sar_ratios

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sar_ratios#

pulserver.ir.sar_ratios()[source]#

Return the SAR ratios of each file of a chain against the reference pulse.

The reference pulse is hard, 180 degrees and 1 ms, played in the default shim of limits; a pulse played in an RF shim is weighed through it. A repetition is a window pypulseqpp.safety.check_sar averages over: each repetition the block definitions repeat with, and the blocks before the first and after the last.

Parameters:

  • seq_path – The first file of the chain.

  • system – The rasters and RF dead times the reference pulse is made with.

  • limits – The VOPs, the head and local SAR limits, the channel drive, the default shim and, when given, the transmit configuration the VOP file must name.

  • designed – The chain as pulserver.mrd.designed_chain() returns it, weighed in place of reading the files.

Returns:

One per file, in play order.

Return type:

list of SarRatio

Raises:

ValueError – If limits carries no VOPs or not both SAR limits, the VOPs carry no global SAR matrices, the VOP file names another transmit configuration than limits.vop_coil, a file of the chain cannot be read, or a pulse or shim weighs another number of channels than the VOPs.

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