scholarly journals Quantification of blood flow index in diffusecorrelation spectroscopy using LSTMarchitecture

2021 ◽  
Author(s):  
Zhe Li ◽  
Qisi Ge ◽  
Jinchao Feng ◽  
Kebin Jia ◽  
Jing Zhao
Keyword(s):  
Blood Flow ◽  
Flow Index ◽  
Blood Flow Index

scholarly journals Blood Flow Assessment of Arteriovenous Malformations Using Intraoperative Indocyanine Green Videoangiography

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Naoki Kato ◽  
Vincent Prinz ◽  
Julius Dengler ◽  
Peter Vajkoczy
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Indocyanine Green ◽  
Region Of Interest ◽  
Flow Dynamics ◽  
Flow Index ◽  
Indocyanine Green Videoangiography ◽  
Blood Flow Index ◽  
High Resolution Images ◽  
The Individual

Intraoperative indocyanine green (ICG) videoangiography is widely used in patients undergoing neurosurgery. FLOW800 is a recently developed analytical tool for ICG videoangiography to assess semi-quantitative flow dynamics; however, its efficacy is unknown. In this study, we evaluated its functionality in the assessment of flow dynamics of arteriovenous malformation (AVM) through ICG videoangiography under clinical settings. ICG videoangiography was performed in the exposed AVM in eight patients undergoing surgery. FLOW800 analysis was applied directly, and gray-scale and color-coded maps of the surgical field were obtained. After surgery, a region of interest was placed on the individual vessels to obtain time-intensity curves. Parameters of flow dynamics, including the maximum intensity, transit time, and cerebral blood flow index, were calculated using the curves. The color-coded maps provided high-resolution images; however, reconstruction of colored images was restricted by the depth, approach angle, and brain swelling. Semi-quantitative parameters were similar among the feeders, niduses, and drainers. However, a higher cerebral blood flow index was observed in the feeders of large AVM (>3 cm) than in those of small AVM (P < 0.05). Similarly, the cerebral blood flow index values were positively correlated with the nidus volume (P < 0.01). FLOW800 enabled visualization of the AVM structure and safer resection, except in case of deep-seated AVM. Moreover, semi-quantitative values in the individual vessels through using ICG intensity diagram showed different patterns according to size of the AVM. ICG videoangiography showed good performance in evaluating flow dynamics of the AVM in patients undergoing surgery.

Blood Flow Index Using Near Infrared Spectroscopy and Indocyanine Green Dye as a Minimally Invasive Method for Assessing Respiratory Muscle Blood Flow in Humans

CHEST Journal ◽  
2010 ◽  
Vol 138 (4) ◽  
pp. 917A
Author(s):  
Jordan A. Guenette ◽  
William R. Henderson ◽  
Paolo B. Dominelli ◽  
Jordan S. Querido ◽  
Donald E. Griesdale ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Minimally Invasive ◽  
Respiratory Muscle ◽  
Near Infrared ◽  
Muscle Blood Flow ◽  
Flow Index ◽  
Indocyanine Green Dye ◽  
Blood Flow Index ◽  
Invasive Method

scholarly journals Guidelines for obtaining an absolute blood flow index with laser speckle contrast imaging

2021 ◽  
Author(s):  
Smrithi Sunil ◽  
Sharvari Zilpelwar ◽  
David A Boas ◽  
Dmitry D Postnov
Keyword(s):  
Blood Flow ◽  
Speckle Pattern ◽  
Quantitative Measure ◽  
Laser Speckle ◽  
Flow Index ◽  
Scattering Media ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Blood Flow Index

Laser speckle contrast imaging (LSCI) is a technique broadly applied in research and clinical settings for full-field characterization of tissue perfusion. It is based on the analysis of speckle pattern contrast, which can be theoretically related to the decorrelation time - a quantitative measure of dynamics. A direct contrast to decorrelation time conversion, however, requires prior knowledge of specific parameters of the optical system and scattering media and thus is often impractical. For this reason, and because of the nature of some of the most common applications, LSCI is historically used to measure relative blood flow change. Over time, the belief that the absolute blood flow index measured with LSCI is not a reliable metric and thus should not be used has become more widespread. This belief has resulted from the use of LSCI to compare perfusion in different animal models and to obtain longitudinal blood flow index observations without proper consideration given to the stability of the measurement. Here, we aim to clarify the issues that give rise to variability in the repeatability of the quantitative blood flow index and to present guidelines on how to make robust absolute blood flow index measurements with conventional single-exposure LSCI. We also explain how to calibrate contrast to compare measurements from different systems and show examples of applications that are enabled by high repeatability.

scholarly journals Features of cerebral blood flow in patients with chronic obstructive pulmonary disease associated with hypertension

2021 ◽  
Vol 26 (6) ◽  
pp. 676-687
Author(s):  
N. B. Poletaeva ◽  
O. V. Teplyakova ◽  
I. F. Grishina ◽  
A. A. Klepikova
Keyword(s):  
Blood Pressure ◽  
Chronic Obstructive Pulmonary Disease ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Blood Flow Velocity ◽  
Flow Index ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Blood Flow Index

Objective. The aim of the work was to study the features of cerebral blood flow in patients with chronic obstructive pulmonary disease (COPD) associated with hypertension (HTN). Design and methods. A crosssectional study was conducted, which included 90 males 40–60 years old. Of these, 30 patients with chronic COPD associated with HTN (COPD + HTN) were included in the study group, 30 individuals with isolated COPD were in the comparison group, 30 healthy volunteers were included in the control group. All participants underwent physical examination, spirography, 24-hour blood pressure monitoring and ultrasound examination of cerebral vessels. Results. Patients with COPD + HTN in comparison with the control showed an increase in the diameter (p = 0,018) and complex of the intima-media of the common carotid artery (p = 0,003) while the velocities, resistance index (RI) and pulsation index (PI) did not change. In the basin of the internal carotid artery an increase in RI values was noted (p = 0,018). At the intracranial level there was a decrease in the end-diastolic velocity (p = 0,03) and the time-averaged average blood flow velocity (TAV) (p = 0,033) without due changes RI and PI. At the same time no changes in speed indicators and indices were noted in the vertebral artery basin. Among the indicators of cerebral perfusion in patients with COPD + HTN, hydrodynamic resistance (p = 0,0015), intracranial pressure (ICP) (p = 0,0048) significantly increased, and the cerebral blood flow index was comparable with the control. Assessment of venous cerebral blood flow showed an increase in the diameter of the internal jugular vein (p = 0,021) with unchanged TAV together with an increase in ICP indicating the formation of venous dysfunction. It was shown that the body mass index, forced expiratory volume at the first second, systolic and diastolic blood pressure together determine the peak systolic blood flow velocity from the midbrain artery. Conclusions. The cerebral blood flow in patients with COPD + HTN is characterized by a change in arterial blood flow at the level of both intra- and extracranial vessels, while maintaining a normal cerebral blood flow index, as well as the formation of arteriovenous dyshemia against the background of remodeling of the cerebral vascular bed.

Cerebral blood flow index image as a simple indicator for the fate of acute ischemic lesion

2003 ◽  
pp. 241-246 ◽  
Author(s):  
Hironaka Igarashi ◽  
M. Hamamoto ◽  
H. Yamaguchi ◽  
S. Ookubo ◽  
J. Nagashima ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Index ◽  
Ischemic Lesion ◽  
Blood Flow Index ◽  
Simple Indicator
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