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Investigation of inter-slice magnetization transfer effects as a new method for MTR imaging of the human brain.

Barker JW, Han PK, Choi SH, Bae KT, Park SH - PLoS ONE (2015)

Bottom Line: The effects of varying flip angle and phase encoding (PE) order were investigated experimentally in normal, healthy subjects.Simulations were also used to investigate the effects of varying acquisition parameters, and the effects of varying flip angle, PE steps, and interslice delay are discussed.Lastly, we demonstrated reduced banding with a non-balanced SSFP-FID sequence and showed preliminary results of interslice MTR imaging of meningioma.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.

ABSTRACT
We present a new method for magnetization transfer (MT) ratio imaging in the brain that requires no separate saturation pulse. Interslice MT effects that are inherent to multi-slice balanced steady-state free precession (bSSFP) imaging were controlled via an interslice delay time to generate MT-weighted (0 s delay) and reference images (5-8 s delay) for MT ratio (MTR) imaging of the brain. The effects of varying flip angle and phase encoding (PE) order were investigated experimentally in normal, healthy subjects. Values of up to ∼50% and ∼40% were observed for white and gray matter MTR. Centric PE showed larger MTR, higher SNR, and better contrast between white and gray matter than linear PE. Simulations of a two-pool model of MT agreed well with in vivo MTR values. Simulations were also used to investigate the effects of varying acquisition parameters, and the effects of varying flip angle, PE steps, and interslice delay are discussed. Lastly, we demonstrated reduced banding with a non-balanced SSFP-FID sequence and showed preliminary results of interslice MTR imaging of meningioma.

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Comparison of interslice MTR imaging with bSSFP and SSFP-FID sequences.The SSFP-FID sequence significantly reduced banding artifacts in slices 3–5, but SNR was 22% lower than with bSSFP.
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pone.0117101.g008: Comparison of interslice MTR imaging with bSSFP and SSFP-FID sequences.The SSFP-FID sequence significantly reduced banding artifacts in slices 3–5, but SNR was 22% lower than with bSSFP.

Mentions: Simulations were performed using sequence parameters that matched the bSSFP acquision for images in Fig. 8.


Investigation of inter-slice magnetization transfer effects as a new method for MTR imaging of the human brain.

Barker JW, Han PK, Choi SH, Bae KT, Park SH - PLoS ONE (2015)

Comparison of interslice MTR imaging with bSSFP and SSFP-FID sequences.The SSFP-FID sequence significantly reduced banding artifacts in slices 3–5, but SNR was 22% lower than with bSSFP.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321840&req=5

pone.0117101.g008: Comparison of interslice MTR imaging with bSSFP and SSFP-FID sequences.The SSFP-FID sequence significantly reduced banding artifacts in slices 3–5, but SNR was 22% lower than with bSSFP.
Mentions: Simulations were performed using sequence parameters that matched the bSSFP acquision for images in Fig. 8.

Bottom Line: The effects of varying flip angle and phase encoding (PE) order were investigated experimentally in normal, healthy subjects.Simulations were also used to investigate the effects of varying acquisition parameters, and the effects of varying flip angle, PE steps, and interslice delay are discussed.Lastly, we demonstrated reduced banding with a non-balanced SSFP-FID sequence and showed preliminary results of interslice MTR imaging of meningioma.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.

ABSTRACT
We present a new method for magnetization transfer (MT) ratio imaging in the brain that requires no separate saturation pulse. Interslice MT effects that are inherent to multi-slice balanced steady-state free precession (bSSFP) imaging were controlled via an interslice delay time to generate MT-weighted (0 s delay) and reference images (5-8 s delay) for MT ratio (MTR) imaging of the brain. The effects of varying flip angle and phase encoding (PE) order were investigated experimentally in normal, healthy subjects. Values of up to ∼50% and ∼40% were observed for white and gray matter MTR. Centric PE showed larger MTR, higher SNR, and better contrast between white and gray matter than linear PE. Simulations of a two-pool model of MT agreed well with in vivo MTR values. Simulations were also used to investigate the effects of varying acquisition parameters, and the effects of varying flip angle, PE steps, and interslice delay are discussed. Lastly, we demonstrated reduced banding with a non-balanced SSFP-FID sequence and showed preliminary results of interslice MTR imaging of meningioma.

Show MeSH
Related in: MedlinePlus