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https://www.readbyqxmd.com/read/29962627/comparison-of-goal-directed-hemodynamic-optimization-using-pulmonary-artery-catheter-and-autocalibrated-arterial-pressure-waveform-analysis-vigileo-flotrac%C3%A2-system-in-on-pump-coronary-artery-bypass-graft-surgery-a-randomized-controlled-studya
#1
Mohamed Ahmed Hamed, Abeer Shaban Goda, Reham Mohmmed Salah Eldein
Background: It is a challenge for anesthesiologists to balance between administering intravenous fluid, vasoactive agents, and inotropic drugs to maintain appropriate cardiac output. Aim: The aim of this study was to evaluate the effect of treatment algorithm guided either by pulmonary artery catheter (PAC) or by the fourth generation FloTrac/Vigileo system combined with monitoring of oxygen transport on hemodynamic management and outcome after coronary artery bypass graft surgery (CABG)...
April 2018: Anesthesia, Essays and Researches
https://www.readbyqxmd.com/read/29935257/content-aware-compressive-magnetic-resonance-image-reconstruction
#2
Daniel S Weller, Michael Salerno, Craig H Meyer
This paper describes an adaptive approach to regularizing model-based reconstructions in magnetic resonance imaging to account for local structure or image content. In conjunction with common models like wavelet and total variation sparsity, this content-aware regularization avoids oversmoothing or compromising image features while suppressing noise and incoherent aliasing from accelerated imaging. To evaluate this regularization approach, the experiments reconstruct images from single- and multi-channel, Cartesian and non-Cartesian, brain and cardiac data...
June 20, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29521963/360-degree-large-scale-multiprojection-light-field-3d-display-system
#3
Lixia Ni, Zhenxing Li, Haifeng Li, Xu Liu
This paper proposes a 360-deg large-scale multiprojection light-field 3D display system, which can reconstruct the light field of models in real space. The reconstructed contents can be observed by multiple viewers from different angles and positions simultaneously. In this system, 360 projectors project images onto a cylindrical light-field diffusion screen whose height is 1.8 m and diameter is 3 m. When moving around the system, viewers can see 3D scenes with smooth-motion parallax, and the frame rate can reach 30 fps and above...
March 10, 2018: Applied Optics
https://www.readbyqxmd.com/read/29427405/robust-sense-reconstruction-of-simultaneous-multislice-epi-with-low-rank-enhanced-coil-sensitivity-calibration-and-slice-dependent-2d-nyquist-ghost-correction
#4
Mengye Lyu, Markus Barth, Victor B Xie, Yilong Liu, Xin Ma, Yanqiu Feng, Ed X Wu
PURPOSE: To improve simultaneous multislice (SMS) EPI by robust Nyquist ghost correction in both coil sensitivity calibration and SMS reconstruction. METHODS: To derive coil sensitivity and slice-dependent phase difference map between positive- and negative-echo images, single-band EPI reference data are fully sampled with EPI parameters matched to SMS acquisition. First, the reference data are organized into positive- and negative-echo virtual channels where missing data are estimated using low-rank-based simultaneous autocalibrating and k-space estimation (SAKE) at small matrix size...
February 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29427393/dynamic-2d-self-phase-map-nyquist-ghost-correction-for-simultaneous-multi-slice-echo-planar-imaging
#5
Uten Yarach, Yi-Hang Tung, Kawin Setsompop, Myung-Ho In, Itthi Chatnuntawech, Renat Yakupov, Frank Godenschweger, Oliver Speck
PURPOSE: To develop a reconstruction pipeline that intrinsically accounts for both simultaneous multislice echo planar imaging (SMS-EPI) reconstruction and dynamic slice-specific Nyquist ghosting correction in time-series data. METHODS: After 1D slice-group average phase correction, the separate polarity (i.e., even and odd echoes) SMS-EPI data were unaliased by slice GeneRalized Autocalibrating Partial Parallel Acquisition. Both the slice-unaliased even and odd echoes were jointly reconstructed using a model-based framework, extended for SMS-EPI reconstruction that estimates a 2D self-phase map, corrects dynamic slice-specific phase errors, and combines data from all coils and echoes to obtain the final images...
February 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29427366/simultaneous-multislice-acquisition-without-trajectory-modification-for-hyperpolarized-13-c-experiments
#6
Angus Z Lau, Justin Y C Lau, Albert P Chen, Charles H Cunningham
PURPOSE: To investigate the feasibility of performing large FOV hyperpolarized 13 C metabolic imaging using simultaneous multislice excitation. METHODS: A spectral-spatial multislice excitation pulse was constructed by cosine modulation and incorporated into a 13 C spiral imaging sequence. Phantom and in vivo pig experiments were performed to test the feasibility of simultaneous multislice data acquisition and image reconstruction. In vivo cardiac-gated images of hyperpolarized pyruvate, bicarbonate, and lactate were obtained at 1 × 1 × 1 cm3 resolution over a 48 × 48 × 24 cm3 FOV with 2-fold acceleration in the slice direction...
February 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29334131/a-bayesian-method-for-accelerated-magnetic-resonance-elastography-of-the-liver
#7
Christopher Ebersole, Rizwan Ahmad, Adam V Rich, Lee C Potter, Huiming Dong, Arunark Kolipaka
PURPOSE: Magnetic resonance elastography is a noninvasive tool for quantifying soft tissue stiffness. Magnetic resonance elastography has been adopted as a clinical method for staging liver fibrosis. However, the application of liver magnetic resonance elastography requires multiple lengthy breath-holds. We propose a new data acquisition and processing method to reduce magnetic resonance elastography scan time. METHODS: A Bayesian image reconstruction method that uses transform sparsity and magnitude consistency across different phase offsets to recover images from highly undersampled data is proposed...
September 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29322551/improving-parallel-imaging-by-jointly-reconstructing-multi-contrast-data
#8
Berkin Bilgic, Tae Hyung Kim, Congyu Liao, Mary Kate Manhard, Lawrence L Wald, Justin P Haldar, Kawin Setsompop
PURPOSE: To develop parallel imaging techniques that simultaneously exploit coil sensitivity encoding, image phase prior information, similarities across multiple images, and complementary k-space sampling for highly accelerated data acquisition. METHODS: We introduce joint virtual coil (JVC)-generalized autocalibrating partially parallel acquisitions (GRAPPA) to jointly reconstruct data acquired with different contrast preparations, and show its application in 2D, 3D, and simultaneous multi-slice (SMS) acquisitions...
August 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29299818/influence-of-the-reference-scan-and-scan-time-on-the-arterial-phase-of-liver-magnetic-resonance-imaging
#9
Yoshinori Tsuji, Satoshi Saitoh, Junji Takahashi, Chisato Abe, Tatsuya Hayashi, Masahiro Kobayashi
The controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique can decrease scan time. The purpose of this study was to determine whether an arterial phase scan can be performed in 5 s using the CAIPIRINHA short-scan and a reference scanning technique. The generalized autocalibrating partially parallel acquisition (GRAPPA), the CAIPIRINHA routine (CAIPI-routine), and the CAIPIRINHA short-scanning (CAIPI-short) methods were compared. The scan time for each method was preset to 20 s, 15 s, and 10 s, respectively...
March 2018: Radiological Physics and Technology
https://www.readbyqxmd.com/read/29247875/autocalibration-method-for-non-stationary-ct-bias-correction
#10
Gonzalo Vegas-Sánchez-Ferrero, Maria J Ledesma-Carbayo, George R Washko, Raúl San José Estépar
Computed tomography (CT) is a widely used imaging modality for screening and diagnosis. However, the deleterious effects of radiation exposure inherent in CT imaging require the development of image reconstruction methods which can reduce exposure levels. The development of iterative reconstruction techniques is now enabling the acquisition of low-dose CT images whose quality is comparable to that of CT images acquired with much higher radiation dosages. However, the characterization and calibration of the CT signal due to changes in dosage and reconstruction approaches is crucial to provide clinically relevant data...
February 2018: Medical Image Analysis
https://www.readbyqxmd.com/read/29242128/performance-of-5-different-displays-in-the-detection-of-artificial-incipient-and-recurrent-caries-like-lesions
#11
COMPARATIVE STUDY
Shawn Chancy Countryman, Saulo Leonardo Sousa Melo, Manuella Dias Furtado Belem, Francisco Haiter-Neto, Marcos A Vargas, Veeratrishul Allareddy
OBJECTIVES: The aim of this study was to assess whether auto-calibrating medical-grade monitors perform better than off-the-shelf monitors and tablet computers in detecting artificial incipient and recurrent caries-like lesions. STUDY DESIGN: Sixty extracted teeth (30 premolars and 30 molars) were selected. All molars received class II amalgam and composite restorations. A 7-mm2 area on the crowns of half of the teeth was demineralized. Phantoms consisting of 4 teeth were created...
February 2018: Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
https://www.readbyqxmd.com/read/29225108/k-space-trajectories-in-3d-grase-sequence-for-high-resolution-structural-imaging
#12
Alexandra Cristobal-Huerta, Dirk H J Poot, Mika W Vogel, Gabriel P Krestin, Juan A Hernandez-Tamames
PURPOSE: To propose and evaluate new k-space trajectories for 3D-GRASE to improve scan time over 3D-FSE/TSE for high resolution structural imaging. METHODS: Five different Cartesian k-space trajectories were developed and evaluated. They combine ideas of existing k-space trajectories for 3D-GRASE and 3D-FSE/TSE. T2 and T2* are linearly or radially modulated in k-space to achieve the desired contrast while including the autocalibration region needed for the parallel imaging reconstruction technique...
May 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29126483/multi-parametric-polymer-based-potentiometric-analytical-microsystem-for-future-manned-space-missions
#13
Antonio Calvo-López, Mar Puyol, Joan Manel Casalta, Julián Alonso-Chamarro
The construction and evaluation of a Cyclic Olefin Copolymer (COC)-based continuous flow potentiometric microanalyzer to simultaneously monitor potassium, chloride and nitrate ions in samples from an on-board water recycling process expected to be installed in future manned space missions is presented. The main goals accomplished in this work address the specific required characteristics for a miniaturized on-line monitoring system to control water quality in such missions. To begin with, the integration of three ion-selective electrodes (ISEs) and a reference electrode in a compact microfluidic platform that incorporates a simple automatic autocalibration process allows obtaining information about the concentration of the three ions with optimal analytical response characteristics, but moreover with low reagents consumption and therefore with few waste generation, which is critical for this specific application...
December 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/29119106/iterative-schemes-to-solve-low-dimensional-calibration-equations-in-parallel-mr-image-reconstruction-with-grappa
#14
Omair Inam, Mahmood Qureshi, Shahzad A Malik, Hammad Omer
GRAPPA (Generalized Autocalibrating Partially Parallel Acquisition) is a widely used parallel MRI reconstruction technique. The processing of data from multichannel receiver coils may increase the storage and computational requirements of GRAPPA reconstruction. Random projection on GRAPPA (RP-GRAPPA) uses random projection (RP) method to overcome the computational overheads of solving large linear equations in the calibration phase of GRAPPA, saving reconstruction time. However, RP-GRAPPA compromises the reconstruction accuracy in case of large reductions in the dimensions of calibration equations...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28984797/validation-of-radial-artery-based-uncalibrated-pulse-contour-method-pulsioflex-in-critically-ill-patients-a-observational-study
#15
Jörn Grensemann, Jerome M Defosse, Meike Willms, Uwe Schiller, Frank Wappler, Samir G Sakka
BACKGROUND: Because of their simplicity, uncalibrated pulse contour (UPC) methods have been introduced into clinical practice in critical care but are often validated with a femoral arterial waveform. OBJECTIVE: We aimed to test the accuracy of cardiac index (CI) measurements and trending ability from a radial artery with one UPC. DESIGN: An observational study. SETTING: Tertiary care mixed-surgical ICU. Data were obtained from April 2015 to July 2016...
November 2017: European Journal of Anaesthesiology
https://www.readbyqxmd.com/read/28910761/phantomless-auto-calibration-and-online-calibration-assessment-for-a-tracked-freehand-2-d-ultrasound-probe
#16
Matthew Toews, William M Wells
This paper presents a method for automatically calibrating and assessing the calibration quality of an externally tracked 2-D ultrasound (US) probe by scanning arbitrary, natural tissues, as opposed a specialized calibration phantom as is the typical practice. A generative topic model quantifies the posterior probability of calibration parameters conditioned on local 2-D image features arising from a generic underlying substrate. Auto-calibration is achieved by identifying the maximum a-posteriori image-to-probe transform, and calibration quality is assessed online in terms of the posterior probability of the current image-to-probe transform...
January 2018: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28872487/validation-of-radial-artery-based-uncalibrated-pulse-contour-method-pulsioflex-in-an-unselected-cohort-of-critically-ill-patients
#17
Jörn Grensemann, Jerome M Defosse, Meike Willms, Uwe Schiller, Frank Wappler, Samir G Sakka
BACKGROUND: Because of their simplicity, uncalibrated pulse contour (UPC) methods have been introduced into clinical practice in critical care but are often validated with a femoral arterial waveform. OBJECTIVE: We aimed to test the accuracy of cardiac index (CI) measurements and trending ability from a radial artery with one UPC. SETTING: Tertiary care mixed-surgical ICU. Data were obtained from April 2015 to July 2016. PATIENTS: We studied 20 critically ill mechanically ventilated patients monitored by UPC (PulsioFlex; Pulsion Medical Systems SE, Munich, Germany)...
September 1, 2017: European Journal of Anaesthesiology
https://www.readbyqxmd.com/read/28716683/trimmed-autocalibrating-k-space-estimation-based-on-structured-matrix-completion
#18
Mark Bydder, Stanislas Rapacchi, Olivier Girard, Maxime Guye, Jean-Philippe Ranjeva
PURPOSE: Parallel imaging allows the reconstruction of undersampled data from multiple coils. This provides a means to reject and regenerate corrupt data (e.g. from motion artefact). The purpose of this work is to approach this problem using the SAKE parallel imaging method. THEORY AND METHODS: Parallel imaging methods typically require calibration by fully sampling the center of k-space. This is a challenge in the presence of corrupted data, since the calibration data may be corrupted which leads to an errors-in-variables problem that cannot be solved by least squares or even iteratively reweighted least squares...
November 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28608411/interleaved-epi-diffusion-imaging-using-spirit-based-reconstruction-with-virtual-coil-compression
#19
Zijing Dong, Fuyixue Wang, Xiaodong Ma, Zhe Zhang, Erpeng Dai, Chun Yuan, Hua Guo
PURPOSE: To develop a novel diffusion imaging reconstruction framework based on iterative self-consistent parallel imaging reconstruction (SPIRiT) for multishot interleaved echo planar imaging (iEPI), with computation acceleration by virtual coil compression. METHODS: As a general approach for autocalibrating parallel imaging, SPIRiT improves the performance of traditional generalized autocalibrating partially parallel acquisitions (GRAPPA) methods in that the formulation with self-consistency is better conditioned, suggesting SPIRiT to be a better candidate in k-space-based reconstruction...
March 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28574665/simultaneous-multislice-based-5-minute-lumbar-spine-mri-protocol-initial-experience-in-a-clinical-setting
#20
Maria G Longo, Joana Fagundes, Susie Huang, William Mehan, Thomas Witzel, Himanshu Bhat, Keith Heberlein, Bruce R Rosen, Daniel Rosenthal, Ramon G Gonzalez, Pamela W Schaefer, Otto Rapalino
BACKGROUND AND PURPOSE: Previous studies have used parallel imaging (PI) techniques to decrease spine magnetic resonance imaging (MRI) protocol acquisition times. Recently developed MRI sequences allow even faster acquisitions. Our purpose was to develop a lumbar spine MRI protocol using PI with GRAPPA (generalized autocalibrating partially parallel acquisition) and a simultaneous multislice (SMS)-based sequence and to evaluate its diagnostic performance compared to a standard lumbar spine MRI protocol...
June 2, 2017: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
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