38 research outputs found
One-class Gaussian process regressor for quality assessment of transperineal ultrasound images
The use of ultrasound guidance in prostate cancer radiotherapy workflows is not widespread. This can be partially attributed to the need for image interpretation by a trained operator during ultrasound image acquisition. In this work, a one-class regressor, based on DenseNet and Gaussian processes, was implemented to assess automatically the quality of transperineal ultrasound images of the male pelvic region. The implemented deep learning approach achieved a scoring accuracy of 94%, a specificity of 95% and a sensitivity of 93% with respect to the majority vote of three experts, which was comparable with the results of these experts. This is the first step towards a fully automatic workflow, which could potentially remove the need for image interpretation and thereby make the use of ultrasound imaging, which allows real-time volumetric organ tracking in the RT environment, more appealing for hospitals
The common ABCA4 variant p.Asn1868ile shows nonpenetrance and variable expression of stargardt disease when present in trans with severe variants
PURPOSE. To assess the occurrence and the disease expression of the common p.Asn1868Ile variant in patients with Stargardt disease (STGD1) harboring known, monoallelic causal ABCA4 variants. METHODS. The coding and noncoding regions of ABCA4 were sequenced in 67 and 63 STGD1 probands respectively, harboring monoallelic ABCA4 variants. In case p.Asn1868Ile was detected, segregation analysis was performed whenever possible. Probands and affected siblings harboring p.Asn1868Ile without additional variants in cis were clinically evaluated retrospe
Real-time visualization of heterotrimeric G protein Gq activation in living cells
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97296.pdf (publisher's version ) (Open Access)BACKGROUND: Gq is a heterotrimeric G protein that plays an important role in numerous physiological processes. To delineate the molecular mechanisms and kinetics of signalling through this protein, its activation should be measurable in single living cells. Recently, fluorescence resonance energy transfer (FRET) sensors have been developed for this purpose. RESULTS: In this paper, we describe the development of an improved FRET-based Gq activity sensor that consists of a yellow fluorescent protein (YFP)-tagged Ggamma2 subunit and a Galphaq subunit with an inserted monomeric Turquoise (mTurquoise), the best cyan fluorescent protein variant currently available. This sensor enabled us to determine, for the first time, the kon (2/s) of Gq activation. In addition, we found that the guanine nucleotide exchange factor p63RhoGEF has a profound effect on the number of Gq proteins that become active upon stimulation of endogenous histamine H1 receptors. The sensor was also used to measure ligand-independent activation of the histamine H1 receptor (H1R) upon addition of a hypotonic stimulus. CONCLUSIONS: Our observations reveal that the application of a truncated mTurquoise as donor and a YFP-tagged Ggamma2 as acceptor in FRET-based Gq activity sensors substantially improves their dynamic range. This optimization enables the real-time single cell quantification of Gq signalling dynamics, the influence of accessory proteins and allows future drug screening applications by virtue of its sensitivity
Automation of ultrasound image acquisition and interpretation for dose guidance in prostate cancer radiotherapy workflows
Artificial intelligence applications in ultrasound-guided radiotherapy
Chapter 10 explores the most recent and fascinating tools from the artificial intelligence (AI) world and their use in ultrasound-guided radiotherapy
Ultrasound for measuring interfraction organ motion
This is a practical guide to the implementation of 3D/4D ultrasound imaging in radiography. Among its features are the coverage of the technology utilised for ultrasound-guided radiotherapy, clinical need and the advantages of using ultrasound. It is a useful tool for users that incorporates implementation, potential errors, uncertainties and training. This is a comprehensive review of the state-of-the-art technologies, which also looks at the future direction of this exciting field.Researchers, students, hospital physicists and radiographers will all find this book of use as it guides them through current clinical situation and examines the full potential of ultrasound in radiotherapy
Registration of ultrasound with radiotherapy room coordinates
The first challenge encountered when introducing ultrasound into radiotherapy is described in chapter 3: localising the probe in the simulation suite and in the treatment room to enable comparison of the positions of anatomical structures at the two stages. The solutions available are introduced together with a detailed description and analysis of the sources of error and uncertainty. After the probe has been localised, the next steps are to evaluate if the image acquired is of sufficient quality and segment all the relevant structures of interest
CT based prostate cancer patient-specific transperineal ultrasound probe setups for image guided radiotherapy
Radiotherapy aims at irradiating tumor tissue, while sparing normal tissue as much as possible and it is a suitable treatment option for prostate cancer. A crucial aspect of the radiotherapy workflow is patient positioning. It has been shown that frequent imaging during the course of the treatment (image guided radiotherapy) can improve this positioning accuracy. Despite the many advantages of ultrasound imaging (high soft tissue contrast, 4D imaging, etc.) its use in image guided radiotherapy workflows is not widespread. This can be primarily attributed to the need for a trained operator during image acquisition. In this study, patient-specific transperineal ultrasound probe setups were automatically calculated based on CT scans of prostate cancer patients. These setups seem to meet clinical requirements and their use can potentially minimize operator dependence and improve usability for relatively untrained operators. In the end, this could allow patients to fully benefit from the unique characteristics of this imaging modality
Modern Applications of 3D/4D Ultrasound Imaging in Radiotherapy
This is a practical guide to the implementation of 3D/4D ultrasound imaging in radiography. Among its features are the coverage of the technology utilised for ultrasound-guided radiotherapy, clinical need and the advantages of using ultrasound. It is a useful tool for users that incorporates implementation, potential errors, uncertainties and training. This is a comprehensive review of the state-of-the-art technologies, which also looks at the future direction of this exciting field.Researchers, students, hospital physicists and radiographers will all find this book of use as it guides them through current clinical situation and examines the full potential of ultrasound in radiotherapy.Key FeaturesTechnology used for ultrasound guided RTClinical need and advantages of using ultrasoundPractical guide to implementation, including errors, uncertainties and trainingComprehensive review of state-of-the-artCritical evaluation of field and future direction