Computerized tomography image correction

An apparatus, comprising:

• a medical probe configured to be inserted into a body cavity;
• a location sensor in the medical probe operating in a sensor coordinate system;
• and
• a processor configured:
• to receive, from an imaging system operating in an image coordinate system, a three-dimensional image of the body cavity comprising open space and body tissue;
• to receive, from the medical probe, a signal indicating a location of a distal tip of the medical probe;
• to register the image coordinate system with the sensor coordinate system so as to identify one or more voxels in the three-dimensional image at the indicated location;
• and
• when the identified voxels have density values in the received three-dimensional image that do not correspond to the open space, to update the density values of the identified voxels to correspond to the open space.

A computer software product, operated in conjunction with a probe that is configured for insertion into a body cavity of a patient and includes a location sensor operating in a sensor coordinate system, the product comprising a non-transitory computer-readable medium, in which program instructions are stored, which instructions, when read by a computer, cause the computer:

• to receive, from an imaging system operating in an image coordinate system, a three-dimensional image of the body cavity comprising open space and body tissue;
• to receive, from the medical probe, a signal indicating a location of a distal tip of the medical probe;
• to register the image coordinate system with the sensor coordinate system so as to identify one or more voxels in the three-dimensional image at the indicated location;
• and
• when the identified voxels have density values in the received three-dimensional image that do not correspond to the open space, to update the density values of the identified voxels to correspond to the open space.