MRQuantif: MRI protocols

We propose to acquire a single gradient echo sequence with 8-10 echoes, alternating in phase and opposed-phase echoes. Only body antenna should be selected. Indeed, the use of a multi-element antenna does not allow to quantify the overload of hepatic iron by the SIR method analyzing the liver to muscle ratio. However, this method is necessary to quantify the high iron overload at 1.5T, but even also moderate overloads at 3T. Acquisition protocols are proposed for the main MRI devices.

Main MRI parameters

Coil Body (autoselection off)
Sequence GRE
Options No fat saturation
TR (msec) 120 (to reduce T1 contrast)
TE (msec) multiple of 1.2
FA (°) 20 (to reduce T1 contrast)
Bandwith Adapt it to get the correct TEs
N excitations 1
Plane Axial
N slices Max allowed (could depend on the number of TEs ...)
Thickness 7 or 8 mm 
Gap Could be large (10mm) if you have a small number of slice
Matrix  Asymetric to reduce acquisition time, ex: 128x116
Phase  Anterior-Posterior
FOV (cm) 40
Aq. time (sec) about 15 

Specific MRI parameters depending to MR devices

To help you set up the sequence in your own MRI scanner you can find below a zip file containing the acquisition parameters in various formats (including EDX for Siemens or ExamCard for Philips) and an example of images obtained with the protocol. For GE MRI scanners, you can set the sequence by importing in your system a DICOM image provided on this site.

To acquire a sequence with more than two echoes you need the STARMAP option. Otherwise you can do single-echo sequences without changing the prepscan between sequences. To import the settings you can:
  • either transfer the DICOM images present in the zip to the IRM device database via an ADW and then use the ProtoCopy function on the system,
  • either import the protocol (.tar file) via the ProtocolExchange function.
If you do not know how to use the ProtocolExchange or ProtoCopy import / export function, ask your application engineer.
  • Optima MR 450 1.5T en version VD25 : download the zip file which contains 3 folders :
    • one with the classic STARMAP sequence, recommended, with multiple TEs of 1.2 ms,
    • one with a STARMAP sequence with shorter TE, multiple of 0.9 ms) if you are exploring patients with high overload,
    • and a folder for those who do not have the STARMAP option with multiple mono echo sequences to acquire in order. The name of the series must contain GRE_Quantif followed by a space and the TE (1.2 ou 2.4 ou 3.6 ou 4.8 ou 7.2 ou 9.6 ou 12 ou 14.4), example: Ax GRE_Quantif 1.2 .... The version of MRQuantif after the 20 January 2018 merges series with this name to create the equivalent of a multi-echo sequence. In order not to modify the signal level between the sequences, you have to choose manual prepscan and not change anything, then validate or cancel, it's the same if you have not touched anything
  • Discovery MR 750 3T: download the zip file.

You can  get a gradient echo sequence with several echoes without option (in the last release of Philips MR systems).

You can  get a gradient echo sequence with several echoes without option.
If any trouble download all the edx files in a zip.
If you don't know how to import an EDX there is here a tutorial but in french (sorry).
If you have improved or created an EDX please send it to me by email.