System and method for measuring bladder wall thickness and presenting a bladder virtual image

• US 20040127797A1
• Filed: 11/10/2003
• Published: 07/01/2004
• Est. Priority Date: 06/07/2002
• Status: Abandoned Application

• Current Assignee: Verathon Incorporated (Roper Technologies, Inc.)
• Original Assignee: Verathon Incorporated (Roper Technologies, Inc.)
• Inventors: Dudycha, Stephen, McMorrow, Gerald, Yuk, Jongtae, Chalana, Vikram, Barnard, Bill
• Application Number:
  US10/704,996
• Publication Number:
  US 20040127797A1
• Time in Patent Office: Days
• US Class Current: 600/449
• CPC Class Codes: A61B 5/1075 for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer A61B8/0858 takes precedence
• CPC Class Codes: A61B 5/204 Determining bladder volume
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: G01S 15/8909 using a static transducer configuration
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G01S 7/52053 Display arrangements
• CPC Class Codes: G01S 7/52085 Details related to the ultrasound signal acquisition, e.g. scan sequences control of medical diagnostic ultrasound devices A61B8/54
• CPC Class Codes: G06T 2207/10136 3D ultrasound image
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume

Abstract

An ultrasound transceiver scans a bladder in a three dimensional array to measure the thickness and surface area of the bladder to determine bladder mass. The bladder wall thickness and masses may be determined for anterior, posterior, and lateral locations of the bladder.

Claims

1. A method to determine bladder wall thickness using an ultrasound transceiver, the method comprising:

positioning an ultrasound transceiver exterior to a patient such that at least a portion of the bladder wall is within the range of the transceiver;

transmitting radio frequency ultrasound pulses to, and receiving those pulses echoed back from, the external and internal surface of the portion of the bladder wall; and

, based on those pulses

calculating for the portion of the bladder wall

(a) the surface area of the external and internal surfaces, and

(b) the distance between the external and internal surfaces.

2. The method of claim 1, wherein the radio frequency ultrasound pulses are sent to the bladder in one or more of the forms selected from the group consisting of a scanplane, a spiral, and a random line.

3. The method of claim 2, wherein the form selected is a scanplane, and the scanplane is associated with an array, the array selected from the group consisting of a translational array, a wedge array, and a rotational array.

4. The method of claim 3, wherein the scanplane in the array is selected from the group consisting of uniformly spaced, non-uniformly spaced, and a combination of uniformly spaced and non-uniformly spaced scanplanes.

5. The system of claim 4, wherein the scanplane comprises a plurality of scanlines, the scanlines selected from the group consisting of uniformly space, non-uniformly spaced, and a combination of uniformly space and non-uniformly spaced scanlines.

6. The system of claim 5, wherein the uniform spacing between each scanplane is approximately 7.5 degrees.

7. The system of claim 5, wherein the uniform spacing between each scanline is approximatel 1.5 degrees.

8. The method of claim 1, wherein the echoes are classified into latitudinal and longitudinal components.

9. The method of claim 8, wherein the latitudinal and longitudinal components of the echoes reflecting back from the area of the portion of the bladder wall is defined to be S, and comprises a plurality of surface patches, s_ij, where i and j represent the latitude and longitude components, such that the area of S of the portion of the bladder wall is the sum of the plurality of patches, S=Σ

s_ij.

10. The method of claim 9, wherein the surface patch s_ij is further defined by a vector s_ij(u,v)=x_ij(u,v)i+y_ij(u,v)j+z_ij(u,v)k, where i, j, k, are unit vectors in the x-, y-, and z-directions respectively, and u and v are surface patch coordinates.

11. The method of claim 1, wherein the thickness separating the surface areas is ƒ

dr determined from the relationship

12. The method of claim 11, wherein the thickness separating the inner and outer wall area ƒ

dr is adjusted by a parabolic function of the form is determined from the relationship ƒ

d_i=ar_i²+br_i+c+ε

_i, where there are 3 parameters (a, b, and c) that define a parabola function with the depth along a scanline r, and the addition of a random element ε

, wherein the subscript i indicates a specific value of r, ƒ

d, and ε

.

13. The method of claim 12, wherein the parabolic function is at least 97% of the maximal value of a fractal dimension is determined from the relationship

14. The method of claim 1, wherein the area each bladder wall is determined for bladders containing approximately 0 ml to approximately 1000 ml.

15. A method to determine bladder wall mass using an ultrasound transceiver, the method comprising:

positioning an ultrasound transceiver exterior to a patient such that at least a portion of the bladder wall is within the range of the transceiver;

transmitting radio frequency ultrasound pulses to, and receiving those pulses echoed back from, external and internal surface of the portion of the bladder wall; and

, based on those pulses

calculating for the portion of the bladder wall

(a) the surface area of the external and internal surfaces of the bladder wall,

(b) the thickness between the surfaces areas, and

(c) the mass between the surface areas.

16. The method of claim 15, wherein the radio frequency ultrasound pulses are sent to the organ in a plurality of forms, the forms selected from the group consisting of a scanplane, a spiral, and a random line.

17. The method of claim 16, wherein the scanplane is associated with an array, the array selected from the group consisting of a translational array, a wedge array, and a rotational array.

18. The method of claim 17, wherein the scanplane of the rotational array includes a plurality of scanlines, the scanplane further being separated from adjacent scanplanes by approximately 7.5 degrees, and the scanline within the scanplane being separated from adjacent scanlines by approximately 1.5 degrees.

19. The method of claim 15, wherein the mass of the portion of the bladder wall is calculated as a function of the calculated surface area and thickness.

20. A system for determining the mass of an internal organ, the system comprising:

a transceiver configured to deliver radio frequency ultrasound pulses in a plurality of scanplanes to the organ of a patient, receive echoes of the pulses reflected from the organ, and process the echoes into horizontal and vertical components; and

a computer system in communication with the transceiver, the computer system having a microprocessor and a memory, the memory further containing stored programming instructions operable by the microprocessor to determine the surface area, thickness, and mass of the organ based on the horizontal and vertical components of the echoes.

21. The system of claim 20, wherein the radio frequency ultrasound pulses are sent to the organ in a plurality of forms, the forms selected from the group consisting of a scanplane, a spiral, and a random line.

22. The system of claim 21, wherein the scanplane is associated into an array, the array selected from the group consisting of a translational array, a wedge array, and a rotational array.

23. The system of claim 22, wherein the scanplane of the rotational array includes a plurality of scanlines, the scanplane further being separated from adjacent scanplanes by approximately 7.5 degrees, and the scanline within the scanplane being separated from adjacent scanlines by approximately 1.5 degrees.

24. The system of claim 20, wherein the organ is a bladder.

25. The system of claim 20, wherein the transceiver includes a display to present the graphic image of a scanplane in two-dimensions and the plurality of scanplanes in three-dimensions.

26. The system of claim 20, wherein the stored programming instructions in the memory further comprise a plurality of equations to calculate bladder wall surface area and bladder wall thickness at one or more of anterior, posterior, or lateral locations of the bladder wall.

27. The system of claim 26, wherein the plurality of equations to measure bladder wall surface area include

28. The system of claim 27, wherein the equations used to calculate bladder wall thickness include

29. The system of claim 20, wherein the bladder wall mass is calculated as a product of bladder wall area, thickness, and specific gravity of the bladder wall.

30. The system of claim 29, wherein the specific gravity of the bladder wall is approximately 0.96.

31. The system of claim 30, wherein bladder thickness is a mean of a plurality of bladder wall thicknesses calculated based on a plurality of scanned bladder locations.

32. The system of claim 20, wherein the computer system is configured for remote operation via an Internet web-based system, the internet web-based system having a plurality of programs that collect, analyze, and store organ thickness and organ mass determinations, such that the rate at which internal organs undergo hypertrophy may be determined.

33. The system of claim 20, wherein the plurality of programs further include instructions to permit disease tracking, disease progression, and provides educational instructions to patients.

34. A system for determining the mass of an internal organ, the system comprising:

a transceiver configured to deliver radio frequency ultrasound pulses in a plurality of scanplanes to the organ of a patient and receive echoes of the pulses reflected from the organ; and

a means for determining the surface area of the organ and the thickness of the organ based on the echoes received by the transceiver, and further to calculate the mass of the organ as a function of the organ thickness and area.

35. The system of claim 34, wherein the transceiver is adjusted for the anatomy of male and female patients.

36. The system of claim 34, wherein the means for determining the surface area of the organ include a first plurality of equations to analyze the echoes received by the transceiver, the first plurality of equations including:

37. The system of claim 34, wherein the means to determine the thickness of the organ include a second plurality of equations to analyze the echoes received by the transceiver, the second plurality of equations including

38. The system of claim 34, wherein the mass of the organ is determined as a product of the surface area, the thickness, and the density of the organ.

39. A system for displaying an internal organ and determining the wall thickness of the internal organ, the system comprising:

a transceiver configured to deliver radio frequency ultrasound pulses to the organ of a patient and receive echoes of the pulses reflected from the organ; and

,

a computer system in communication with the transceiver, the computer system having a microprocessor and a memory, the memory further containing stored programming instructions operable by the microprocessor to

a) present a 3-D rendering of the organ, and

b) determine the thickness of the organ based on the echoes received by the transceiver.

40. The system of claim 39, wherein the 3-D rendering comprises:

an image segmentation process;

an image enhancement process to correct ultrasound echo artifacts;

a 2-D region of interest selection process;

a 3-D interpolation process; and

a 3-D projection process on a 2-D image.

41. The system of claim 40, wherein the segmentation process comprises thresholding one or more scanlines.

42. The system of claim 40, wherein the image enhancement process to correct ultrasound echo artifacts comprises:

a general software time gain control algorithm to normalize ultrasound echo strength variations due to differences in the depth of reflecting surfaces;

a reverberation control algorithm to distinguish ultrasound echoes caused by differences in ultrasound surface reflectivity; and

an underneath fluid compensation algorithm to normalize ultrasound echo strength variations due to differences in ultrasound conduction between fluid regions and surrounding tissues.

43. The system of claim 40, wherein the 2-D region of interest selection process comprises delineating pixels within a scanplane to define a region of interest.

44. The system of claim 40, wherein the 3-D interpolation process comprises selecting the pixel within the region of interest of a scanplane to define 3-D voxels spanning the region between pixels of regions of interest between adjacent scanplanes.

45. The system of claim 40, wherein the 3-D projection process upon a 2-D image comprises distributing the 3-D voxels upon the 2-D image in bas-relief using a software rendering tool.

46. The system of claim 39, wherein the organ is a bladder.

47. A method to determine bladder wall thickness using an ultrasound transceiver, the method comprising:

positioning an ultrasound transceiver exterior to a patient such that at least a portion of the bladder wall is within the range of the transceiver;

transmitting radio frequency ultrasound pulses as a plurality of three-dimensional distributed scanlines to, and receiving those pulses echoed back from, the external and internal surface of the portion of the bladder wall; and

, based on those pulses

calculating for the portion of the bladder wall

a) the surface area of the external and internal surfaces, and

b) the distance between the external and internal surfaces.

48. The method of claim 47, wherein the plurality of three-dimensional distributed scanlines form a scan cone having a plurality of image signals of the bladder.

49. The method of claim 48, wherein the image signals are processed by a computer system in communication with the transceiver, the computer system having a microprocessor and a memory, the memory further containing stored programming instructions operable by the microprocessor to present a 3-D rendering of the bladder based upon the image signals.

50. The system of claim 49, wherein the 3-D rendering comprises:

an image segmentation process;

an image enhancement process to correct ultrasound echo artifacts;

a 2-D region of interest selection process;

a 3-D interpolation process; and

a 3-D projection process on a 2-D image.

51. The system of claim 50, wherein the segmentation process comprises thresholding one or more scanlines.

52. The method of claim 51, wherein the 3-D projection process of the bladder in the scan cone forms two approximately equal hemispheres as a 2-D bas-relief image.

53. The method of claim 52, wherein the bladder hemispheres present a cross-sectional depiction of the bladder wall, the internal structures within the bladder, and the internal structures within and the thickness of the bladder wall.