System and method for scanning medical images using adjustable exposure time and brightness

• US 5,946,407 A
• Filed: 03/06/1997
• Issued: 08/31/1999
• Est. Priority Date: 08/13/1993
• Status: Expired due to Term

• Current Assignee: Cadvision Medical Technologies Ltd., Siemens Computer Aided Diagnosis Ltd. (Siemens AG)
• Original Assignee: Isaac Leichter, Philippe Bamberger, Scott Fields
• Inventors: Bamberger, Philippe, Leichter, Isaac, Fields, Scott
• Primary Examiner(s): Johns, Andrew W.
• Application Number:
  US08/811,783
• Time in Patent Office: 908 Days
• Field of Search: 382/132, 382/274, 382/318, 382/319, 128/922, 378/96, 378/98.7, 396/213, 396/236
• US Class Current: 382/132
• CPC Class Codes: G06T 2207/30068 Mammography; Breast
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement

Abstract

A system and method for diagnosis of living tissue diseases is described. The system includes a computer device for controlling its operation. An operator control device is coupled to the computer device. A viewing screen is coupled to the computer device for displaying digitized images of the living tissue. The operator, using the control device, selects desired portions of the digitized image for further image enhancement according to a desired image enhancement feature selectable from a plurality of image enhancement features. The image enhancement features include any combination of grey scale stretching, contrast enhancement based on logarithmic histogram equalization, spot enhancement and magnification. The system further includes means for visualization and quantification of micro-calcifications, and means for visualization and quantification of mass spiculations.

Claims

1. A system for scanning medical images, comprising:

a microcomputer for controlling the operation of said system;

a memory coupled to said microcomputer for storing a plurality of data at the direction of said microcomputer;

a scanning device having adjustable exposure time and brightness coupled to said microcomputer, said scanning device when in operation mode, scanning an X-ray film to provide a digital image with pixels having grey level values based on optical density of corresponding points on said X-ray film, said scanning device scanning said X-ray film more than once while said microcomputer adjusts said exposure time and brightness on each scan to optimize a display characteristic of said image.

2. The system of claim 1 wherein said microcomputer adjusts said exposure time and brightness on each scan to provide a digital image such that the difference between the highest and lowest grey level values in said digital image after a given number of scans is larger than the difference between the highest and lowest grey level values after the first scan.

3. The system according to claim 2 wherein said scanning device further comprises a calibration mode, said scanning device when in calibration mode repeatedly scans regions of a sample X-ray film, each region having a predetermined optical density value, each scan of each region having a different exposure time value and brightness value so that for each predetermined optical density a three dimensional table is produced, said dimensions being exposure time value, brightness value and resulting grey level value corresponding to said predetermined optical density value.

4. The system according to claim 3 wherein said memory during said calibration mode, stores a plurality of said three dimensional tables, each three dimensional table corresponding to a predetermined optical density value.

5. The system according to claim 4 wherein said computer during said operation mode after each scan estimates the highest and lowest optical density values corresponding to the exposure time and brightness value used during said scan based on said three dimensional tables and selects a combination of exposure time and brightness value such that the difference between grey level values corresponding to said highest and lowest optical density values is maximum.

6. The system according to claim 5 wherein said selection of exposure time and brightness avoids system saturation.

7. A method for scanning medical images, comprising the steps of:

coupling a scanning device having adjustable exposure time and brightness to a microcomputer device;

scanning an X-ray film to provide a digital image with pixels having grey level values based on optical density of corresponding points on said X-ray film;

repeating said step of scanning said X-ray film while said microcomputer adjusts said exposure time and brightness for each scan to optimize a display characteristic of said image.

8. The method of claim 7 wherein said microcomputer adjusts said exposure time and brightness for each scan to provide a digital image such that the difference between the highest and lowest grey level values in said digital image after a given number of scans is larger than the difference between the highest and lowest grey level values after the first scan.

9. The method according to claim 8 further comprising the steps of:

repeatedly scanning regions of a sample X-ray film, each region of said sampled X-ray film having a predetermined optical density value, each scan of each region having a different exposure time value and brightness value;

generating a three dimensional table for each predetermined optical density, said dimensions being exposure time value, brightness value and resulting grey level value corresponding to said predetermined optical density value.

10. The method according to claim 9 further comprising the steps of:

storing a plurality of said three dimensional tables, each three dimensional table corresponding to a predetermined optical density value;

estimating the highest and lowest optical density values corresponding to the exposure time and brightness value used during each scan of said X-ray image based on said three dimensional tables; and

selecting a combination of exposure time and brightness value such that the difference between grey level values corresponding to said highest and lowest optical density values is maximum.

11. A method for scanning x-ray film, comprising the steps of:

coupling a scanning device having one or more adjustable operating parameters to a microcomputer device;

scanning an x-ray film to provide a digital image with pixels having grey levels based on optical density values of corresponding points on said x-ray film;

repeating said step of scanning said x-ray film while said microcomputer adjusts at least one of said parameters for each of one or more subsequent scans of said x-ray film to optimize a display characteristic of said image.

12. The method of claim 11 wherein said operating parameters comprise one or more of brightness, exposure time, and contrast.

13. The method of claim 12 wherein said microcomputer adjusts one or more of said brightness, exposure time, and contrast for each scan to provide a digital image such that the difference between the highest and lowest grey level values in said digital image after a given number of scans is larger than the difference between the highest and lowest grey level values after the first scan.

14. The method of claim 12 further comprising:

repeatedly scanning regions of a sample x-ray film, each region of said film having a predetermined optical density value, each scan of each region having a different value for one or more of said brightness, exposure time, and contrast.

15. The method of claim 14 further comprising generating a multi-dimensional table for each predetermined optical density, said dimensions being values of one or more of brightness, exposure time, contrast, and resulting grey level corresponding to said predetermined optical density value.

16. The method of claim 11 further comprising:

repeatedly scanning regions of a sample x-ray film, each region of said film having a predetermined optical density value, each scan of each region having a different value for one or more of said adjustable operating parameters.

17. The method of claim 16 further comprising generating a multi-dimensional table for each predetermined optical density, said dimensions being values of said one or more adjustable operating parameters and resulting grey level corresponding to said predetermined optical density value.

18. The method of claim 11 wherein said microcomputer adjusts one or more of said operating parameters for each scan to provide a digital image such that the difference between the highest and lowest grey level values in said digital image after a given number of scans is larger than the difference between the highest and lowest grey level values after the first scan.