Image capturing apparatus and method
To acquire a higher-quality image with high-speed imaging in an MRI apparatus or the like to which compressed sensing is applied. Included are: an observation unit that does not observe, when any one of two points being point-symmetric with respect to the origin is observed, the other point in observation of a high frequency component of a K-space of the MRI apparatus; and a reconstruction unit that reconstructs an image from a component of the K-space observed by the observation unit. The reconstruction process of the reconstruction unit includes an image correction process based on an observation pattern of the observation unit.
1. An image capturing apparatus that images an image of a subject, the image capturing apparatus comprising:
a magnetic resonance apparatus which performs sparse observation of the subject to collect data from the subject based on an observation pattern and outputs observation data; and
an image processor which reconstructs an image from the observation data received from the magnetic resonance apparatus and iteratively performs an image correction process using a filter based on the observation pattern with respect to the observation data,
wherein the image capturing apparatus is a magnetic resonance imaging apparatus, and the observation data is K-space data,
the observation pattern of the magnetic resonance apparatus is a radial form on which observations are performed at angular directions that do not overlap each other even when being rotated by 180 degrees, and
the image correction process of the image processor includes a smoothing process in which the observation pattern is smoothed by a Gaussian filter to form a smoothed observation pattern which is used as the filter in a next iteration of the image correction process.
2. The image capturing apparatus according to claim 1 , wherein
a result corrected by the image correction process is used in an estimation updating process thereof.
3. The image capturing apparatus according to claim 1 , wherein
when any one of two points which are point-symmetric with respect to an origin of the K-space is observed in a high frequency component of the K-space,
the magnetic resonance apparatus does not perform observation for the other point.
4. The image capturing apparatus according to claim 1 , wherein
a plurality of image correction processes are performed by the image processor.
5. An image capturing apparatus that images an image of a subject, the image capturing apparatus comprising:
a magnetic resonance apparatus which performs sparse observation of the subject to collect data from the subject based on an observation pattern and outputs observation data of a K-space; and
an image processor which reconstructs an image from the observation data from the magnetic resonance apparatus and iteratively performs an image correction process using a filter based on the observation pattern with respect to the observation data,
wherein the magnetic resonance apparatus does not perform the sparse observation, when any one between two points which are point-symmetric with respect to an origin of the K-space is observed in a high frequency component of the K-space, for the other point,
the observation pattern of the magnetic resonance apparatus is a radial form on which observations are performed at angular directions that do not overlap each other even when being rotated by 180 degrees, and
the image correction process of the image processor includes a smoothing process in which the observation pattern is smoothed by a Gaussian filter to form a smoothed observation pattern which is used as the filter in a next iteration of the image correction process.
6. The image capturing apparatus according to claim 5 , wherein
the image processor performs an image correction process based on the observation pattern with respect to the observation data of the K-space.
7. The image capturing apparatus according to claim 6 , wherein
the image correction process performed by the image processor is repeated a plurality of times.
8. An image capturing method that images an image of a subject, the image capturing method comprising:
acquiring observation data of the subject based on an observation pattern to perform sparse observation; and
iteratively performing an image correction process using a filter based on the observation pattern with respect to the observation data when an image is reconstructed from the observation data,
wherein the observation data is data of a K-space which is acquired by an observation unit of an MM apparatus,
the observation pattern is a radial form on which observations are performed at angular directions that do not overlap each other even when being rotated by 180 degrees, and
the image correction process of the reconstruction unit includes a smoothing process in which the observation pattern is smoothed by a Gaussian filter to form a smoothed observation pattern which is used as the filter in a next iteration of the image correction process.
9. The image capturing method according to 8 , wherein
when any one of two points which are point-symmetric with respect to an origin of the K-space is observed in observation of a high frequency component of the K-space, observation for the other point is not performed.