Cone beam volume CT angiography imaging system and method

A method for generating a digital angiographic image of a vascular structure of interest using an intravenous injection, comprising the steps of:

• intravenously injecting a contrast solution such that it reaches said vascular structure of interest;
• scanning said vascular structure of interest with a radiation cone-beam scanner including a two-dimensional detector using a data acquisition geometry which is different from a single circle cone-beam data acquisition geometry;
• generating a three-dimensional reconstruction matrix of said vascular structure of interest using data signals generated by said two-dimensional detector;
• and
• generating a three-dimensional image of said vascular structure of interest using said three-dimensional reconstruction matrix.

A method for generating a digital angiographic image of a vascular structure of interest using an intravenous injection, comprising the steps of:

• intravenously injecting a contrast solution such that it reaches said vascular structure of interest;
• scanning said vascular structure of interest with a radiation cone-beam scanner including a two-dimensional detector to acquire first and second sets of nonsubtraction two-dimensional projections with a data acquisition geometry which is different from a single circle cone-beam data acquisition geometry;
• generating a three-dimensional reconstruction matrix of said vascular structure of interest using data signals generated by said two-dimensional detector;
• and
• generating a three-dimensional image of said vascular structure of interest using said three-dimensional reconstruction matrix.

Apparatus for performing intravenous tomographic digital angiography of a region of a patient which has received a contrast solution, comprising:

• a moveable support on which said patient is placed;
• a gantry frame which rotates around said patient;
• a cone-beam x-ray source and a two-dimensional detector mounted 180° apart from each, other on said gantry frame for synchronous rotation with said gantry frame;
• and
• means for acquiring data signals from said two-dimensional detector and for generating three-dimensional angiography images from said acquired data;
• wherein:
• said data signals comprise circular projection signals and arc projection signals;
• said two-dimensional detector defines a detector plane and has a local detector coordinate system with an origin, a Radon plane intersecting the detector plane to define a line of intersection, the origin and the line of intersection being connected by a p axis which is perpendicular to the line of intersection;
• and
• the means for acquiring comprises means for rebinning said data signals according to the following equations, where D is a radius of the circle, (θ,φ,ρ) is a given point in Radon space, p is a perpendicular distance from the origin to the line of intersection measured along the p axis, α is an angular orientation of the p axis relative to the local detector coordinate system, β is an angle of rotation of said scanner relative to a plane of said circular orbit, and β1 and β2 are two points of intersection of the Radon plane with the circle:
• (a) for said circular projection signals:
• ( i ) ⁢ ⁢ for ⁢ ⁢ β 1 ⁢ :
• p = D ⁢ ⁢ [LeftBracketingBar] ρ [RightBracketingBar] D 2 - ρ 2 , ⁢ α = { sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ ≥ 0 , - sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ < 0 , ⁢ ⁢ ( ii ) ⁢ ⁢ for ⁢ ⁢ β 2 ⁢ :
• ⁢ ⁢ p = - D ⁢ ⁢ [LeftBracketingBar] ρ [RightBracketingBar] D 2 - ρ 2 , ⁢ α = { - sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ ≥ 0 , sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ < 0 ,
• (b) for said arc projection signals:
• p = D ⁢ ⁢ ρ D 2 - ρ 2 , ⁢ α = sin - 1 ( D ⁢ D 2 - ρ 2 ⁢ sin ⁢ ⁢ θ ⁢ ⁢ cos ⁢ ⁢ ϕ - ⁢ ρ D 2 - ρ 2 ⁢ cos ⁢ ⁢ β sin ⁢ ⁢ β ) .

Apparatus for performing intravenous digital angiography of a vascular structure of interest of a patient using a contrast solution, comprising:

• a radiation cone-beam scanner which generates cone-beam projection signals of said vascular structure of interest containing said contrast solution;
• and
• means for converting said cone-beam projection signals into three-dimensional reconstructions of said vascular structure being imaged;
• wherein said radiation cone-beam scanner generates cone-beam circular projection signals representative of a circular orbit around said vascular structure and cone-beam arc projection signals representative of an arc about said vascular structure;
• and wherein:
• said radiation cone-beam scanner comprises a two-dimensional detector which defines a detector plane and has a local detector coordinate system with an origin, a Radon plane intersecting the detector plane to define a line of intersection, the origin and the line of intersection being connected by a p axis which is perpendicular to the line of intersection;
• and
• the means for converting comprises means for rebinning said cone-beam projection signals according to the following equations, where D is a radius of a circular orbit of the radiation cone-beam scanner, (θ,φ,ρ) is a given point in Radon space, p is a perpendicular distance from the origin to the line of intersection measured along the p axis, α is an angular orientation of the p axis relative to the local detector coordinate system, β is an angle of rotation of said scanner relative to a plane of said circular orbit, and β1 and β2 are two points of intersection of the Radon plane with the circular orbit:
• (a) for said cone-beam circular projection signals:
• ( i ) ⁢ ⁢ for ⁢ ⁢ β 1 ⁢ :
• p = D ⁢ ⁢ [LeftBracketingBar] ρ [RightBracketingBar] D 2 - ρ 2 , ⁢ α = { sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ ≥ 0 , - sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ < 0 , ⁢ ⁢ ( ii ) ⁢ ⁢ for ⁢ ⁢ β 2 ⁢ :
• ⁢ ⁢ p = - D ⁢ ⁢ [LeftBracketingBar] ρ [RightBracketingBar] D 2 - ρ 2 , ⁢ α = { - sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ ≥ 0 , sin - 1 ⁡ ( D ⁢ ⁢ cos ⁢ ⁢ θ D - ρ 2 ) for ⁢ ⁢ ρ < 0 ,
• (b) for said cone-beam arc projection signals:
• p = D ⁢ ⁢ ρ D 2 - ρ 2 , ⁢ α = sin - 1 ( D ⁢ D 2 - ρ 2 ⁢ sin ⁢ ⁢ θ ⁢ ⁢ cos ⁢ ⁢ ϕ - ⁢ ρ D 2 - ρ 2 ⁢ cos ⁢ ⁢ β sin ⁢ ⁢ β ) .

A method for generating a digital angiographic image of a vascular structure of interest using an intravenous injection, comprising the steps of:

• intravenously injecting a contrast solution such that it reaches said vascular structure of interest;
• scanning said vascular structure of interest with a radiation cone-beam scanner including a two-dimensional detector;
• generating a three-dimensional reconstruction matrix of said vascular structure of interest using data signals generated by said two-dimensional detector;
• and
• generating a three-dimensional image of said vascular structure of interest using said three-dimensional reconstruction matrix;
• wherein said step of intravenously injecting is performed with a contrast solution injector.

A method for generating a digital angiographic image of a vascular structure of interest using an intravenous injection, comprising the steps of:

• intravenously injecting a contrast solution such that it reaches said vascular structure of interest;
• scanning said vascular structure of interest with a radiation cone-beam scanner including a two-dimensional detector to acquire first and second sets of nonsubtraction two-dimensional projections;
• generating a three-dimensional reconstruction matrix of said vascular structure of interest using data signals generated by said two-dimensional detector;
• and
• generating a three-dimensional image of said vascular structure of interest using said three-dimensional reconstruction matrix;
• wherein said step of intravenously injecting is performed with a contrast solution injector.

Apparatus for performing intravenous tomographic digital angiography of a region of a patient which has received a contrast solution, comprising:

• a moveable support on which said patient is placed;
• a gantry frame which rotates around said patient;
• a cone-beam x-ray source and a two-dimensional detector mounted 180° apart from each other on said gantry frame for synchronous rotation with said gantry frame;
• means for acquiring data signals from said two-dimensional detector and for generating three-dimensional angiography images from said acquired data;
• and
• a contrast solution injector for injecting the contrast solution into the patient.

Apparatus for performing intravenous digital angiography of a vascular structure of interest of a patient using a contrast solution, comprising:

• a radiation cone-beam scanner which generates cone-beam projection signals of said vascular structure of interest containing said contrast solution;
• means for converting said cone-beam projection signals into three-dimensional reconstructions of said vascular structure being imaged;
• and
• a contrast solution injector for injecting the contrast solution into the patient.