Photon counting type X-ray computed tomography apparatus and data transfer method for the same
View Patent ↗A photon counting type X-ray computed tomography apparatus includes an X-ray tube, a detector, a raw data generating section, an information compression section, and a data transmission section. The X-ray tube is configured to irradiate an X-ray. The detector is configured to count photons derived from the irradiated X-ray. The raw data generating section is configured to collect results of counting performed by the detector and to generate, from the results of counting, raw data for each of a plurality of energy bands. The information compression section is configured to compare values of the raw data between the raw data generated respectively for the energy bands, and to perform information compression of each of the raw data. The data transmission section is configured to transmit the raw data compressed by the information compression.
1. A photon counting type X-ray computed tomography apparatus comprising:
an X-ray tube configured to irradiate an X-ray;
a detector configured to count photons derived from the irradiated X-ray;
a raw data generating section configured to collect results of counting performed by the detector and to generate, from the results of counting, raw data for each of a plurality of energy bands;
an information compression section including a difference calculation processing section that is configured to
select, for each energy range of energy ranges, one of the plurality of energy bands belonging to the corresponding each energy range as a reference energy band, the energy ranges being divided into the each energy range at an energy where a change amount of count value exceeds a threshold,
set raw data of the reference energy band for the each energy range as reference data for the each energy range, and
perform, for the each energy range, information compression of multiple pieces of raw data for energy bands other than the reference energy band by obtaining corresponding multiple pieces of difference data, each piece of difference data being difference between raw data of respective two adjacent energy bands belonging to the corresponding each energy range; and
a data transmission section configured to transmit the multiple pieces of difference data and the reference data as raw data compressed by the information compression.
2. The photon counting type X-ray computed tomography apparatus according to claim 1 , wherein
on the basis of the generated raw data, the difference calculation processing section is further configured to change the energy bands so as to increase the width of the energy bands in energy regions having a small change in the value of the raw data, and on the other hand, reduce the width of the energy bands in energy regions having a large change in the value of the raw data.
3. The photon counting type X-ray computed tomography apparatus according to claim 1 , wherein
the raw data generating section is further configured to generate raw data of the plurality of energy bands according to an energy threshold value.
4. The photon counting type X-ray computed tomography apparatus according to claim 1 , further comprising
a raw data regeneration section configured to receive the transmitted raw data compressed by the information compression and to regenerate raw data of each of the plurality of energy bands on the basis of the received raw data compressed by the information compression.
5. The photon counting type X-ray computed tomography apparatus according to claim 4 , further comprising
a memory section configured to store data associated with the received raw data compressed by the information compression.
6. The photon counting type X-ray computed tomography apparatus according to claim 1 , wherein on the basis of the generated raw data, the difference calculation processing section is further configured to change the energy bands on the basis of the characteristics represented by the count values.
7. The photon counting type X-ray computed tomography apparatus according to claim 1 , wherein on the basis of the generated raw data, the difference calculation processing section is further configured to change the energy bands on the basis of an absorption rate or scattering rate of X-rays.
8. A data transfer method of a photon counting type X-ray computed tomography apparatus including an X-ray tube configured to irradiate an X-ray, and a detector configured to count photons derived from the irradiated X-ray, the data transfer method comprising:
a raw data generation step of collecting results of counting performed by the detector and generating, from the results of counting, raw data for each of a plurality of energy bands;
an information compression step including steps of
selecting for each energy range of energy ranges, one of the plurality of energy bands belonging to the corresponding each energy range as a reference energy band, the energy ranges being divided into the each energy range at an energy where a change amount of count value exceeds a threshold,
setting a raw data of the reference energy band for the each energy range as reference data for the each energy range, and
performing, for the each energy range, information compression of multiple pieces of raw data for energy bands other than the reference energy band by obtaining corresponding multiple pieces of difference data, each piece of difference data being difference between two pieces of raw data of respective two adjacent energy bands belonging to the corresponding each energy range; and
a data transmission step of transmitting the multiple pieces of difference data and the reference data as raw data compressed by the information compression.