Jan Sedlacik1,2, Raphael Tomi-Tricot1,3, Pip Bridgen1,2, Tom Wilkinson1,2, Sharon Giles1,2, Karin Shmueli4, Jo V Hajnal1,2, and Shaihan J Malik1,2
1Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King’s College London, London, United Kingdom, 2Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King’s College London, London, United Kingdom, 3MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom, 4MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
1Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King’s College London, London, United Kingdom, 2Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King’s College London, London, United Kingdom, 3MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom, 4MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
Optimal scanning parameters were found and tested for quantitative
susceptibility mapping
at
7T aiming to most efficiently assess the white matter microstructure. The optimum was found for gradient echo imaging without RF spoiling, TR=29ms,
longest TE=26ms and FA=15.5°.
Figure 2:
Maps of the relative signal changes
(A-B)/B∙100%
between the different scan settings. The colour bar is scaled from -30
to 30%. Temporal and cerebellar regions benefit when increasing FA,
but signal is lost in the central brain region (top). Turning
the RF spoiling
OFF increased
the signal in the overall brain and particularly for the CSF (middle). Increasing the FA for RF spoiling
OFF, however, shows more signal loss in the overall brain (bottom).
Figure 1: WM
signal
magnitude
(A)
for
different TE, TR and FA settings following
equations 1 and 2,
phase
SNR (B),
scanning efficiency (C)
and
the
corresponding FAs
and imposed SAR (D).
