X-ray image diagnostic device, and x-ray image data correcting method

• US 20040240612A1
• Filed: 12/22/2003
• Published: 12/02/2004
• Est. Priority Date: 06/22/2001
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Suzuki, Katsumi
• Granted Patent: US 6,944,267 B2
• Time in Patent Office: Days
• US Class Current: 378/91
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: A61B 6/585 Calibration of detector units

Abstract

An X-ray image diagnostic device of the invention has sensitivity-information-acquisition controlling means commanding synchronization between X-ray irradiation from the X-ray source and readout of X-ray plane detector for correcting sensitivity. When sensitivity information of the X-ray plane detector is calculated using the intensities of X-rays irradiated onto the X-ray plane detector and X-rays detected by the X-ray plane detector, readout of the X-ray plane detector is performed synchronously with X-ray irradiation, and sensitivity information corresponding to variation of the amount of X-ray radiation onto the X-ray plane detector during the reading time is determined using data of every readout channel. Therefore, sensitivity information enabling an accurate sensitivity correction can be obtained from a single output image. This sensitivity information is stored in sensitivity-information-storing means and used for correcting sensitivity of X-ray image data acquired in actual measurements.

Claims

1. An X-ray image diagnostic device comprising an X-ray source for irradiating X-rays onto an object to be examined, an X-ray plane detector placed opposite to the X-ray source for outputting X-ray image data corresponding to X-rays transmitted through the object, image storage means for storing the X-ray image data output from the X-ray plane detector as digital data, and sensitivity correcting means for performing sensitivity correction on the X-ray image data stored in the image storage means, wherein

said sensitivity correcting means comprises sensitivity-information-acquisition controlling means for commanding that X-ray irradiation from said X-ray source be synchronized with readout of the X-ray image data from the X-ray plane detector, sensitivity-information calculating means for calculating sensitivity information for a plurality of readout channels of the X-ray plane detector using the X-ray image data read out synchronously with X-ray irradiation, and sensitivity-information storage means for storing the sensitivity information calculated by the calculating means.

2. The X-ray image diagnostic device of claim 1, wherein said sensitivity-information calculating means calculates the sensitivity information using X-ray image data other than data detected during the rise time and fall time of irradiated X-rays.

3. The X-ray image diagnostic device of claim 1, wherein said sensitivity-information-acquisition controlling means controls the X-ray plane detector such that the X-ray image data are read out at a predetermined time synchronously with X-ray irradiation.

4. The X-ray image diagnostic device of claim 1, wherein said sensitivity-information-acquisition controlling means sets a delay time corresponding to the rise time of the irradiated X-rays for reading out the X-ray image data.

5. The X-ray image diagnostic device of claim 1, wherein said sensitivity correcting means performs sensitivity correction using a value obtained by interpolating from sensitivity information for at least two points of a plurality of readout channels calculated by said sensitivity information calculating means.

6. The X-ray image diagnostic device of claim 1, wherein said sensitivity-information-acquisition controlling means determines X-ray image data readout timing based on X-ray waveform information obtained from the X-ray source.

7. A method of correcting X-ray image data transmitted through an object to be examined and detected by an X-ray plane detector by calculating sensitivity information for readout channels of the X-ray plane detector using the intensities of irradiated X-rays and of detected X-rays and using the sensitivity information, wherein readout of the X-ray plane detector is performed synchronously with X-ray irradiation and sensitivity information corresponding to variation of the amount of X-ray radiation on the X-ray plane detector during the readout time is determined.

8. An X-ray image diagnostic device comprising an X-ray source for irradiating X-rays onto an object to be examined, an X-ray plane detector placed opposite to the X-ray source for outputting X-rays transmitted through the object as X-ray image data, image storage means for storing X-ray image data output from the X-ray plane detector as digital data, sensitivity correcting means for correcting sensitivity of the X-ray image data stored in the image storage means and for storing sensitivity corrected X-ray image data in the image storage means again, sensitivity-information-acquisition controlling means for commanding that X-ray irradiation from the X-ray source be synchronized with readout of X-ray image data from the X-ray plane detector, sensitivity-information calculating means for calculating sensitivity information for each readout channel of the X-ray plane detector out of the readout X-ray image data, sensitivity-information storing means for storing sensitivity information calculated by said calculating means for correcting sensitivity of the X-ray image data by said sensitivity correcting means.