There are no hard-and-fast numbers. The data do look noisy, and there might be some artifacts (vertical lines) in the data. But the surface placement looks decent in the images that you show.

On 10/27/2020 6:51 PM, 南修司郎 wrote:

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Dear expert

We are planning multi-center study with the hearing impaired patients using FreeSurfer. The signal-to-noise ratio (SNR) of the test MRI from a center does not look very good, but the FreeSurfer can analyze the gray matter. How much the allowable SNR for FreeSurfer analysis?

This is the MRI protocol and the test image.

Thank you in advance.

Shujiro

test image.png

Siemens MAGNETOM Altea 1.5T

Voxel size 1.0X1.0X1.0mm3 Geometry 　 FOV 256mm(256X256 matrix) Slice 176 Orientation sagittal Slice thickness 1mm Phase Encoding Dir A→P Timing 　 TR 2730 TI 1100 TE 1.64/3.59/5.36/7.31 bandwidth 651 RF 　 Magn.Preparation Non-sel.IR FA 7° Acceleration GRAPPA 　 Acceleration Factor PE 2 Reference Line PE 32

Slice Partial fourier 6/8

ScanTime 6:08

Shujiro Minami M.D., Ph.D. Dpt. of Otolaryngology National Tokyo Medical Center 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan E-mail shujirominami@me.com mailto:shujirominami@me.com

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