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3D Echo

Florian Wiesinger, Anne Menini, Ana Beatriz Solana
PURPOSE: To introduce a novel MR pulse sequence, termed Looping Star, for fast, robust, and yet quiet, 3D radial multi-gradient echo T2* MR imaging. METHODS: The Looping Star pulse sequence is based on the 3D radial Rotating Ultra-Fast Imaging Sequence (RUFIS) extended by a time-multiplexed gradient-refocusing mechanism. First, multiple magnetic coherences are excited, which are subsequently gradient-refocused in form of a looping k-space trajectory. Accordingly, Looping Star captures an initial FID image followed by gradient echo images at equidistant echo times...
August 14, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Giancarlo Coghe, Giuseppe Fenu, Lorena Lorefice, Erica Zucca, Micaela Porta, Giuseppina Pilloni, Federica Corona, Jessica Frau, Maria Giovanna Marrosu, Massimiliano Pau, Eleonora Cocco
INTRODUCTION: Cognitive motor interference (CMI) is performance impairment due to simultaneuous task execution and is measured using the dual task cost (DTC). No pathological feature of MS has to date been associated with CMI. AIM: To assess the relationship between brain volumes and CMI, as measured using the DTC, in a cross-sectional study. METHODS: A group of persons with MS (pwMS) and an age- and sex-matched healthy control (HC) group underwent 3D gait analysis during using the dual task paradigm...
July 31, 2018: Multiple Sclerosis and related Disorders
Jacob A Macdonald, Philip A Corrado, Sydney M Nguyen, Kevin M Johnson, Christopher J Francois, Ronald R Magness, Dinesh M Shah, Thaddeus G Golos, Oliver Wieben
BACKGROUND: Pregnancy complications are often associated with poor uteroplacental vascular adaptation and standard diagnostics are unable to reliably quantify flow in all uteroplacental vessels and have poor sensitivity early in gestation. PURPOSE: To investigate the feasibility of using 4D flow MRI to assess total uteroplacental blood flow in pregnant rhesus macaques as a precursor to human studies. STUDY TYPE: Retrospective feasibility study...
August 13, 2018: Journal of Magnetic Resonance Imaging: JMRI
Niloufar Zarghami, Alexandre A Khrapitchev, Francisco Perez-Balderas, Manuel Sarmiento Soto, James R Larkin, Luca Bau, Nicola R Sibson
Background: Molecular MRI is an evolving field of research with strong translational potential. Selection of the appropriate MRI sequence, field strength and contrast agent depend largely on the application. The primary aims of the current study were to: 1) assess the sensitivity of different MRI sequences for detection of iron oxide particles in mouse brain; 2) determine the effect of magnetic field strength on detection of iron oxide particles in vivo; and 3) compare the sensitivity of targeted microparticles of iron oxide (MPIO) or ultra-small superparamagnetic iron oxide (USPIO) for detection of vascular cell adhesion molecule-1 (VCAM-1) in vivo...
2018: International Journal of Nanomedicine
Samuel M Kim, Harsimran S Singh, Jillian Nati, Jonathan N Ginns
PURPOSE OF REVIEW: The goal of this review is to cover the epidemiology of tricuspid regurgitation (TR), anatomy of the tricuspid valve (TV), and the mechanisms and modern treatment of TR. The focus will be on the role of echocardiography, cardiac CT, and MRI to determine the mechanism, severity, and management strategies of TR. RECENT FINDINGS: The evaluation and management of TR is a rapidly growing field with significant advances in both imaging and interventions...
August 9, 2018: Current Treatment Options in Cardiovascular Medicine
Filippo Del Grande, Marco Delcogliano, Riccardo Guglielmi, Esther Raithel, Steven E Stern, Derek F Papp, Christian Candrian, Jan Fritz
OBJECTIVES: The aim of this study was to test the hypothesis that magnetic resonance imaging (MRI) of the knee with 10-minute 3-dimensional (3D) controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) turbo spin echo (TSE) protocols can replace 20-minute 2-dimensional (2D) TSE standard-of-reference protocols for the diagnosis of internal derangement. MATERIALS AND METHODS: After internal review board approval and prospective informed consent, 100 symptomatic subjects underwent MRI of the knee at 3 T and 50 symptomatic subjects at 1...
August 6, 2018: Investigative Radiology
Sandra L Gonzalez Navarrete, José Alberto de Agustín Loeches, Eduardo Pozo Osinalde, Keyla de Jesús, Adahir Madrigal, Silvana L López, Eduardo Ortiz, Adriana Saltijeral, Eduardo Enriquez-Rodriguez, José J Gómez de Diego, Patricia Mahía, Pedro Marcos Alberca, Miguel A García Fernández, Carlos Macaya, Leopoldo Pérez de Isla
INTRODUCTION: Mitral regurgitation severity assessment is usually carried out using qualitative, semiquantitative, and quantitative parameters. The mitral valve navigation (MVN) tool allows to measure the mitral effective regurgitant orifice (MERO) from 3D echo datasets. Our aim was to validate the MVN as a new tool to quantify MERO. A secondary aim was to assess the intra- and interobserver variability. METHODS: This is a retrospective study in which consecutive subjects undergoing a transoesophageal echocardiogram for more than mild mitral regurgitation evaluation were included...
August 5, 2018: Echocardiography
Verya Daeichin, Deep Bera, Shreyas Raghunathan, Maysam Shabani Motlagh, Zhao Chen, Chao Chen, Emile Noothout, Hendrik J Vos, Michiel Pertijs, Johan G Bosch, Nico de Jong, Martin Verweij
This paper presents the design, fabrication and characterization of a miniature PZT-on-CMOS matrix transducer for real-time pediatric 3-dimensional (3D) transesophageal echocardiography (TEE). This 3D TEE probe consists of a 32 × 32 array of PZT elements integrated on top of an Application Specific Integrated Circuit (ASIC). We propose a partitioned transmit/receive array architecture wherein the 8 × 8 transmitter elements, located at the centre of the array, are directly wired out and the remaining receive elements are grouped into 96 sub-arrays of 3 × 3 elements...
July 30, 2018: Ultrasound in Medicine & Biology
Albert T Roh, Zhibo Xiao, Joseph Y Cheng, Shreyas S Vasanawala, Andreas M Loening
PURPOSE: Magnetic resonance imaging (MRI) sequences with conical k-space trajectories are able to decrease motion artifacts while achieving ultrashort echo times (UTE). We assessed the performance of free-breathing conical UTE MRI in the evaluation of the pediatric pelvis for suspected appendicitis. METHODS: Our retrospective review of 84 pediatric patients who underwent MRI for suspected appendicitis compared three contrast-enhanced sequences: free-breathing conical UTE, breath-hold three-dimensional (3D) spoiled gradient echo (BH-SPGR), and free-breathing high-resolution 3D SPGR (FB-SPGR)...
July 31, 2018: Abdominal Radiology
Jubo Hao, Jin Li, Yiming Pi
Due to the non-contact detection ability of radar and the harmlessness of terahertz waves to the human body, three-dimensional (3D) imaging using terahertz synthetic aperture radar (SAR) is an efficient method of security detection in public areas. To achieve high-resolution and all aspect imaging, circular trajectory movement of radar and linear sensor array along the height direction were used in this study. However, the short wavelength of terahertz waves makes it practically impossible for the hardware to satisfy the half-wavelength spacing condition to avoid grating lobes...
July 31, 2018: Sensors
Sajan Andrews, Qing Yuan, April Bailey, Yin Xi, Rajiv Chopra, Robert Staruch, Ivan Pedrosa
RATIONALE AND OBJECTIVES: To compare quantitative multiparametric magnetic resonance imaging (mpMRI) data of symptomatic uterine fibroids being considered for MR-guided high-intensity focused ultrasound ablation with fibroid characterization based on the Funaki Classification scheme. MATERIALS AND METHODS: This was a prospective, Institutional Review Board -approved, Health Insurance Portability, and Accountability Act-compliant study. Informed consent was obtained...
July 28, 2018: Academic Radiology
Rachel W Chan, Angus Z Lau, Garry Detzler, Vivekanandan Thayalasuthan, Robert K Nam, Masoom A Haider
PURPOSE: Prostate cancer can be detected using a multicomponent T2 mapping technique termed luminal water imaging. The purpose of this study is twofold: 1) To accelerate the luminal water imaging acquisition by using inner volume selection as part of a gradient and spin echo sequence, and 2) to evaluate the accuracy of luminal water fractions and multicomponent T2 relaxation times. METHODS: The accuracy of parameter estimates was assessed using Monte Carlo simulations, in phantom experiments and in the prostate (in 5 healthy subjects)...
July 29, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Jin Zhang, Li Feng, Ricardo Otazo, Sungheon Gene Kim
PURPOSE: To develop a rapid dynamic contrast-enhanced MRI method with high spatial and temporal resolution for small-animal imaging at 7 Tesla. METHODS: An ultra-short echo time (UTE) pulse sequence using a 3D golden-angle radial sampling was implemented to achieve isotropic spatial resolution with flexible temporal resolution. Continuously acquired radial spokes were grouped into subsets for image reconstruction using a multicoil compressed sensing approach (Golden-angle RAdial Sparse Parallel; GRASP)...
July 29, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Lisa Leroi, Arthur Coste, Ludovic de Rochefort, Mathieu D Santin, Romain Valabregue, Franck Mauconduit, Eric Giacomini, Michel Luong, Edouard Chazel, Julien Valette, Denis Le Bihan, Cyril Poupon, Fawzi Boumezbeur, Cécile Rabrait-Lerman, Alexandre Vignaud
PURPOSE: Quantifying multiple NMR properties of sodium could be of benefit to assess changes in cellular viability in biological tissues. A proof of concept of Quantitative Imaging using Configuration States (QuICS) based on a SSFP sequence with multiple contrasts was implemented to extract simultaneously 3D maps of applied flip angle (FA), total sodium concentration, T1 , T2 , and Apparent Diffusion Coefficient (ADC). METHODS: A 3D Cartesian Gradient Recalled Echo (GRE) sequence was used to acquire 11 non-balanced SSFP contrasts at a 6 × 6 × 6 mm3 isotropic resolution with carefully-chosen gradient spoiling area, RF amplitude and phase cycling, with TR/TE = 20/3...
July 25, 2018: Magnetic Resonance Imaging
Laura Cacciaguerra, Elisabetta Pagani, Sharlota Mesaros, Jelena Dackovic, Irena Dujmovic-Basuroski, Jelena Drulovic, Paola Valsasina, Massimo Filippi, Maria Assunta Rocca
BACKGROUND: Different subregional patterns of hippocampal involvement have been observed in diverse multiple sclerosis (MS) phenotypes. OBJECTIVE: To evaluate the occurrence of regional hippocampal variations in clinically isolated syndrome (CIS) patients, their relationships with focal white matter (WM) lesions, and their prognostic implications. METHODS: Brain dual-echo and three-dimensional (3D) T1-weighted scans were acquired from 14 healthy controls and 36 CIS patients within 2 months from clinical onset and after 3, 12, and 24 months...
July 1, 2018: Multiple Sclerosis: Clinical and Laboratory Research
Elisabeth Klupp, Barbara Cervantes, Nico Sollmann, Franziska Treibel, Dominik Weidlich, Thomas Baum, Ernst J Rummeny, Claus Zimmer, Jan S Kirschke, Dimitrios C Karampinos
PURPOSE: The close proximity of blood vessels to the brachial plexus nerves can confound nerve visualization in conventional fat-suppressed 3D T2-weighted sequences. Vessel suppression can be accomplished by means of motion-sensitizing preparation. The aim of this study was to qualitatively and semi-quantitatively evaluate short tau inversion recovery (STIR) 3D turbo spin echo (TSE) in conjunction with an adiabatic T2 preparation incorporating motion sensitization for magnetic resonance neurography (MRN) of the brachial plexus in a clinical routine setting...
July 23, 2018: Clinical Neuroradiology
Nadia R Ayat, Jing-Can Qin, Han Cheng, Sarah Roelle, Songqi Gao, Yajuan Li, Zheng-Rong Lu
The aim of this work is to optimize a peptide targeted macrocyclic MRI contrast agent for detection and risk-stratification of aggressive prostate cancer. The optimized agent was prepared using click chemistry in the presence of CuSO4 and ascorbate at room temperature. The T1 and T2 relaxivities of ZD2-N3-Gd(HP-DO3A) are 5.44 and 7.10 mM-1 s-1 at 1.4 T, and 5.53 and 7.81 mM-1 s-1 at 7 T, respectively, higher than the previously reported ZD2-Gd(HP-DO3A). The specific tumor enhancement of the agent was investigated in male nude mice bearing aggressive PC3 human prostate cancer xenografts and slow-growing LNCaP tumor xenografts...
July 12, 2018: ACS Medicinal Chemistry Letters
Z F Li, W Zhao, T F Qi, C Gao, Q Gu, J S Zhao, T S Koh
The double-angle method (DAM) is commonly used as a reference standard in radiofrequency field (B 1 ) mapping studies. This study explored two aspects of DAM: (i) use of small flip angle pairs to reduce the repetition time (TR) needed for adequate longitudinal relaxation (T 1 ); and (ii) the effect of using different flip angle ratios for B 1 mapping. Results of phantom studies show that B 1 correction using small flip angle pairs ≤ 60° with TR  =  5000 ms can allow for accurate estimation of T 1 up to about 1500 ms; and that increasing the ratio of the two flip angles used for B 1 correction resulted in more accurate estimation of T 1 ...
August 10, 2018: Physics in Medicine and Biology
Jun Nishida, John P Breen, Kurt P Lindquist, Daiki Umeyama, Hemamala I Karunadasa, Michael D Fayer
The dynamically flexible lattices in lead halide perovskites may play important roles in extending carrier recombination lifetime in 3D perovskite solar-cell absorbers and in exciton self-trapping in 2D perovskite white-light phosphors. Two-dimensional infrared (2D IR) spectroscopy was applied to study a recently reported Pb-I-SCN layered perovskite. The Pb-I-SCN perovskite was spin-coated on a SiO2 surface as a thin film, with a thickness of ∼100 nm, where the S12 CN- anions were isotopically diluted with the ratio of S12 CN:S13 CN = 5:95 to avoid vibrational coupling and excitation transfer between adjacent SCN- anions...
August 8, 2018: Journal of the American Chemical Society
Huiyu Qiao, Feiyu Li, Dongxiang Xu, Gaifen Liu, Chun Yuan, Xihai Zhao
BACKGROUND AND PURPOSE: This study sought to investigate the feasibility of three-dimensional MPRAGE in identifying the lipid-rich necrotic core (LRNC) and calcification (CA) of carotid atherosclerotic plaques. MATERIALS AND METHODS: Twelve patients (mean age 68.4 ± 11.8 years; 7 males) with carotid atherosclerotic plaques on ultrasound were included and underwent multicontrast magnetic resonance (MR) vessel wall imaging. The contrast enhanced T1W (CE-T1W) images were considered as reference for identifying LRNC...
July 17, 2018: Magnetic Resonance Imaging
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