scholarly journals In vivo pulsatility measurement of cerebral microcirculation in rodents using Dynamic Ultrasound Localization Microscopy

2021 ◽  
pp. 1-1
Author(s):  
Chloe Bourquin ◽  
Jonathan Poree ◽  
Frederic Lesage ◽  
Jean Provost
Keyword(s):  
Cerebral Microcirculation ◽  
Localization Microscopy ◽  
Ultrasound Localization ◽  
Dynamic Ultrasound

scholarly journals An Anatomically and Hemodynamically Realistic Simulation Framework for 3D Ultrasound Localization Microscopy

2021 ◽  
Author(s):  
Hatim Belgharbi ◽  
Jonathan Poree ◽  
Rafat Damseh ◽  
Vincent Perrot ◽  
Patrick Delafontaine-Martel ◽  
...  
Keyword(s):  
3D Ultrasound ◽  
Acquisition Time ◽  
Simulation Framework ◽  
Low Frequencies ◽  
Localization Microscopy ◽  
Two Photon Microscopy ◽  
Ultrasound Localization ◽  
Two Photon ◽  
Wavelength Resolution

The resolution of 3D Ultrasound Localization Microscopy (ULM) is determined by acquisition parameters such as frequency and transducer geometry but also by microbubble (MB) concentration, which is also linked to the total acquisition time needed to sample the vascular tree at different scales. In this study, we introduce a novel 3D anatomically- and physiologically-realistic ULM simulation framework based on two-photon microscopy (2PM) and in-vivo MB perfusion dynamics. As a proof of concept, using metrics such as MB localization error, MB count and network filling, we could quantify the effect of MB concentration and PSF volume by varying probe transmit frequency (3-15 MHz). We find that while low frequencies can achieve sub-wavelength resolution as predicted by theory, they are also associated with prolonged acquisition times to map smaller vessels, thus limiting effective resolution. A linear relationship was found between maximal MB concentration and inverse point spread function (PSF) volume. Since inverse PSF volume roughly scales cubically with frequency, the reconstruction of the equivalent of 10 minutes at 15 MHz would require hours at 3 MHz. We expect that these findings can be leveraged to achieve effective reconstruction and serve as a guide for choosing optimal MB concentrations in ULM.

Brain-wide pulsatility mapping with gated ultrasound localization microscopy in vivo

2019 ◽  
Vol 146 (4) ◽  
pp. 3031-3031
Author(s):  
Chloé Bourquin ◽  
Jonathan Porée ◽  
Frédéric Lesage ◽  
Jean Provost
Keyword(s):  
Localization Microscopy ◽  
Ultrasound Localization

scholarly journals Aging-related cerebral microvascular changes visualized using ultrasound localization microscopy in the living mouse

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew R. Lowerison ◽  
Nathiya Vaithiyalingam Chandra Sekaran ◽  
Wei Zhang ◽  
Zhijie Dong ◽  
Xi Chen ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Super Resolution ◽  
Brain Regions ◽  
Blood Velocity ◽  
Aging Brain ◽  
Health Crisis ◽  
Localization Microscopy ◽  
Ultrasound Localization ◽  
Microvascular Changes

AbstractAging-related cognitive decline is an emerging health crisis; however, no established unifying mechanism has been identified for the cognitive impairments seen in an aging population. A vascular hypothesis of cognitive decline has been proposed but is difficult to test given the requirement of high-fidelity microvascular imaging resolution with a broad and deep brain imaging field of view, which is restricted by the fundamental trade-off of imaging penetration depth and resolution. Super-resolution ultrasound localization microscopy (ULM) offers a potential solution by exploiting circulating microbubbles to achieve a vascular resolution approaching the capillary scale without sacrificing imaging depth. In this report, we apply ULM imaging to a mouse model of aging and quantify differences in cerebral vascularity, blood velocity, and vessel tortuosity across several brain regions. We found significant decreases in blood velocity, and significant increases in vascular tortuosity, across all brain regions in the aged cohort, and significant decreases in blood volume in the cerebral cortex. These data provide the first-ever ULM measurements of subcortical microvascular dynamics in vivo within the context of the aging brain and reveal that aging has a major impact on these measurements.

scholarly journals Ultrafast Doppler imaging and Ultrasound Localization Microscopy reveal the complexity of vascular rearrangement in chronic spinal lesion

2022 ◽  
Author(s):  
Benoit Beliard ◽  
Chaimae Ahmanna ◽  
Elodie Tiran ◽  
Kadia Kante ◽  
Thomas Deffieux ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Imaging Modality ◽  
Doppler Imaging ◽  
Localization Microscopy ◽  
Ultrasound Localization ◽  
Statistical Correlations ◽  
Cord Injury

Abstract Acute spinal cord injury (SCI) leads to severe damage to the microvascular network. The process of spontaneous repair is accompanied by formation of new blood vessels; their functionality, however, presumably very important for functional recovery, has never been clearly established, as most studies so far used fixed tissues. Here, combining ultrafast Doppler imaging and Ultrasound Localization Microscopy (ULM) on the same animals, we proceeded at a detailed analysis of structural and functional vascular alterations associated with the establishment of chronic SCI, both at macroscopic and microscopic scales. Using a standardized animal model of SCI, our results demonstrate striking hemodynamic alterations in several subparts of the spinal cord: a reduced blood velocity in the lesion site, and an asymmetrical hypoperfusion caudal but not rostral to the lesion. In addition, the worsening of many evaluated parameters at later time points suggests that the neoformed vascular network is not yet fully operational, and reveals ULM as an efficient in vivo readout for spinal cord vascular alterations. Finally, we show statistical correlations between the diverse biomarkers of vascular dysfunction and SCI severity. The imaging modality developed here will allow evaluating recovery of vascular function over time in pre-clinical models of SCI. Also, used on SCI patients in combination with other quantitative markers of neural tissue damage, it may help classifying lesion severity and predict possible treatment outcomes in patients.

scholarly journals Ultrafast Doppler imaging and Ultrasound Localization Microscopy reveal the complexity of vascular rearrangement in chronic spinal lesion

2021 ◽  
Author(s):  
Sophie Pezet ◽  
Benoit Beliard ◽  
Chaimae Ahmanna ◽  
Elodie Tiran ◽  
Kadia Kanté ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Imaging Modality ◽  
Doppler Imaging ◽  
Localization Microscopy ◽  
Ultrasound Localization ◽  
Statistical Correlations ◽  
Cord Injury

Abstract Acute spinal cord injury (SCI) leads to severe damage to the microvascular network. The process of spontaneous repair is accompanied by formation of new blood vessels; their functionality, however, presumably very important for functional recovery, has never been clearly established, as most studies so far used fixed tissues. Here, combining ultrafast Doppler imaging and Ultrasound Localization Microscopy (ULM) on the same animals, we proceeded at a detailed analysis of structural and functional vascular alterations associated with the establishment of chronic SCI, both at macroscopic and microscopic scales. Using a standardized animal model of SCI, our results demonstrate striking hemodynamic alterations in several subparts of the spinal cord: a reduced blood velocity in the lesion site, and an asymmetrical hypoperfusion caudal but not rostral to the lesion. In addition, the worsening of many evaluated parameters at later time points suggests that the neoformed vascular network is not yet fully operational, and reveals ULM as an efficient in vivo readout for spinal cord vascular alterations. Finally, we show statistical correlations between the diverse biomarkers of vascular dysfunction and SCI severity. The imaging modality developed here will allow evaluating recovery of vascular function over time in pre-clinical models of SCI. Also, used on SCI patients in combination with other quantitative markers of neural tissue damage, it may help classifying lesion severity and predict possible treatment outcomes in patients.

scholarly journals In Vivo Confocal Imaging of Fluorescently Labeled Microbubbles: Implications for Ultrasound Localization Microscopy

2020 ◽  
Vol 67 (9) ◽  
pp. 1811-1819 ◽  
Author(s):  
Matthew R. Lowerison ◽  
Chengwu Huang ◽  
Yohan Kim ◽  
Fabrice Lucien ◽  
Shigao Chen ◽  
...  
Keyword(s):  
Confocal Imaging ◽  
Localization Microscopy ◽  
Ultrasound Localization
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