Extraction of Myocardial Contour Points

• US 20150063670A1
• Filed: 08/27/2014
• Published: 03/05/2015
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Nihon Medi-Physics Company Limited
• Original Assignee: Nihon Medi-Physics Company Limited
• Inventors: Kobayashi, Kazunori, HAMADA, Kazuo
• Granted Patent: US 9,424,642 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 5/0044 for the heart
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: G06T 11/008 Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10076 4D tomography; Time-sequential 3D tomography
• CPC Class Codes: G06T 2207/10104 Positron emission tomography [PET]
• CPC Class Codes: G06T 2207/10108 Single photon emission computed tomography [SPECT]
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

One of the preferred embodiments includes: (a) creating a summed 3D nuclear medicine imaging data by summing a plurality of 3D nuclear medicine imaging data pixel by pixel; (b) determining pixels corresponding to myocardial regions in the summed 3D nuclear medicine imaging data; (c) defining a plurality of tracing directions based on the summed 3D nuclear medicine imaging data, and determining a reference myocardial center base point, a reference inner myocardial wall base point and a reference outer myocardial wall base point for each of the tracing directions; (d) determining a phase-specific myocardial center base point for each of the tracing directions for each of the phases; and (e) seeking a difference between the reference myocardial center base point and the phase-specific myocardial center base point, and determining a phase-specific inner myocardial wall base point and a phase-specific outer myocardial wall base point.

Claims

1. A method performed by a system upon a processing means of the system executing computer readable instructions, comprising:

(a) creating a summed 3D nuclear medicine imaging data by summing a plurality of 3D nuclear medicine imaging data pixel by pixel, wherein each of the plurality of 3D nuclear medicine imaging data is associated with a different phase of a cardiac cycle;

(b) determining pixels corresponding to myocardial regions in the summed 3D nuclear medicine imaging data;

(c) defining a plurality of tracing directions based on the summed 3D nuclear medicine imaging data, and determining a reference myocardial center base point, a reference inner myocardial wall base point and a reference outer myocardial wall base point for each of the tracing directions;

(d) determining a phase-specific myocardial center base point for each of the tracing directions for each of the phases based on the corresponding 3D nuclear medicine imaging data; and

(e) seeking a difference between the reference myocardial center base point and the phase-specific myocardial center base point, and determining a phase-specific inner myocardial wall base point and a phase-specific outer myocardial wall base point by shifting the reference inner myocardial wall base point and the reference outer myocardial wall base point respectively based on the determined difference, for each of the tracing directions for each of the phases.

2. A method according to claim 1, wherein creating a summed 3D nuclear medicine imaging data in said step (a) being performed after applying a position adjustment operation for at least some of said 3D nuclear medicine imaging data.

3. A method according to claim 1, wherein said step (c) comprising:

creating a binary image data by assigning a first value to pixels in the summed 3D nuclear medicine imaging data which are determined as being associated with myocardial regions, and assigning a second value to pixels in the summed 3D nuclear medicine imaging data which are determined as not being associated with myocardial regions; and

determining the reference myocardial center base point, the reference inner myocardial wall base point and the reference outer myocardial wall base point based on said binary image data in each of the tracing directions.

4. A method according to claim 1, wherein said plurality of tracing directions defined in said step (c) are defined such that:

for a region located apical side, the tracing directions are defined as radially and three-dimensionally from a predetermined starting point in a cardiac ventricle;

for a region located basal side, the tracing directions are also defined as radially and three-dimensionally from a different starting point in a cardiac ventricle; and

for a central myocardial region located between the region located apical side and the region located basal side, the tracing directions are defined as radially and two-dimensionally in a short axial plane.

5. A method according to claim 1, wherein said step (d) is performed such that the phase-specific myocardial center base point may be determined based not only on the 3D nuclear medicine imaging data of the corresponding phase, but also on the 3D nuclear medicine imaging data of the neighboring phases.

6. A method according to claim 1, wherein an inter-slice correction and/or an intra-slice correction are applied to positions of at least some of the phase-specific myocardial center base points, before determining the phase-specific inner myocardial wall base points and/or the phase-specific outer myocardial wall base points.

7. A method according to claim 1, an inter-phase correction is applied to positions of at least some of the phase-specific myocardial center base points, before determining the phase-specific inner myocardial wall base points and phase-specific outer myocardial wall base points.

8. A method according to claim 1, wherein the amount of shifting of the inner myocardial wall base points is greater than the amount of shifting of the outer myocardial wall base points.

9. A method according to claim 1, inner myocardial wall points and outer myocardial wall points are determined for over the 3D nuclear medicine imaging data phase by phase based on the corresponding phase-specific inner myocardial wall base points and the corresponding phase-specific outer myocardial wall base points.

10. A computer program comprising computer readable instructions configured to cause a system, by being executed by a processing means of the system, to perform a method according to claim 1.

11. A system comprising a processing means and a memory means embodying computer readable instructions configured to cause the system, by being executed by the processing means, to perform a method according to claim 1.