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Real-time Tracking (real-time + tracking)

Distribution by Scientific Domains
Medical Sciences80%

Selected Abstracts

MR imaging in assessing cardiovascular interventions and myocardial injury

CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007
Alexis Jacquier
Abstract Performing an MR-guided endovascular intervention requires (1) real-time tracking and guidance of catheters/guide wires to the target, (2) high-resolution images of the target and its surroundings in order to define the extent of the target, (3) performing a therapeutic procedure (delivery of stent or injection of gene or cells) and (4) evaluating the outcome of the therapeutic procedure. The combination of X-ray and MR imaging (XMR) in a single suite was designed for new interventional procedures. MR contrast media can be used to delineate myocardial infarcts and microvascular obstruction, thereby defining the target for local delivery of therapeutic agents under MR-guidance. Iron particles, or gadolinium- or dysprosium-chelates are mixed with the soluble injectates or stem cells in order to track intramyocardial delivery and distribution. Preliminary results show that genes encoded for vascular endothelial and fibroblast growth factor and cells are effective in promoting angiogenesis, arteriogenesis, perfusion and LV function. Angiogenic growth factors, genes and cells administered under MR-guided minimally invasive catheter-based procedures will open up new avenues in treating end-stage ischemic heart disease. The optimum dose of the therapeutic agents, delivery devices and real-time imaging techniques to guide the delivery are currently the subject of ongoing research. The aim of this review is to (1) provide an updated review of experiences using MR imaging to guide transcatheter therapy, (2) address the potential of cardiovascular magnetic resonance (MR) imaging and MR contrast media in assessing myocardial injury at a molecular level and labeling cells and (3) illustrate the applicability of the non-invasive MR imaging in the field of angiogenic therapies through recent clinical and experimental publications. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Older persons' experiences of whole systems: the impact of health and social care organizational structures

JOURNAL OF NURSING MANAGEMENT, Issue 2 2008
BRENDAN McCORMACK BSc (Hons) Nursing, DPhil (Oxon)
Aim(s), An in-depth case study of whole systems working. Background, This paper reports on the second part of a two-part study exploring whole systems working. Part 1 of the study focused on an in-depth review of the literature pertaining to continuity of care and service integration. The second part, reported here, focused on an in-depth case study of one whole system. Evaluation, Informed by the findings of part 1 of the study, data collection methods included in-depth interviews, real-time tracking of 18 older people, focus groups and consensus conferencing. Different data sets were analysed individually and synthesized using matrices derived from the literature review findings. Key issue(s), Key themes from data synthesis include: (1) access to the most appropriate services; (2) service fragmentation; (3) continuity of care; and (4) routinized care. Conclusion(s), The four themes of the case study reflect the need to address issues of demarcation of professional responsibilities, complicated channels of communication, information flows, assessment and reassessment in whole systems working. Implications for nursing management, The impact of disempowering relationships on actual continuity of care and perceptions of quality among service users and providers. Lessons need to be learnt from specialist services and applied to service delivery in general. [source]

Automatic slice positioning (ASP) for passive real-time tracking of interventional devices using projection-reconstruction imaging with echo-dephasing (PRIDE)

MAGNETIC RESONANCE IN MEDICINE, Issue 4 2009
S. Patil
Abstract A novel and fast approach for passive real-time tracking of interventional devices using paramagnetic markers, termed "projection-reconstruction imaging with echo-dephasing" (PRIDE) is presented. PRIDE is based on the acquisition of echo-dephased projections along all three physical axes. Dephasing is preferably set to 4, within each projection ensuring that background tissues do not contribute to signal formation and thus appear heavily suppressed. However, within the close vicinity of the paramagnetic marker, local gradient fields compensate for the intrinsic dephasing to form an echo. Successful localization of the paramagnetic marker with PRIDE is demonstrated in vitro and in vivo in the presence of different types of off-resonance (air/tissue interfaces, main magnetic field inhomogeneities, etc). In order to utilize the PRIDE sequence for vascular interventional applications, it was interleaved with balanced steady-state free precession (bSSFP) to provide positional updates to the imaged slice using a dedicated real-time feedback link. Active slice positioning (ASP) with PRIDE is demonstrated in vitro, requiring approximately 20 ms for the positional update to the imaging sequence, comparable to existing active tracking methods. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [source]

FRET-Based Activity Biosensors to Probe Compartmentalized Signaling

CHEMBIOCHEM, Issue 2 2010
Xinxin Gao Dr.
Illuminating compartmentalized signaling: We discuss the applications of FRET-based biosensors with a focus on understanding compartmentalized signaling of kinase and second-messenger dynamics. With their unique features of genetic encodability and targetability, these biosensors allow real-time tracking of activity dynamics with high spatiotemporal resolution. [source]