RELATIVE VALUE SUMMARY PERFUSION MAP

• US 20080262344A1
• Filed: 04/23/2007
• Published: 10/23/2008
• Est. Priority Date: 04/23/2007
• Status: Abandoned Application

• Current Assignee: David P. Brummett
• Original Assignee: David P. Brummett
• Inventors: Brummett, David P.
• Application Number:
  US11/738,900
• Publication Number:
  US 20080262344A1
• Time in Patent Office: Days
• US Class Current: 600/426
• CPC Class Codes: A61B 5/0275 using tracers, e.g. dye dilution
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• 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

Abstract

Disclosed is a system and method for diagnosing a perfusion condition in the human brain. The process used includes measuring parameter values at a location of interest in one hemisphere and determining relative differences between those measured values against values measured at a substantially symmetrically opposite location in the other hemisphere. These relative differences are used to generate a composite output which is displayed using different colors. Each color is reflective of a different tissue state, e.g., ischemic core, penumbra, etc. If the substantially symmetrically opposite location is abnormal, and thus, is not a good reference, an alternative reference location which is not substantially symmetrically opposite the location of interest is chosen, and a relative difference map generated. Alternatively, an absolute value map can be generated.

Claims

1. A process for diagnosing a perfusion condition in the brain of a patient, comprising:

selecting an anatomical location of interest in a first hemisphere of a brain;

identifying a substantially symmetrically opposite location in an other hemisphere of said brain;

measuring a first set of values for plurality of parameters at said location of interest;

measuring a second set of values for said plurality of parameters at said substantially symmetrically opposite location in said other hemisphere;

determining relative differences between said first and second sets of values; and

using said relative differences to generate a composite output which is reflective of said condition at said location of interest.

2. The process of claim 1, comprising:

providing a device to display said output as an image;

using a plurality of colors to differentiate between different tissue states in said image.

3. The process of claim 1, comprising:

adapting said image to be a perfusion map.

4. The process of claim 1 wherein said process of using said relative differences to generate a composite output step comprises:

classifying tissues into different perfusion states utilizing threshold values applied to each of said plurality of parameters.

5. The process of claim 1, comprising:

determining whether tissues at both of said location of interest and said substantially symmetrically opposite locations are abnormal; and

directing the process to an alternative method of diagnosing said perfusion condition if both of said location of interest and said substantially symmetrically opposite location include tissues which are abnormal.

6. The method of claim 5 wherein said alternative method comprises:

selecting an alternative reference location which is not substantially symmetrically opposite said location of interest, said alternative reference location including tissues in a normal condition in one of said first and other hemispheres;

measuring said plurality of parameter to determine an alternative set of values at said alternative reference location;

determining alternative relative differences between said first set of values and said alternative set of values; and

using said alternative relative differences to generate a composite output which is reflective of said condition at said location of interest.

7. The method of claim 5 comprising:

generating an alternative summary map using absolute values.

8. The method of claim 1 comprising:

providing the user with an ability to view output values relating to each of said parameters individually rather than in composite form.

9. The method of claim 1 comprising:

including MTT in said plurality of parameters for the purpose of determining the existence of ischemia; and

including CBV in said plurality of parameters for the purpose of determining the existence of infarct.

10. The method of claim 9 comprising:

including CBF in said plurality of parameters for the purpose of determining the existence of ischemia along with said MTT.

11. The method of claim 1 comprising:

including CBF in said plurality of parameters for the purpose of determining the existence of ischemia; and

including CBV in said plurality of parameters for the purpose of determining the existence of infarct.

12. The method of claim 1 comprising:

including TTP in said plurality of parameters for the purpose of determining the existence of ischemia; and

including CBV in said plurality of parameters for the purpose of determining the existence of infarct.

13. The method of claim 12 comprising:

including CBF in said plurality of parameters for the purpose of determining the existence of ischemia along with said TTP.