Pixel-based number of energy bin material decomposition for reducing data requirements
A photon-counting imaging system is provided. The system includes a photon-counting detector and processing circuitry. The detector acquires, from an imaging object, projection data for a plurality of projection views. The detector has a plurality of detector pixels that are arranged in both a channel direction and a segment direction on a surface of the detector. The processing circuitry obtains the projection data acquired by the detector. The projection data includes first and second projection data. The processing circuitry processes, with a first energy bin setting, the first projection data, the first energy bin setting having m energy bins, and processes, with a second energy bin setting, the second projection data, the second energy bin setting having n energy bins, where n>m. The processing circuitry generates, based on the processed first projection data and the processed second projection data, a material decomposition image of the imaging object.
1 . A photon-counting imaging system, comprising:
a photon-counting detector configured to acquire, from an imaging object, projection data for a plurality of projection views, the photon-counting detector having a plurality of detector pixels that are arranged in both a channel direction and a segment direction on a surface of the photon-counting detector; and
processing circuitry configured to
obtain the projection data acquired by the photon-counting detector, the projection data including first projection data and second projection data, the first projection data being acquired by detector pixels different from detector pixels that acquired the second projection data,
process, with a first energy bin setting, the first projection data, the first energy bin setting indicating use of m energy bins,
process, with a second energy bin setting, the second projection data, the second energy bin setting indicating use of n energy bins, where n>m, and
generate, based on the processed first projection data and the processed second projection data, a material decomposition image of the imaging object.
2 . The system of claim 1 , wherein
the n energy bins are determined by a set of pre-defined energy thresholds of the photon-counting imaging system, and
the m energy bins are determined by recombining the n energy bins in a pre-defined manner.
3 . The system of claim 1 , wherein the photon-counting detector is further configured to:
acquire the first projection data from detector pixels within a first area of the photon-counting detector, and
acquire the second projection data from detector pixels within a second area of the photon-counting detector different from the first area.
4 . The system of claim 3 , wherein the photon-counting detector is further configured to:
acquire, from the detector pixels within the first area of the photon-counting detector, the first projection data from a first region of the imaging object where required image quality is lower than a predefined threshold, and
acquire, from the detector pixels within the second area of the photon-counting detector, the second projection data from a second region of the imaging object where required image quality is equal to or higher than the predefined threshold.
5 . The system of claim 4 , wherein
the first area of the photon-counting detector corresponds to a peripheral portion of the photon-counting detector in at least one of the channel direction and the segment direction, and
the second area of the photon-counting detector corresponds to a central portion of the photon-counting detector in the at least one of the channel direction and the segment direction.
6 . The system of claim 3 , wherein the first area of the photon-counting detector and the second area of the photon-counting detector are located on the surface of the photon-counting detector side by side in at least one of the channel direction and the segment direction.
7 . The system of claim 3 , wherein a transition zone is arranged around a boundary between the first area and the second area of the photon-counting detector, and
the processing circuitry is further configured to process, with both the first energy bin setting and the second energy bin setting, projection data acquired by detector pixels within the transition zone.
8 . The system of claim 3 , wherein
the first area of the photon-counting detector includes k subareas, detector pixels within each of the k subareas acquiring one of k subsets of the first projection data, and
the processing circuitry is further configured to process, with k energy bin subsettings, the k subsets of the first projection data, respectively, wherein for 1≤i≤k, an i-th energy bin subsetting indicates use of m i energy bins, and m i <n.
9 . The system of claim 8 , wherein
for 1≤j≤k−1, a transition zone is arranged around a boundary between a j-th subarea and a (j+1)-th subarea of the photon-counting detector, and
the processing circuitry is further configured to process, with both a j-th energy bin subsetting and a (j+1)-th energy bin subsetting, projection data acquired by detector pixels within the transition zone between the j-th subarea and the (j+1)-th subarea.
10 . The system of claim 3 , wherein the processing circuitry is further configured to:
process, with a predefined group of p energy bin subsettings, the first projection data, in a channel-based, segment-based, or view-based manner.
11 . The system of claim 10 , wherein the processing circuitry is further configured to:
process, with an x-th energy bin subsetting of the predefined group, projection data acquired by an x-th pixel channel of each p consecutive pixel channels within the first area, where 1≤x≤p.
12 . The system of claim 10 , wherein the processing circuitry is further configured to:
process, with an x-th energy bin subsetting of the predefined group, projection data acquired by an x-th pixel segment of each p consecutive pixel segments within the first area, where 1≤x≤p.
13 . The system of claim 10 , wherein the processing circuitry is further configured to:
process, with an x-th energy bin subsetting of the predefined group, the first projection data acquired for an x-th projection view of each p consecutive projection views, where 1≤x≤p.
14 . The system of claim 1 , wherein the photon-counting detector is further configured to:
acquire the first projection data for a first subset of the plurality of projection views, and
acquire the second projection data for a second subset of the plurality of projection views.
15 . The system of claim 14 , wherein
the first subset of the plurality of projection views includes even-numbered projection views, while the second subset of projection views includes odd-numbered projection views, or
the first subset of the plurality of projection views includes odd-numbered projection views, while the second subset of projection views includes even-numbered projection views.
16 . A method for performing pixel-based energy bin number modulation in a photon-counting imaging system, the photon-counting imaging system including a photon-counting detector that acquires, from an imaging object, projection data for a plurality of projection views, the photon-counting detector having a plurality of detector pixels that are arranged in both a channel direction and a segment direction on a surface of the photon-counting detector, the method comprising:
obtaining the projection data acquired by the photon-counting detector, the projection data including first projection data and second projection data, the first projection data being acquired by detector pixels different from detector pixels that acquired the second projection data;
processing, with a first energy bin setting, the first projection data, the first energy bin setting indicating use of m energy bins;
processing, with a second energy bin setting, the second projection data, the second energy bin setting indicating use of n energy bins, where n>m; and
generating, based on the processed first projection data and the processed second projection data, a material decomposition image of the imaging object.
17 . The method of claim 16 , wherein
the n energy bins are determined by a set of pre-defined energy thresholds of the photon-counting imaging system, and
the m energy bins are determined by recombining the n energy bins in a pre-defined manner.
18 . The method of claim 16 , wherein the obtaining step further comprises:
acquiring the first projection data from detector pixels within a first area of the photon-counting detector, and
acquiring the second projection data from detector pixels within a second area of the photon-counting detector.
19 . The method of claim 16 , wherein the obtaining step further comprises:
acquiring the first projection data for a first subset of the plurality of projection views, and
acquiring the second projection data for a second subset of the plurality of projection views.
20 . A non-transitory computer-readable medium storing a program that, when executed by processing circuitry, causes the processing circuitry to execute a method for performing pixel-based energy bin number modulation in a photon-counting imaging system, the photon-counting imaging system including a photon-counting detector that acquires, from an imaging object, projection data for a plurality of projection views, the photon-counting detector having a plurality of detector pixels that are arranged in both a channel direction and a segment direction on a surface of the photon-counting detector, the method comprising:
obtaining the projection data acquired by the photon-counting detector, the projection data including first projection data and second projection data, the first projection data being acquired by detector pixels different from detector pixels that acquired the second projection data;
processing, with a first energy bin setting, the first projection data, the first energy bin setting indicating use of m energy bins;
processing, with a second energy bin setting, the second projection data, the second energy bin setting indicating use of n energy bins, where n>m; and
generating, based on the processed first projection data and the processed second projection data, a material decomposition image of the imaging object.