METHOD FOR PROCESSING MEASUREMENT DATA FROM PERFUSION COMPUTER TOMOGRAPHY

• US 20100290686A1
• Filed: 05/12/2010
• Published: 11/18/2010
• Est. Priority Date: 05/14/2009
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Ditt, Hendrik, Canstein, Christian
• Granted Patent: US 9,089,308 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/501 for diagnosis of the head, e.g. neuroimaging or craniography
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/30104 Vascular flow; Blood flow; Perfusion
• CPC Class Codes: G06T 7/215 Motion-based segmentation

Abstract

A method is disclosed for processing measurement data from perfusion computed tomography, in which both perfusion parameters, in order to calculate which arterial and venous TACs are generated, and dynamic CTA images are generated from the measurement data. In at least one embodiment of the proposed method, averaging is performed over the dynamic CTA images from a plurality of temporally successive time phases in order to obtain averaged CTA images, wherein the time phases over which averaging is performed are determined from the arterial or venous TAC(s). In some cases, the method can dispense with an additional static CTA and so the amount of the injected contrast agent and the radiation dose can be reduced.

Claims

1. A method for processing measurement data from perfusion computed tomography, comprising:

calculating perfusion parameters, in order to calculate which arterial and venous time-attenuation curves are generated, and calculating at least one dynamic CT-angiography image from the measurement data;

performing averaging, in each case over a plurality of dynamic CT-angiography images from temporally successive time phases, to obtain one or more averaged CT-angiography image, the temporally successive time phases for averaging being determined from the at least one time-attenuation curve; and

at least one of

determining, in order to segment bones from the at least one dynamic or the at least one averaged CT-angiography images for distinguishing between voxels representing bones and voxels representing vessels, a change in time of an HU value of a respective voxel over a number of time phases, wherein voxels without variation in the HU value, or voxels with only one variation in the HU value lying within an interval, are assigned to the bones, and

determining, in order to segment vessels from the at least one dynamic or at least one averaged CT-angiography images for distinguishing between voxels representing vessels and voxels representing other regions, a change in time of the HU value of the respective voxel over a number of time phases, wherein regions with a variation in the HU value lying above an interval are assigned to the vessels.

2. The method as claimed in claim 1, wherein the averaging is performed over time phases for generating an arterially-weighted CT-angiography image that lie around a maximum of the arterial time-attenuation curve.

3. The method as claimed in claim 1, wherein the averaging is performed over time phases for generating a venous-weighted CT-angiography image that lie around a maximum of the venous time-attenuation curve.

4. The method as claimed in claim 1, wherein the number of time phases over which averaging is performed is selected as a function of a gradient of the increase or decay of the respective time-attenuation curve, and wherein averaging is performed over a lower number of time phases in the case of a steeper increase or decay than in a case of a flatter increase or decay.

5. The method as claimed in claim 4, wherein the number of time phases is selected automatically by a processing program.

6. The method as claimed in claim 1, wherein, in order to generate CT-angiography images with an improved image quality, averaging is performed over time phases that lie around a maximum of the at least one of venous and arterial time-attenuation curve, wherein the number of time phases over which averaging is performed is interactively adjustable.

7. The method as claimed in claim 1, wherein, in order to generate further averaged CT-angiography images, averaging is also performed over respectively successive time phases before and after the maximum of the time-attenuation curves, wherein the obtained images are illustrated in temporal succession.

8. The method as claimed in claim 1, wherein time-attenuation curves of vessels are determined from the dynamic CT-angiography images and functional parameters of the vessels are calculated from said curves.

9. The method as claimed in claim 8, wherein one or more parameters in an image display of the dynamic CT-angiography images are visualized as colored representations of the vessels or in a separate diagrammatic illustration.

10. A computer readable medium including program segments for, when executed on a computer device, causing the computer device to implement the method of claim 1.