Determining calcium content from spectral ct data

An image data processing device for determining a calcium content by analyzing cardiac spectral CT data, the image data processing device comprising:

• a data input for receiving spectral CT projection data obtained by scanning a cardiac region of a subject using a spectral CT scanning unit;
• a modelling unit for applying a material decomposition algorithm to said spectral CT projection data such as to provide a calcium-specific component of said spectral CT projection data;
• a tomographic reconstruction unit for reconstructing said spectral CT projection data such as to provide a first 3D image of said cardiac region and for reconstructing said calcium-specific component of the spectral CT projection data such as to provide a second 3D image representative of calcium content in said cardiac region;
• a segmentation unit for segmenting said first 3D image such as to provide an image mask corresponding to a cardiovascular structure of interest in said cardiac region;
• a selection unit for selecting a part of said second 3D image based on said image mask;
• and
• a computation unit for calculating a calcium content in said cardiovascular structure of interest based on said selected part of the second 3D image.