A pitfall associated with determination of transverse relaxation times of the31P NMR signals of ATP using the Hahn spin-echo

1993 ◽  
Vol 30 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Wulf-Ingo Jung ◽  
Klaus Straubinger ◽  
Michael Bunse ◽  
Stefan Widmaier ◽  
Fritz Schick ◽  
...  
Keyword(s):  
Spin Echo ◽  
Relaxation Times ◽  
Transverse Relaxation ◽  
Nmr Signals

Spin-echo methods for the determination of 31P transverse relaxation times of the ATP NMR signals in vivo

1994 ◽  
Vol 12 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Klaus Straubinger ◽  
Wulf-Ingo Jung ◽  
Michael Bunse ◽  
Otto Lutz ◽  
Klaus Küper ◽  
...  
Keyword(s):  
Spin Echo ◽  
Relaxation Times ◽  
Transverse Relaxation ◽  
Nmr Signals

31P Transverse Relaxation Times of the ATP NMR Signals of Human Skeletal Muscle in Vivo

1992 ◽  
Vol 28 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Wulf-Ingo Jung ◽  
Klaus Straubinger ◽  
Michael Bunse ◽  
Fritz Schick ◽  
Klaus Küper ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Relaxation Times ◽  
Transverse Relaxation ◽  
Nmr Signals

Relaxation of Spin 1/2 in the Scalar Coupled Spin System AMX with Quadrupolar Nuclei in the Presence of Cross-correlation Effects

2004 ◽  
Vol 59 (4-5) ◽  
pp. 217-4
Author(s):  
G. S. Kupriyanova
Keyword(s):  
Spin System ◽  
Cross Correlation ◽  
Relaxation Times ◽  
Formal Theory ◽  
Quadrupolar Nuclei ◽  
Transverse Relaxation ◽  
Selective Determination ◽  
Product Operator ◽  
Dynamic Frequency

We present the formal theory of the nuclear magnetic relaxation of spin ½ A in a scalar coupled spin system AMX with quadrupolar nuclei of spin 1 (M, X) considering cross-correlation relaxation based on second order time-dependent perturbation theory and the product operator formalism. The expressions for longitudinal and transverse relaxation times and dynamic frequency shifts of each component of the spectral pattern are derived. Several experimental schemes for the selective determination of the cross-correlation rate between different spin orders are proposed.

Determination of H relaxation times of water in human bone marrow by fat-suppressed turbo spin echo in comparison to MR spectroscopic methods

1996 ◽  
Vol 6 (3) ◽  
pp. 541-548 ◽  
Author(s):  
Frank Träber ◽  
Wolfgang Block ◽  
Günter Layer ◽  
Gitte Bräucker ◽  
Jürgen Gieseke ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Spin Echo ◽  
Relaxation Times ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Spectroscopic Methods ◽  
Turbo Spin Echo ◽  
Turbo Spin

scholarly journals Effects of Liver Fibrosis Progression on Tissue Relaxation Times in Different Mouse Models Assessed by Ultrahigh Field Magnetic Resonance Imaging

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Andreas Müller ◽  
Katrin Hochrath ◽  
Jonas Stroeder ◽  
Kanishka Hittatiya ◽  
Günther Schneider ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Liver Fibrosis ◽  
Disease Severity ◽  
Spin Echo ◽  
Relaxation Times ◽  
Fast Spin Echo ◽  
Spin Echo Sequence ◽  
Fast Spin Echo Sequence ◽  
Tissue Relaxation

Recently, clinical studies demonstrated that magnetic resonance relaxometry with determination of relaxation times T1 andT2⁎may aid in staging and management of liver fibrosis in patients suffering from viral hepatitis and steatohepatitis. In the present study we investigated T1 andT2⁎in different models of liver fibrosis to compare alternate pathophysiologies in their effects on relaxation times and to further develop noninvasive quantification methods of liver fibrosis. MRI was performed with a fast spin echo sequence for measurement of T1 and a multigradient echo sequence for determination ofT2⁎. Toxic liver fibrosis was induced by injections of carbon tetrachloride (1.4 mL CCl4per kg bodyweight and week, for 3 or 6 weeks) in BALB/cJ mice. Chronic sclerosing cholangitis was mimicked using the ATP-binding cassette transporter B4 knockout(Abcb4 -/-)mouse model. Untreated BALB/cJ mice served as controls. To assess hepatic fibrosis, we ascertained collagen contents and fibrosis scores after Sirius red staining. T1 andT2⁎correlate differently to disease severity and etiology of liver fibrosis.T2⁎shows significant decrease correlating with fibrosis in CCl4treated animals, while demonstrating significant increase with disease severity inAbcb4 -/-mice. Measurements of T1 andT2⁎may therefore facilitate discrimination between different stages and causes of liver fibrosis.

scholarly journals Magnetic Resonance Imaging of Water Content and Flow Processes in Natural Soils by Pulse Sequences with Ultrashort Detection

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5130
Author(s):  
Sabina Haber-Pohlmeier ◽  
David Caterina ◽  
Bernhard Blümich ◽  
Andreas Pohlmeier
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Water Content ◽  
Soil Water ◽  
Spin Echo ◽  
Pulse Sequences ◽  
Relaxation Times ◽  
Natural Soil ◽  
Resonance Imaging ◽  
Transverse Relaxation

Magnetic resonance imaging is a valuable tool for three-dimensional mapping of soil water processes due to its sensitivity to the substance of interest: water. Since conventional gradient- or spin-echo based pulse sequences do not detect rapidly relaxing fractions of water in natural porous media with transverse relaxation times in the millisecond range, pulse sequences with ultrafast detection open a way out. In this work, we compare a spin-echo multislice pulse sequence with ultrashort (UTE) and zero-TE (ZTE) sequences for their suitability to map water content and its changes in 3D in natural soil materials. Longitudinal and transverse relaxation times were found in the ranges around 80 ms and 1 to 50 ms, respectively, so that the spin echo sequence misses larger fractions of water. In contrast, ZTE and UTE could detect all water, if the excitation and detection bandwidths were set sufficiently broad. More precisely, with ZTE we could map water contents down to 0.1 cm3/cm3. Finally, we employed ZTE to monitor the development of film flow in a natural soil core with high temporal resolution. This opens the route for further quantitative imaging of soil water processes.

scholarly journals Low Frequency Nuclear Quadrupole Resonance with SQUID Amplifiers

1994 ◽  
Vol 49 (1-2) ◽  
pp. 5-13 ◽  
Author(s):  
John Clarke
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Quantum Interference ◽  
Spin Echo ◽  
Relaxation Times ◽  
Noise Temperature ◽  
Low Frequency ◽  
Input Circuit ◽  
Transverse Relaxation ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

Abstract The dc SQUID (Superconducting QUantum Interference Device) can be configured as an ampli­fier of spin-echos with a noise temperature of approximately 10 mK (f/1 M Hz) at an operating temperature of 1.5 K. A Fourier transform spectrometer based on a SQUID with a superconducting input circuit and operated in a flux-locked loop is used to obtain nuclear quadrupole resonance (NQR) spectra in a broadband m ode over the bandwith 0 -1 M Hz. Spin-echo spectra of 14N in NH4ClO4 reveal sharp NQR resonances, obtained simultaneously, at 17.4, 38.8 and 56.2 kHz. At 1.5 K, the measured longitudinal and transverse relaxation times T1 and T2 for the 38.8 kHz transition are 63 ± 3 ms and 22±2 ms, respectively.

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