Multi modality imaging methods and apparatus

An imaging apparatus comprising:

• a Computed Tomography (CT) system comprising an x-ray source and a detector responsive to x-rays positioned to receive x-rays emitted from said source;
• a Positron Emission Tomography (PET) system comprising a detector responsive to a gamma ray;
• and
• a computer operationally coupled to said CT system and said PET system, said computer configured to:
• receive data from a CT scan of an object, the data including fully sampled field of view data and partially sampled field of view data;
• augment the received partially sampled field of view data using the fully sampled field of view data;
• receive data from a PET scan of the object;
• and
• reconstruct an image of the object using the received PET data and the augmented partially sampled field of view data.

A method for use with first and second image data sets corresponding to first and second fields of view (FOV), respectively, the first data set including a plurality of projection views that each include first through last attenuation measurements corresponding to first through last parallel trajectories through the first FOV, respectively, the first FOV smaller than and included within the second FOV such that only area common to the first and second FOVs is traversed by each of the projection views and area within the second FOV and outside the first FOV is traversed by only a sub-set of the projection views, the method comprising the steps of:

• using the attenuation measurements from at least one projection view to augment the attenuation measurements from at least one other projection view to add attenuation measurements to the at least one other projection view corresponding to trajectories that traverse at least a portion of the second FOV;
• using the augmented projection views to compensate the second data set for attenuation;
• and
• combining the compensated second data set to construct an image.

A method for use with a structural data set and a functional data set indicating structural and functional characteristics of an imaged object, the structural and functional sets corresponding to first and second fields of view (FOV), respectively, the structural data set including a plurality of projection views that each include first through last attenuation measurements corresponding to first through last parallel trajectories through the first FOV, respectively, the first FOV smaller than and included within the second FOV such that only area common to the first and second FOVs is traversed by each of the projection views and area within the second FOV and outside the first FOV is traversed by only a sub-set of the projection views, the method comprising the steps of:

• for each projection view, summing up all of the attenuation measurements to generate a view attenuation measurement;
• identifying the maximum view attenuation measurement;
• and
• for each of at least a sub-set of the view attenuation measurements that is less than the maximum attenuation measurement, augmenting the associated projection view to generate an augmented attenuation view such that the sum of all of the attenuation measurements of the augmented view is substantially similar to the maximum attenuation measurement;
• using the augmented projection views and the un-augmented projection views to compensate the second data set for attenuation;
• and
• combining the compensated second data set to construct an image.

A method for use with first and second detectors arranged to collect first and second data sets from a plurality of projection angles about first and second fields of view (FOVs), respectively, the data at each projection angle including a projection view, the second FOV larger than and including the first FOV such that each first set projection view only traverses a portion of the second FOV, the method for generating an image of an object that resides within the second FOV and comprising the steps of:

• collecting the first and second data sets;
• identifying at least one first set projection view that likely encompasses the entire object as a complete projection view;
• where the object extends outside the first FOV:
• identifying first set projection views that the object extends out of as truncated projection views;
• using the complete projection view data to augment the data of each truncated projection view thereby generating an augmented first set;
• combining the augmented first set and the second set to generate a compensated second set;
• and
• combining the compensated second set to generate an image.

An imaging apparatus for use with a structural data set and a functional data set indicating structural and functional characteristics of an imaged object, the structural and functional sets corresponding to first and second fields of view (FOV), respectively, the structural data set including a plurality of projection views that each include first through last attenuation measurements corresponding to first through last parallel trajectories through the first FOV, respectively, the first FOV smaller than and included within the second FOV such that only area common to the first and second FOVs is traversed by each of the projection views and area within the second FOV and outside the first FOV is traversed by only a sub-set of the projection views, the apparatus comprising:

• a computer configured to:
• for each projection view, sum up all of the attenuation measurements to generate a view attenuation measurement;
• identify the maximum view attenuation measurement;
• and
• for each of at least a sub-set of the view attenuation measurements that is less than the maximum attenuation measurement, augment the associated projection view to generate an augmented attenuation view such that the sum of all of the attenuation measurements of the augmented view is substantially similar to the maximum attenuation measurement;
• use the augmented projection views and the un-augmented projection views to compensate the second data set for attenuation;
• and
• combine the compensated second data set to construct an image.