SVS_B1cal – Transmit Reference voltage calibration for Siemens MRI


SVS_B1cal is designed to perform rapid determination of the correct Transmit Reference Voltage on a Siemens MRI scanner. The program reads several Single Voxel Spectroscopy (SVS) Dicom data files, acquired from a user-specified ROI with varying transmit reference voltages. The program fits the spectroscopy signal amplitudes to a sin^3() curve to determine the optimal reference voltage. The program is written in Matlab.


Use of SVS_B1cal proceeds as follows:

  • Specify an ROI in the sample or subject for an SVS acquisition with either the Siemens svs_st or svs_se sequences
  • If acquiring 1H MRS, turn off water suppression
  • Acquire at least 3 SVS spectra with different Transmit Reference voltages as specified on the System tab
  • Export the Dicom data files from the SVS acquisitions to somewhere on the computer file system
  • Run the svs_b1cal program in Matlab, and select the Dicom data files when prompted by the file select GUI
  • The curve-fitted data will be plotted with the calibrated Transmit Reference voltage value displayed
  • Works directly off Siemens SVS Dicom data files.
  • Reads the transmit reference voltages used in the SVS acquisitions from the Siemens Private headers.
  • Works for both proton (1H) and non-proton (multi-nuc) SVS data
  • MATLAB 7.5 (or newer).
  • SVS_B1cal requires the SPM8 program to read the Siemens Dicoms Private header.
  • SPM can be obtained from the Wellcome Trust Centre for Neuroimaging at )
Installation Instructions
  • Download the .zip file (see Downloading section below).
  • Unzip the files and add them to your Matlab Path.
  • Be sure that you have SPM8 installed and in your Matlab path.
  • Run Matlab and type svs_b1calat the prompt.

The SVS_B1cal program is available here in a .zip bundle: Download SVS_B1cal

The SVS_B1cal program is available here in a .zip bundle: 


For comments or questions on the SVS_B1cal program, send e-mail to:

Mark Elliott at