Effects of RF pulse profile and intra-voxel phase dispersion on MR fingerprinting with balanced SSFP readout

Chiu, Su-Chin; Lin, Te-Ming; Lin, Jyh-Miin; Chung, Hsiao Wen; Ko, Chung‐Wen; Büchert, Martin; Bock, Michael

doi:10.1016/j.mri.2017.04.002

Cited by 10 publications

(10 citation statements)

References 26 publications

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“…Another finding concerning intravoxel dephasing effects on MRF values was made. Although a high intravoxel phase dispersion only scales the signal in FISP‐based and FLASH‐based MRF, it can have a strong effect on TrueFISP signals . A particularly strong effect can be observed on the TrueFISP signal when the stop band condition is met.…”

Section: Discussionmentioning

confidence: 99%

“…Although a high intravoxel phase dispersion only scales the signal in FISP-based and FLASH-based MRF, it can have a strong effect on TrueFISP signals. 39,40 A particularly strong effect can be observed on the TrueFISP signal when the stop band condition is met. By also matching the phase dispersion, this effect that is mostly influencing T 2 values can be alleviated.…”

Section: Discussionmentioning

confidence: 99%

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Magnetic resonance field fingerprinting

Körzdörfer

Jiang

Speier

et al. 2018

Magnetic Resonance in Med

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Purpose To develop and evaluate the magnetic resonance field fingerprinting method that simultaneously generates T1, T2, B0, and B1+ maps from a single continuous measurement. Methods An encoding pattern was designed to integrate true fast imaging with steady‐state precession (TrueFISP), fast imaging with steady‐state precession (FISP), and fast low‐angle shot (FLASH) sequence segments with varying flip angles, radio frequency (RF) phases, TEs, and gradient moments in a continuous acquisition. A multistep matching process was introduced that includes steps for integrated spiral deblurring and the correction of intravoxel phase dispersion. The method was evaluated in phantoms as well as in vivo studies in brain and lower abdomen. Results Simultaneous measurement of T1, T2, B0, and B1+ is achieved with T1 and T2 subsequently being less afflicted by B0 and B1+ variations. Phantom results demonstrate the stability of generated parameter maps. Higher undersampling factors and spatial resolution can be achieved with the proposed method as compared with solely FISP–based magnetic resonance fingerprinting. High‐resolution B0 maps can potentially be further used as diagnostic information. Conclusion The proposed magnetic resonance field fingerprinting method can estimate T1, T2, B0, and B1+ maps accurately in phantoms, in the brain, and in the lower abdomen.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Magnetic resonance field fingerprinting

Körzdörfer

Jiang

Speier

et al. 2018

Magnetic Resonance in Med

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“…Two additional corrections are included in the dictionary, as recommended in prior work . First, the non‐rectangular slice profile is incorporated in the Bloch simulation . To this end, the RF and gradient waveforms are simulated in the sequence programming environment.…”

Section: Methodsmentioning

confidence: 99%

“…37 First, the non-rectangular slice profile is incorporated in the Bloch simulation. [46][47][48] To this end, the RF and gradient waveforms are simulated in the sequence programming environment. Next, a Bloch simulation is performed using these RF and gradient waveforms, with 500 spins distributed across the slice direction.…”

Section: Dictionary Generationmentioning

confidence: 99%

Simultaneous multislice cardiac magnetic resonance fingerprinting using low rank reconstruction

Hamilton

Jiang

et al. 2018

NMR in Biomedicine

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This study introduces a technique for simultaneous multislice (SMS) cardiac magnetic resonance fingerprinting (cMRF), which improves the slice coverage when quantifying myocardial T1, T2, and M0. The single‐slice cMRF pulse sequence was modified to use multiband (MB) RF pulses for SMS imaging. Different RF phase schedules were used to excite each slice, similar to POMP or CAIPIRINHA, which imparts tissues with a distinguishable and slice‐specific magnetization evolution over time. Because of the high net acceleration factor (R = 48 in plane combined with the slice acceleration), images were first reconstructed with a low rank technique before matching data to a dictionary of signal timecourses generated by a Bloch equation simulation. The proposed method was tested in simulations with a numerical relaxation phantom. Phantom and in vivo cardiac scans of 10 healthy volunteers were also performed at 3 T. With single‐slice acquisitions, the mean relaxation times obtained using the low rank cMRF reconstruction agree with reference values. The low rank method improves the precision in T1 and T2 for both single‐slice and SMS cMRF, and it enables the acquisition of maps with fewer artifacts when using SMS cMRF at higher MB factors. With this technique, in vivo cardiac maps were acquired from three slices simultaneously during a breathhold lasting 16 heartbeats. SMS cMRF improves the efficiency and slice coverage of myocardial T1 and T2 mapping compared with both single‐slice cMRF and conventional cardiac mapping sequences. Thus, this technique is a first step toward whole‐heart simultaneous T1 and T2 quantification with cMRF.

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“…FISP序列是一种成熟的快速磁共振成像激发序列 [15] , 对外磁场强度的均匀性不敏感, 适用于大面积、存在运动干扰的成像物体造影. [22,23] . 另外, 对于长期以来, 人们普遍认为的射频场…”

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