Processing of abdominal images
View Patent ↗According to one embodiment there is provided a computer-automated image processing method applied to a four-dimensional (4D) image data set of a patient's abdomen, e.g. by dynamic contrast enhanced computer-assisted tomography (DCE-CT). One of the three-dimensional (3D) scan images is taken to as the reference volume and the others as target volumes. Before registration between the 3D scan images, the image data set is partitioned into an abdominal cavity domain, containing the organs inside the abdominal wall, and an abdominal wall domain including the abdominal wall and externally adjacent skeletal features, such as the spine and ribs. Registration is then carried out separately on the two domains to obtain two warp fields which are then merged into a 4D image data set of the whole volume for further use, which may be to carry out perfusion measurements, to display and to store the registered 4D image data set.
1. A computer-automated image processing method, comprising:
accessing a 4D image data set comprising a plurality of 3D image data sets of a volume taken in time sequence, wherein the volume includes at least part of the abdomen of a living subject;
selecting one of the 3D image data sets to serve as a reference volume 3D image data set;
partitioning the reference volume 3D image data set into an abdominal cavity domain inside the abdominal wall and an abdominal wall domain including the abdominal wall and externally adjacent anatomical features;
registering each of the 3D image data sets to the abdominal cavity domain of the reference volume 3D image data set to obtain a first warp field defined over the abdominal cavity domain without including a portion of the reference volume 3D image data set within the abdominal wall domain;
registering each of the 3D image data sets to the abdominal wall domain of the reference volume 3D image data set to obtain a second warp field defined over the abdominal wall domain without including a portion of the reference volume 3D image data set within the abdominal cavity domain;
for each of the 3D image data sets, merging the first and second warp fields into a single consistent merged warp field defined over the whole volume; and
using each of the merged warp fields to bring the corresponding 3D image data set into registration with the reference volume 3D image data set.
2. The method of claim 1 , wherein each of the first and second registrations comprises a rigid registration.
3. The method of claim 2 , wherein the first registration further comprises a non-rigid registration after the rigid registration.
4. The method of claim 2 , wherein a non-rigid registration is applied to the merged warp fields.
5. The method of claim 1 , wherein the 4D image data set represents a study in which a contrast agent has been introduced to the subject, which is manifested by some, but not all, of the 3D image data sets having voxels affected by the contrast agent, and wherein the reference volume 3D image data set is selected to be a 3D image data set whose voxels are free of effects of the contrast agent.
6. The method of claim 5 , wherein the study is a perfusion study of an abdominal organ contained in the abdominal cavity domain.
7. The method of claim 1 , further comprising:
volume rendering the processed 4D image data set into a sequence of 2D image data sets; and
displaying the 2D image data sets in sequence to a user.
8. A non-transitory computer-readable medium storing machine readable instructions for carrying out the method of claim 1 .
9. A computer loaded with and operable to execute machine readable instructions for carrying out the method of claim 1 .