Diagnostic image generation apparatus and diagnostic image generation method
View Patent ↗A three-dimensional region of interest (ROI) is established with a high degree of accuracy, by a simple method without increasing a burden on the operator, in generating a three-dimensional projected image from medical volume data according to rendering, achieving more efficient interpretation of three-dimensional image and streamlining of diagnostic flow, with the use of the diagnostic image generation apparatus. An energy map is generated on a predetermined tomographic plane, assuming a preset start point as a reference and searching for a path that minimizes the energy, and then the path is set as a boundary of the three-dimensional ROI. The start point may be decided on the basis of the boundary inputted by a user, or the user may set the start point. The user may be allowed to adjust the boundary having been set. The boundary may also be determined on another plane orthogonal to the predetermined tomographic plane.
1. A diagnostic image generation apparatus, comprising:
a processor; and
a memory coupled to the processor and which stores instructions that cause the processor to execute:
a three-dimensional region of interest (ROI) setter configured to establish a three-dimensional ROI on volume data being an aggregate of data acquired from three-dimensional space within a living body, and
a projected image generator configured to execute a rendering process on the data within the three-dimensional ROI, and generate a three-dimensional projected image,
wherein the three-dimensional ROI setter includes:
an accepting part configured to accept an instruction from a user on a predetermined tomographic image of the volume data and an initial boundary curve being a line intersection of a desired clipping plane and the tomographic image, and
a clipping plane determiner configured to determine a clipping plane that spatially separates tissue to be imaged and tissue not to be imaged in the three-dimensional ROI,
wherein the clipping plane determiner determines a first boundary curve on the tomographic image, the first boundary curve passing a start point and being a path connecting pixels that minimizes a sum of energy values calculated from respective pixel values of the pixels, and determines the clipping plane from the first boundary curve,
wherein the clipping plane determiner includes:
a start point detector configured to detect the start point on the initial boundary curve,
an energy map generator configured to divide the tomographic image into two, by a line of the pixels passing the start point, calculate the energy values of each of the pixels in each of the images being divided, and generate respective energy maps therefrom,
a path searcher configured to search for a minimum energy path being a path connecting the pixels that minimizes the sum of the energy values in each of the energy maps,
a validity determiner configured to determine a divided boundary curve in each of the divided images in response to a maximum distance between the initial boundary curve and the minimum energy path, and
a coupler configured to couple the divided boundary curves so as to obtain the first boundary curve.
2. The diagnostic image generation apparatus according to claim 1 , wherein the clipping plane determiner further includes:
a corrector configured to accept a designated point provided on the first boundary curve, and correct the first boundary curve to pass the designated point and connect the pixels with a minimum brightness value.
3. The diagnostic image generation apparatus according to claim 1 , wherein the clipping plane determiner is further configured to:
determine a second boundary curve that passes the start point being an intersection point of the first boundary curve on another tomographic image being orthogonal to the tomographic image, connect the pixels with a minimum brightness value, and determine the clipping plane which includes the first boundary curve and the second boundary curve.
4. The diagnostic image generation apparatus according to claim 1 , wherein the validity determiner is further configured to:
assume the initial boundary curve as the first boundary curve, when the maximum distance between the initial boundary curve and the minimum energy path is equal to or larger than a predetermined distance threshold, and
assume the minimum energy path as the first boundary curve, when the maximum distance is smaller than the predetermined distance threshold.
5. The diagnostic image generation apparatus according to claim 1 , wherein the validity determiner is further configured to:
assume the initial boundary curve as the first boundary curve, when the maximum distance between the initial boundary curve and the minimum energy path is equal to or larger than a first distance threshold,
assume a second distance threshold as the first boundary curve, when the maximum distance is smaller than the first distance threshold and equal to or larger than a second distance threshold that is smaller than the first distance threshold, and
assume the minimum energy path as the first boundary curve when the maximum distance is smaller than the second distance threshold.
6. A diagnostic image generation apparatus, comprising:
a processor; and
a memory coupled to the processor and which stores instructions that cause the processor to execute:
a three-dimensional region of interest (ROI) setter configured to establish a three-dimensional ROI on volume data being an aggregate of data acquired from three-dimensional space within a living body, and
a projected image generator configured to execute a rendering process on the data within the three-dimensional ROI, and generate a three-dimensional projected image,
wherein the three-dimensional ROI setter includes:
an accepting part configured to accept an instruction from a user which includes a start point on a predetermined tomographic image of the volume data, and a clipping plane determiner configured to determine a clipping plane that spatially separates tissue to be imaged and tissue not to be imaged in the three-dimensional ROI,
wherein the clipping plane determiner determines a first boundary curve on the tomographic image, the first boundary curve passing the start point and being a path connecting pixels that minimizes a sum of energy values calculated from respective pixel values of the pixels, and determines the clipping plane from the first boundary curve,
wherein the clipping plane determiner includes:
an energy map generator configured to divide the tomographic image into two, by a pixel line passing the start point, calculate the energy values of each of the pixels in each of the divided images, and generate respective energy maps therefrom,
a path search determiner configured to search for a minimum energy path being a path connecting the pixels that minimize the sum of the energy values in each of the energy maps, and determine divided boundary curves in the respective divided images, and
a coupler configured to couple the divided boundary curves and obtain the first boundary curve, and
wherein the path search determiner is further configured to calculate a variance of the energy values of at least one path candidate being obtained in searching for the minimum energy path, and assume, as the divided boundary curve, the path candidate with the sum of the energy values being equal to or smaller than a first threshold, and the variance being equal to or smaller than a second threshold.