High-resolution 7T MRI of the human hippocampus in vivo.
OBJECTIVE
To describe an initial experience imaging the human hippocampus in vivo using a 7T magnetic resonance (MR) scanner and a protocol developed for very high field neuroimaging.


METHODS
Six normal subjects were scanned on a 7T whole body MR scanner equipped with a 16-channel head coil. Sequences included a full field of view T1-weighted 3D turbo field echo (T1W 3D TFE: time of acquisition (TA)=08:58), T2*-weighted 2D fast field echo (T2*W 2D FFE: TA=05:20), and susceptibility-weighted imaging (SWI: TA=04:20). SWI data were postprocessed using a minimum intensity projection (minIP) algorithm. Total imaging time was 23 minutes.


RESULTS
T1W 3D TFE images with 700 microm isotropic voxels provided excellent anatomic depiction of macroscopic hippocampal structures. T2*W 2D FFE images with 0.5 mm in-plane resolution and 2.5 mm slice thickness provided clear discrimination of the Cornu Ammonis and the compilation of adjacent sublayers of the hippocampus. SWI images (0.5 mm in-plane resolution, 1.0 mm slice thickness) delineated microvenous anatomy of the hippocampus.


CONCLUSIONS
In vivo 7T MR imaging can take advantage of higher signal-to-noise and novel contrast mechanisms to provide increased conspicuity of hippocampal anatomy.
Thomas
Bradley P
BP
Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, Tennessee 37232-2675, USA. bradley.thomas@vanderbilt.edu
Welch
E Brian
EB
Niederhauser
Blake D
BD
Whetsell
William O
WO
Anderson
Adam W
AW
Gore
John C
JC
Avison
Malcolm J
MJ
Creasy
Jeffrey L
JL
D000328:Adult; D000465:Algorithms; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity