Ecat

A proprietary image format for older CTI PET scanners. We offer native read & write support for ECAT 6 format. For ECAT 7 files we use a stripped external library from Turku PET Centre.

scaling factors / quantitation:

Each image in the file has two scaling factors depending on which units you prefer for your pixel values. Therefore (X)MedCon knows about two kinds of quantitations:

Most other formats only have a global or no scaling factor at all (so option [-qc] will guarantee the use of any scaling factor)

patient/slice orientations:

The format does not specify any patient/slice orientation. Which means that supine-headfirst-transverse will be considered as the default orientation.

extra notes:

- Because there is no signature, the ECAT_SYSTEM_TYPE number is used to autodetect the following ECAT6.4 like systems: 831, 911, 931, 933, 951, 953. See the MdcCheckECAT6() function in the m-ecat64.c source file. It is possible to use ECAT 6 as the fallback read format (see -fb-ecat option).

- Images are no longer restricted to square dimensions. This can be re-enabled in the file m-ecat64.c by setting:

- The planes sorting is now default set to anatomical (based on slice location). You can sort by frame using the option -byframe but beware that this is not an anatomically correct volume anymore.

- These files do not compress well with gzip or compress.

- Unreconstructed or gated studies haven't really been tested with (X)MedCon ... feel free to do so.