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Literature DB >> 17191245

Compensation for spin-lock artifacts using an off-resonance rotary echo in T1rhooff-weighted imaging.

Walter R T Witschey¹, Arijitt Borthakur, Mark A Elliott, Eric Mellon, Sampreet Niyogi, Chenyang Wang, Ravinder Reddy.

Abstract

The origin of image artifacts in an off-resonance spin-locking experiment is shown to be imperfections in the excitation flip angle. A pulse sequence for off-resonance spin locking is implemented that compensates for imperfections in the excitation flip angle through an off-resonance rotary echo. The off-resonance rotary echo alternates the frequency offset and phase of the RF transmitter during two spin-locking pulses of equal duration. The underlying theory is detailed, and MR images demonstrate the effectiveness of the technique in agarose gel phantoms and in in vivo human brain at 3T.

Entities: Chemical Species

Mesh：

Year: 2007 PMID： 17191245 PMCID： PMC2877388 DOI： 10.1002/mrm.21134

Source DB: PubMed Journal: Magn Reson Med ISSN： 0740-3194 Impact factor: 4.668

18 in total

1. In vivo proton MR three-dimensional T1rho mapping of human articular cartilage: initial experience.

Authors: Ravinder Reddy Regatte; Sarma V S Akella; Arijitt Borthakur; J Bruce Kneeland; Ravinder Reddy
Journal: Radiology Date: 2003-10 Impact factor: 11.105

2. Artifacts in T(1rho)-weighted imaging: correction with a self-compensating spin-locking pulse.

Authors: Sridhar R Charagundla; Arijitt Borthakur; John S Leigh; Ravinder Reddy
Journal: J Magn Reson Date: 2003-05 Impact factor: 2.229

3. Correlation of T1rho with fixed charge density in cartilage.

Authors: Andrew J Wheaton; Francis L Casey; Alexander J Gougoutas; George R Dodge; Arijitt Borthakur; Jess H Lonner; H Ralph Schumacher; Ravinder Reddy
Journal: J Magn Reson Imaging Date: 2004-09 Impact factor: 4.813

4. SAR and B1 field distributions in a heterogeneous human head model within a birdcage coil. Specific energy absorption rate.

Authors: C M Collins; S Li; M B Smith
Journal: Magn Reson Med Date: 1998-12 Impact factor: 4.668

5. One-shot measurement of spin-lattice relaxation times in the off-resonance rotating frame using MR imaging, with application to breast.

Authors: E J Fairbanks; G E Santyr; J A Sorenson
Journal: J Magn Reson B Date: 1995-03

6. Off-resonance spin locking for MR imaging.

Authors: G E Santyr; E J Fairbanks; F Kelcz; J A Sorenson
Journal: Magn Reson Med Date: 1994-07 Impact factor: 4.668

7. Spin locking for magnetic resonance imaging with application to human breast.

Authors: G E Santyr; R M Henkelman; M J Bronskill
Journal: Magn Reson Med Date: 1989-10 Impact factor: 4.668

8. Indirect 17(O)-magnetic resonance imaging of cerebral blood flow in the rat.

Authors: Dharmesh R Tailor; Arijit Roy; Ravinder R Regatte; Sridhar R Charagundla; Alan C McLaughlin; John S Leigh; Ravinder Reddy
Journal: Magn Reson Med Date: 2003-03 Impact factor: 4.668

9. Water magnetic relaxation dispersion in biological systems: the contribution of proton exchange and implications for the noninvasive detection of cartilage degradation.

Authors: U Duvvuri; A D Goldberg; J K Kranz; L Hoang; R Reddy; F W Wehrli; A J Wand; S W Englander; J S Leigh
Journal: Proc Natl Acad Sci U S A Date: 2001-10-16 Impact factor: 11.205

10. High-resolution assessment of blood flow in murine RIF-1 tumors by monitoring uptake of H(2)(17)O with proton T(1rho)-weighted imaging.

Authors: Dharmesh R Tailor; Harish Poptani; Jerry D Glickson; John S Leigh; Ravinder Reddy
Journal: Magn Reson Med Date: 2003-01 Impact factor: 4.668

16 in total

Compensation for spin-lock artifacts using an off-resonance rotary echo in T1rhooff-weighted imaging.

1. In vivo proton MR three-dimensional T1rho mapping of human articular cartilage: initial experience.

2. Artifacts in T(1rho)-weighted imaging: correction with a self-compensating spin-locking pulse.

3. Correlation of T1rho with fixed charge density in cartilage.

4. SAR and B1 field distributions in a heterogeneous human head model within a birdcage coil. Specific energy absorption rate.

5. One-shot measurement of spin-lattice relaxation times in the off-resonance rotating frame using MR imaging, with application to breast.

6. Off-resonance spin locking for MR imaging.

7. Spin locking for magnetic resonance imaging with application to human breast.

8. Indirect 17(O)-magnetic resonance imaging of cerebral blood flow in the rat.

9. Water magnetic relaxation dispersion in biological systems: the contribution of proton exchange and implications for the noninvasive detection of cartilage degradation.

10. High-resolution assessment of blood flow in murine RIF-1 tumors by monitoring uptake of H(2)(17)O with proton T(1rho)-weighted imaging.

1. Exchange-mediated contrast agents for spin-lock imaging.

2. Probing chemical exchange using quantitative spin-lock R_1ρ asymmetry imaging with adiabatic RF pulses.

3. RAFFn relaxation rate functions.

4. Volumetric multislice gagCEST imaging of articular cartilage: Optimization and comparison with T1rho.

5. T1rho MRI quantification of arthroscopically confirmed cartilage degeneration.

6. Relaxation dispersion in MRI induced by fictitious magnetic fields.

Review 7. Novel contrast mechanisms at 3 Tesla and 7 Tesla.

8. Measurement of regional cerebral glucose uptake by magnetic resonance spin-lock imaging.

9. MRI contrast from relaxation along a fictitious field (RAFF).

10. Spin-locked balanced steady-state free-precession (slSSFP).