Magnetic resonance imaging apparatus and method for color-coding tissue based on T1 values

• US RE47,604 E1
• Filed: 10/25/2017
• Issued: 09/17/2019
• Est. Priority Date: 10/13/2010
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Inventors: Miyazaki, Mitsue
• Primary Examiner(s): Jastrzab, Jeffrey R
• Application Number:
  US15/793,564
• Time in Patent Office: 692 Days
• CPC Class Codes: N/A

Abstract

A magnetic resonance imaging apparatus according to an exemplary embodiment includes a memory, a specifying unit, and a display controller. The memory stores a corresponding color table representing correspondence relationships between T1 values of which value ranges with respect to each tissue are known and colors to be assigned to pixels with the T1 values. The specifying unit analyzes a T1-valued image and specifies colors to be assigned to each pixel on the basis of T1 values converted from pixel values of each pixel and the corresponding color table. The display controller displays on a display the image color-coded with the specified colors.

Claims

1. A magnetic resonance imaging (MRI) apparatus comprising:

MRI gantry components including static and gradient magnetic field generators, at least one radio frequency (RF) coil coupled to an imaging volume, at least one RF transmitter, at least one RF receiver and at least one control computer having at least one processor and memory configured to control said gantry components to collect a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image is increased relative to non-target tissues;

the memory configured to store a color table representing correspondence relationships between (A) ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the known T1 values;

the at least one processor configured to analyze the plurality of T1-valued images and to specify colors to be assigned to each pixel of each of the plurality of T1-valued images on the basis of (a) T1 values, converted from pixel values of each pixel, and said color table; and

the at least one processor configured to display on a display the plurality of T1-valued images color-coded with the specified colors.

2. The magnetic resonance imaging apparatus according to claim 1, wherein:

the gantry components collect the plurality of T1-valued images in which signal intensity of the distinct target tissue in each image is increased relative to non-target tissues by imaging under different imaging conditions, and

the plurality of T1-valued images are analyzed by the at least one processor by converting pixel values of each pixel to T1 values by calculations using (i) the imaging conditions and (ii) pixel values of the images.

3. The magnetic resonance imaging apparatus according to claim 1, wherein:

the memory further stores a value table representing correspondence relationships between (C) pixel values of which value ranges with respect to each tissue are known and (A) T1 values of which value ranges with respect to each tissue are known; and

pixel values of each pixel of the plurality of T1-valued images are converted by the at least one processor to T1 values on the basis of (i) the pixel values of each pixel and (ii) said value table.

4. The magnetic resonance imaging apparatus according to claim 1, wherein:

the gantry components collect the plurality of T1-valued images in which signal intensity of the distinct target tissue in each image is increased relative to non-target tissues by imaging under different imaging conditions, and

each of said color-coded images are composited together by the at least one processor and displayed as a resulting color-coded composite image on the display.

5. The magnetic resonance imaging apparatus according to claim 1, wherein, in accordance with the plurality of T1-valued images, the at least one processor determines whether a pixel with a T1 value outside of a predetermined range is contained within an area formed of a pixel group with T1 values within the predetermined range,

wherein, when it is analyzed that a pixel with a T1 value outside of the predetermined range is contained within the area, the specifying unit (a) specifies that a first color is assigned to the pixel group with the T1 values within the predetermined range and (b) specifies that a second color, different from the first color, is assigned to the pixel with the T1 value outside of the predetermined range.

6. The magnetic resonance imaging apparatus according to claim 5, wherein the specifying unit assigns a predetermined color as the second color.

7. The magnetic resonance imaging apparatus according to claim 1, wherein at least one of the T1-valued images is an image collected without contrast agent having been injected into a subject.

8. The magnetic resonance imaging apparatus according to claim 1, wherein at least one of the T1-valued images is an image collected while an injected contrast agent is present in a subject.

9. The magnetic resonance imaging apparatus according to claim 1, wherein:

the plurality of T1-valued images include a first image collected before a contrast agent is injected to a subject and a second image collected after the contrast agent is injected, and

the display controller simultaneously displays on the display both the first image and the second image that are color-coded.

10. The magnetic resonance imaging apparatus according to claim 1, wherein the display controller displays the color-coded images superimposed on a non-color-coded morphological image of the same patient anatomy.

11. The magnetic resonance imaging apparatus according to claim 1, wherein the T1 values are (a) ideal T1 values associated with each tissue of a subject or (b) actually-measured empirical T1 values associated with each tissue of the subject.

12. A magnetic resonance imaging apparatus comprising:

MRI gantry components including static and gradient magnetic field generators, at least one radio frequency (RF) coil coupled to an imaging volume, at least one RF transmitter, at least one RF receiver and at least one control computer having at least one processor and memory configured to control said gantry components to collect a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image is increased relative to non-target tissues;

the memory configured to store a color table representing correspondence relationships between (A) pixel values corresponding to ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the pixel values;

the at least one processor configured to analyze the plurality of T1-valued images and to specify colors to be assigned to each pixel of each of the plurality of T1-valued images on the basis of (a) pixel values of each pixel and (b) said color table; and

the at least one processor configured to display on a display the plurality of T1-valued images color-coded with the specified colors.

13. A magnetic resonance imaging method performed by a magnetic resonance imaging (MRI) apparatus including a memory configured to store a color table representing correspondence relationships between (A) ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the known T1 values, the method comprising:

collecting, with the MRI apparatus, a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image is increased relative to non-target tissues;

analyzing the plurality of T1-valued images and specifying colors to be assigned to each pixel of each of the plurality of T1-valued images on the basis of (a) T1 values, converted from pixel values of each pixel, and (b) said color table; and

displaying on a display the plurality of T-1 valued images color-coded with the specified colors.

14. A magnetic resonance imaging method performed by a magnetic resonance imaging (MRI) apparatus including a memory configured to store a color table representing correspondence relationships between (A) pixel values corresponding to ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the pixel values, the method comprising:

collecting, with the MRI apparatus, a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image is increased relative to non-target tissues;

analyzing the plurality of T1-valued images and specifying colors to be assigned to each pixel of each of the plurality of T1-valued images on the basis of (a) pixel values of each pixel and (b) said color table; and

displaying on a display the plurality of T-1 valued images color-coded with the specified colors.

15. A magnetic resonance image display apparatus comprising:

at least one processor and memory configured to store a color table representing correspondence relationships between (A) ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the known T1 values;

the at least one processor configured to analyze a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image has been increased relative to non-target tissues by an MRI signal acquisition process, and specifies colors to be assigned to each pixel of each of the plurality of T1 valued images on the basis of (a) T1 values converted from pixel values of each pixel and (b) said color table; and

the at least one processor configured to display on a display the plurality of T1-valued images color-coded with the specified colors.

16. A magnetic resonance image display apparatus comprising:

at least one processor and a memory configured to store a color table representing correspondence relationships between (A) pixel values corresponding to ranges of known T1 values with respect to each tissue and (B) colors to be assigned to pixels with the pixel values;

the at least one processor configured to analyze a plurality of T1-valued images in which signal intensity of a distinct target tissue in each image has been increased relative to non-target tissues by an MRI signal acquisition process, and to specify colors to be assigned to each pixel of each of the plurality of T1-valued images on the basis of (a) pixel values of each pixel and (b) said color table; and

the at least one processor configured to display on a display the plurality of T1-valued images color-coded with the specified colors.

17. An image processing apparatus comprising:

a memory configured to accumulate and store value tables representing correspondence relationships between signal intensities of pixels of an MR image and quantitative values, wherein the value tables are actually measured by performing various imagings using different imaging conditions; and

a programmed processor connected to communicate with said memory and configured to refer to a value table corresponding to imaging conditions of pixels of an MR image obtained by imaging, obtain a quantitative value corresponding to a signal intensity of each pixel of the MR image, and display on a display an image color-coded with colors corresponding to the determined quantitative values.

18. The image processing apparatus according to claim 17, wherein

the memory is further configured to store a color table representing correspondence relationships between ranges of quantitative values and specific colors, each range of quantitative values corresponding to a specific tissue, and

the processor displays the image being color-coded based on the color table.

19. The image processing apparatus according to claim 17, wherein the quantitative value is at least one of a T1 value and a T2 value.

20. A magnetic resonance imaging apparatus comprising:

MRI gantry components including static and gradient magnetic field generators, at least one radio frequency (RF) coil coupled to an imaging volume, at least one RF transmitter, at least one RF receiver and at least one control computer having at least one programmed processor and memory configured to control said gantry components;

the memory being configured to accumulate and store value tables representing correspondence relationships between signal intensities of pixels of an MR image and quantitative values, wherein the value tables are actually measured by performing various imagings using different imaging conditions; and

the at least one programmed processor being connected to communicate with said memory and configured to refer to a value table corresponding to imaging conditions of an MR image obtained by imaging, obtain a quantitative value corresponding to a signal intensity of each pixel of the MR image, and display on a display an image color-coded with colors corresponding to the determined quantitative values.

21. The magnetic resonance imaging apparatus according to claim 20, wherein

the memory is further configured to store a color table representing correspondence relationships between ranges of quantitative values and specific colors, each range of quantitative values corresponding to a specific tissue, and

the processor displays the image being color-coded based on the color table.

22. The magnetic resonance imaging apparatus according to claim 20, wherein the quantitative value is at least one of a T1 value and a T2 value.

23. An image processing method comprising:

using a programmed computer connected for communication with a data memory to;

refer to a value table corresponding to imaging conditions of an MR image obtained by imaging, wherein the value table is stored in the memory configured to accumulate and store value tables representing correspondence relationships between signal intensities of pixels of an MR image and quantitative values, wherein the value tables are actually measured by performing various imagings using different imaging conditions;

obtain a quantitative value corresponding to a signal intensity of each pixel of the MR image; and

display on a display an image color-coded with colors corresponding to the determined quantitative values.

24. The image processing method according to claim 23, wherein

the image displayed on the display is color-coded based on a color table that is stored in the memory and that represents correspondence relationships between ranges of quantitative values and specific colors, each range of quantitative values corresponding to a specific tissue.

25. The image processing method according to claim 23, wherein the quantitative value is at least one of a T1 value and a T2 value.