1043 High spatial and temporal resolution MRA of the entire peripheral vascular system using a new 3D time-resolved MRA technique (TWIST)

AbstractFast, direct electron detectors have significantly improved the spatio-temporal resolution of electron microscopy movies. Preserving both spatial and temporal resolution in extended observations, however, requires storing prohibitively large amounts of data. Here, we describe an efficient and flexible data reduction and compression scheme (ReCoDe) that retains both spatial and temporal resolution by preserving individual electron events. Running ReCoDe on a workstation we demonstrate on-the-fly reduction and compression of raw data streaming off a detector at 3 GB/s, for hours of uninterrupted data collection. The output was 100-fold smaller than the raw data and saved directly onto network-attached storage drives over a 10 GbE connection. We discuss calibration techniques that support electron detection and counting (e.g., estimate electron backscattering rates, false positive rates, and data compressibility), and novel data analysis methods enabled by ReCoDe (e.g., recalibration of data post acquisition, and accurate estimation of coincidence loss).

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Super-resolution time-resolved imaging using computational sensor fusion

Scientific Reports ◽

10.1038/s41598-021-81159-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. Callenberg ◽

A. Lyons ◽

D. den Brok ◽

A. Fatima ◽

A. Turpin ◽

...

Keyword(s):

Sensor Fusion ◽

Spatial Resolution ◽

Temporal Resolution ◽

Single Photon ◽

Super Resolution ◽

Numerical Data ◽

Data Cube ◽

Fluorescence Lifetime Imaging ◽

Time Resolved ◽

Temporal Precision

AbstractImaging across both the full transverse spatial and temporal dimensions of a scene with high precision in all three coordinates is key to applications ranging from LIDAR to fluorescence lifetime imaging. However, compromises that sacrifice, for example, spatial resolution at the expense of temporal resolution are often required, in particular when the full 3-dimensional data cube is required in short acquisition times. We introduce a sensor fusion approach that combines data having low-spatial resolution but high temporal precision gathered with a single-photon-avalanche-diode (SPAD) array with data that has high spatial but no temporal resolution, such as that acquired with a standard CMOS camera. Our method, based on blurring the image on the SPAD array and computational sensor fusion, reconstructs time-resolved images at significantly higher spatial resolution than the SPAD input, upsampling numerical data by a factor $$12 \times 12$$ 12 × 12 , and demonstrating up to $$4 \times 4$$ 4 × 4 upsampling of experimental data. We demonstrate the technique for both LIDAR applications and FLIM of fluorescent cancer cells. This technique paves the way to high spatial resolution SPAD imaging or, equivalently, FLIM imaging with conventional microscopes at frame rates accelerated by more than an order of magnitude.

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Pilot Study: Quantitative Photoacoustic Evaluation of Peripheral Vascular Dynamics Induced by Carfilzomib In Vivo

Sensors ◽

10.3390/s21030836 ◽

2021 ◽

Vol 21 (3) ◽

pp. 836

Author(s):

Thi Thao Mai ◽

Manh-Cuong Vo ◽

Tan-Huy Chu ◽

Jin Young Kim ◽

Chulhong Kim ◽

...

Keyword(s):

Pilot Study ◽

Side Effects ◽

Cardiovascular Events ◽

Evaluation Method ◽

Vascular System ◽

Maximum Amplitude ◽

Peripheral Vascular ◽

Peripheral Vasculature ◽

Mouse Ear

Carfilzomib is mainly used to treat multiple myeloma. Several side effects have been reported in patients treated with carfilzomib, especially those associated with cardiovascular events, such as hypertension, congestive heart failure, and coronary artery disease. However, the side effects, especially the manifestation of cardiovascular events through capillaries, have not been fully investigated. Here, we performed a pilot experiment to monitor peripheral vascular dynamics in a mouse ear under the effects of carfilzomib using a quantitative photoacoustic vascular evaluation method. Before and after injecting the carfilzomib, bortezomib, and PBS solutions, we acquired high-resolution three-dimensional PAM data of the peripheral vasculature of the mouse ear during each experiment for 10 h. Then, the PAM maximum amplitude projection (MAP) images and five quantitative vascular parameters, i.e., photoacoustic (PA) signal, diameter, density, length fraction, and fractal dimension, were estimated. Quantitative results showed that carfilzomib induces a strong effect on the peripheral vascular system through a significant increase in all vascular parameters up to 50%, especially during the first 30 min after injection. Meanwhile, bortezomib and PBS do not have much impact on the peripheral vascular system. This pilot study verified PAM as a comprehensive method to investigate peripheral vasculature, along with the effects of carfilzomib. Therefore, we expect that PAM may be useful to predict cardiovascular events caused by carfilzomib.

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The dependence of the cardiac effects of nifedipine on the responses of the peripheral vascular system.

Circulation ◽

10.1161/01.cir.69.5.963 ◽

1984 ◽

Vol 69 (5) ◽

pp. 963-972 ◽

Cited By ~ 36

Author(s):

P B Kurnik ◽

A J Tiefenbrunn ◽

P A Ludbrook

Keyword(s):

Vascular System ◽

Peripheral Vascular ◽

Cardiac Effects

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CORP: Ultrasound assessment of vascular function with the passive leg movement technique

Journal of Applied Physiology ◽

10.1152/japplphysiol.00557.2017 ◽

2017 ◽

Vol 123 (6) ◽

pp. 1708-1720 ◽

Cited By ~ 22

Author(s):

Jayson R. Gifford ◽

Russell S. Richardson

Keyword(s):

Vascular Function ◽

Cardiovascular Health ◽

Vascular System ◽

The Elderly ◽

Passive Movement ◽

Flow Mediated Dilation ◽

Peripheral Vascular ◽

Ultrasound Assessment ◽

Leg Movement ◽

Hyperemic Response

As dysfunction of the vascular system is an early, modifiable step in the progression of many cardiovascular diseases, there is demand for methods to monitor the health of the vascular system noninvasively in clinical and research settings. Validated by very good agreement with more technical assessments of vascular function, like intra-arterial drug infusions and flow-mediated dilation, the passive leg movement (PLM) technique has emerged as a powerful, yet relatively simple, test of peripheral vascular function. In the PLM technique, the change in leg blood flow elicited by the passive movement of the leg through a 90° range of motion is quantified with Doppler ultrasound. This relatively easy-to-learn test has proven to be ≤80% dependent on nitric oxide bioavailability and is especially adept at determining peripheral vascular function across the spectrum of cardiovascular health. Indeed, multiple reports have documented that individuals with decreased cardiovascular health such as the elderly and those with heart failure tend to exhibit a substantially blunted PLM-induced hyperemic response (~50 and ~85% reduction, respectively) compared with populations with good cardiovascular health such as young individuals. As specific guidelines have not yet been put forth, the purpose of this Cores of Reproducibility in Physiology (CORP) article is to provide a comprehensive reference for the assessment and interpretation of vascular function with PLM with the aim to increase reproducibility and consistency among studies and facilitate the use of PLM as a research tool with clinical relevance.

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