Report No xxxx - Instytut Fizyki JÄ drowej PAN

SEQUENCE PROGRAMMING ON BRUKER MRI SYSTEMS
Franciszek Hennel
Bruker BioSpin MRI, D-76275 Ettlingen, Germany
Bruker BioSpin MRI is a producer of MRI/MRS systems for clinical and biomedical
research. The two main products – BioSpec ® and PharmaScan ® – based on the Bruker
Avance ® spectrometer and ultra-shielded 4.7T, 7T and 9.4T horizontal magnets are controlled
by the ParaVision ® software package running on a LINUX PC. In addition to the acquisition
control, image/spectra reconstruction and processing components this software package
contains an environment for the development of new experimental methods, which will be the
topic of this presentation.
The main feature of the ParaVision development environment is the organization of the
experiment control at two levels. At the base level, the direct control of the pulse sequence is
taken by a pulse program: a text file written in a very simple and intuitive language. The pulse
program consists of a sequence of events such as RF pulses, delays, gradient pulses, etc. and
of flow control commands (loops, conditional statements, etc.). A graphic tool is provided to
visualize the sequence. Programming at this level is very rapid but requires some NMR skills.
It is extremely useful for experts in the development phase, but not very practical for routine
applications.
The development of routine applications in ParaVision is allowed by the programming
of "methods". Methods are independent pieces of software containing definitions of high-level
parameters, which have no direct representation in the pulse program, but allow an intuitive
description of the experiment. These are, e.g., geometry parameters like field-of-view, or
contrast parameters like "diffusion b-value". The internal code of the method calculates the
base level parameters needed by the pulse program from the high level parameters taken from
the experiment protocol. Methods are programmed in c-language.
A particularly interesting feature of method programming is the possibility of using
modules. Modules are elements of pulse program which can be re-used for several
applications. Each module comes with a group of high-level parameters which can be added to
the method's protocol and with a group handling mechanism allowing an easy connection with
the method's code. Elements as complex as the echo-planar acquisition, or multi-directional
diffusion weighting, defined in ParaVision as modules, can be included in user's projects by a
couple of lines of code.
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