CT surrogate by auto-segmentation of magnetic resonance images

A method of providing electron density information for voxels in a magnetic resonance imaging (MRI) image, including:

• generating generic co-registered computed tomography (CT) and MRI reference images from a plurality of respective CT and MRI images of a region of interest;
• receiving a patient MRI image;
• registering the patient MRI image and the reference MRI image;
• retrieving electron density information from corresponding segments of the co-registered CT image for the registered patient MRI image;
• associating the retrieved electron density information with the registered patient MRI image;
• and
• employing a registered patient MRI image, including the electron density data, to correct for attenuation during at least one of a positron emission tomography (PET) data acquisition and single photon emission computed tomography (SPECT) data acquisition.

A processor configured to:

• generate generic co-registered computed tomography (CT) and MRI reference images from a plurality of respective CT and MRI images of a region of interest;
• receive a patient MRI image;
• register the patient MRI image and the reference MRI image;
• retrieve electron density information from corresponding segments of the co-registered CT image for the registered patient MRI image;
• and
• associate the retrieved electron density information with the registered patient MRI image.

A system including:

• a non-transitory computer-readable medium that stores an atlas of co-registered computed tomography (CT) and magnetic resonance imaging (MRI) reference images of anatomical structures, the atlas including:
• a plurality of CT and MRI reference images of anatomical structures, generated from scanned images of anatomical structures of one or more subjects, wherein the reference images are co-registered to associate electron density information from voxels in the CT reference images to corresponding voxels in respective MRI reference images;
• wherein the non-transitory machine-readable medium stores the plurality of co-registered CT and MRI reference images for recall and manipulation by an operator;
• and
• a display on which is presented to a user a patient MRI image and at least one of the co-registered MRI reference image;
• wherein the co-registered MRI reference images comprise electron density data from corresponding CT images that is employed to correct for attenuation during at least one of a positron emission tomography (PET) data acquisition and single photon emission computed tomography (SPECT) data acquisition.