Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

Gunther Helms; Hampus Olsson; Mads Andersen

Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

Gunther Helms, Hampus Olsson, Mads Andersen

Research output: Chapter in Book/Report/Conference proceeding › Paper in conference proceeding › peer-review

Abstract

DREAM is an ultra-fast multi-slice B1+-mapping technique based on the single-shot STEAM sequence. To study noise and bias related to slice-profiles, DREAM B1+-maps at 3.75 mm resolution were acquired at 7T in phantoms and in human brain with nominal flip angles (FA) between 20° and 90° of the two STEAM preparation pulses. B1+ was decreasing at actual FAs above 50°; noise became apparent at actual FAs below 20° reducing dynamic range. By varying the preparation FA, this reliable range (20°<FA<50°) is shifted over a B1+ range from 20% to 250%. The FA map is constructed from overlapping B1+ maps after thresholding.

Original language	English
Title of host publication	Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T
Place of Publication	Berkeley
Publisher	International Society for Magnetic Resonance in Medicine
Number of pages	3
Volume	27
Publication status	Published - 2019 Apr 26
Event	ISMRM 27th Annual Meeting and Exhibition - Montreal, Canada Duration: 2019 May 11 → 2019 May 16 https://www.ismrm.org/19m/

Publication series

Name	Proc Intl Soc Magn Reson Med
Publisher	International Society for Magnetic Resonance in Medicine ISMRM
Volume	27
ISSN (Electronic)	1545-4428

Conference

Conference	ISMRM 27th Annual Meeting and Exhibition
Country/Territory	Canada
City	Montreal
Period	2019/05/11 → 2019/05/16
Internet address	https://www.ismrm.org/19m/

Subject classification (UKÄ)

Medical and Health Sciences
Medical Engineering
Other Physics Topics

Access to Document

https://index.mirasmart.com/ISMRM2019/PDFfiles/4500.htmlLicence: Other

Cite this

Helms, G., Olsson, H., & Andersen, M. (2019). Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T. In Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T (Vol. 27). Article 4500 (Proc Intl Soc Magn Reson Med; Vol. 27). International Society for Magnetic Resonance in Medicine. https://index.mirasmart.com/ISMRM2019/PDFfiles/4500.html

@inproceedings{27c979e8a0524f24a85741f5084b28e9,

title = "Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T",

abstract = "DREAM is an ultra-fast multi-slice B1+-mapping technique based on the single-shot STEAM sequence. To study noise and bias related to slice-profiles, DREAM B1+-maps at 3.75 mm resolution were acquired at 7T in phantoms and in human brain with nominal flip angles (FA) between 20° and 90° of the two STEAM preparation pulses. B1+ was decreasing at actual FAs above 50°; noise became apparent at actual FAs below 20° reducing dynamic range. By varying the preparation FA, this reliable range (20°<FA<50°) is shifted over a B1+ range from 20% to 250%. The FA map is constructed from overlapping B1+ maps after thresholding. ",

author = "Gunther Helms and Hampus Olsson and Mads Andersen",

year = "2019",

month = apr,

day = "26",

language = "English",

volume = "27",

series = "Proc Intl Soc Magn Reson Med",

publisher = "International Society for Magnetic Resonance in Medicine",

booktitle = "Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T",

note = "ISMRM 27th Annual Meeting and Exhibition ; Conference date: 11-05-2019 Through 16-05-2019",

url = "https://www.ismrm.org/19m/",

}

Helms, G, Olsson, H & Andersen, M 2019, Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T. in Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T. vol. 27, 4500, Proc Intl Soc Magn Reson Med, vol. 27, International Society for Magnetic Resonance in Medicine, Berkeley, ISMRM 27th Annual Meeting and Exhibition, Montreal, Canada, 2019/05/11. <https://index.mirasmart.com/ISMRM2019/PDFfiles/4500.html>

Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T. / Helms, Gunther; Olsson, Hampus; Andersen, Mads.
Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T. Vol. 27 Berkeley: International Society for Magnetic Resonance in Medicine, 2019. 4500 (Proc Intl Soc Magn Reson Med; Vol. 27).

Research output: Chapter in Book/Report/Conference proceeding › Paper in conference proceeding › peer-review

TY - GEN

T1 - Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

AU - Helms, Gunther

AU - Olsson, Hampus

AU - Andersen, Mads

PY - 2019/4/26

Y1 - 2019/4/26

N2 - DREAM is an ultra-fast multi-slice B1+-mapping technique based on the single-shot STEAM sequence. To study noise and bias related to slice-profiles, DREAM B1+-maps at 3.75 mm resolution were acquired at 7T in phantoms and in human brain with nominal flip angles (FA) between 20° and 90° of the two STEAM preparation pulses. B1+ was decreasing at actual FAs above 50°; noise became apparent at actual FAs below 20° reducing dynamic range. By varying the preparation FA, this reliable range (20°<FA<50°) is shifted over a B1+ range from 20% to 250%. The FA map is constructed from overlapping B1+ maps after thresholding.

AB - DREAM is an ultra-fast multi-slice B1+-mapping technique based on the single-shot STEAM sequence. To study noise and bias related to slice-profiles, DREAM B1+-maps at 3.75 mm resolution were acquired at 7T in phantoms and in human brain with nominal flip angles (FA) between 20° and 90° of the two STEAM preparation pulses. B1+ was decreasing at actual FAs above 50°; noise became apparent at actual FAs below 20° reducing dynamic range. By varying the preparation FA, this reliable range (20°<FA<50°) is shifted over a B1+ range from 20% to 250%. The FA map is constructed from overlapping B1+ maps after thresholding.

M3 - Paper in conference proceeding

VL - 27

T3 - Proc Intl Soc Magn Reson Med

BT - Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

PB - International Society for Magnetic Resonance in Medicine

CY - Berkeley

T2 - ISMRM 27th Annual Meeting and Exhibition

Y2 - 11 May 2019 through 16 May 2019

ER -

Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

Abstract

Publication series

Conference

Subject classification (UKÄ)

Access to Document

Other files and links

Fingerprint

Gradient echo-based quantitative MRI of human brain at 7T: Mapping of T1, MT saturation and local flip angle

Combine_DREAM

Multiparametric mapping of the brain at 7T using gradient echoes

Lund University Bioimaging Center

Cite this

Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T

Abstract

Publication series

Conference

Subject classification (UKÄ)

Access to Document

Other files and links

Fingerprint

Research output

Gradient echo-based quantitative MRI of human brain at 7T: Mapping of T1, MT saturation and local flip angle

Combine_DREAM

Projects

Multiparametric mapping of the brain at 7T using gradient echoes

Equipment

Lund University Bioimaging Center

Cite this