Dataset Information

A new acoustic coupling fluid with ability to reduce ultrasound imaging artefacts in brain tumour surgery-a phase I study.

ABSTRACT:

Background

A novel acoustic coupling fluid (ACF), with the potential to reduce surgically induced image artefacts during intraoperative ultrasound imaging in brain tumour surgery, has been evaluated with respect to image quality and safety in a clinical phase 1 study.

Methods

Fifteen patients with glioblastoma (WHO grade IV) were included. All adverse events were registered in a 6-month study period. During acquisition of 3D ultrasound image volumes, three different concentrations of the ACF and Ringer's solution were filled into the resection cavity. The effect of ACF on the ultrasound images was rated by the operating surgeon, and by five independent neurosurgeons evaluating a pair of blinded images from all patients. Images from all patients were analysed by comparing pixel brightness in a noise-affected region and a reference region.

Results

The operating surgeon deemed the ACF images to have less noise than images obtained with Ringers's solution. The blinded evaluations by the independent neurosurgeons were significantly in favour of ACF (p < 0.0001). The analyses of pixel intensities showed that the ACF images had lower amount of noise than images obtained with Ringer's solution. No radiological sign of inflammation nor circulatory changes was found in the early postoperative MR images. Of the nine complications registered as serious events in the study period, none was deemed to be caused by the ACF.

Conclusion

The ultrasound (US) images obtained using ACF have significantly less noise than US images obtained with Ringer's solution. The rate of adverse events was comparable to what has been reported for similar groups of patients.

SUBMITTER: Unsgard G

PROVIDER: S-EPMC6581938 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A new acoustic coupling fluid with ability to reduce ultrasound imaging artefacts in brain tumour surgery-a phase I study.

Unsgård Geirmund G Sagberg Lisa Millgård LM Müller Sébastien S Selbekk Tormod T

Acta neurochirurgica 20190518 7

<h4>Background</h4>A novel acoustic coupling fluid (ACF), with the potential to reduce surgically induced image artefacts during intraoperative ultrasound imaging in brain tumour surgery, has been evaluated with respect to image quality and safety in a clinical phase 1 study.<h4>Methods</h4>Fifteen patients with glioblastoma (WHO grade IV) were included. All adverse events were registered in a 6-month study period. During acquisition of 3D ultrasound image volumes, three different concentrations ...[more]

PMID: 31104122

Similar Datasets

Project description:PurposeIn this study, we examine the effects of a recently developed, iron-based coupling medium (IBCM) on guidance magnetic resonance (MR) scans during transcranial, magnetic-resonance-guided, focused ultrasound surgery (tMRgFUS) procedures. More specifically, this study tests the hypotheses that the use of the IBCM will (a) not adversely affect image quality, (b) remove aliasing from small field-of-view scans, and (c) decouple image quality from the motion state of the coupling fluid.MethodsAn IBCM, whose chemical synthesis and characterization are reported elsewhere, was used as a coupling medium during tMRgFUS procedures on gel phantoms. Guidance magnetization-prepared rapid-gradient-echo (MP-RAGE), TSE, and GRE scans were acquired with fields of view of 28 and 18 cm. Experiments were repeated with the IBCM in several distinct flow states. GRE scans were used to estimate temperature time courses as a gel target was insonated. IBCM performance was measured by computing (i) the root mean square difference (RMSD) of TSE and GRE pixel values acquired using water and the IBCM, relative to the use of water; (ii) through-time temperature uncertainty for GRE scans; and (iii) Bland-Altman analysis of the temperature time courses. Finally, guidance TSE and GRE scans of a human volunteer were acquired during a separate sham tMRgFUS procedure. As a control, all experiments were repeated using a water coupling medium.ResultsUse of the IBCM reduced RMSD in TSE scans by a factor of 4 or more for all fields of view and nonstationary motion states, but did not reduce RMSD estimates in MP-RAGE scans. With the coupling media in a stationary state, the IBCM altered estimates of temperature uncertainty relative to the use of water by less than 0.2°C. However, with a high flow state, the IBCM reduced temperature uncertainties by the statistically significant amounts (at the 0.01 level) of 0.5°C (28 cm field of view) and 5°C (18 cm field of view). Bland-Altman analyses found a 0.1°C ± 0.5°C difference between temperature estimates acquired using water and the IBCM as coupling media. Finally, scans of a human volunteer using the IBCM indicate more conspicuous grey/white matter contrast, a reduction in aliasing, and a less than 0.2°C change in temperature uncertainty.ConclusionsThe use of an IBCM during tMRgFUS procedures does not adversely affect image quality for TSE and GRE scans, can decouple image quality from the motion state of the coupling fluid, and can remove aliasing from scans where the field of view is set to be much smaller than the spatial extent of the coupling fluid.

Project description:BackgroundLow-intensity Continuous Ultrasound (LICUS) therapy heals soft tissue injuries. It alleviates acute and chronic musculoskeletal pain by activating multiple healing processes through its diathermic and mechanotransducive properties. Diclofenac has been FDA-approved as a Non-Steroidal Anti-Inflammatory Drug (NSAID). It is an analgesic and anti-inflammatory drug available in oral and topical forms. Adding 2.5% diclofenac sodium to ultrasound coupling gel can be used to deliver LICUS in addition to the analgesic effects of diclofenac sodium without altering the diathermic and acoustic effects of the ultrasound penetration with no undesired adverse effects.ObjectiveTo determine the effects of adding 2.5% diclofenac sodium to standard aqueous ultrasound gel on the ultrasound coupling and diathermic properties of a long duration Sustained Acoustic Medicine (SAM) treatment.MethodsIn a two-phase study, first, the acoustic and diathermic changes were determined in bovine tissue during 4-hour-long SAM stimulation at 1 cm, 2 cm, and 5 cm with aqueous and 2.5% diclofenac ultrasound coupling patch. Then, in the second phase, the heating profiles were recorded with and without 2.5% diclofenac gel in 54 healthy adult subjects at the forearm and calf during the SAM treatment.ResultThe addition of 2.5% diclofenac sodium significantly increased coupling gel density, acoustic impedance, and signal propagation (p<0.0001) with little or no effect on the diathermic profiles at 1 cm, 2 cm, and 5 cm depth. The coupling gel with 2.5% diclofenac sodium sustained the therapeutic ultrasound intensity longer than the aqueous coupling gel (5.5 cm relative to 4.5, p<0.0009). No significant diathermic difference was recorded on the calf and forearm skin with a 2.5% diclofenac ultrasound gel coupling patch.ConclusionAdding 2.5% diclofenac sodium to ultrasound gel increases acoustic impedance, improves ultrasound signal coupling into deep tissue, and provides longer sustained deep tissue heating without negatively impacting the diathermic profile during SAM treatment.

Project description:Biologists regularly create phylogenetic trees to better understand the evolutionary origins of their species of interest, and often use genomes as their data source. However, as more and more incomplete genomes are published, in many cases it may not be possible to compute genome-based phylogenetic trees due to large gaps in the assembled sequences. In addition, comparison of complete genomes may not even be desirable due to the presence of horizontally acquired and homologous genes. A decision must therefore be made about which gene, or gene combinations, should be used to compute a tree. Deflated Cladistic Information based on Total Entropy (dCITE) is proposed as an easily computed metric for measuring the cladistic information in multiple sequence alignments representing a range of taxa, without the need to first compute the corresponding trees. dCITE scores can be used to rank candidate genes or decide whether input sequences provide insufficient cladistic information, making artefactual polytomies more likely. The dCITE method can be applied to protein, nucleotide or encoded phenotypic data, so can be used to select which data-type is most appropriate, given the choice. In a series of experiments the dCITE method was compared with related measures. Then, as a practical demonstration, the ideas developed in the paper were applied to a dataset representing species from the order Campylobacterales; trees based on sequence combinations, selected on the basis of their dCITE scores, were compared with a tree constructed to mimic Multi-Locus Sequence Typing (MLST) combinations of fragments. We see that the greater the dCITE score the more likely it is that the computed phylogenetic tree will be free of artefactual polytomies. Secondly, cladistic information saturates, beyond which little additional cladistic information can be obtained by adding additional sequences. Finally, sequences with high cladistic information produce more consistent trees for the same taxa.

Project description:Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB) is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME) for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR), and distinct mechanism(s) that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may improve targeted drug delivery.

Dataset Information

A new acoustic coupling fluid with ability to reduce ultrasound imaging artefacts in brain tumour surgery-a phase I study.

Background

Methods

Results

Conclusion

Publications

A new acoustic coupling fluid with ability to reduce ultrasound imaging artefacts in brain tumour surgery-a phase I study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets