Image Processing Techniques in Emission Tomography - Correction Techniques in Emission Tomography - page 137

7.4.3 Software
To develop new registration approaches it is often useful to build them on
existing registration toolboxes. Technical and time-consuming tasks, such as
implementing a multi-resolution framework, standard distance measures and
loading, saving and plotting of images, can thus be avoided. Regarding stan-
dard registration tasks, it is advisable to use validated and reliable software
tools. Therefore a small and incomplete list of freely (for non-commercial use)
available registration software is given.
The ITK (Insight Toolkit, http://www.itk.org/ ) is a registration and
segmentation framework written in C++. ITK is a suitable tool to implement
new approaches or to use existing tools from the comprehensive collection.
A registration toolbox based on ITK was recently published and is called
elastix [34].
FAIR (Flexible Algorithms for Image Registration, http://www.cas.
mcmaster.ca/ ~ modersit/FAIR/ ) is a MATLAB r toolbox with an accom-
panying topic [43]. Detailed examples are available with the software package.
The basic distance measures and registration techniques already come along
with the package. It is also a good framework to develop techniques.
The FSL (FMRIB Software Library, http://www.fmrib.ox.ac.uk/fsl/ )
software package is mainly developed for aligning MRI brain images. FSL
contains the FLIRT tool for linear registration and the FNIRT tool (only
SSD) for non-linear registration. The registration can be started from the
command line or using a graphical user interface (GUI). FSL is made for
direct use rather than for developing.
AIR (Automated Image Registration, http://bishopw.loni.ucla.edu/
AIR5/ ) can perform intra- and intermodal registration tasks. It has been val-
idated for linear and non-linear PET-PET and PET-MRI registration.
ART (Automatic Registration Toolbox, http://www.nitrc.org/projects/
art ) is made for linear and non-linear registration of brain images. Similar to
FSL it is mainly used for aligning MRI images, but also for MRI-PET/SPECT
registration.
In Table 7.2 the presented software packages are listed with some details
about important features. These features are based on the following questions:
Is the source code available? Which programming language is used? On which
platform does the code run? Is a graphical user interface (GUI) available? Are
examples included in the package?
7.5 Partial volume correction
Besides noise, as covered in Section 7.2, the partial volume effect (PVE)
is a source of image degradation in medical imaging in general. The causes of