elsa generators

Phantoms

template<typename data_t>
DataContainer<data_t> elsa::phantoms::modifiedSheppLogan(IndexVector_t sizes)

Create a modified Shepp-Logan phantom in 2d or 3d (with enhanced contrast).

The phantom specifications are adapted from Matlab (which in turn references A.K. Jain, “Fundamentals of Digital Image Processing”, p. 439, and P.A. Toft, “The Radon Transform,

Theory and Implementation”, p. 199).

Warning: the 3D version is currently very inefficient to compute (cubic algorithm).

Return

DataContainer of specified size containing the phantom.

Parameters

  • [in] sizes: a 2d/3d vector indicating the requested size (has to be square!)

template<typename data_t>
DataContainer<data_t> elsa::phantoms::forbildHead(IndexVector_t sizes)
template<typename data_t>
DataContainer<data_t> elsa::phantoms::forbildAbdomen(IndexVector_t sizes)
template<typename data_t>
DataContainer<data_t> elsa::phantoms::forbildThorax(IndexVector_t sizes)

CircleTrajectoryGenerator

class elsa::CircleTrajectoryGenerator : public elsa::BaseCircleTrajectoryGenerator

Generator for traditional circular trajectories as used in X-ray Computed Tomography (for 2d/3d).

Author

Maximilan Hornung - initial code

Author

Tobias Lasser - modernization, fixes

Author

Julia Spindler, Robert Imschweiler - restructuring

Public Static Functions

std::unique_ptr<PlanarDetectorDescriptor> createTrajectory(index_t numberOfPoses, const DataDescriptor &volumeDescriptor, index_t arcDegrees, real_t sourceToCenter, real_t centerToDetector, std::optional<RealVector_t> principalPointOffset = std::nullopt, std::optional<RealVector_t> centerOfRotOffset = std::nullopt, std::optional<IndexVector_t> detectorSize = std::nullopt, std::optional<RealVector_t> detectorSpacing = std::nullopt)

Generate a list of geometries corresponding to a circular trajectory around a volume.

Please note: the first pose will be at 0 degrees, the last pose will be at arcDegrees For example: 3 poses over a 180 arc will yield: 0, 90, 180 degrees.

Return

a pair containing the list of geometries with a circular trajectory, and the sinogram data descriptor

Parameters

  • numberOfPoses: the number of (equally spaced) acquisition poses to be generated

  • volumeDescriptor: the volume around which the trajectory should go

  • arcDegrees: the size of the arc of the circle covered by the trajectory (in degrees, 360 for full circle)

  • sourceToCenter: the distance of the X-ray source to the center of the volume

  • centerToDetector: the distance of the center of the volume to the X-ray detector

Please note: the sinogram size/spacing will match the volume size/spacing.

std::unique_ptr<PlanarDetectorDescriptor> trajectoryFromAngles(const std::vector<real_t> &thetas, const DataDescriptor &volumeDescriptor, real_t sourceToCenter, real_t centerToDetector, std::optional<RealVector_t> principalPointOffset = std::nullopt, std::optional<RealVector_t> centerOfRotOffset = std::nullopt, std::optional<IndexVector_t> detectorSize = std::nullopt, std::optional<RealVector_t> detectorSpacing = std::nullopt)

Generate a list of geometries corresponding to a circular trajectory around a volume.

Return

a pair containing the list of geometries with a circular trajectory, and the sinogram data descriptor

Parameters

  • thetas: Sequence of degrees

  • volumeDescriptor: the volume around which the trajectory should go

  • sourceToCenter: the distance of the X-ray source to the center of the volume

  • centerToDetector: the distance of the center of the volume to the X-ray detector

SphereTrajectoryGenerator

class elsa::SphereTrajectoryGenerator : public elsa::TrajectoryGenerator

Generator for spherical trajectories as used in X-ray Computed Tomography (for 2d/3d).

Author

Michael Loipführer - initial code

Public Static Functions

std::unique_ptr<DetectorDescriptor> createTrajectory(index_t numberOfPoses, const DataDescriptor &volumeDescriptor, index_t numberOfCircles, geometry::SourceToCenterOfRotation sourceToCenter, geometry::CenterOfRotationToDetector centerToDetector)

Generate a list of geometries corresponding to a spherical trajectory around a volume. The spherical trajectory is made up of multiple circular trajectories around the volume.

Please note: the sinogram size/spacing will match the volume size/spacing.

Return

a DetectorDescriptor describing the spherical trajectory

Parameters

  • numberOfPoses: the number of (equally spaced) acquisition poses to be generated

  • volumeDescriptor: the volume around which the trajectory should go

  • numberOfCircles: the number of circular trajectories this acquisition path is made up of

  • sourceToCenter: the distance of the X-ray source to the center of the volume

  • centerToDetector: the distance of the center of the volume to the X-ray detector

TODO: Make it possible to return either PlanarDetectorDescriptor, or CurvedDetectorDescriptor

PlanarHelixTrajectoryGenerator

class elsa::PlanarHelixTrajectoryGenerator : public elsa::BaseHelixTrajectoryGenerator

Generator for helical trajectories as used in X-ray Computed Tomography (for 3d).

Author

Fabian Degen - initial code

Public Static Functions

std::unique_ptr<PlanarDetectorDescriptor> createTrajectory(const DataDescriptor &volumeDescriptor, std::vector<real_t> thetas, real_t pitch, real_t sourceToCenter, real_t centerToDetector, std::optional<RealVector_t> principalPointOffset = std::nullopt, std::optional<RealVector_t> centerOfRotOffset = std::nullopt, std::optional<IndexVector_t> detectorSize = std::nullopt, std::optional<RealVector_t> detectorSpacing = std::nullopt)

Generate a list of geometries corresponding to a helical trajectory around a volume captured on a planar detector.

Please note: the sinogram size/spacing will match the volume size/spacing.

Return

a pair containing the list of geometries with a helical trajectory, and the sinogram data descriptor

Parameters

  • volumeDescriptor: the volume around which the trajectory should go

  • thetas: array of acquisition angles

  • pitch: the distance a helix advances along its central axis per one complete turn

  • sourceToCenter: the distance of the X-ray source to the center of the volume

  • centerToDetector: the distance of the center of the volume to the X-ray detector

CurvedHelixTrajectoryGenerator

class elsa::CurvedHelixTrajectoryGenerator : public elsa::BaseHelixTrajectoryGenerator

Generator for helical trajectories as used in X-ray Computed Tomography (for 3d).

Author

Fabian Degen - initial code

Public Static Functions

std::unique_ptr<CurvedDetectorDescriptor> createTrajectory(const DataDescriptor &volumeDescriptor, std::vector<real_t> thetas, real_t pitch, real_t sourceToCenter, real_t centerToDetector, geometry::Radian angle, std::optional<RealVector_t> principalPointOffset = std::nullopt, std::optional<RealVector_t> centerOfRotOffset = std::nullopt, std::optional<IndexVector_t> detectorSize = std::nullopt, std::optional<RealVector_t> detectorSpacing = std::nullopt)

Generate a list of geometries corresponding to a helical trajectory around a volume captured on a curved detector.

Please note: the sinogram size/spacing will match the volume size/spacing.

Return

a pair containing the list of geometries with a helical trajectory, and the sinogram data descriptor

Parameters

  • volumeDescriptor: the volume around which the trajectory should go

  • thetas: array of acquisition angles

  • pitch: the distance a helix advances along its central axis per one complete turn

  • sourceToCenter: the distance of the X-ray source to the center of the volume

  • centerToDetector: the distance of the center of the volume to the X-ray detector

  • angle: rotation angle (in radians)