Number of receiver channels from ismrmrd_header and kspace data size

#1

Hello all,

I followed Jupyter notebook for reading fastmri dataset. I read file1000010.h5 from knee_singlecoil_train dataset. The ismrmrd_header within dataset shows the number of receiver channels as 15.
But the size of kspace data is (36, 640, 368) ie. (number of slices, height, width). So is it a single channel or multi channel data?
If multi channel, how can i get data from individual channels?

Thanks.

#2

Hello, although the data is compressed to a single channel, the headers are unaltered from the original multicoil data, which in this case had 15 channels.

For getting data from individual channels from multicoil data, just apply

hf = h5py.File(‘file1000010.h5’)
kdata = hf[‘kspace’][()][:, 0]

This will return a (36, 640, 368) array of k-space data from the first coil. If you want the second coil, replace 0 with 1.

#3

Thank you for the reply.