Characterization of normal appearing brain structures using high-resolution quantitative magnetization transfer steady-state free precession imaging

Garcia, Meritxell; Gloor, M; Wetzel, Stephan G.; Radue, Ernst‐Wilhelm; Scheffler, Klaus; Bieri, Oliver

doi:10.1016/j.neuroimage.2010.04.242

Cited by 14 publications

(11 citation statements)

References 30 publications

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“…Additional work is needed to explore the field- and TE-dependence of PSR values obtained via the SIR technique. Nevertheless, the reported regional variation in PSR values was consistent with previous qMT imaging studies (Dortch et al, 2011; Garcia et al, 2010; Sled et al, 2004; Underhill et al, 2009); and additional SIR-TFE studies in bovine serum albumin phantoms at 7.0 T (data not shown) found a linear relationship between macromolecular content and PSR . Thus, we postulate that the regional differences in PSR values reported herein are driven primarily by regional differences in myelin content, although the absolute values may be systematically larger than reported by other techniques.…”

Section: Discussionsupporting

confidence: 90%

“…Previous qMT imaging studies at lower field strengths (Dortch et al, 2011; Garcia et al, 2010; Gloor et al, 2008; Ropele et al, 2003; Sled and Pike, 2001; Sled et al, 2004; Yarnykh and Yuan, 2004) have reported PSR values in the range of 11–16% and 5–9% for WM and GM structures, respectively [ PSR = F using the notation of Sled and Pike (2000, 2001) and M 0b using the notation of Henkelman et al (1993)]. The PSR values presented herein (WM: 15–20%, GM: 9–13%) were approximately 25% higher.…”

Section: Discussionmentioning

confidence: 99%

“…Previous pulsed saturation and SSFP-based studies (Garcia et al, 2010; Gloor et al, 2008; Ropele et al, 2003; Sled and Pike, 2001; Sled et al, 2004; Yarnykh and Yuan, 2004) report k mf values [ k mf = k f /F using the notation of Sled and Pike (2000, 2001); k mf = R when M 0 f =1 using the notation of Henkelman et al (1993)] in the range of 20–40 s −1 across the brain. A previous SIR study (Dortch et al, 2011) at 3.0 T reports k mf values that are approximately 2-fold slower (10–15 s —1 ) with values that are slower in WM than GM, which is consistent with the results presented herein.…”

Section: Discussionmentioning

confidence: 99%

“…The number of total images required can be reduced by designing optimal sampling strategies (Cercignani and Alexander, 2006; Levesque et al, 2011) or by fixing certain model parameters in the fitting procedure (Underhill et al, 2009, 2011). Potentially more efficient strategies based upon steady-state free-precession (SSFP) sequences (Garcia et al, 2010; Gloor et al, 2008) may also be employed.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative magnetization transfer imaging of human brain at 7 T

Dortch

Moore

et al. 2013

NeuroImage

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Quantitative magnetization transfer (qMT) imaging yields indices describing the interactions between free water protons and immobile macromolecular protons. These indices include the macromolecular to free pool size ratio (PSR), which has been shown to be correlated with myelin content in white matter. Because of the long scan times required for whole-brain imaging (≈20–30 min), qMT studies of the human brain have not found widespread application. Herein, we investigated whether the increased signal-to-noise ratio available at 7.0 T could be used to reduce qMT scan times. More specifically, we developed a selective inversion recovery (SIR) qMT imaging protocol with a i) novel transmit radiofrequency (B1+) and static field (B0) insensitive inversion pulse, ii) turbo field-echo readout, and iii) reduced TR. In vivo qMT data were obtained in the brains of healthy volunteers at 7.0 T using the resulting protocol (scan time≈40 s/slice, resolution=2×2×3 mm3). Reliability was also assessed in repeated acquisitions. The results of this study demonstrate that SIR qMT imaging can be reliably performed within the radiofrequency power restrictions present at 7.0 T, even in the presence of large B1+ and B0 inhomogeneities. Consistent with qMT studies at lower field strengths, the observed PSR values were higher in white matter (mean±SD=17.6±1.3%) relative to gray matter (10.3±1.6%) at 7.0 T. In addition, regional variations in PSR were observed in white matter. Together, these results suggest that qMT measurements are feasible at 7.0 T and may eventually allow for the high-resolution assessment of changes in composition throughout the normal and diseased human brain in vivo.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Quantitative magnetization transfer imaging of human brain at 7 T

Dortch

Moore

et al. 2013

NeuroImage

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“…Previous pulsed saturation (14, 17, 28, 29) and balanced steady‐state free precession (30, 31) qMT imaging studies have reported PSR values in the range of 11−16% and 5−9% for WM and GM structures, respectively. Our results (WM: 10−12%, GM: 8%) are consistent with these findings, although perhaps on the low end of this range for WM.…”

Section: Discussionmentioning

confidence: 98%

Quantitative magnetization transfer imaging in human brain at 3 T via selective inversion recovery

Dortch

Gochberg

et al. 2011

Magnetic Resonance in Med

115

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Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons—including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools kmf. This study describes the first implementation of the selective inversion recovery quantitative magnetization transfer method on a clinical 3.0-T scanner in human brain in vivo. Selective inversion recovery data were acquired at 16 different inversion times in nine healthy subjects and two patients with relapsing remitting multiple sclerosis. Data were collected using a fast spin-echo readout and reduced repetition time, resulting in an acquisition time of 4 min for a single slice. In healthy subjects, excellent intersubject and intrasubject reproducibilities (assessed via repeated measures) were demonstrated. Furthermore, PSR values in white (mean ± SD = 11.4 ± 1.2%) and gray matter (7.5 ± 0.7%) were consistent with previously reported values, while kmf values were approximately 2-fold slower in both white (11 ± 2 s−1) and gray matter (15 ± 6 s−1). In relapsing remitting multiple sclerosis patients, quantitative magnetization transfer indices were sensitive to pathological changes in lesions and in normal appearing white matter.

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Fast bound pool fraction mapping using stimulated echoes

Soellinger

Langkammer

Seifert-Held

et al. 2011

Magnetic Resonance in Med

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Magnetization transfer imaging advanced to an indispensible tool for investigating white matter changes. Quantitative magnetization transfer imaging methods allow the determination of the bound pool fraction (BPF), which is thought to be directly linked to myelin integrity. Long acquisition times and high specific absorption rates are still inhibiting broad in vivo utilization of currently available BPF mapping techniques. Herewith, a stimulated echoes amplitude modulation-based, single-shot echo planar imaging technique for BPF and T1 quantification is presented at 3T. It allows whole brain mapping in 10–15 min and is low in specific absorption rates. The method was validated with different concentrations of bovine serum albumin (BSA) phantoms. Intra- and inter-subject variability was assessed in vivo. Phantom measurements verified linearity between bovine serum albumin concentrations and measured BPF, which was independent of T1 variations. T1 values in the phantoms correlated well with values provided by standard T1 mapping methods. Intrasubject variability was minimal and mean regional BPFs of 10 volunteers (e.g., left frontal white matter = 0.135 ± 0.003, right frontal white matter = 0.129 ± 0.006) were in line with previously published data. Assessment of interhemispheric BPF differences revealed significantly higher BPF for the left brain hemisphere. To sum up, these results suggest the proposed method useful for cross-sectional and longitudinal studies of white matter changes in the human brain. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.

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Characterization of normal appearing brain structures using high-resolution quantitative magnetization transfer steady-state free precession imaging

Cited by 14 publications

References 30 publications

Quantitative magnetization transfer imaging of human brain at 7 T

Quantitative magnetization transfer imaging of human brain at 7 T

Quantitative magnetization transfer imaging in human brain at 3 T via selective inversion recovery

Fast bound pool fraction mapping using stimulated echoes

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