Module `ukat.utils.siemens`

Functions

def write_dvs(scheme, filepath, normalization='none', coordinate_system='xyz', comment='N/A')

Create Siemens .dvs file for diffusion imaging acquisitions

Parameters

scheme : string

Scheme can be two types of strings: 1) File path to a text file containing a gradient scheme (see below) 2) A gradient scheme string (see below)

The following is an example of a dummy gradient scheme initialised in the SCHEME varible: >> print(SCHEME) 0.70710678 0.0 0.70710678 0 0.70710678 0.0 0.70710678 5 0.70710678 0.0 0.70710678 100 0.70710678 0.0 0.70710678 500 -0.70710678 0.70710678 0.0 5 -0.70710678 0.70710678 0.0 100 -0.70710678 0.70710678 0.0 500

Where each row corresponds to one measurement, the first 3 columns are the b-vector components (b-vector with norm 1) and the 4th column is the b-value in s/mm2. This example shows an acquisition with 3 nonzero b-values (5, 100, 500), each with two directions, and one b=0 in the start of the acquisition. Such a gradient scheme string can be generated using ukat.dwi.make_gradient_scheme().

filepath : string

The filepath (without extension) for the .dvs file which will be generated by this function

Returns

string: filepath of generated file, including extension
string: content of generated file

Notes

The specification for Siemens .dvs files implemented here is described in the Siemens syngo MR E11 Operator Manual page 140. It may not work for other software lines (e.g. VX*). Note that the validity in the formatting of the scheme string is not checked so ensure you have generated it properly as shown above.