System and method of characterizing vascular tissue

• US 7,940,969 B2
• Filed: 06/01/2006
• Issued: 05/10/2011
• Est. Priority Date: 08/26/2002
• Status: Active Grant

• Current Assignee: Cleveland Clinic Foundation
• Original Assignee: Cleveland Clinic Foundation
• Inventors: Nair, Anuja, Vince, D. Geoffrey, Klingensmith, Jon D., Kuban, Barry D.
• Primary Examiner(s): Ahmed; Samir A
• Assistant Examiner(s): RASHIDIAN, MOHAMMAD M
• Application Number:
  US11/445,782
• Publication Number:
  US 20060241487A1
• Time in Patent Office: 1,804 Days
• Field of Search: 382/100, 382128-132, 382/195, 382/287, 382/294, 600/301, 600/437, 600/443, 600/463, 600/467, 600/447, 600/455, 600/456, 600/407, 600/471, 128/922, 128/916, 601/2, 606/7, 250/455, 356/39, 377/10
• US Class Current: 382/128
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

A system and method is provided for using backscattered data and known parameters to characterize vascular tissue. Specifically, in one embodiment of the present invention, an ultrasonic device is used to acquire RF backscattered data (i.e., IVUS data) from a blood vessel. The IVUS data is then transmitted to a computing device and used to create an IVUS image. The blood vessel is then cross-sectioned and used to identify its tissue type and to create a corresponding image (i.e., histology image). A region of interest (ROI), preferably corresponding to the identified tissue type, is then identified on the histology image. The computing device, or more particularly, a characterization application operating thereon, is then adapted to identify a corresponding region on the IVUS image. To accurately match the ROI, however, it may be necessary to warp or morph the histology image to substantially fit the contour of the IVUS image. After the corresponding region is identified, the IVUS data that corresponds to this region is identified. Signal processing is then performed and at least one parameter is identified. The identified parameter and the tissue type (e.g., characterization data) is stored in a database. In another embodiment of the present invention, the characterization application is adapted to receive IVUS data, determine parameters related thereto (either directly or indirectly), and use the parameters stored in the database to identify a tissue type or a characterization thereof.

Claims

1. A method for generating a tissue map, comprising the steps of:

obtaining an intra-vascular ultrasound (IVUS) signal;

transforming the IVUS signal into the frequency domain;

analyzing the signal based on at least two parameters selected from the group consisting of maximum power, minimum power, frequency at maximum power, frequency at minimum power, y intercept, slope, mid-band fit, and integrated backscatter; and

classifying the tissue properties based on matching the analyzed data with a database.

2. The method of claim 1, wherein said step of transforming the IVUS signal into the frequency domain further comprises processing the IVUS signal using a Welch periodogram.

3. The method of claim 1, wherein said step of transforming the IWS signal into the frequency domain further comprises processing the IWS signal using autoregressive power spectrum (AR) analysis.

4. A method of characterizing vascular tissue, comprising:

obtaining an intra-vascular ultrasound (NUS) signal, said IVUS signal comprising RF data backscattered from vascular tissue;

transforming said IVUS signal into at least one other domain;

identifying a plurality of parameters of said transformed signal, wherein at least two of the plurality of parameters are selected from a group consisting of maximum power, minimum power, frequency at maximum power, frequency at minimum power, y intercept, slope, mid-band fit, and integrated backscatter; and

using said plurality of parameters and previously stored histology data to characterize at least a portion of said vascular tissue, wherein said previously stored histology data corresponds at least in part to a first region of interest (ROI) of a previously acquired IVUS image having a first landmark and a second ROI of a previously acquired histology image having a second landmark, said first and second landmarks being substantially aligned using an algorithm.

5. The method of claim 4, wherein said step of transforming said IVUS signal further comprises transforming said IVUS signal from the time domain into the frequency domain.

6. The method of claim 4, wherein said step of transforming said IVUS signal further comprises performing a wavelet transformation on said IVUS signal.

7. The method of claim 5, wherein said step of transforming said IVUS signal further comprises processing said identified portion of said IVUS signal using a fast Fourier transform (FFT).

8. The method of claim 5, wherein said step of transforming said IVUS signal further comprises processing said identified portion of said IVUS signal using a Welch periodogram.

9. The method of claim 5, wherein said step of transforming said IVUS signal further comprises processing said identified portion of said IVUS signal using autoregressive power spectrum (AR) analysis.

10. The method of claim 4, further comprising transmitting acoustic signals within a vascular object and at least toward said vascular tissue.

11. The method of claim 4, wherein said step of using said plurality of parameters and previously stored histology data to characterize at least a portion of said vascular tissue further comprises using said plurality of parameters and said previously stored histology data to identify a tissue type of said at least a portion of said vascular tissue, said tissue type being selected from a group consisting of fibrous tissues, fibro-lipidic tissues, calcified necrotic tissues, and calcific tissues.

12. The method of claim 11, further comprising imaging said at least a portion of said vascular tissue on a display.

13. The method of claim 12, wherein said step of imaging said at least a portion of said vascular tissue further comprises using a particular color to identify said tissue type of said at least a portion of said vascular tissue.

14. The method of claim 12, wherein said step of imaging said at least a portion of said vascular tissue on a display further comprises using said IVUS signal to identify a location of said tissue type on said display.

15. The method of claim 4, wherein said first and second landmarks are substantially aligned using a morphometric algorithm.

16. The method of claim 4, wherein said previously acquired IVUS image further comprises a first non-landmark portion and said previously acquired histology image further comprises a second non-landmark portion, said first and second non-landmark portions being substantially aligned using an algorithm.

17. The method of claim 4, wherein said first and second non-landmark portions are substantially aligned using a thin plate algorithm.