Digital X-ray image processing apparatus

• US 5,198,669 A
• Filed: 07/02/1992
• Issued: 03/30/1993
• Est. Priority Date: 09/20/1989
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Isamu, Namiki, Fumihiro, Takeda, Shiro, Shimura, Takaki
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US07/908,915
• Time in Patent Office: 271 Days
• Field of Search: 250/327.2 C, 250/327.2 G, 250/484.1, 382/42, 382/52, 382/18
• US Class Current: 250/587
• CPC Class Codes: G01T 1/2014 Reading out of stimulable sheets, e.g. latent image
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/92 based on global image properties

Abstract

A digital X-ray image processing apparatus for exposing an X-ray transmitted through an object onto a photostimulable phosphor plate, for scanning the photostimulable phosphor plate by using an excitation beam to obtain an X-ray image, and for reading the X-ray image. The digital X-ray image processing apparatus includes an image storage unit for storing the X-ray image used for an actual read when diagnosing the object and a histogram storage unit for storing a standard histogram of the X-ray image. The standard histogram is formed by an intensity and frequency of the X-ray. Also provided is a first monitor unit for displaying the standard histogram read out from the histogram storage unit and a read conditions determination unit for determining actual read conditions of the X-ray image based on a latitude of the intensity of the X-ray in the standard histogram.

Claims

1. A digital X-ray image processing apparatus for exposing an X-ray transmitted through an object on to a photostimulable phosphor plate, for scanning the photostimulable phosphor plate by means of an excitation beam to obtain an X-ray image, and for reading the X-ray image, the digital X-ray image processing apparatus comprising:

image storing means for storing the X-ray image used for an actual read when diagnosing the object;

histogram storage means for storing a standard histogram of the X-ray image, a standard histogram being formed by data of the photographic conditions from the X-ray including voltage, current, exposure time and distance of an X-ray tube, conditions of the photographic member including bone, skin, lungs and breasts, and conditions of the object to be X-rayed including thinness or thickness of the object;

first monitor mans for displaying the standard histogram read out from said histogram storage means; and

read conditions determination means for determining actual read conditions of the X-ray image based on a latitude of the intensity of the X-ray in the standard histogram stored in said histogram storage means, without a pre-scanning operation.

2. A digital X-ray image processing apparatus as claimed in claim 1, further comprising:

gradation look up table means for determining conditions of the gradation processing of the standard histogram in accordance with the diagnosis area of the object; and

emphasis coefficient means for spacial filtering, the gradation curve from said gradation look-up tables means, an emphasis coefficient from said emphasis coefficient means, and the standard histogram being simultaneously displayed at said monitor means.

3. A digital X-ray image processing apparatus as claimed in claim 1, further comprising:

a second histogram correction unit, operatively connected to said histogram storage means, for correcting the standard histogram stored in said histogram storage means based on the actual read histogram, and the corrected standard histogram being stored again in said histogram storage means.

4. A digital X-ray image process apparatus as claimed in claim 1, further comprising second monitor means for displaying the pre-scan histogram, and the actual read conditions being determined based on the latitude of the intensity of the X-ray in the pre-scan histogram.

5. A digital X-ray image processing apparatus for exposing an X-ray transmitted through an object onto a photostimulable phosphor plate, for scanning the photostimulable phosphor plate by means of an excitation beam to obtain an X-ray image, and for reading the X-ray image, the digital X-ray image processing apparatus comprising;

image storing means for storing the X-ray image used for an actual read when diagnosing the object;

histogram storage means for storing a standard histogram of the X-ray image, a standard histogram being formed by data of the photographic conditions from the X-ray including voltage, current, exposure time and distance of an X-ray tube, conditions of the photographic member including bond, skin, lungs and breasts, and conditions of the object to be X-rayed including the thinness or thickness of the object;

first monitor means for displaying the standard histogram read out from said histogram storage means;

read conditions determination means for determining actual read conditions of the X-ray image based on a latitude of the intensity of the X-ray in the standard histogram stored in said histogram storage means, without a pre-scanning operation;

switching means for switching between a pre-scan operation and the actual read operation;

a histogram calculation unit, operatively connected to said switching means, for calculating a pre-scan histogram based on a pre-scan data obtained prior to the actual read in the pre-scan operation, the pre-scan histogram being input to said first monitor means and used instead of the standard histogram;

a correlation analysis unit, operatively connected to said histogram storage means and said histogram calculation unit, for receiving the pre-scan and standard histograms, and calculating a correlation value to move the standard histogram in the direction of the intensity of the X-ray to obtain a maximum correlation value between the histograms; and

a histogram correction unit, operatively connected to said correlation analysis unit, for calculating a difference between the standard histogram and the pre-scan histogram, and correcting the latitude of the intensity of the X-ray used for the actual read operation.