The Experts below are selected from a list of 130983 Experts worldwide ranked by ideXlab platform
Venkatesh L Murthy - One of the best experts on this subject based on the ideXlab platform.
-
blood pool and tissue phase patient Motion effects on 82 rubidium pet myocardial blood flow quantification
Journal of Nuclear Cardiology, 2018Co-Authors: Benjamin C Lee, Jonathan B Moody, Alexis Poitrassonriviere, Amanda C Melvin, Richard L Weinberg, James R Corbett, Edward P Ficaro, Venkatesh L MurthyAbstract:Patient Motion can lead to misalignment of left ventricular volumes of interest and subsequently inaccurate quantification of myocardial blood flow (MBF) and flow reserve (MFR) from dynamic PET myocardial perfusion images. We aimed to identify the prevalence of patient Motion in both blood and tissue phases and analyze the effects of this Motion on MBF and MFR estimates. We selected 225 consecutive patients that underwent dynamic stress/rest rubidium-82 chloride (82Rb) PET imaging. Dynamic image series were iteratively reconstructed with 5- to 10-second frame durations over the first 2 minutes for the blood phase and 10 to 80 seconds for the tissue phase. Motion shifts were assessed by 3 physician readers from the dynamic series and analyzed for frequency, magnitude, time, and Direction of Motion. The effects of this Motion isolated in time, Direction, and magnitude on global and regional MBF and MFR estimates were evaluated. Flow estimates derived from the Motion corrected images were used as the error references. Mild to moderate Motion (5-15 mm) was most prominent in the blood phase in 63% and 44% of the stress and rest studies, respectively. This Motion was observed with frequencies of 75% in the septal and inferior Directions for stress and 44% in the septal Direction for rest. Images with blood phase isolated Motion had mean global MBF and MFR errors of 2%-5%. Isolating blood phase Motion in the inferior Direction resulted in mean MBF and MFR errors of 29%-44% in the RCA territory. Flow errors due to tissue phase isolated Motion were within 1%. Patient Motion was most prevalent in the blood phase and MBF and MFR errors increased most substantially with Motion in the inferior Direction. Motion correction focused on these Motions is needed to reduce MBF and MFR errors.
Benjamin C Lee - One of the best experts on this subject based on the ideXlab platform.
-
blood pool and tissue phase patient Motion effects on 82 rubidium pet myocardial blood flow quantification
Journal of Nuclear Cardiology, 2018Co-Authors: Benjamin C Lee, Jonathan B Moody, Alexis Poitrassonriviere, Amanda C Melvin, Richard L Weinberg, James R Corbett, Edward P Ficaro, Venkatesh L MurthyAbstract:Patient Motion can lead to misalignment of left ventricular volumes of interest and subsequently inaccurate quantification of myocardial blood flow (MBF) and flow reserve (MFR) from dynamic PET myocardial perfusion images. We aimed to identify the prevalence of patient Motion in both blood and tissue phases and analyze the effects of this Motion on MBF and MFR estimates. We selected 225 consecutive patients that underwent dynamic stress/rest rubidium-82 chloride (82Rb) PET imaging. Dynamic image series were iteratively reconstructed with 5- to 10-second frame durations over the first 2 minutes for the blood phase and 10 to 80 seconds for the tissue phase. Motion shifts were assessed by 3 physician readers from the dynamic series and analyzed for frequency, magnitude, time, and Direction of Motion. The effects of this Motion isolated in time, Direction, and magnitude on global and regional MBF and MFR estimates were evaluated. Flow estimates derived from the Motion corrected images were used as the error references. Mild to moderate Motion (5-15 mm) was most prominent in the blood phase in 63% and 44% of the stress and rest studies, respectively. This Motion was observed with frequencies of 75% in the septal and inferior Directions for stress and 44% in the septal Direction for rest. Images with blood phase isolated Motion had mean global MBF and MFR errors of 2%-5%. Isolating blood phase Motion in the inferior Direction resulted in mean MBF and MFR errors of 29%-44% in the RCA territory. Flow errors due to tissue phase isolated Motion were within 1%. Patient Motion was most prevalent in the blood phase and MBF and MFR errors increased most substantially with Motion in the inferior Direction. Motion correction focused on these Motions is needed to reduce MBF and MFR errors.
M J Bell - One of the best experts on this subject based on the ideXlab platform.
-
experimental study of oscillatory Motion of particles and bubbles with applications to coriolis flow meters
Physics of Fluids, 2008Co-Authors: J A Weinstein, D R Kassoy, M J BellAbstract:The present experimental study is designed to measure the Motion of a spherical particle in a noninertial reference frame when the environment oscillates horizontally at a prescribed frequency and amplitude. Measurements are compared with theoretical equations of Motion, for example, Basset [A Treatise on Hydrodynamics (Deighton Hall, London, 1888), Vol. 2], over wide ranges of density ratio (ρf/ρp), inverse Stokes number (δ), and amplitude ratio (Ap/Af), the three most critical nondimensional parameters. The experimental configuration consists of a bubble or solid sphere rising or falling in a bubble column while vibration occurs in the horizontal Direction. Motion is measured with a high speed video camera and contemporary image and signal processing techniques are used to evaluate the data. The setup closely resembles multiphase flow in a Coriolis flow meter, a device which measures mass flow rate and density by oscillating two tubes at resonance. Accurate predictions of the Motion of the sphere may le...
Min Jun Kim - One of the best experts on this subject based on the ideXlab platform.
-
Three-dimensional control of Tetrahymena pyriformis using artificial magnetotaxis
Applied Physics Letters, 2012Co-Authors: Dal Hyung Kim, Paul Kim, A. Agung Julius, Min Jun KimAbstract:We demonstrate three-dimensional control with the eukaryotic cell Tetrahymena pyriformis (T. pyriformis) using two sets of Helmholtz coils for xy-plane Motion and a single electromagnet for z-Direction Motion. T. pyriformis is modified to have artificial magnetotaxis with internalized magnetite. To track the cell’s z-axis position, intensity profiles of non-motile cells at varying distances from the focal plane are used. During vertical Motion along the z-axis, the intensity difference is used to determine the position of the cell. The three-dimensional control of the live microorganism T. pyriformis as a cellular robot shows great potential for practical applications in microscale tasks, such as target transport and cell therapy.
Edward P Ficaro - One of the best experts on this subject based on the ideXlab platform.
-
blood pool and tissue phase patient Motion effects on 82 rubidium pet myocardial blood flow quantification
Journal of Nuclear Cardiology, 2018Co-Authors: Benjamin C Lee, Jonathan B Moody, Alexis Poitrassonriviere, Amanda C Melvin, Richard L Weinberg, James R Corbett, Edward P Ficaro, Venkatesh L MurthyAbstract:Patient Motion can lead to misalignment of left ventricular volumes of interest and subsequently inaccurate quantification of myocardial blood flow (MBF) and flow reserve (MFR) from dynamic PET myocardial perfusion images. We aimed to identify the prevalence of patient Motion in both blood and tissue phases and analyze the effects of this Motion on MBF and MFR estimates. We selected 225 consecutive patients that underwent dynamic stress/rest rubidium-82 chloride (82Rb) PET imaging. Dynamic image series were iteratively reconstructed with 5- to 10-second frame durations over the first 2 minutes for the blood phase and 10 to 80 seconds for the tissue phase. Motion shifts were assessed by 3 physician readers from the dynamic series and analyzed for frequency, magnitude, time, and Direction of Motion. The effects of this Motion isolated in time, Direction, and magnitude on global and regional MBF and MFR estimates were evaluated. Flow estimates derived from the Motion corrected images were used as the error references. Mild to moderate Motion (5-15 mm) was most prominent in the blood phase in 63% and 44% of the stress and rest studies, respectively. This Motion was observed with frequencies of 75% in the septal and inferior Directions for stress and 44% in the septal Direction for rest. Images with blood phase isolated Motion had mean global MBF and MFR errors of 2%-5%. Isolating blood phase Motion in the inferior Direction resulted in mean MBF and MFR errors of 29%-44% in the RCA territory. Flow errors due to tissue phase isolated Motion were within 1%. Patient Motion was most prevalent in the blood phase and MBF and MFR errors increased most substantially with Motion in the inferior Direction. Motion correction focused on these Motions is needed to reduce MBF and MFR errors.