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T1 map

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
Grzegorz Bauman, Francesco Santini, Orso Pusterla, Oliver Bieri
PURPOSE: To present a technique for simultaneous mapping of T1 , T2 , and relative spin density (M0 ) in human lung using inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) imaging. METHODS: Pulmonary relaxometry with IR-ufSSFP is based on an interleaved time series acquisition of 2D images acquired at 1.5T. The technique was tested in a phantom and in four healthy volunteers using breath-hold and electrocardiogram triggering. Typically, 30 transient state images were acquired in a single breath-hold within < 10 s...
October 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xiaoqing Wang, Arun A Joseph, Oleksandr Kalentev, K Dietmar Merboldt, Dirk Voit, Volkert B Roeloffs, Maaike van Zalk, Jens Frahm
OBJECTIVE: To develop a novel method for rapid myocardial T1 mapping at high spatial resolution. METHODS: The proposed strategy represents a single-shot inversion-recovery (IR) experiment triggered to early diastole during a brief breathhold. The measurement combines an adiabatic inversion pulse with a real-time readout by highly undersampled radial FLASH, iterative image reconstruction and T1 fitting with automatic deletion of systolic frames. The method was implemented on a 3 T MRI system using a GPU-equipped bypass computer for online application...
October 19, 2016: British Journal of Radiology
Eider M Arenaza-Urquijo, Robin de Flores, Julie Gonneaud, Miranka Wirth, Valentin Ourry, William Callewaert, Brigitte Landeau, Stéphanie Egret, Florence Mézenge, Béatrice Desgranges, Gaël Chételat
Engagement in cognitive activity (CA) and physical activity (PA) during the lifespan may counteract brain atrophy later in life. Here, we investigated engagement in CA and PA during late adulthood in association with gray matter volume (GM) in normal older adults, with special focus on the hippocampus. Forty-five cognitively normal older individuals (mean age: 72) underwent T1-weighted MRI and self-reported CA and PA assessment. Whole brain voxel-wise multiple regression models were carried out to assess the relationships between CA, PA and GM volume adjusted by age and sex...
October 18, 2016: Brain Imaging and Behavior
Martina F Callaghan, Siawoosh Mohammadi, Nikolaus Weiskopf
Quantitative MRI (qMRI) provides standardized measures of specific physical parameters that are sensitive to the underlying tissue microstructure and are a first step towards achieving maps of biologically relevant metrics through in vivo histology using MRI. Recently proposed models have described the interdependence of qMRI parameters. Combining such models with the concept of image synthesis points towards a novel approach to synthetic qMRI, in which maps of fundamentally different physical properties are constructed through the use of biophysical models...
October 18, 2016: NMR in Biomedicine
Yuko Y Inoue, Bharath Ambale-Venkatesh, Nathan Mewton, Gustavo J Volpe, Yoshiaki Ohyama, Ravi K Sharma, Colin O Wu, Chia-Ying Liu, David A Bluemke, Elsayed Z Soliman, João A C Lima, Hiroshi Ashikaga
Purpose To examine the associations of myocardial diffuse fibrosis and scar with surface electrocardiographic (ECG) parameters in individuals free of prior coronary heart disease in four different ethnicities. Materials and Methods This prospective cross-sectional study was approved by the institutional review boards, and all participants gave informed consent. A total of 1669 participants in the Multi-Ethnic Study of Atherosclerosis, or MESA, who were free of prior myocardial infarction underwent both ECG and cardiac magnetic resonance imaging...
October 13, 2016: Radiology
Hadi Fayad, Holger Schmidt, Thomas Kuestner, Dimitris Visvikis
: Respiratory motion may reduce accuracy in fusion of functional and anatomical images using combined Positron emission tomography / Magnetic resonance (PET/MR) systems. Methodologies for the correction of respiratory motion in PET acquisitions using such systems are mostly based on the use of respiratory synchronized MR acquisitions to derive motion fields. Existing approaches based on tagging acquisitions may introduce artifacts in the MR images, while motion model approaches require the acquisition of training datasets...
October 13, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Sofya Kulikova, Lucie Hertz-Pannier, Ghislaine Dehaene-Lambertz, Cyril Poupon, Jessica Dubois
The volume fraction of water related to myelin (fmy) is a promising MRI index for in vivo assessment of brain myelination, that can be derived from multi-component analysis of T1 and T2 relaxometry signals. However, existing quantification methods require rather long acquisition and/or post-processing times, making implementation difficult both in research studies on healthy unsedated children and in clinical examinations. The goal of this work was to propose a novel strategy for fmy quantification within acceptable acquisition and post-processing times...
2016: PloS One
Jeremy W Gordon, Eugene Milshteyn, Irene Marco-Rius, Michael Ohliger, Daniel B Vigneron, Peder E Z Larson
PURPOSE: The purpose of this work was to explore the impact of slice profile effects on apparent diffusion coefficient (ADC) mapping of hyperpolarized (HP) substrates. METHODS: Slice profile effects were simulated using a Gaussian radiofrequency (RF) pulse with a variety of flip angle schedules and b-value ordering schemes. A long T1 water phantom was used to validate the simulation results, and ADC mapping of HP [(13) C,(15) N2 ]urea was performed on the murine liver to assess these effects in vivo...
October 13, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Agnes Mayr, Daniel Kitterer, Joerg Latus, Hannah Steubing, Joerg Henes, Francesco Vecchio, Philipp Kaesemann, Alexandru Patrascu, Andreas Greiser, Stefan Groeninger, Niko Braun, M Dominik Alscher, Udo Sechtem, Heiko Mahrholdt, Simon Greulich
BACKGROUND: Severe arrhythmias or heart failure may be surrogates of myocardial involvement in patients with connective tissue disorders (CTD). However, most patients present with unspecific symptoms, normal ECG, and preserved left ventricular ejection fraction (LV-EF). Therefore, timely diagnosis by an accurate technique is crucial. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has proven value for the detection of focal processes, but due to the often diffuse character of fibrosis/inflammation in CTD patients, CMR mapping techniques might be of incremental value for the assessment of myocardial involvement...
October 13, 2016: Journal of Cardiovascular Magnetic Resonance
Hosung Kim, Ji-Hoon Kim, Katherine L Possin, Joseph Winer, Michael D Geschwind, Duan Xu, Christopher P Hess
In patients with premotor Huntington's disease (pmHD), literature has reported decreases in caudate volume. However, the regional vulnerability of the caudate nucleus to pmHD remains to be clarified. We aimed to determine whether regional structural damage of the caudate nucleus was present in pmHD and was correlated with clinical profile using a surface-based morphometric technique applied to T1-weighted MRI. The study cohort consisted of 14 volunteers with genetically confirmed pmHD (6 males; 41.8 ± 13...
October 11, 2016: Brain Imaging and Behavior
Jidan Zhong, David Q Chen, Matthew Walker, Adam Waspe, Thomas Looi, Karolina Piorkowska, James M Drake, Mojgan Hodaie
An increasing number of applications use the postnatal piglet model in neuroimaging studies, however, these are based primarily on T1 weighted image templates. There is a growing need for a multimodal structural brain template for a comprehensive depiction of the piglet brain, particularly given the growing applications of diffusion weighted imaging for characterizing tissue microstructures and white matter organization. In this study, we present the first multimodal piglet structural brain template which includes a T1 weighted image with tissue segmentation probability maps, diffusion weighted metric templates with multiple diffusivity maps, and population-based whole-brain fiber tracts for postnatal piglets...
2016: Frontiers in Neuroanatomy
Mustapha Bouhrara, Richard G Spencer
A number of central nervous system (CNS) diseases exhibit changes in myelin content and magnetic resonance longitudinal, T1, and transverse, T2, relaxation times, which therefore represent important biomarkers of CNS pathology. Among the methods applied for measurement of myelin water fraction (MWF) and relaxation times, the multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) approach is of particular interest. mcDESPOT permits whole brain mapping of multicomponent T1 and T2, with data acquisition accomplished within a clinically realistic acquisition time...
October 8, 2016: NeuroImage
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
Gopal Nataraj, Jon-Fredrick Nielsen, Jeffrey Fessler
Rapid, reliable quantification of MR relaxation parameters T1 and T2 is desirable for many clinical applications. Steady-state sequences such as Spoiled Gradient-Recalled Echo (SPGR) and Dual-Echo Steady-State (DESS) are fast and wellsuited for relaxometry because the signals they produce are quite sensitive to T1 and T2 variation. However, T1, T2 estimation with these sequences typically requires multiple scans with varied sets of acquisition parameters. This paper describes a systematic framework for selecting scan types (e...
October 4, 2016: IEEE Transactions on Medical Imaging
Jackie Leung, James Duffin, Joseph A Fisher, Andrea Kassner
OBJECTIVES: Cerebrovascular reactivity (CVR) measures the ability of cerebral blood vessels to change their diameter and, hence, their capacity to regulate regional blood flow in the brain. High resolution quantitative maps of CVR can be produced using blood-oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in combination with a carbon dioxide stimulus, and these maps have become a useful tool in the clinical evaluation of cerebrovascular disorders. However, conventional CVR analysis does not fully characterize the BOLD response to a stimulus as certain regions of the brain are slower to react to the stimulus than others, especially in disease...
2016: NeuroImage: Clinical
Jitin Narula, Usha Kiran, Poonam Malhotra Kapoor, Minati Choudhury, Palleti Rajashekar, Ujjwal Kumar Chowdhary
OBJECTIVE: To evaluate the effect of autologous blood harvest (ABH)-induced volume shifts using electrical cardiometry (EC) in patients with pulmonary artery hypertension secondary to left heart disease. DESIGN: Prospective, randomized, controlled trial. SETTING: A tertiary care hospital. PARTICIPANTS: The study comprised 50 patients scheduled to undergo heart valve replacement. INTERVENTIONS: Patients were divided randomly into 2 experimental groups that were distinguished by whether ABH was performed...
July 26, 2016: Journal of Cardiothoracic and Vascular Anesthesia
N De Geeter, P Lioumis, A Laakso, G Crevecoeur, L Dupré
When delivered over a specific cortical site, TMS can temporarily disrupt the ongoing process in that area. This allows mapping of speech-related areas for preoperative evaluation purposes. We numerically explore the observed variability of TMS responses during a speech mapping experiment performed with a neuronavigation system. We selected four cases with very small perturbations in coil position and orientation. In one case (E) a naming error occurred, while in the other cases (NEA, B, C) the subject appointed the images as smoothly as without TMS...
October 7, 2016: Physics in Medicine and Biology
Tiago Teixeira, Tarik Hafyane, Nikola Stikov, Cansu Akdeniz, Andreas Greiser, Matthias G Friedrich
BACKGROUND: T1 mapping based on cardiovascular magnetic resonance (CMR) is a novel approach using the magnetic relaxation T1 time as a quantitative marker for myocardial tissue composition. Various T1 mapping sequences are being used, with different strengths and weaknesses. Data comparing different sequences head to head however are sparse. METHODS: We compared three T1 mapping sequences, ShMOLLI, MOLLI and SASHA in phantoms and in a mid-ventricular slice of 40 healthy individuals (mean age 59 ± 7 years, 45 % male) with low (68 %) or moderate cardiovascular risk...
October 4, 2016: Journal of Cardiovascular Magnetic Resonance
Elma Jahic, Amela Sofic, Azra Husic Selimovic
MATERIAL AND METHODS: The study was of prospective-retrospective character. It was carried out at the AKH in Vienna (Austria), where 100 patients with focal liver lesions were included in the study. All patients underwent the routine MR sequences on appliances 1,5 and 3T (Siemens, Germany): T1, T2, HASTE, VIBE, and a DWI with three b values (b 50, b 300 b 600 s / mm(2)) and ADC map with ROI (regions of interest). The numerical value of ADC map was calculated, where n = 100 liver lesions, by two independent radiologists...
July 16, 2016: Acta Informatica Medica: AIM
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