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https://www.readbyqxmd.com/read/27889836/clinical-validation-of-synthetic-brain-mri-in-children-initial-experience
#1
Hollie West, James L Leach, Blaise V Jones, Marguerite Care, Rupa Radhakrishnan, Arnold C Merrow, Enrique Alvarado, Suraj D Serai
INTRODUCTION: The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. METHODS: Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences...
November 26, 2016: Neuroradiology
https://www.readbyqxmd.com/read/27880798/added-value-of-3d-proton-density-weighted-images-in-diagnosis-of-intracranial-arterial-dissection
#2
Jin Woo Kim, Na-Young Shin, Young Dae Kim, Seung-Koo Lee, Soo Mee Lim, Se Won Oh
BACKGROUND: An early and reliable diagnosis of intracranial arterial dissection is important to reduce the risk of neurological complication. The purpose of this study was to assess the clinical usefulness of three-dimensional high-resolution MRI (3D-HR-MRI) including pre- and post-contrast T1-weighted volumetric isotropic turbo spin echo acquisition with improved motion-sensitized driven equilibrium preparation (3D-iMSDE-T1) and proton-density weighted image (3D-PD) in detecting dissection and to evaluate the added value of 3D-PD in diagnosing intracranial arterial dissection...
2016: PloS One
https://www.readbyqxmd.com/read/27869333/patient-specific-3d-flair-for-enhanced-visualization-of-brain-white-matter-lesions-in-multiple-sclerosis
#3
Refaat E Gabr, Amol S Pednekar, Koushik A Govindarajan, Xiaojun Sun, Roy F Riascos, María G Ramírez, Khader M Hasan, John A Lincoln, Flavia Nelson, Jerry S Wolinsky, Ponnada A Narayana
PURPOSE: To improve the conspicuity of white matter lesions (WMLs) in multiple sclerosis (MS) using patient-specific optimization of single-slab 3D fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sixteen MS patients were enrolled in a prospective 3.0T MRI study. FLAIR inversion time and echo time were automatically optimized for each patient during the same scan session based on measurements of the relative proton density and relaxation times of the brain tissues...
November 21, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27856399/enhanced-laws-textures-a-potential-mri-surrogate-marker-of-hepatic-fibrosis-in-a-murine-model
#4
Baojun Li, Hernan Jara, Heishun Yu, Michael O'Brien, Jorge Soto, Stephan W Anderson
PURPOSE: To compare enhanced Laws textures derived from parametric proton density (PD) maps to other MRI surrogate markers (T2, PD, apparent diffusion coefficient (ADC)) in assessing degrees of liver fibrosis in an ex vivo murine model of hepatic fibrosis imaged using 11.7T MRI. METHODS: This animal study was IACUC approved. Fourteen male, C57BL/6 mice were divided into control and experimental groups. The latter were fed a 3,5-dicarbethoxy-1,4-dihydrocollidine (DDC) supplemented diet to induce hepatic fibrosis...
November 14, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27856398/recovery-of-accurate-t2-from-historical-1-5-tesla-proton-density-and-t2-weighted-images-application-to-7-year-t2-changes-in-multiple-sclerosis-brain
#5
Md Nasir Uddin, Kelly C McPhee, Gregg Blevins, Alan H Wilman
OBJECTIVE: To determine accurate quantitative transverse relaxation times (T2) using retrospective clinical images and apply it to examine 7-year changes in multiple sclerosis (MS) brain. METHODS: A method for T2 mapping from retrospective proton density (PD) and T2-weighted fast spin echo images was recently introduced, but requires measurement of flip angles. We examined whether 1.5T flip angle variation in brain can be predicted, thus enabling T2 analysis of historical PD and T2-weighted images without a concurrent flip angle map...
November 14, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27832068/time-dependent-changes-in-t1-during-fracture-healing-in-juvenile-rats-a-quantitative-mr-approach
#6
Katharina Baron, Bernhard Neumayer, Eva Amerstorfer, Eva Scheurer, Clemens Diwoky, Rudolf Stollberger, Hanna Sprenger, Annelie M Weinberg
Quantitative magnetic resonance imaging (qMRI) offers several advantages in imaging and determination of soft tissue alterations when compared to qualitative imaging techniques. Although applications in brain and muscle tissues are well studied, its suitability to quantify relaxation times of intact and injured bone tissue, especially in children, is widely unknown. The objective observation of a fracture including its age determination can become of legal interest in cases of child abuse or maltreatment. Therefore, the aim of this study is the determination of time dependent changes in intact and corresponding injured bones in immature rats via qMRI, to provide the basis for an objective and radiation-free approach for fracture dating...
2016: PloS One
https://www.readbyqxmd.com/read/27820852/osteoarthritis-in-the-knee-joints-of-g%C3%A3-ttingen-minipigs-after-resection-of-the-anterior-cruciate-ligament-missing-correlation-of-mri-gene-and-protein-expression-with-histological-scoring
#7
Gregor Reisig, Michael Kreinest, Wiltrud Richter, Mechthild Wagner-Ecker, Dietmar Dinter, Ulrike Attenberger, Barbara Schneider-Wald, Stefan Fickert, Markus L Schwarz
INTRODUCTION: The Göttingen Minipig (GM) is used as large animal model in articular cartilage research. The aim of the study was to introduce osteoarthritis (OA) in the GM by resecting the anterior cruciate ligament (ACLR) according to Pond and Nuki, verified by histological and magnetic resonance imaging (MRI) scoring as well as analysis of gene and protein expression. MATERIALS AND METHODS: The eight included skeletally mature female GM were assessed after ACLR in the left and a sham operation in the right knee, which served as control...
2016: PloS One
https://www.readbyqxmd.com/read/27818597/comparison-of-magnetic-resonance-spectroscopy-proton-density-fat-fraction-and-histological-analysis-in-the-quantification-of-liver-steatosis-in-children-and-adolescents
#8
Michele Di Martino, Lucia Pacifico, Mario Bezzi, Rossella Di Miscio, Beatrice Sacconi, Claudio Chiesa, Carlo Catalano
AIM: To establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard. METHODS: The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis...
October 21, 2016: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/27790751/repeatability-of-magnetic-resonance-fingerprinting-t1-and-t2-estimates-assessed-using-the-ismrm-nist-mri-system-phantom
#9
Yun Jiang, Dan Ma, Kathryn E Keenan, Karl F Stupic, Vikas Gulani, Mark A Griswold
PURPOSE: The purpose of this study was to evaluate accuracy and repeatability of T1 and T2 estimates of a MR fingerprinting (MRF) method using the ISMRM/NIST MRI system phantom. METHODS: The ISMRM/NIST MRI system phantom contains multiple compartments with standardized T1 , T2 , and proton density values. Conventional inversion-recovery spin echo and spin echo methods were used to characterize the T1 and T2 values in the phantom. The phantom was scanned using the MRF-FISP method over 34 consecutive days...
October 27, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27789453/utility-of-a-multiparametric-quantitative-mri-model-that-assesses-myelin-and-edema-for-evaluating-plaques-periplaque-white-matter-and-normal-appearing-white-matter-in-patients-with-multiple-sclerosis-a-feasibility-study
#10
A Hagiwara, M Hori, K Yokoyama, M Y Takemura, C Andica, K K Kumamaru, M Nakazawa, N Takano, H Kawasaki, S Sato, N Hamasaki, A Kunimatsu, S Aoki
BACKGROUND AND PURPOSE: T1 and T2 values and proton density can now be quantified on the basis of a single MR acquisition. The myelin and edema in a voxel can also be estimated from these values. The purpose of this study was to evaluate a multiparametric quantitative MR imaging model that assesses myelin and edema for characterizing plaques, periplaque white matter, and normal-appearing white matter in patients with MS. MATERIALS AND METHODS: We examined 3T quantitative MR imaging data from 21 patients with MS...
October 27, 2016: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/27783208/non-invasive-diagnosis-of-hepatic-steatosis
#11
REVIEW
Christiane Stern, Laurent Castera
Non-invasive diagnosis and quantification of hepatic steatosis rely on two different but complementary approaches: biomarkers or imaging techniques, either ultrasound-based such as liver ultrasonography and controlled attenuation parameter (CAP), or computed tomography (CT) and magnetic resonance imaging (MRI). Scores for the detection of steatosis have not gained much popularity in clinical practice so far. CAP, using the M probe, is the most promising technique but needs to be implemented with the XL probe and compared to ultrasound that, despite its limitations, remains the most widely used method...
October 25, 2016: Hepatology International
https://www.readbyqxmd.com/read/27731948/ultrashort-echo-time-mri-biomarkers-of-asthma
#12
Khadija Sheikh, Fumin Guo, Dante P I Capaldi, Alexei Ouriadov, Rachel L Eddy, Sarah Svenningsen, Grace Parraga
PURPOSE: To develop and assess ultrashort echo-time (UTE) magnetic resonance imaging (MRI) biomarkers of lung function in asthma patients. MATERIALS AND METHODS: Thirty participants including 13 healthy volunteers and 17 asthmatics provided written informed consent to UTE and pulmonary function tests in addition to hyperpolarized-noble-gas 3T MRI and computed tomography (CT) for asthmatics only. The difference in MRI signal-intensity (SI) across four lung volumes (full-expiration, functional-residual-capacity [FRC], FRC+1L, and full-inspiration) was determined on a voxel-by-voxel basis to generate dynamic proton-density (DPD) maps...
October 12, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27726414/accuracy-of-liver-fat-quantification-with-advanced-ct-mri-and-ultrasound-techniques-prospective-comparison-with-mr-spectroscopy
#13
Harald Kramer, Perry J Pickhardt, Mark A Kliewer, Diego Hernando, Guang-Hong Chen, James A Zagzebski, Scott B Reeder
OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of proton-density fat-fraction, single- and dual-energy CT (SECT and DECT), gray-scale ultrasound (US), and US shear-wave elastography (US-SWE) in the quantification of hepatic steatosis with MR spectroscopy (MRS) as the reference standard. SUBJECTS AND METHODS: Fifty adults who did not have symptoms (23 men, 27 women; mean age, 57 ± 5 years; body mass index, 27 ± 5) underwent liver imaging with un-enhanced SECT, DECT, gray-scale US, US-SWE, proton-density fat-fraction MRI, and MRS for this prospective trial...
October 11, 2016: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/27704199/evaluation-of-chondrocalcinosis-and-associated-knee-joint-degeneration-using-mr-imaging-data-from-the-osteoarthritis-initiative
#14
Alexandra S Gersing, Benedikt J Schwaiger, Ursula Heilmeier, Gabby B Joseph, Luca Facchetti, Martin Kretzschmar, John A Lynch, Charles E McCulloch, Michael C Nevitt, Lynne S Steinbach, Thomas M Link
OBJECTIVES: To evaluate the ability of different MRI sequences to detect chondrocalcinosis within knee cartilage and menisci, and to analyze the association with joint degeneration. METHODS: Subjects with radiographic knee chondrocalcinosis (n = 90, age 67.7 ± 7.3 years, 50 women) were selected from the Osteoarthritis Initiative and matched to controls without radiographic chondrocalcinosis (n = 90). Visualization of calcium-containing crystals (CaC) was compared between 3D T1-weighted gradient-echo (T1GE), 3D dual echo steady-state (DESS), 2D intermediate-weighted (IW), and proton density (PD)-weighted fast spin-echo (FSE) sequences obtained with 3T MRI and correlated with a semiquantitative CaC score obtained from radiographs...
October 4, 2016: European Radiology
https://www.readbyqxmd.com/read/27666610/efficacy-of-periodically-rotated-overlapping-parallel-lines-with-enhanced-reconstruction-propeller-for-shoulder-magnetic-resonance-mr-imaging
#15
Kazuya Nagatomo, Hidetake Yabuuchi, Yuzo Yamasaki, Hiroshi Narita, Seiji Kumazawa, Tsukasa Kojima, Noriyuki Sakai, Masahumi Masaki, Hiroshi Kimura
OBJECTIVES: To elucidate the utility of PROPELLER for motion artefact reduction on shoulder MRI and to examine the influence of streak artefacts on diagnosis of clinical images. METHODS: 15 healthy volunteers and 48 patients underwent shoulder MRI with/without PROPELLER (coronal oblique proton density-fast spin echo [PD-FSE], sagittal oblique T2-FSE). In a volunteer study, all sequences were performed in both static and exercise-loaded conditions. Two radiologists graded artefacts and delineation of various anatomical structures in the volunteer study and motion and streak artefacts in the clinical study...
October 2016: European Journal of Radiology
https://www.readbyqxmd.com/read/27666183/assessment-of-anterior-subcutaneous-hypersignal-on-proton-density-weighted-mr-imaging-of-the-knee-and-relationship-with-anterior-knee-pain
#16
E N Unlu, Y Turhan, D M Kos, A A Safak
PURPOSE: The purpose of this study was to evaluate the prevalence of anterior subcutaneous hypersignal indicating edema on proton-density (PD)-weighted MRI of the knee and to determine whether reporting anterior edema is clinically relevant. MATERIALS AND METHODS: One hundred and ninety-one knee MRIs from 162 patients were reviewed for anterior subcutaneous edema. There were 92 men and 70 women with a mean age of 41.72years±13.92 (SD) (range, 15-80years) years and a mean body weight of 75...
September 22, 2016: Diagnostic and Interventional Imaging
https://www.readbyqxmd.com/read/27664830/g-ratio-weighted-imaging-of-the-human-spinal-cord-in-vivo
#17
T Duval, S Le Vy, N Stikov, J Campbell, A Mezer, T Witzel, B Keil, V Smith, L L Wald, E Klawiter, J Cohen-Adad
The fiber g-ratio is defined as the ratio of the inner to the outer diameter of the myelin sheath. This ratio provides a measure of the myelin thickness that complements axon morphology (diameter and density) for assessment of demyelination in diseases such as multiple sclerosis. Previous work has shown that an aggregate g-ratio map can be computed using a formula that combines axon and myelin density measured with quantitative MRI. In this work, we computed g-ratio weighted maps in the cervical spinal cord of nine healthy subjects...
September 22, 2016: NeuroImage
https://www.readbyqxmd.com/read/27650137/the-effects-of-concomitant-gradients-on-chemical-shift-encoded-mri
#18
Timothy J Colgan, Diego Hernando, Samir D Sharma, Scott B Reeder
PURPOSE: The purpose of this work was to characterize the effects of concomitant gradients (CGs) on chemical shift encoded (CSE)-based estimation of B0 field map, proton density fat fraction (PDFF), and R2*. THEORY: A theoretical framework was used to determine the effects of CG-induced phase errors on CSE-MRI data. METHODS: Simulations, phantom experiments, and in vivo experiments were conducted at 3 Tesla to assess the effects of CGs on quantitative CSE-MRI techniques...
September 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27648395/magnetic-resonance-imaging-of-the-craniovertebral-junction-ligaments-normal-anatomy-and-traumatic-injury
#19
REVIEW
Anna E Nidecker, Peter Y Shen
The superb stability and flexibility of the craniovertebral junction (CVJ) are enabled by the ligaments that connect the occipital bone and the C1 and C2 vertebral bodies. Radiographically, these ligaments are best assessed with magnetic resonance imaging (MRI), which has excellent soft tissue contrast, but typically poor spatial resolution. With the advent of advanced MRI techniques, including volumetric sequences, high spatial resolution and contrast resolution can both be attained, allowing for detailed analysis of the ligaments, particularly in trauma settings...
October 2016: Journal of Neurological Surgery. Part B, Skull Base
https://www.readbyqxmd.com/read/27648374/feasibility-of-carotid-artery-pet-mri-in-psoriasis-patients
#20
Prabhakar Rajiah, Mojgan Hojjati, Ziang Lu, Vijaya Kosaraju, Sasan Partovi, James K O'Donnell, Christopher Longenecker, Grace A McComsey, Jackelyn B Golden, Fuad Muakkassa, Scott Santilli, Thomas S McCormick, Kevin D Cooper, Neil J Korman
We report our initial experience of performing integrated PET/MR imaging of the carotid arteries in psoriatic patients. Eleven patients with psoriasis and ten controls underwent carotid PET/MRI. Following injection of the FDG tracer, 3d T1w gradient echo sequence (atMR) was obtained for attenuation correction of PET data. High resolution images of carotid artery were then obtained, including pre-and post-contrast T1-w, T2-w and proton-density images as well as TOF images followed by PET imaging of the torso...
2016: American Journal of Nuclear Medicine and Molecular Imaging
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