Search results for " Thermometry"
showing 10 items of 14 documents
Brain-core temperature of patients before and after orthotopic liver transplantation assessed by DWI thermometry
2018
To assess brain-core temperature of end-stage liver disease patients undergoing orthotopic liver transplantation (OLT) using a temperature measurement technique based on the apparent diffusion coefficient of the cerebrospinal fluid in the lateral ventricles. The study group was composed of 19 patients with a model for end-stage liver disease (MELD) score of 23.7 who underwent MR imaging before and after OLT. MR imaging studies were performed with a 1.5T MR scanner. Brain-core temperature (T: °C) was calculated using the following equation from the apparent diffusion coefficient (D) of the cerebrospinal fluid in the lateral ventricles: $$T = {{2256.74} \mathord{\left/ {\vphantom {{2256.74} {…
Brain core temperature of patients before and after orthotopic liver transplantation assessed by diffusion weighted imaging thermometry
2018
Aims and objectives Methods and materials Results Conclusion Personal information References
Thermal properties in low dimensional structures below 1 K
2009
In this thesis thermal properties of low dimensional structures were experimentally studied at low temperatures with the help of tunnel junction thermometry and the Joule heating technique. The main objects of study were electron-phonon coupling in disordered thin metal films and phonon transport in suspended silicon nitride membranes. Our aim has been to clarify the effect of the phonon dimensionality, i.e. the effect of boundaries to the phonon modes and the transition from 3D to 2D phonons. The dimensionality cross over had not been observed before this work even though it is fabricationally a standard procedure to create the low dimensional environments for nanoscale applications and de…
Brain Core Temperature of Patients Before and After Orthotopic Liver Transplantation Assessed by DWI-Thermometry
2019
Purpose The brain produces heat as a result of cerebral metabolism, and the heat is removed mainly through circulation of the intracranial blood vessels and cerebrospinal fluid (CSF). The aim of this study was to assess the brain core temperature of adult patients with end stage liver disease before and after orthotopic liver transplantation (OLT) using a noninvasive temperature measurement technique based on the diffusion coefficient of the cerebrospinal fluid. Materials and Methods This retrospective study used the data collected from January, 2014 to January, 2017. The study group comprised 19 patients (16 men, 3 women, mean age 57.9 ± 7.4 years) with a MELD score 23.7 who underwent magn…
MR Thermometry Data Correlate with Pathological Response for Soft Tissue Sarcoma of the Lower Extremity in a Single Center Analysis of Prospectively …
2020
Background: There is a strong biologic rationale for using locoregional hyperthermia in soft tissue sarcoma and a randomized trial reported significant improvements with hyperthermia. The aim of this study was to describe the opportunities of magnetic resonance (MR)-based thermometry in a cohort of soft tissue sarcoma patients undergoing combined radiotherapy and locoregional hyperthermia. Patients and Methods: For eleven evaluable patients, tumor volume (VTu) and a separate volume for temperature analysis with reliable temperature distribution (Vtherm) were contoured for every hyperthermia treatment (103 therapies). Temperature data were recorded for all tumors and were correlated with cli…
Dual-broadband rotational CARS modelling of nitrogen at pressures up to 9 MPa. II. Rotational Raman line widths
2002
International audience; Rotational coherent anti-Stokes Raman spectroscopy (CARS) is a well-established spectroscopic technique for thermometry at pre-combustion temperatures an atmospheric pressure. However, at pressures of several MPa, a previous investigation revealed large discrepancies between experimental data and the theoretical model. A re-evaluation has been made of these data (at room temperature and in the range 1.5-9 MPa) with two improvements to the spectral code. The first is the inclusion of an inter-branch interference effect, which is described in detail in Paper I. The second is the use of experimental S-1-branch Raman line widths measured at 295 K, with a temperature depe…
A Computational Study on Temperature Variations in MRgFUS Treatments Using PRF Thermometry Techniques and Optical Probes
2021
Structural and metabolic imaging are fundamental for diagnosis, treatment and follow-up in oncology. Beyond the well-established diagnostic imaging applications, ultrasounds are currently emerging in the clinical practice as a noninvasive technology for therapy. Indeed, the sound waves can be used to increase the temperature inside the target solid tumors, leading to apoptosis or necrosis of neoplastic tissues. The Magnetic resonance-guided focused ultrasound surgery (MRgFUS) technology represents a valid application of this ultrasound property, mainly used in oncology and neurology. In this paper
Relativistic quantum thermometry through a moving sensor
2023
Using a two-level moving probe, we address the temperature estimation of a static thermal bath modeled by a massless scalar field prepared in a thermal state. Different couplings of the probe to the field are discussed under various scenarios. We find that the thermometry is completely unaffected by the Lamb shift of the energy levels. We take into account the roles of probe velocity, its initial preparation, and environmental control parameters for achieving optimal temperature estimation. We show that a practical technique can be utilized to implement such a quantum thermometry. Finally, exploiting the thermal sensor moving at high velocity to probe temperature within a multiparameter-est…
Rotational CARS thermometry at high temperature (1800 K) and high pressure (0.1-1.55 MPa)
2007
International audience; Dual-broadband rotational CARS (DB-RCARS) thermometry has been investigated at high temperature and high pressure. Single-shot measurements were performed at 1800 K, in air and nitrogen at pressures up to 1.55 MPa and in oxygen at pressures up to 0.5 MPa. For all conditions, the resonant signal contribution to the spectra clearly dominated over the non-resonant one, implying the high potential for DB-RCARS for temperature and concentration measurements also at the high temperatures and pressures used in the present investigation. The relative standard deviation was generally similar to 2% for single-shot data at pressures from 0.5 to 1.55 MPa. At the investigated tem…
Radial Basis Function Interpolation for Referenceless Thermometry Enhancement
2015
MRgFUS (Magnetic Resonance guided Focused UltraSound) is a new and non-invasive technique to treat different diseases in the oncology field, that uses Focused Ultrasound (FUS) to induce necrosis in the lesion. Temperature change measurements during ultrasound thermo-therapies can be performed through magnetic resonance monitoring by using Proton Resonance Frequency (PRF) thermometry. It measures the phase variation resulting from the temperature-dependent changes in resonance frequency by subtracting one phase baseline image from actual phase. Referenceless thermometry aims to re-duce artefacts caused by tissue motion and frequency drift, fitting the back-ground phase outside the heated reg…