Evaluation of liver T1 using MOLLI gradient echo readout under the influence of fat

2022 ◽  
Vol 85 ◽  
pp. 57-63
Author(s):  
Chia-Ying Liu ◽  
Chikara Noda ◽  
Bharath Ambale-Venkatesh ◽  
Yoshimori Kassai ◽  
David Bluemke ◽  
...  
Keyword(s):  
Gradient Echo

Assessment of Myocardial Viability in Persistent Defects on Thallium-201 SPECT after Reinjection Using Gradient-Echo MRI

1996 ◽  
Vol 35 (05) ◽  
pp. 146-152 ◽  
Author(s):  
A. Kögler ◽  
H.-A. Schmitt ◽  
D. Emrich ◽  
H. Kreuzer ◽  
D. L. Munz ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Myocardial Viability ◽  
Cardiac Cycle ◽  
Single Photon ◽  
Contractile Function ◽  
Left Ventricular ◽  
Wall Thickening ◽  
Gradient Echo ◽  
Systolic Wall Thickening

SummaryThis prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (± SD) was 11.5 ± 2.7 mm and 5.8 ± 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 ± 3.4 mm and 3.7 ± 3.1 mm in 31 with reversible lesions, 11.3 ± 2.8 mm and 3.3 ± 1.9 mm in 10 with mild persistent defects, 9.2 ± 2.9 mm and 3.2 ±2.2 mm in 15 with moderate persistent defects, 5.8 ± 1.7 mm and 1.3 ± 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p <0.0005) and systolic wall thickening (p <0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

scholarly journals Gradient Echo T2*-weighted MR Findings of Diabetic Chorea and Ballismus

2010 ◽  
Vol 49 (11) ◽  
pp. 1045-1046 ◽  
Author(s):  
Yoshiharu Taguchi ◽  
Shutaro Takashima ◽  
Kortaro Tanaka
Keyword(s):  
Gradient Echo

Variations in BOLD response latency estimated from event-related fMRI at 3T: Comparisons between gradient-echo and Spin-echo

2013 ◽  
Vol 23 (3) ◽  
pp. 215-221 ◽  
Author(s):  
Mei-Yu Yeh ◽  
Changwei W. Wu ◽  
Wan-Chun Kuan ◽  
Pei-Shan Wei ◽  
Yung-Liang Wan ◽  
...  
Keyword(s):  
Response Latency ◽  
Spin Echo ◽  
Bold Response ◽  
Gradient Echo

scholarly journals Juxtacortical susceptibility changes in progressive multifocal leukoencephalopathy at the gray–white matter junction correlates with iron-enriched macrophages

2021 ◽  
pp. 135245852199965
Author(s):  
Kedar R Mahajan ◽  
Moein Amin ◽  
Matthew Poturalski ◽  
Jonathan Lee ◽  
Danielle Herman ◽  
...  
Keyword(s):  
White Matter ◽  
Progressive Multifocal Leukoencephalopathy ◽  
Central Nervous System Lymphoma ◽  
Susceptibility Weighted Imaging ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Total N ◽  
Mri Brain ◽  
Fluid Attenuated Inversion Recovery ◽  
Magnetic Resonance Imaging Mri

Objective: Describe magnetic resonance imaging (MRI) susceptibility changes in progressive multifocal leukoencephalopathy (PML) and identify neuropathological correlates. Methods: PML cases and matched controls with primary central nervous system lymphoma (PCNSL) were retrospectively identified. MRI brain at 3 T and 7 T were reviewed. MRI-pathology correlations in fixed brain autopsy tissue were conducted in three subjects with confirmed PML. Results: With PML ( n = 26 total, n = 5 multiple sclerosis natalizumab-associated), juxtacortical changes on susceptibility-weighted imaging (SWI) or gradient echo (GRE) sequences were noted in 3/3 cases on 7 T MRI and 14/22 cases (63.6%) on 1.5 T or 8/22 (36.4%) 3 T MRI. Similar findings were only noted in 3/25 (12.0%) of PCNSL patients (odds ratio (OR) 12.83, 95% confidence interval (CI), 2.9–56.7, p < 0.001) on 1.5 or 3 T MRI. On susceptibility sequences available prior to diagnosis of PML, 7 (87.5%) had changes present on average 2.7 ± 1.8 months (mean ± SD) prior to diagnosis. Postmortem 7 T MRI showed SWI changes corresponded to areas of increased iron density along the gray–white matter (GM-WM) junction predominantly in macrophages. Conclusion: Susceptibility changes in PML along the GM-WM junction can precede noticeable fluid-attenuated inversion recovery (FLAIR) changes and correlates with iron accumulation in macrophages.

scholarly journals Nuclear Magnetic Resonance Metabolomics with Double Pulsed-Field-Gradient Echo and Automatized Solvent Suppression Spectroscopy for Multivariate Data Matrix Applied in Novel Wine and Juice Discriminant Analysis

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4146
Author(s):  
José Enrique Herbert-Pucheta ◽  
José Daniel Lozada-Ramírez ◽  
Ana E. Ortega-Regules ◽  
Luis Ricardo Hernández ◽  
Cecilia Anaya de Parrodi
Keyword(s):  
Statistical Analysis ◽  
Discriminant Analysis ◽  
Field Gradient ◽  
Multivariate Statistical Analysis ◽  
Data Matrix ◽  
Cabernet Sauvignon ◽  
Gradient Echo ◽  
Multivariate Statistical ◽  
Orthogonal Projections ◽  
Pulsed Field

The quality of foods has led researchers to use various analytical methods to determine the amounts of principal food constituents; some of them are the NMR techniques with a multivariate statistical analysis (NMR-MSA). The present work introduces a set of NMR-MSA novelties. First, the use of a double pulsed-field-gradient echo (DPFGE) experiment with a refocusing band-selective uniform response pure-phase selective pulse for the selective excitation of a 5–10-ppm range of wine samples reveals novel broad 1H resonances. Second, an NMR-MSA foodomics approach to discriminate between wine samples produced from the same Cabernet Sauvignon variety fermented with different yeast strains proposed for large-scale alcohol reductions. Third a comparative study between a nonsupervised Principal Component Analysis (PCA), supervised standard partial (PLS-DA), and sparse (sPLS-DA) least squares discriminant analysis, as well as orthogonal projections to a latent structures discriminant analysis (OPLS-DA), for obtaining holistic fingerprints. The MSA discriminated between different Cabernet Sauvignon fermentation schemes and juice varieties (apple, apricot, and orange) or juice authentications (puree, nectar, concentrated, and commercial juice fruit drinks). The new pulse sequence DPFGE demonstrated an enhanced sensitivity in the aromatic zone of wine samples, allowing a better application of different unsupervised and supervised multivariate statistical analysis approaches.

Coronal Gradient Echo MRI to Visualize the Zona Incerta for Deep Brain Stimulation Targeting in Parkinson’s Disease

2021 ◽  
pp. 1-8
Author(s):  
Ashesh A. Thaker ◽  
Kartik M. Reddy ◽  
John A. Thompson ◽  
Pamela David Gerecht ◽  
Mark S. Brown ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Regions Of Interest ◽  
Zona Incerta ◽  
Gradient Echo ◽  
Noise Ratio ◽  
Deep Brain

<b><i>Introduction:</i></b> Deep brain stimulation of the zona incerta is effective at treating tremor and other forms of parkinsonism. However, the structure is not well visualized with standard MRI protocols making direct surgical targeting unfeasible and contributing to inconsistent clinical outcomes. In this study, we applied coronal gradient echo MRI to directly visualize the rostral zona incerta in Parkinson’s disease patients to improve targeting for deep brain stimulation. <b><i>Methods:</i></b> We conducted a prospective study to optimize and evaluate an MRI sequence to visualize the rostral zona incerta in patients with Parkinson’s disease (<i>n</i> = 31) and other movement disorders (<i>n</i> = 13). We performed a contrast-to-noise ratio analysis of specific regions of interest to quantitatively assess visual discrimination of relevant deep brain structures in the optimized MRI sequence. Regions of interest were independently assessed by 2 neuroradiologists, and interrater reliability was assessed. <b><i>Results:</i></b> Rostral zona incerta and subthalamic nucleus were well delineated in our 5.5-min MRI sequence, indicated by excellent interrater agreement between neuroradiologists for region-of-interest measurements (&#x3e;0.90 intraclass coefficient). Mean contrast-to-noise ratio was high for both rostral zona incerta (6.39 ± 3.37) and subthalamic nucleus (17.27 ± 5.61) relative to adjacent white matter. There was no significant difference between mean signal intensities or contrast-to-noise ratio for Parkinson’s and non-Parkinson’s patients for either structure. <b><i>Discussion/Conclusion:</i></b> Our optimized coronal gradient echo MRI sequence delineates subcortical structures relevant to traditional and novel deep brain stimulation targets, including the zona incerta, with high contrast-to-noise. Future studies will prospectively apply this sequence to surgical planning and postimplantation outcomes.

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