Method for recognizing and marking contrast agents in blood vessels of the lung with the aid of a CT examination and an image evaluation unit of a CT system
First Claim
1. A method for recognizing and marking blood vessels of a lung with the aid of a CT examination using at least two different x-ray energy spectra, the method comprising:
- scanning a patient, at least in a region of the lung, with two different x-ray energy spectra, with the patient having only a single contrast agent administered; and
reconstructing an at least two dimensional tomographic image for each x-ray energy spectrum which reproduces local spectrum-specific absorption properties of the scanned region, whereina surrounding area is defined for a multiplicity of voxels for which an average ratio is calculated with the aid of local absorption values of the at least two x-ray energy spectra, the average ratio representing a measure for a ratio of a proportion of the single contrast agent to a proportion of soft tissue in the surrounding area of the respectively considered voxel, andupon the average ratio dropping below a threshold value, the respectively considered voxel is considered to have reduced blood circulation and is marked in the reconstructing at least two dimensional tomographic image.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and an image evaluation unit are disclosed for recognizing and marking contrast agents in blood vessels of the lung with the aid of a CT examination using at least two different x-ray energy spectra. In at least one embodiment, the method includes scanning a patient at least in the region of the lung with two different x-ray energy spectra, with the patient having contrast agents in the blood stream; reconstructing an at least two or three dimensional tomographic display for each x-ray energy spectrum which reproduces the local spectrum-specific absorption properties of the scanned region, wherein a surrounding area is defined for a multiplicity of voxels for which an average ratio is calculated with the aid of the local absorption values of the at least two x-ray energy spectra, which surrounding area specifies a measure for the ratio of the proportion of contrast agent to the proportion of soft tissue in the surrounding area of the respectively considered voxel, and wherein, in the case of this ratio dropping below a threshold value, this voxel is considered to have reduced circulation and is marked in a tomographic display.
25 Citations
19 Claims
-
1. A method for recognizing and marking blood vessels of a lung with the aid of a CT examination using at least two different x-ray energy spectra, the method comprising:
-
scanning a patient, at least in a region of the lung, with two different x-ray energy spectra, with the patient having only a single contrast agent administered; and reconstructing an at least two dimensional tomographic image for each x-ray energy spectrum which reproduces local spectrum-specific absorption properties of the scanned region, wherein a surrounding area is defined for a multiplicity of voxels for which an average ratio is calculated with the aid of local absorption values of the at least two x-ray energy spectra, the average ratio representing a measure for a ratio of a proportion of the single contrast agent to a proportion of soft tissue in the surrounding area of the respectively considered voxel, and upon the average ratio dropping below a threshold value, the respectively considered voxel is considered to have reduced blood circulation and is marked in the reconstructing at least two dimensional tomographic image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17)
-
-
15. An image evaluation unit for a CT system comprising:
-
a processor; and a program memory, the program memory including a program code where, after a scan of a patient, using the CT system, of at least the region of a lung with two different x-ray energy spectra, with the patient having only a single contrast agent administered, the program code executes the following when the image evaluation unit is operating; reconstructing an at least two dimensional tomographic image for each x-ray energy spectrum which reproduces local spectrum-specific absorption properties of the scanned region; defining a surrounding area for a multiplicity of voxels for which an average ratio is calculated with the aid of local absorption values of the at least two x-ray energy spectra, the average ratio representing a measure for a ratio of a proportion of the single contrast agent to a proportion of soft tissue in the surrounding area of the respectively considered voxel; and displaying a tomographic display of the scanned region, with voxels being considered to have reduced blood circulation and marked as soon as the average ratio drops below a threshold value. - View Dependent Claims (16)
-
-
18. A method for recognizing and marking blood vessels of the lung with the aid of a CT examination using at least two different x-ray energy spectra, the method comprising:
-
scanning a patient, at least in a region of the lung, with two different x-ray energy spectra, with the patient having only a single contrast agent administered; reconstructing an at least two dimensional tomographic image for each x-ray energy spectrum which reproduces local spectrum-specific absorption properties of the scanned region; defining a surrounding area for a multiplicity of voxels for which an average ratio is calculated with the aid of local absorption values of the at least two x-ray energy spectra, average ratio representing a measure for a ratio of a proportion of the single contrast agent to a proportion of soft tissue in the surrounding area of the respectively considered voxel; and displaying a tomographic image of the scanned region, with voxels being considered to have reduced blood circulation and marked as soon as the average ratio drops below a threshold value. - View Dependent Claims (19)
-
Specification