Diffusion‐prepared 3D gradient spin‐echo sequence for improved oscillating gradient diffusion MRI

2020 ◽  
Vol 85 (1) ◽  
pp. 78-88
Author(s):  
Dan Wu ◽  
Dapeng Liu ◽  
Yi‐Cheng Hsu ◽  
Haotian Li ◽  
Yi Sun ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
Spin Echo ◽  
Gradient Diffusion ◽  
Spin Echo Sequence

scholarly journals Probing mouse brain microstructure using oscillating gradient diffusion MRI

2011 ◽  
Vol 67 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Manisha Aggarwal ◽  
Melina V. Jones ◽  
Peter A. Calabresi ◽  
Susumu Mori ◽  
Jiangyang Zhang
Keyword(s):  
Mouse Brain ◽  
Diffusion Mri ◽  
Gradient Diffusion ◽  
Brain Microstructure

scholarly journals Sialolithiasis and Salivary Ductal Stenosis: Diagnostic Accuracy of MR Sialography with a Three-dimensional Extended-Phase Conjugate-Symmetry Rapid Spin-Echo Sequence

Radiology ◽  
2000 ◽  
Vol 217 (2) ◽  
pp. 347-358 ◽  
Author(s):  
Minerva Becker ◽  
Francis Marchal ◽  
Christoph D. Becker ◽  
Pavel Dulguerov ◽  
Georges Georgakopoulos ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Spin Echo ◽  
Three Dimensional ◽  
Extended Phase ◽  
Phase Conjugate ◽  
Spin Echo Sequence ◽  
Conjugate Symmetry

scholarly journals Dynamic diffusion‐weighted hyperpolarized 13 C imaging based on a slice‐selective double spin echo sequence for measurements of cellular transport

2018 ◽  
Vol 81 (3) ◽  
pp. 2001-2010 ◽  
Author(s):  
Xucheng Zhu ◽  
Jeremy W. Gordon ◽  
Robert A. Bok ◽  
John Kurhanewicz ◽  
Peder E.Z. Larson
Keyword(s):  
Spin Echo ◽  
Cellular Transport ◽  
Double Spin ◽  
Diffusion Weighted ◽  
Spin Echo Sequence ◽  
Dynamic Diffusion

scholarly journals Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo magnetization transfer sequence: preliminary report

1999 ◽  
Vol 57 (4) ◽  
pp. 912-915 ◽  
Author(s):  
ANTÔNIO JOSÉ DA ROCHA ◽  
ANTONIO CARLOS MARTINS MAIA JUNIOR ◽  
ROBERTO GOMES NOGUEIRA ◽  
HENRIQUE MANOEL LEDERMAN
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Magnetic Resonance ◽  
Preliminary Report ◽  
Corticospinal Tract ◽  
Spin Echo ◽  
Magnetization Transfer ◽  
Control Group ◽  
Spin Echo Sequence ◽  
Lateral Sclerosis

We present the magnetic resonance (MR) findings of five patients with amyotrophic lateral sclerosis (ALS) using a spin-echo sequence with an additional magnetization transfer (MT) pulse on T1-weighted images (T1 SE/MT). These findings were absent in the control group and consisted of hyperintensity of the corticospinal tract. Moreover we discuss the principles and the use of this fast but simple MR technique in the diagnosis of ALS

scholarly journals P112 Muscles in myositis with normal MRI appearance have higher quantitative T2 compared to those in healthy controls

Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Matthew Farrow ◽  
John Biglands ◽  
Andrew Grainger ◽  
Elizabeth Hensor ◽  
Philip O'Connor ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Spin Echo ◽  
Muscle Pathology ◽  
Healthy Controls ◽  
Muscle Enzymes ◽  
Spin Echo Sequence ◽  
Healthy Control ◽  
And Gender ◽  
The Individual ◽  
T2 Mri

Abstract Background Myositis is an autoimmune disease which can cause a decrease in quality of life and increased mortality, presenting with muscle weakness, raised muscle enzymes and myalgia. Diagnosis is reliant on subjective clinical examinations, blood tests, conventional MRI and invasive muscle biopsies. Quantitative T2 MRI offers a non-invasive measurement of muscle oedema which could help improve the understanding of muscle pathology and potentially inform diagnosis. The aim of this study was to evaluate whether quantitative T2 MRI of muscles is sensitive enough to detect differences in myositis patients compared to healthy controls, and how it compares with current radiologist scoring methods. Methods 16 myositis patients were recruited (10/16 female, 10 polymyositis, 6 dermatomyositis, mean age 50 ± 26), median CK 1000IU/L ± 3100IU/L, and 16 age and gender matched healthy controls were recruited. MRI of the dominant thigh were performed. Imaging was performed using a fat-suppressed turbo-spin echo sequence. Quantitative T2 measurements were obtained from regions of interest (ROI) drawn manually within the individual muscles that make up the quadriceps and hamstrings with no distinction made between affected and unaffected muscles. A mono-exponential fit was used to obtain an estimate of the T2 from each ROI. Two radiologists blinded to the diagnosis, semi-quantitatively scored by consensus the muscles on a 4-point visual scale as either no oedema (0), mild oedema (1), moderate oedema (2) or severe oedema (3). Muscle strength was assessed using an isokinetic dynamometer. Results T2 values were higher in myositis patients compared to healthy controls [mean (SD) hamstring myositis 47.8ms (7.7ms), healthy 39.9ms (1.5ms), p < 0.001; quadriceps myositis 53.8ms (12.1ms), healthy 42.1ms (2.1ms), p < 0.001]. Quantitative T2 correlated with the radiologists’ oedema scores with rs=0.7 in the hamstrings (p < 0.001) and rs=0.6 in the quadriceps (p < 0.001), with an upward trend in T2 as radiologist scored visible oedema increased. Patients who had been classified as normal by the radiologists were compared with matched healthy controls (n = 8), T2 values for patients with ‘normal muscle’ were still higher than those for healthy controls: mean T2 in the hamstrings (myositis 42.2ms, healthy controls 38.7ms, p = 0.004); mean T2 in the quadriceps (myositis 43.9ms, healthy controls 40.1ms, p = 0.001). T2 was inversely correlated with muscle strength in all participants. Conclusion Quantitative T2 measurements can detect muscle differences between myositis patients and healthy control groups, which suggests that this measurement could be used as an objective method to monitor muscles. They are also sensitive to differences that may not be detected by radiologists. This suggests that subtle systemic changes in muscle in myositis patients, which go undetected in semi-quantitative visual scoring, can be detected using quantitative T2 measurements. This shows the potential for T2 measurements to be a diagnostic measure in the diagnosis and management of myositis. Disclosures M. Farrow None. J. Biglands None. A. Grainger None. E. Hensor None. P. O'Connor None. A. Ladas None. S. Tanner None. A. Aslam None. P. Emery None. A. Tan None.

scholarly journals Assimilation of α-glutamyl-peptides by human erythrocytes. A possible means of glutamate supply for glutathione synthesis

1985 ◽  
Vol 227 (3) ◽  
pp. 833-842 ◽  
Author(s):  
G F King ◽  
P W Kuchel
Keyword(s):  
Spin Echo ◽  
Linear Regression Analysis ◽  
Cell Suspensions ◽  
Human Erythrocytes ◽  
Peptide Hydrolysis ◽  
Whole Cell ◽  
Glutathione Synthesis ◽  
Whole Cells ◽  
Transmembrane Flux ◽  
Spin Echo Sequence

Human erythrocytes are essentially impermeable to glutamate and yet there is a continual requirement for the amino acid for glutathione synthesis. In addition, the intracellular glutamate concentration is approximately five times that of plasma. We present evidence that glutamate enters the red cell as small peptides which are rapidly hydrolysed by cytoplasmic peptidase(s) and that with the estimated physiological levels of plasma glutamyl-peptides the rate of inward flux would be adequate to maintain the glutamate pool at its observed level. Experimentally, we used 1H spin-echo n.m.r. spectroscopy to follow peptide hydrolysis, since peptide spectra are different from those of the free amino acids and the spin-echo sequence enables the monitoring of reactions in concentrated lysates and whole cell suspensions. Thus, the system was studied under near-physiological conditions. Weighted non-linear regression analysis of progress curves using the integrated Michaelis-Menten equation was used to obtain estimates of Km and Vmax. for the hydrolysis of alpha-L-glutamyl-L-alanine and L-alanyl-alpha-L-glutamate in lysates and whole cell suspensions; the values for lysates were Km = 3.60 +/- 0.29 and 5.4 +/- 0.4 mmol/l and Vmax. = 120 +/- 4 and 46.7 +/- 1.7 mmol/h per 1 of packed cells respectively. In whole cell suspensions the rate of peptide hydrolysis was much slower and dominated by the transmembrane flux-rate. The estimates of the steady-state kinetic parameters for the transport were Kt = 2.35 +/- 0.41 and 11.2 +/- 1.0 mmol/l and Vmax. = 3.26 +/- 0.13 and 19.7 +/- 0.7 mmol/h per 1 of packed cells respectively for the previously mentioned peptides. Using the n.m.r. procedure we failed to detect any glutaminase activity in whole cells or lysates; thus, we exclude the possibility that glutamate gains entry to the cell as glutamine which is subsequently hydrolysed by glutaminase.

scholarly journals Imaging neurodegeneration in the mouse hippocampus after neonatal hypoxia-ischemia using oscillating gradient diffusion MRI

2013 ◽  
Vol 72 (3) ◽  
pp. 829-840 ◽  
Author(s):  
Manisha Aggarwal ◽  
Jennifer Burnsed ◽  
Lee J. Martin ◽  
Frances J. Northington ◽  
Jiangyang Zhang
Keyword(s):  
Diffusion Mri ◽  
Neonatal Hypoxia ◽  
Gradient Diffusion ◽  
Hypoxia Ischemia ◽  
Mouse Hippocampus
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