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

Helms, Gunther LU ; Olsson, Hampus LU and Andersen, Mads LU (2019) ISMRM 27th Annual Meeting and Exhibition In Proc Intl Soc Magn Reson Med 27.
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.
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T
series title
Proc Intl Soc Magn Reson Med
volume
27
article number
4500
pages
3 pages
publisher
International Society for Magnetic Resonance in Medicine
conference name
ISMRM 27th Annual Meeting and Exhibition
conference location
Montreal, Canada
conference dates
2019-05-11 - 2019-05-16
ISSN
1545-4428
project
Multiparametric mapping of the brain at 7T using gradient echoes
language
English
LU publication?
yes
id
27c979e8-a052-4f24-a857-41f5084b28e9
alternative location
https://index.mirasmart.com/ISMRM2019/PDFfiles/4500.html
date added to LUP
2019-04-02 12:15:40
date last changed
2020-08-17 14:49:00
@inproceedings{27c979e8-a052-4f24-a857-41f5084b28e9,
  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°&lt;FA&lt;50°) is shifted over a B1+ range from 20% to 250%. The FA map is constructed from overlapping B1+ maps after thresholding.     },
  author       = {Helms, Gunther and Olsson, Hampus and Andersen, Mads},
  booktitle    = {Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T},
  issn         = {1545-4428},
  language     = {eng},
  month        = {04},
  publisher    = {International Society for Magnetic Resonance in Medicine},
  series       = {Proc Intl Soc Magn Reson Med},
  title        = {Removing bias and increasing dynamic range in DREAM flip angle mapping at 7T},
  url          = {https://index.mirasmart.com/ISMRM2019/PDFfiles/4500.html},
  volume       = {27},
  year         = {2019},
}