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Takashi Hashido, Shigeyoshi Saito
PURPOSE: Neuromelanin is a dark pigment granule present within certain catecholamine neurons of the human brain. Here, we aimed to clarify the relationship between contrast of neuromelanin-sensitive magnetic resonance imaging (MRI) and MR relaxation times using T1, T2, and T2* mapping of the lower midbrain. METHODS: The subjects were 14 healthy volunteers (11 men and 3 women, mean age 29.9 ± 6.9 years). Neuromelanin-sensitive MRI was acquired using an optimized T1-weighted two-dimensional (2D)-turbo spin-echo sequence...
2016: PloS One
Yasuo Amano, Fumi Yanagisawa, Masaki Tachi, Hidenobu Hashimoto, Shogo Imai, Shinichiro Kumita
OBJECTIVE: The aim of this study was to evaluate the usefulness of T2 mapping for detecting myocardial injuries in patients with hypertrophic cardiomyopathy (HCM). METHODS: Twenty-one HCM patients and 7 healthy volunteers were examined. The T2 values were measured at hyperintense areas (high-T2 areas) identified with T2 mapping, at late gadolinium enhancement (LGE) areas, and in nullified myocardium of the HCM patients. The associations between T2 values and laboratory data or LGE areas were assessed...
October 19, 2016: Journal of Computer Assisted Tomography
Joshua T Chai, Luca Biasiolli, Linqing Li, Mohammad Alkhalil, Francesca Galassi, Chris Darby, Alison W Halliday, Linda Hands, Timothy Magee, Jeremy Perkins, Ed Sideso, Ashok Handa, Peter Jezzard, Matthew D Robson, Robin P Choudhury
OBJECTIVES: The aim of this study was to: 1) provide tissue validation of quantitative T2 mapping to measure plaque lipid content; and 2) investigate whether this technique could discern differences in plaque characteristics between symptom-related and non-symptom-related carotid plaques. BACKGROUND: Noninvasive plaque lipid quantification is appealing both for stratification in treatment selection and as a possible predictor of future plaque rupture. However, current cardiovascular magnetic resonance (CMR) methods are insensitive, require a coalesced mass of lipid core, and rely on multicontrast acquisition with contrast media and extensive post-processing...
October 6, 2016: JACC. Cardiovascular Imaging
Gabrielle Martel, Charles-André Couture, Guillaume Gilbert, Stéphane Bancelin, Hélène Richard, Thomas Moser, Sabrina Kiss, François Légaré, Sheila Laverty
Osteochondrosis is an ischemic chondronecrosis of epiphyseal growth cartilage that results in focal failure of endochondral ossification and osteochondritis dissecans at specific sites in the epiphyses of humans and animals, including horses. The upstream events leading to the focal ischemia remain unknown. The epiphyseal growth cartilage matrix is composed of proteoglycan and collagen macromolecules and encases its vascular tree in canals. The matrix undergoes major dynamic changes in early life that could weaken it biomechanically and predispose it to focal trauma and vascular failure...
October 2016: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Prateek Katiyar, Mathew R Divine, Ursula Kohlhofer, Leticia Quintanilla-Martinez, Bernhard Schölkopf, Bernd J Pichler, Jonathan A Disselhorst
PURPOSE: We aimed to precisely estimate intra-tumoral heterogeneity using spatially regularized spectral clustering (SRSC) on multiparametric MRI data and compare the efficacy of SRSC with the previously reported segmentation techniques in MRI studies. PROCEDURES: Six NMRI nu/nu mice bearing subcutaneous human glioblastoma U87 MG tumors were scanned using a dedicated small animal 7T magnetic resonance imaging (MRI) scanner. The data consisted of T2 weighted images, apparent diffusion coefficient maps, and pre- and post-contrast T2 and T2* maps...
October 12, 2016: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
Neville D Gai, Ashkan A Malayeri, David A Bluemke
PURPOSE: To develop and assess a new technique for three-dimensional (3D) full lung T1 and T2* mapping using a single free breathing scan during a clinically feasible time. MATERIALS AND METHODS: A 3D stack of dual-echo ultrashort echo time (UTE) radial acquisition interleaved with and without a WET (water suppression enhanced through T1 effects) saturation pulse was used to map T1 and T2* simultaneously in a single scan. Correction for modulation due to multiple views per segment was derived...
October 11, 2016: Journal of Magnetic Resonance Imaging: JMRI
Yi Wei, Sen Wu, Feifei Gao, Tingyi Sun, Dandan Zheng, Peigang Ning, Cuihua Zhao, Ziyuan Li, Xiaodong Li, Linlin Li, Shaocheng Zhu
PURPOSE: To prospectively determine the feasibility of T2 -mapping magnetic resonance imaging (MRI) to quantitatively describe the signal characteristics of the normal esophageal wall and assess the depth of esophageal wall invasion by carcinoma at 3.0T. MATERIALS AND METHODS: Thirty-two patient specimens, each having foci of carcinoma, were studied using 3.0T MR. Freehand regions of interest were placed to measure the T2 value of the normal esophageal layers and were compared with the regions of carcinoma...
October 6, 2016: Journal of Magnetic Resonance Imaging: JMRI
Rafael Menezes-Reis, Carlos E Garrido Salmon, Gustavo P Bonugli, Debora Mazoroski, Mauricio H Tamashiro, Leonor G Savarese, Marcello Henrique Nogueira-Barbosa
BACKGROUND: To investigate the detection of intervertebral disc (IVD) composition aging-related changes using T2 and T1ρ relaxometry in vivo in asymptomatic young adults. METHODS: We recruited ninety asymptomatic and young adults (42 men and 48 women) between 20 and 40 years old. T2 and T1ρ lumbar spine mappings were acquired using 1.5 T magnetic resonance imaging (MRI) scanner. Two independent observers manually segmented 450 lumbar discs in all slices. They also performed sub region segmentation of annulus fibrosus (AF) and nucleus pulposus (NP) at the central MRI sagittal slices...
August 2016: Quantitative Imaging in Medicine and Surgery
Anna I Blazejewska, Sharmishtaa Seshamani, Susan K McKown, Jason S Caucutt, Manjiri Dighe, Christopher Gatenby, Colin Studholme
PURPOSE: Maximization of the blood oxygen level-dependent (BOLD) functional MRI (fMRI) contrast requires the echo time of the MR sequence to match the T2* value of the tissue of interest, which is expected to be higher in the fetal brain compared with the brain of a child or an adult. METHODS: T2* values of the cortical plate/cortical gray matter tissue in utero in healthy fetuses from mid-gestation onward (20-36 gestational weeks) were measured using 3D T2* maps calculated from 2D dual-echo T2*-weighted data corrected for between-slice motion and reconstructed in 1...
October 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Ericky C A Araujo, N Azzabou, A Vignaud, G Guillot, P G Carlier
PURPOSE: To introduce an ultrashort echo time (UTE) based method for quantitative mapping of short-T2 signals in skeletal muscle (SKM) in the presence of fat, with the aim of monitoring SKM fibrosis. METHODS: From a set of at least five UTE images of the same slice, a long- T2* map, a fat-fraction map, and a map of short-T2 -signal fraction are extracted. The method was validated by numerical simulations and in vitro studies on collagen solutions. Finaly, the method was applied to image the short-T2 signals in the leg of eight healthy volunteers...
October 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
W Wirth, S Maschek, F W Roemer, F Eckstein
Magnetic resonance imaging (MRI)-based spin-spin relaxation time (T2) mapping has been shown to be associated with cartilage matrix composition (hydration, collagen content &orientation). To determine the impact of early radiographic knee osteoarthritis (ROA) and ROA risk factors on femorotibial cartilage composition, we studied baseline values and one-year change in superficial and deep cartilage T2 layers in 60 subjects (age 60.6 ± 9.6 y; BMI 27.8 ± 4.8) with definite osteophytes in one knee (earlyROA, n = 32) and with ROA risk factors in the contralateral knee (riskROA, n = 28), and 89 healthy subjects (age 55...
September 27, 2016: Scientific Reports
Sophia Hammer-Hansen, Steve W Leung, Li-Yueh Hsu, Joel R Wilson, Joni Taylor, Anders M Greve, Jens Jakob Thune, Lars Køber, Peter Kellman, Andrew E Arai
OBJECTIVES: The aim of this study was to determine whether early gadolinium enhancement (EGE) by cardiac magnetic resonance (CMR) in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis. BACKGROUND: It remains controversial whether only the irreversibly injured myocardium enhances when CMR is performed in the setting of acute myocardial infarction. Recently, EGE has been proposed as a measure of the AAR in acute myocardial infarction because it correlates well with T2-weighted imaging of the AAR, but this still requires pathological validation...
September 16, 2016: JACC. Cardiovascular Imaging
G E Hagberg, J Bause, T Ethofer, P Ehses, T Dresler, C Herbert, R Pohmann, G Shajan, A Fallgatter, M A Pavlova, K Scheffler
Mapping of the longitudinal relaxation time (T1) with high accuracy and precision is central for neuroscientific and clinical research, since it opens up the possibility to obtain accurate brain tissue segmentation and gain myelin-related information. An ideal, quantitative method should enable whole brain coverage within a limited scan time yet allow for detailed sampling with sub-millimeter voxel sizes. The use of ultra-high magnetic fields is well suited for this purpose, however the inhomogeneous transmit field potentially hampers its use...
September 21, 2016: NeuroImage
Harrison Kim, Tao Yu, Betul Cam-Etoz, Thomas van Groen, William J Hubbard, Irshad H Chaudry
OBJECTIVE 17α-ethynylestradiol-3-sulfate (EE-3-SO4) is a highly water-soluble synthetic estrogen that has an extended half-life (∼ 10 hours) over that of naturally occurring estrogen (∼ 10 minutes). In this study, EE-3-SO4 was evaluated in a lateral fluid percussion-induced traumatic brain injury (TBI) model in rats. METHODS A total of 9 groups of Sprague-Dawley rats underwent craniectomy. Twenty-four hours later, lateral fluid percussion was applied to 6 groups of animals to induce TBI; the remaining 3 groups served as sham control groups...
September 23, 2016: Journal of Neurosurgery
Yan Zhang, Ruiqing Tian, Xiangchun Shen, Yushu Chen, Wei Chen, Lu Gan, Guiquan Shen, Haiyue Ju, Li Yang, Fabao Gao
This study aims to build the myocardial infarction model in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid and study the effect of the transfection using 7T MRI. Twenty-four male SD rats were randomly divided into 2 groups, pcDNA 3.1(+)/VEGF121 plasmid transfection group (with improved coronary perfusion delivery) and myocardial infarction model group. Cardiac cine magnetic resonance imaging (Cine-MRI), T2-mapping and late gadolinium enhancement (LGE) cardiac imaging were performed at 24 h, 48 h, 72 h and 7 d after myocardial infarction, respectively...
2016: American Journal of Translational Research
Anna V Naumova, Andrey E Akulov, Marina Yu Khodanovich, Vasily L Yarnykh
A well-known problem in ultra-high-field MRI is generation of high-resolution three-dimensional images for detailed characterization of white and gray matter anatomical structures. T1-weighted imaging traditionally used for this purpose suffers from the loss of contrast between white and gray matter with an increase of magnetic field strength. Macromolecular proton fraction (MPF) mapping is a new method potentially capable to mitigate this problem due to strong myelin-based contrast and independence of this parameter of field strength...
September 17, 2016: NeuroImage
Sven Nebelung, Markus Tingart, Thomas Pufe, Christiane Kuhl, Holger Jahr, Daniel Truhn
OBJECTIVES: To evaluate the diagnostic performance of T1, T1ρ, T2, T2*, and UTE-T2* (ultrashort-echo time-enhanced T2*) mapping in the refined graduation of human meniscus degeneration with histology serving as standard-of-reference. MATERIALS AND METHODS: This IRB-approved intra-individual comparative ex vivo study was performed on 24 lateral meniscus body samples obtained from 24 patients undergoing total knee replacement. Samples were assessed on a 3.0-T MRI scanner using inversion-recovery (T1), spin-lock multi-gradient-echo (T1ρ), multi-spin-echo (T2) and multi-gradient-echo (T2* and UTE-T2*) sequences to determine relaxation times of quantitative MRI (qMRI) parameters...
September 17, 2016: Skeletal Radiology
Simon Greulich, Andrew E Arai, Udo Sechtem, Heiko Mahrholdt
Cardiac magnetic resonance (CMR) is a non-invasive imaging modality that has rapidly emerged during the last few years and has become a valuable, well-established clinical tool. Beside the evaluation of anatomy and function, CMR has its strengths in providing detailed non-invasive myocardial tissue characterization, for which it is considered the current diagnostic gold standard. Late gadolinium enhancement (LGE), with its capability to detect necrosis and to separate ischemic from non-ischemic cardiomyopathies by distinct LGE patterns, offers unique clinical possibilities...
2016: F1000Research
Katja Hueper, Marcel Gutberlet, Jan Hinrich Bräsen, Mi-Sun Jang, Anja Thorenz, Rongjun Chen, Barbara Hertel, Amelie Barrmeyer, Martina Schmidbauer, Martin Meier, Sibylle von Vietinghoff, Abedalrazag Khalifa, Dagmar Hartung, Hermann Haller, Frank Wacker, Song Rong, Faikah Gueler
BACKGROUND: Kidney transplantation (ktx) in mice is used to learn about rejection and to develop new treatment strategies. Past studies have mainly been based on histological or molecular biological methods. Imaging techniques to monitor allograft pathology have rarely been used. METHODS: Here we investigated mice after isogenic and allogenic ktx over time with functional MRI with diffusion-weighted imaging (DWI) and mapping of T2-relaxation time (T2-mapping) to assess graft inflammation and edema formation...
2016: PloS One
Jutta Ellermann, Casey P Johnson, Luning Wang, Jeffrey A Macalena, Bradley J Nelson, Robert F LaPrade
Purpose To retrospectively determine if a modified clinical magnetic resonance (MR) imaging protocol provides information on the origin of juvenile osteochondritis dissecans (JOCD) lesions and allows for staging on the basis of the proposed natural history of JOCD to better guide clinical management of the disease. Materials and Methods This institutional review board-approved, HIPAA-compliant, retrospective study was performed in 13 consecutive patients (mean age, 14.9 years; age range, 10-22 years; nine male and four female patients) and one additional comparative patient (a 44-year-old man), in which 19 knees with 20 JOCD lesions were imaged...
September 15, 2016: Radiology
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