Method and system for evaluating two time-separated medical images

• US 7,933,440 B2
• Filed: 06/28/2007
• Issued: 04/26/2011
• Est. Priority Date: 06/28/2006
• Status: Expired due to Fees

• Current Assignee: Siemens Healthcare GMBH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Littmann, Arne
• Primary Examiner(s): Wu; Jingge
• Assistant Examiner(s): Thomas; Mia M
• Application Number:
  US11/769,821
• Publication Number:
  US 20080159607A1
• Time in Patent Office: 1,398 Days
• Field of Search: 382/128, 382/131, 382/278, 382/288, 382/199, 378/4, 378/21, 600/410, 600/415, 600/419
• US Class Current: 382/131
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/4088 Diagnosing of monitoring cognitive diseases, e.g. Alzheimer, prion diseases or dementia
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/463 characterised by displaying multiple images or images and diagnostic data on one display
• CPC Class Codes: G06T 7/30 Determination of transform parameters for the alignment of images, i.e. image registration

Abstract

In a method for evaluation of two images of an organ system acquired at different points in time to establish a pathological variation, the organ system exhibits a first region and a second region that are present in and that are differentiated in each of the images, with the second region of the pathological variation being acquired more strongly than the first region. A registration is determined that causes the respective first region in two images to be in registration with each other. Imaging system-dependent differences, in particular deformations, are determined and compensated between the two images. After an extension of the registration such that the second region is encompassed as well by the extended registration, via a transformation one of the two images to the other can be made, presented and/or stored that includes the second region, using the extended registration. A medical imaging system with a computer can implement the method.

Claims

1. A method for assisting evaluation of first and second images, respectively acquired at different points in time, of an organ system, said first and second images containing corresponding representations of said organ system with said organ system, in each of said first and second images, exhibiting a first region and a differentiatable second region representing a pathological condition, with said pathological condition being represented more strongly in said first region of each of said first and second images, said method comprising the steps of:

automatically electronically determining a registration procedure that brings only the respective first regions in the first and second images into registration with each other;

extending said registration procedure determined for said first region to encompass said second region in said first image by enlarging said first region in one of said first and second images and expanding the registration of said first region in said first image with said first region in said image corresponding to the enlarged first region, thereby obtaining an extended registration in said first image;

transforming said second image by applying said extended registration thereto to cause said second region in said second image to conform to the second region in said first image according to said registration procedure, thereby obtaining a transformed second image; and

automatically presenting an evaluation result that establishes a change in said pathological condition between said respective points in time, said result being selected from a group consisting of visually presenting said transformed second image simultaneously with the image with the extended registration, and automatically determining a difference image between said transformed second image and said image with the extended registration.

2. A method as claimed in claim 1 wherein said change in said pathological condition is represented in said first and second images only in said second region.

3. A method as claimed in claim 1 comprising determining said registration procedure as a non-linear registration of said first region in each of said first and second images.

4. A method as claimed in claim 1 comprising iteratively enlarging said first region.

5. A method as claimed in claim 1 comprising segmenting said first region before determining said registration procedure.

6. A method as claimed in claim 1 comprising employing three-dimensional images of said organ system, generated with an imaging modality selected from the group consisting of a magnetic resonance apparatus and a computed tomography apparatus, as said first and second images.

7. A method as claimed in claim 1 comprising employing first and second images of the brain of a patient as said organ system in said first and second images.

8. A method as claimed in claim 7 wherein said first region represents white brain matter and wherein said second region represents gray brain matter.

9. A method as claimed in claim 7 comprising acquiring said first and second images at an interval in a range between three to six months from each other.

10. A medical image evaluation system for assisting evaluation of first and second images, respectively acquired at different points in time, of an organ system, said first and second images containing corresponding representations of said organ system with said organ system, in each of said first and second images, exhibiting a first region and a differentiatable second region representing a pathological condition, with said pathological condition being represented more strongly in said first region of each of said first and second images, said system comprising:

a computer configured to automatically determine a registration procedure that brings only the respective first regions in the first and second images into registration with each other, and to extend said registration procedure determined for said first region to encompass said second region in said first image by enlarging said first region in one of said first and second images and expanding the registration of said first region in said first image with said first region in said image corresponding to the enlarged first region, thereby obtaining an extended registration in said first image, and to transform said second image by applying said extended registration to said second region in said second image cause said region in said second image to conform to said second region in said first image, thereby obtaining a transformed second image, and to automatically generate an evaluation result that establishes a change in said pathological condition between said respective points in time, said result being selected from a group consisting of generating first display data to simultaneously visually present said transformed second image and the first image with the extended registration, and generating second display data representing a difference image between said transformed second image and said first image with the extended registration; and

a display unit in communication with said computer that displays said evaluation result.