The landmark_utils.py module

Summary

Functions

compute_anatomy_axis	Compute the long and short axes of the left ventricle.
compute_aha17_points	Compute 26 AHA17 landmark points on the left ventricle surface.
compute_aha17_lines	Compute AHA 17 segment horizontal and vertical lines.
compute_aha17	Compute the AHA17 label for left ventricle elements.
compute_element_cs	Compute elemental coordinate system for AHA elements.

Description

Module for computing heart anatomical landmarks.

This module provides utilities for computing heart anatomical landmarks including: - Long and short axes of the left ventricle - AHA17 segment landmarks and segmentation - Coordinate systems for strain calculations

Module detail

landmark_utils.compute_anatomy_axis(mv_center: numpy.ndarray, av_center: numpy.ndarray, apex: numpy.ndarray, first_cut_short_axis: float = 0.2) → tuple[dict, dict, dict]

Compute the long and short axes of the left ventricle.

Parameters:

mv_centernp.ndarray

Mitral valve center.

av_centernp.ndarray

Aortic valve center.

apexnp.ndarray

Left ventricle epicardium apex point.

first_cut_short_axisfloat, default: 0.2

Relative distance between the mitral valve center and apex, which is used for defining the center of the short axis.

Returns:

tuple[dict, dict, dict]

4CV, 2CV, and short-axis. Each dictionary contains center and normal.

landmark_utils.compute_aha17_points(model: ansys.health.heart.models.HeartModel, short_axis: dict, long_axis: dict, surface: pyvista.PolyData = None) → list[numpy.ndarray]

Compute 26 AHA17 landmark points on the left ventricle surface.

The AHA17 landmark points define the geometry for the 17-segment model of the left ventricle. These 26 points are distributed across three levels (basal, mid, apical) and are located at specific angular positions around the circumference.

P1—H1—P2—H2—P3—-H3–P4—H4—P5—H5—P6—H6—P1 | | | | | | | | | | | | | | V1 S4 V2 S5 V3 S6 V4 S1 V5 S2 V6 S3 V1 | | | | | | | | | | | | | | P7—H7—P8—H8—P9—-H9–P10–H10–P11–H11–P12–H12–P7 | | | | | | | | | | | | | | V7 S10 V8 S11 V9 S12 V10 S7 V11 S8 V12 S9 V7 | | | | | | | | | | | | | | P13–H13–P14–H14–P15–H15–P16–H16–P17–H17–P18–H18–P13

P19—H19—P20—H20—P21—H21—P22—H22—P19

| | | |

| | | |

V13 S15 V14 S16 V15 S13 V16 S14 V13 | | | | | | | | | |

P23—H23—P24—H24—P25—H25—P26—H26—P23

modelHeartModel

Heart model containing the left ventricle geometry.

short_axisdict

Short axis definition with ‘center’ and ‘normal’ keys.

long_axisdict

Long axis (4CV) definition with ‘center’ and ‘normal’ keys.

surfacepv.PolyData, optional

Endocardial surface on which to compute landmarks. If None, the endocardium from the heart model is used.

Returns:

list[np.ndarray]

List of 26 landmark point coordinates on the endocardial surface.

landmark_utils.compute_aha17_lines(surface: pyvista.PolyData, points: list[numpy.ndarray]) → tuple[list[pyvista.PolyData], list[pyvista.PolyData]]

Compute AHA 17 segment horizontal and vertical lines.

Parameters:

surfacepv.PolyData

The endocardial surface to project the lines onto.

pointslist[np.ndarray]

The list of AHA17 landmark points defining the lines.

Returns:

tuple[list[pv.PolyData], list[pv.PolyData]]

Tuple of horizontal and vertical line segments projected onto the surface.

landmark_utils.compute_aha17(model: ansys.health.heart.models.HeartModel, short_axis: dict, l4cv_axis: dict, seg: Literal[16, 17] = 17, p_junction: numpy.ndarray = None) → numpy.ndarray

Compute the AHA17 label for left ventricle elements.

Parameters:

modelHeartModel

Heart model.

short_axisdict

Short axis.

l4cv_axisdict

Long 4CV axis.

segLiteral[16, 17], default: 17

Compute 16 or 17 segments.

p_junctionnp.ndarray, default: None

LV and RV junction points. If these points are given, they defines the start of segment 1. If they are not given, the start point is defined by rotating 60 degrees from the 4CV axis.

Returns:

np.ndarray

AHA17 IDs. No concerned elements are assigned with np.nan.

landmark_utils.compute_element_cs(model: ansys.health.heart.models.HeartModel, short_axis: dict, aha_element: numpy.ndarray) → tuple[numpy.ndarray, numpy.ndarray, numpy.ndarray]

Compute elemental coordinate system for AHA elements.

Parameters:

modelHeartModel

Heart model.

short_axisdict

Short axis.

aha_elementnp.ndarray

Elements with AHA labels. Compute only on these elements.

Returns:

tuple[np.ndarray, np.ndarray, np.ndarray]

Longitudinal, radial, and circumferential vectors of each AHA element.