Background And Objective: In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.
Methods: Ultrasonic examination of the L3/4 interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).
Results: Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.
Conclusions: Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.
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http://dx.doi.org/10.1046/j.1365-2346.2001.00993.x | DOI Listing |
J Assoc Res Otolaryngol
January 2025
Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, 3010, Freiburgstrasse, Bern, Switzerland.
Purpose: There are challenges in understanding the biomechanics of the human middle ear, and established methods for studying this system show significant limitations. In this study, we evaluate a novel dynamic imaging technique based on synchrotron X-ray microtomography designed to assess the biomechanical properties of the human middle ear by comparing it to laser-Doppler vibrometry (LDV).
Methods: We examined three fresh-frozen temporal bones (TB), two donated by white males and one by a Black female, using dynamic synchrotron-based X-ray microtomography for 256 and 512 Hz, stimulated at 110 dB and 120 dB sound pressure level (SPL).
Ultrasound Med Biol
January 2025
Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
Objective: Conventional coherent plane wave compounding (CPWC) and sum-of-square power Doppler (PD) estimation lead to low contrast and high noise level in ultrafast PD imaging when the number of plane-wave angle and the ensemble length is limited. The coherence-based PD estimation using temporal-multiply-and-sum (TMAS) of high-lag autocorrelation can effectively suppress the uncorrelated noises but at the cost of signal power due to the blood flow decorrelation.
Methods: In this study, the TMAS PD estimation is incorporated with complementary subset transmit in nonlinear compounding (DMAS-CST) to leverage the signal coherence in both angular and temporal dimensions for improvement of PD image quality.
Comput Methods Programs Biomed
January 2025
Christian Doppler Laboratory for Artificial Intelligence in Retina, Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria; Institute of Artificial Intelligence, Center for Medical Data Science, Medical University of Vienna, Vienna, Austria.
Background And Objectives: Automated, anatomically coherent retinal layer segmentation in optical coherence tomography (OCT) is one of the most important components of retinal disease management. However, current methods rely on large amounts of labeled data, which can be difficult and expensive to obtain. In addition, these systems tend often propose anatomically impossible results, which undermines their clinical reliability.
View Article and Find Full Text PDFBMJ Open
December 2024
Department of Vascular Surgery, Leids Universitair Medisch Centrum, Leiden, The Netherlands.
Introduction: Foot ulcers are one of the most serious complications of diabetes, leading to significant risks on amputation and mortality. Peripheral arterial disease (PAD) is an important factor for the development and the outcome of diabetic foot ulcers (DFU). Although prompt and accurate detection of PAD is critical to reduce complications, its diagnosis can be challenging with currently used bedside tests (such as ankle-brachial index and toe pressure) due to medial arterial calcification.
View Article and Find Full Text PDFNeuroinformatics
January 2025
Neuro-Electronics Research Flanders, Kapeldreef 75, Leuven, 3001, Belgium.
The brain is composed of a dense and ramified vascular network of arteries, veins and capillaries of various sizes. One way to assess the risk of cerebrovascular pathologies is to use computational models to predict the physiological effects of reduced blood supply and correlate these responses with observations of brain damage. Therefore, it is crucial to establish a detailed 3D organization of the brain vasculature, which could be used to develop more accurate in silico models.
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