Single-shot, variable flip-angle slice-selective excitation with four gradient-modulated adiabatic half-passage segments

1998 ◽  
Vol 40 (2) ◽  
pp. 334-340 ◽  
Author(s):  
Edward W. Hsu ◽  
Scott B. Reeder ◽  
James R. MacFall
Keyword(s):  
Selective Excitation ◽  
Flip Angle ◽  
Single Shot ◽  
Variable Flip Angle

scholarly journals Multiparametric mapping in post-mortem perinatal MRI: a feasibility study

2020 ◽  
Vol 93 (1111) ◽  
pp. 20190952
Author(s):  
Amy R McDowell ◽  
Susan C Shelmerdine ◽  
Sara Lorio ◽  
Wendy Norman ◽  
Rod Jones ◽  
...  
Keyword(s):  
Flip Angle ◽  
Whole Body ◽  
Proton Density ◽  
Single Shot ◽  
Post Mortem ◽  
Variable Flip Angle ◽  
High Quality ◽  
Isotropic Resolution ◽  
Tissue Contrast ◽  
Magnetic Transfer

Objectives: To demonstrate feasibility of a 3 T multiparametric mapping (MPM) quantitative pipeline for perinatal post-mortem MR (PMMR) imaging. Methods: Whole body quantitative PMMR imaging was acquired in four cases, mean gestational age 34 weeks, range (29–38 weeks) on a 3 T Siemens Prisma scanner. A multicontrast protocol yielded proton density, T1 and magnetic transfer (MT) weighted multi-echo images obtained from variable flip angle (FA) 3D fast low angle single-shot (FLASH) acquisitions, radiofrequency transmit field map and one B0 field map alongside four MT weighted acquisitions with saturation pulses of 180, 220, 260 and 300 degrees were acquired, all at 1 mm isotropic resolution. Results: Whole body MPM was achievable in all four foetuses, with R1, R2*, PD and MT maps reconstructed from a single protocol. Multiparametric maps were of high quality and show good tissue contrast, especially the MT maps. Conclusion: MPM is a feasible technique in a perinatal post-mortem setting, which may allow quantification of post-mortem change, prior to being evaluated in a clinical setting. Advances in knowledge: We have shown that the MPM sequence is feasible in PMMR imaging and shown the potential of MT imaging in this setting.

Accuracy of equilibrium magnetization mapping in sliced two-dimensional spoiled gradient-recalled echo pulse sequence with variable flip angle

2013 ◽  
Vol 38 (5) ◽  
pp. 1245-1250
Author(s):  
Hideto Kuribayashi ◽  
Masaki Sekino ◽  
Takuya Minowa ◽  
Yoshie Maitani ◽  
Hiroyuki Ohsaki ◽  
...  
Keyword(s):  
Pulse Sequence ◽  
Flip Angle ◽  
Two Dimensional ◽  
Variable Flip Angle ◽  
Equilibrium Magnetization ◽  
Echo Pulse

scholarly journals A practical guideline for T1 reconstruction from various flip angles in MRI

2016 ◽  
Vol 10 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Constantin Sandmann ◽  
Erlend Hodneland ◽  
Jan Modersitzki
Keyword(s):  
Sensitivity Analysis ◽  
Linear Method ◽  
Real Data ◽  
Flip Angle ◽  
Robust Method ◽  
Variable Flip Angle ◽  
Nonlinear Approach ◽  
Reconstruction Methods ◽  
The Family ◽  
Linear Reconstruction

A fast and robust method for T1 estimation in MRI is the so-called variable flip angle technique. We introduce a novel family of T1 reconstruction methods from data acquired with various flip angles and propose a family member which combines the robustness of a nonlinear- with the computational advantages of a linear reconstruction. The constructed family contains the most common approaches for T1 estimation, namely a linear and a nonlinear approach. A general sensitivity analysis for arbitrary members of the family is established. Advantages of the optimized reconstruction are demonstrated on phantom- as well as real data, showing improvements of up to 24% as compared with the linear method. As a further means to stabilize T1 estimation, spatial stabilization methods are compared. We demonstrate on phantom and on real data that improved results can be obtained if not only T1 but also a second unknown M0 in the reconstruction is stabilized.

Quantitative T 1 and proton density mapping with direct calculation of radiofrequency coil transmit and receive profiles from two-point variable flip angle data

2016 ◽  
Vol 29 (3) ◽  
pp. 349-360 ◽  
Author(s):  
Simon Baudrexel ◽  
Sarah C. Reitz ◽  
Stephanie Hof ◽  
René-Maxime Gracien ◽  
Vinzenz Fleischer ◽  
...  
Keyword(s):  
Direct Calculation ◽  
Flip Angle ◽  
Proton Density ◽  
Variable Flip Angle ◽  
Density Mapping ◽  
Radiofrequency Coil ◽  
Angle Data

scholarly journals Tissue sodium concentration and sodium T1 mapping of the human brain at 3 T using a Variable Flip Angle method

2019 ◽  
Vol 58 ◽  
pp. 116-124 ◽  
Author(s):  
Arthur Coste ◽  
Fawzi Boumezbeur ◽  
Alexandre Vignaud ◽  
Guillaume Madelin ◽  
Kathrin Reetz ◽  
...  
Keyword(s):  
Human Brain ◽  
T1 Mapping ◽  
Sodium Concentration ◽  
Flip Angle ◽  
Variable Flip Angle ◽  
Angle Method ◽  
Tissue Sodium
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