated adoption for blood flow studies in the different surgical departments. Here we represent and review the application of laser speckle contrast methods to the field of perfusion visualization as clinical studies from various medical fields and discuss the limitations hindering clinical acceptance.</p>

Abstract W MP20: PerfAngio: A Software Solution for Quantitative Perfusion Angiography

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Fabien Scalzo ◽  
Amrit S Ahluwalia ◽  
Zibing Huang ◽  
Gary Ren ◽  
David S Liebeskind
Keyword(s):  
Blood Flow ◽  
Arterial Input Function ◽  
Input Function ◽  
Cerebrovascular Diseases ◽  
Hemorrhagic Transformation ◽  
Continuous Measure ◽  
Collateral Flow ◽  
High Definition ◽  
And Performance ◽  
User Friendly

Background: Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. The video densitometric theory has established in the early 1980’s the relationship between the intensity of DSA images and blood flow. This theoretical foundation enables the computation of parametric maps summarizing blood volume, flow, and delay by tracking the injected contrast agent across the vasculature. Although perfusion imaging is widely used with MR and CT, it has yet to be translated into accessible software for DSA. Methods: We introduce Perfusion Angiography (PerfAngio) software to calculate multi-parametric perfusion maps, including: CBV, CBF, MTT, TTP, and Tmax. These are produced by deconvolution of the time-density curve with the arterial input function and displayed as high-definition color-coded images; an innovative way to visualize perfusion. The application, PerfAngio, will be freely available for the iPad tablet. A user-friendly web interface (http://www.perfangio.com) will allow clinicians to upload their own datasets and visualize/download the quantitative results. Results: In addition to providing visualization of unique features, never seen before on DSA, PerfAngio has been successfully used to retrospectively analyze multi-center datasets. The software demonstrated feasibility and performance to evaluate angiographic outcome in TREVO2. It was also a useful tool to compare the hemodynamic impact of devices during thrombectomy in TREVO2 and stenting in SAMMPRIS. Yet, numerous questions remain to be studied with PerfAngio, including identification of futile recanalizaton, hemorrhagic transformation, correlation with MRI and CT and automatic quantification of collateral flow. Conclusions: This revolutionary imaging software can provide insights into Stroke from standard DSA. It is particularly promising for retrospective studies and during clot-retrieval interventions as it offers an objective, continuous measure to characterize angiographic observations.

An Advanced Filter Adaptive to Non-Stationary Clutter in Ultrasonic Color Flow Imaging

2011 ◽  
Vol 186 ◽  
pp. 141-145
Author(s):  
Cong Sheng Xie ◽  
Dong C. Liu
Keyword(s):  
Blood Flow ◽  
Adaptive Filter ◽  
Constant Velocity ◽  
Cutoff Frequency ◽  
Flow Imaging ◽  
Color Flow ◽  
Flow Estimation ◽  
Clutter Rejection ◽  
Color Flow Imaging ◽  
Tissue Motion

Traditional clutter rejection methods are based on the hypothesis that the clutter signal originates from stationary or moving tissue with a constant velocity, and they are not valid when there exists considerable acceleration of tissue motion. In this paper, we propose an advanced clutter filter adapted to accelerated tissue motion. It uses the instantaneous frequency to realize the DC remove, and uses the bandwidth of the clutter signal to choose the cutoff frequency of the wall filter, Simulation shows this advanced adaptive filter can efficiently attenuate the non-stationary clutter signals and improves the accuracy and the flexibility of the blood flow estimation.

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