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ultrashort echo time

Michael Carl, Yajun Ma, Jiang Du
PURPOSE: Off-resonance saturation (ORS) is a tool which can be used in ultrashort echo time (UTE) magnetic resonance imaging to selectively reduce short T2 signals. When these ORS prepared UTE images are subtracted from a non-suppressed UTE acquisition, the short T2 signals are highlighted. The aim of this paper is to develop a theoretical ORS model and optimize short T2 contrast. THEORY: Using a theoretical model the sequence parameters such as saturation flip angle and off-resonance frequency were optimized to maximize short T2 contrast...
March 8, 2018: Magnetic Resonance Imaging
Daniel F Alamidi, Amir Smailagic, Abdel W Bidar, Nicole S Parker, Marita Olsson, Paul D Hockings, Kerstin M Lagerstrand, Lars E Olsson
BACKGROUND: Lung T1 is a potential translational biomarker of lung disease. The precision and repeatability of variable flip angle (VFA) T1 mapping using modern 3D ultrashort echo time (UTE) imaging of the whole lung needs to be established before it can be used to assess response to disease and therapy. PURPOSE: To evaluate the feasibility of regional lung T1 quantification with VFA 3D-UTE and to investigate long- and short-term T1 repeatability in the lungs of naive mice...
March 8, 2018: Journal of Magnetic Resonance Imaging: JMRI
Ya-Jun Ma, Michael Carl, Adam Searleman, Xing Lu, Eric Y Chang, Jiang Du
PURPOSE: To develop a 3D adiabatic T1ρ prepared ultrashort echo time cones (3D AdiabT1ρ UTE-Cones) sequence for whole knee imaging on a clinical 3T scanner. METHODS: A train of adiabatic full passage pulses were used for spin locking, followed by time-efficient multispoke UTE acquisition to detect signals from both short and long T2 tissues in the whole knee joint. A modified signal model was proposed for multispoke UTE data fitting. The feasibility of this 3D AdiabT1ρ UTE-Cones technique was demonstrated through numerical simulation, phantom, and ex vivo knee sample studies...
February 28, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Quan Zhou, Shao-Lin Li, Ya-Jun Ma, Vicki de Tal, Wei Li, Ying-Hua Zhao
Objective: Currently, magnetic resonance imaging (MRI) is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells (MSCs) after in vivo transplantation to treat osteoarthritis (OA). However, it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage (ZCC) with OA. This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents. In contrast, ultrashort time echo (UTE) MRI has been shown to be sensitive to the presence of the ZCC, creating the potential for more effectively observing the repair of the ZCC in OA by MSCs...
February 5, 2018: Chinese Medical Journal
A A Williams, M R Titchenal, T P Andriacchi, C R Chu
OBJECTIVE: Quantitative magnetic resonance imaging (MRI) ultrashort echo time (UTE) T2* is sensitive to cartilage deep tissue matrix changes after anterior cruciate ligament reconstruction (ACLR). This study was performed to determine whether UTE-T2* profile analysis is a useful clinical metric for assessing cartilage matrix degeneration. This work tests the hypotheses that UTE-T2* depthwise rates of change (profile slopes) correlate with clinical outcome metrics of walking mechanics and patient reported outcomes (PRO) in patients 2 years after ACLR...
February 7, 2018: Osteoarthritis and Cartilage
Qianru Li, Kui Ma, Hongyue Tao, Yinghui Hua, Shuang Chen, Shiyi Chen, Yutong Zhao
PURPOSE: To compare the results of anatomical lateral ankle ligament (LAL) reconstruction with tendon allograft and autograft using clinical scores and ultrashort echo time (UTE) sequence of MRI. METHODS: A total of 26 patients with LAL reconstruction were recruited in this study, including 16 using semitendinosus allografts and 10 using semitendinosus autograft. All of them were diagnosed as chronic ankle instability and accepted anatomic reconstruction. The American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, and radiological evaluation using MRI UTE scanning were extracted from each patient...
February 5, 2018: International Orthopaedics
Nara S Higano, Alister J Bates, Jean A Tkach, Robert J Fleck, Foong Y Lim, Jason C Woods, Paul S Kingma
Esophageal atresia (EA) is a relatively uncommon congenital anomaly, often observed in conjunction with tracheoesophageal fistula (TEF). Surgical repair in neonates typically takes place with little information about the pre-existing EA/TEF structure because there are currently no acceptable tools for evaluating EA/TEF anatomy prior to repair; chest x-ray radiograph does not identify malformation sub-type or gap length, while x-ray computed tomography (CT) demonstrate an unacceptably high exposure to ionizing radiation...
February 2018: Journal of Pediatric Surgery Case Reports
Ya-Jun Ma, Justin West, Amin Nazaran, Xin Cheng, Heinz Hoenecke, Jiang Du, Eric Y Chang
OBJECTIVE: To utilize the 3D inversion recovery prepared ultrashort echo time with cones readout (IR-UTE-Cones) MRI technique for direct imaging of lamellar bone with comparison to the gold standard of computed tomography (CT). MATERIALS AND METHODS: CT and MRI was performed on 11 shoulder specimens and three patients. Five specimens had imaging performed before and after glenoid fracture (osteotomy). 2D and 3D volume-rendered CT images were reconstructed and conventional T1-weighted and 3D IR-UTE-Cones MRI techniques were performed...
February 2, 2018: Skeletal Radiology
Annette von Drygalski, Randy E Moore, Sonha Nguyen, Richard F W Barnes, Lena M Volland, Tudor H Hughes, Jiang Du, Eric Y Chang
OBJECTIVES: Point-of-care musculoskeletal ultrasound (US) is increasingly used by hemophilia providers to guide management; however, pathologic tissue differentiation with US is uncertain. We sought to determine the extent to which point-of-care musculoskeletal US can identify and discriminate pathologic soft tissue changes in hemophilic arthropathy. METHODS: Thirty-six adult patients with hemophilia A/B were prospectively enrolled. Point-of-care musculoskeletal US examinations were performed on arthropathic joints (16 knees, 10 ankles, and 10 elbows) using standard views by a musculoskeletal US-trained and certified hematologist, who recorded abnormal intra-articular soft tissue accumulation...
January 24, 2018: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
Soon Ho Yoon, Chanhee Lee, Jinil Park, Jin Mo Goo, Jang-Yeon Park
Objective: To preliminarily evaluate technical feasibility of a dual-echo ultrashort echo time (UTE) subtraction MR imaging by using concurrent dephasing and excitation (CODE) sequence for visualization of iron-oxide enhancement in focal inflammatory pulmonary lesions. Materials and Methods: A UTE pulmonary MR imaging before and after the injection of clinically usable superparamagnetic iron-oxide nanoparticles, ferumoxytol, was conducted using CODE sequence with dual echo times of 0...
January 2018: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
Constance R Chu, Lisa A Fortier, Ashley Williams, Karin A Payne, Taralyn M McCarrel, Megan E Bowers, Diego Jaramillo
BACKGROUND: Microfracture is commonly performed for cartilage repair but usually results in fibrocartilage. Microfracture augmented by autologous bone marrow concentrate (BMC) was previously shown to yield structurally superior cartilage repairs in an equine model compared with microfracture alone. The current study was performed to test the hypothesis that autologous BMC without concomitant microfracture improves cartilage repair compared with microfracture alone. METHODS: Autologous sternal bone marrow aspirate (BMA) was concentrated using a commercial system...
January 17, 2018: Journal of Bone and Joint Surgery. American Volume
Ya-Jun Ma, Xing Lu, Michael Carl, Yanchun Zhu, Nikolaus M Szeverenyi, Graeme M Bydder, Eric Y Chang, Jiang Du
PURPOSE: To develop an accurate T1 measurement method for short T2 tissues using a combination of a 3-dimensional ultrashort echo time cones actual flip angle imaging technique and a variable repetition time technique (3D UTE-Cones AFI-VTR) on a clinical 3T scanner. METHODS: First, the longitudinal magnetization mapping function of the excitation pulse was obtained with the 3D UTE-Cones AFI method, which provided information about excitation efficiency and B1 inhomogeneity...
January 3, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xing Lu, Yajun Ma, Eric Y Chang, Qun He, Adam Searleman, Annette von Drygalski, Jiang Du
PURPOSE: To evaluate the echo dependence of 3D ultrashort echo time (TE) quantitative susceptibility mapping (3D UTE-QSM) and effective transverse relaxation rate ( R2*) measurement in the setting of high concentrations of iron oxide nanoparticles. METHODS: A phantom study with iron concentrations ranging from 2 to 22 mM was performed using a 3D UTE Cones sequence. Simultaneous QSM processing with morphology-enabled dipole inversion (MEDI) and R2* single exponential fitting was conducted offline with the acquired 3D UTE data...
January 4, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Trisha L Roy, Hou-Jen Chen, Andrew D Dueck, Graham A Wright
OBJECTIVE: Limitations with current peripheral arterial imaging modalities make selection of patients for percutaneous vascular interventions difficult. The purpose of this study was to determine whether a novel preprocedural magnetic resonance imaging (MRI) method can identify lesions that would be more challenging to cross during percutaneous vascular intervention. METHODS: Fourteen patients with peripheral arterial disease underwent MRI before their intervention...
December 13, 2017: Journal of Vascular Surgery
Robba Rai, David Manton, Michael G Jameson, Sonal Josan, Michael B Barton, Lois C Holloway, Gary P Liney
PURPOSE: Human cortical bone has a rapid T2 * decay, and it can be visualised using ultrashort echo time (UTE) techniques in magnetic resonance imaging (MRI). These sequences operate at the limits of gradient and transmit-receive signal performance. Development of multicompartment anthropomorphic phantoms that can mimic human cortical bone can assist with quality assurance and optimisation of UTE sequences. The aims of this study were to 1) characterise the MRI signal properties of a photopolymer resin that can be 3D printed, 2) develop multi-compartment phantoms based on the resin, and 3) demonstrate the feasibility of using these phantoms to mimic human anatomy in the assessment of UTE sequences...
December 13, 2017: Medical Physics
Yanchun Zhu, Xin Cheng, Yajun Ma, Jonathan H Wong, Yaoqin Xie, Jiang Du, Eric Y Chang
BACKGROUND: Rotator cuff tendons (RCTs) are challenging to image due to the "magic angle effect" and their short T2 . PURPOSE: To assess the degree of magic angle sensitivity of human RCTs and to utilize a 3D ultrashort echo time Cones sequence with magnetization transfer preparation (UTE-Cones-MT) and two-pool quantitative MT modeling with histological correlation. We hypothesized that MT parameters would be less sensitive to the magic angle compared with conventional T2 measurements...
December 8, 2017: Journal of Magnetic Resonance Imaging: JMRI
Tanguy Boucneau, Peng Cao, Shuyu Tang, Misung Han, Duan Xu, Roland G Henry, Peder E Z Larson
PURPOSE: Recent nuclear magnetic resonance and MRI studies have measured a fast-relaxing signal component with T2∗<1 ms in white matter and myelin extracts. In ex vivo studies, evidence suggests that a large fraction of this component directly arises from bound protons in the myelin phospholipid membranes. Based on these results, this ultrashort-T2 component in nervous tissue is a new potential imaging biomarker of myelination, which plays a critical role in neuronal signal conduction across the brain and loss or degradation of myelin is a key feature of many neurological disorders...
December 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Weiqiang Dou, Simone Mastrogiacomo, Andor Veltien, Hamdan S Alghamdi, X Frank Walboomers, Arend Heerschap
(1) H magnetic resonance imaging (MRI) by a zero echo time (ZTE) sequence is an excellent method to image teeth. Calcium phosphate cement (CPC) materials are applied in the restoration of tooth lesions, but it has not yet been investigated whether they can be detected by computed tomography (CT) or MRI. The aim of this study was to optimize high-field ZTE imaging to enable the visualization of a new CPC formulation implanted in teeth and to apply this in the assessment of its decomposition in vivo. CPC was implanted in three human and three goat teeth ex vivo and in three goat teeth in vivo...
November 21, 2017: NMR in Biomedicine
Leonardo A Rivera-Rivera, Tilman Schubert, Gesine Knobloch, Patrick A Turski, Oliver Wieben, Scott B Reeder, Kevin M Johnson
PURPOSE: Cerebral perfusion is commonly assessed clinically with dynamic susceptibility contrast MRI using a bolus injection of gadolinium-based contrast agents, resulting in semi-quantitative values of cerebral blood volume (CBV). Steady-state imaging with ferumoxytol allows estimation of CBV with the potential for higher precision and accuracy. Prior CBV studies have focused on the signal disrupting T2* effects, but ferumoxytol also has high signal-enhancing T1 relaxivity. The purpose of this study was to investigate and compare CBV estimation using T1 and T2*, with the goal of understanding the contrast mechanisms and quantitative differences...
November 2, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xi Peng, Fan Lam, Yudu Li, Bryan Clifford, Zhi-Pei Liang
PURPOSE: To map brain metabolites and tissue magnetic susceptibility simultaneously using a single three-dimensional (1) H-MRSI acquisition without water suppression. METHODS: The proposed technique builds on a subspace imaging method called spectroscopic imaging by exploiting spatiospectral correlation (SPICE), which enables ultrashort echo time (TE)/short pulse repetition time (TR) acquisitions for (1) H-MRSI without water suppression. This data acquisition scheme simultaneously captures both the spectral information of brain metabolites and the phase information of the water signals that is directly related to tissue magnetic susceptibility variations...
October 24, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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