Radiography system and radiation source controller

• US 9,351,699 B2
• Filed: 07/30/2012
• Issued: 05/31/2016
• Est. Priority Date: 09/05/2011
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kuwabara, Takeshi, Kamiya, Takeshi, Kitagawa, Yusuke, Tajima, Takashi
• Primary Examiner(s): Logie, Michael
• Application Number:
  US13/561,919
• Publication Number:
  US 20130058453A1
• Time in Patent Office: 1,401 Days
• Field of Search: 378/97, 378/62, 378/108, 378/205, 250/370.08, 250/370.09, 382/132
• US Class Current: 1/1
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30
• CPC Class Codes: H05G 1/44 in which the switching instant is determined by measuring the amount of radiation directly dosimetry in general G01T1/02

Abstract

A source controller unit for controlling an x-ray source is provided with a detection signal interface for receiving detection signals from detective pixels of an electronic cassette or an integrated value of the detection signals only, or an interface for receiving a radiation stopping signal only. The source controller unit receives other radiation signals than the radiation stopping signal, such as a radiation admitting signal, through a radiation signal interface. The source controller unit uses the detection signals, the integrated value thereof, or the radiation stopping signal as exposure control signals for stopping radiation from the x-ray source. Since the exposure control signals are received on the specific interface therefor, the source controller unit does not need signal sorting operation nor receive different kinds of signals at the same time, improving the speed of radiation stopping procedure.

Claims

1. A radiography system comprising:

a radiation source for projecting radioactive rays toward a subject;

a source controller unit for controlling activation of the radiation source; and

a radiographic image detector for detecting a radiograph of the subject from radioactive rays penetrating the subject and being incident on an imaging plane of a detection panel, to output image data of the radiograph, wherein

the radiographic image detector has a sensor for detecting the incident amount of radioactive rays and outputs exposure control signals to the source controller unit in order to stop radiation from the radiation source when an integrated amount of the radioactive rays reaches a predetermined threshold the radiographic image detector having the sensor on the detection panel, wherein

the source controller unit comprises;

a first signal interface for receiving directly from the radiographic image detector the exposure control signals only;

a second signal interface for receiving other signals than the exposure control signals, the other signals being outputted from the radiographic image detector; and

further comprising a console, provided separately from the source controller unit, for processing the radiograph detected by the radiographic image detector.

2. The radiography system as recited in claim 1, wherein the exposure control signals include detection signals from the sensor, an integrated value of the detection signals, or a radiation stopping signal that is generated based on the integrated value of the detection signals.

3. The radiography system as recited in claim 2, wherein the other signals include a radiation admitting signal.

4. The radiography system as recited in claim 1, wherein the radiographic image detector comprises a third signal interface for sending the exposure control signals only, and a fourth signal interface for sending the other signals.

5. The radiography system as recited in claim 4, wherein the fourth signal interface wirelessly transmits the other signals than the exposure control signals to the second signal interface.

6. The radiography system as recited in claim 1, wherein the radiographic image detector comprises a detection field selecting device for selecting a detection field of the sensor in accordance with a detection field of an ex-sensor which the source controller unit has previously used for automatic exposure control, on the basis of location data of the detection field of the ex-sensor when the sensor provided in the radiographic image detector is used in place of the ex-sensor.

7. The radiography system as recited in claim 6, wherein the detection field selecting device takes the posture of the radiographic image detector into consideration on selecting the detection field.

8. The radiography system as recited in claim 1, wherein the source controller unit transmits through the second signal interface an inquiry signal to the radiographic image detector inquiring whether the radiation source may start the radiation, and receives a radiation admitting signal from the radiographic image detector through the second signal interface.

9. The radiography system as recited in claim 1, wherein the sensor provided in the radiographic image detector comprises pixels which are directly connected to signal lines for reading out signal charges without any interconnected switching elements.

10. The radiography system as recited in claim 1, wherein the radiographic image detector is an electronic cassette that contains the detection panel in a portable housing.

11. A radiography system comprising:

a radiation source for projecting radioactive rays toward a subject;

a source controller unit for controlling activation of the radiation source; and

a radiographic image detector for detecting a radiograph of the subject from radioactive rays penetrating the subject and being incident on an imaging plane of a detection panel, wherein

the radiographic image detector has a sensor for detecting the incident amount of radioactive rays and outputs exposure control signals to the source controller unit in order to stop radiation from the radiation source when an integrated amount of the radioactive rays reaches a predetermined threshold, wherein

the source controller unit comprises;

a first signal interface for receiving the exposure control signals only; and

a second signal interface for receiving other signals than the exposure control signals, wherein the radiographic image detector comprises a correcting device for correcting detection signals from the sensor to be equivalent to detection signals from an ex-sensor which has been used by the source controller unit for automatic exposure control, when the sensor provided in the radiographic image detector is used in place of the ex-sensor in order to exclude influence of variations in intervening parts between the radiation source and the imaging plane of the detection panel of the radiographic image detector from the detection signals.

12. The radiography system as recited in claim 11, wherein the intervening parts include at least one of a housing that covers the detection panel of the radiographic image detector a scintillator for converting radioactive rays into visible light, and a grid for eliminating diffused radioactive rays as diffused through the subject.

13. The radiography system as recited in claim 11, wherein data of correlation between detection signals from the sensor and detection signals from the ex-sensor is stored in a storage device and the correcting device corrects detection signals from the sensor on the basis of the correlation data.

14. The radiography system as recited in claim 11, wherein the radiographic image detector comprises an integrating device for integrating the detection signals corrected through the correcting device.

15. The radiography system as recited in claim 14, wherein when the source controller unit has a function of integrating the detection signals, the radiographic image detector sends out the detection signals of the sensor as the exposure control signal, whereas when the source controller unit has no function of integrating the detection signals, the radiographic image detector sends out the integrated value of the detection signals as the exposure control signal.

16. The radiography system as recited in claim 14, wherein the radiographic image detector comprises a comparing device that compares the integrated value of the detection signals from the integrating device with a given threshold level and outputs a radiation stopping signal when the integrated value reaches the given threshold level.

17. A source controller unit for controlling activation of a radiation source to project radioactive rays toward a subject, the source controller unit comprising:

a first signal interface for receiving directly from a radiographic image detector only exposure control signals output from a sensor which detects the amount of radioactive rays having been projected toward and penetrated through the subject, the exposure control signal being used for stopping radiation from the radiation source when an integrated amount of the radioactive rays reaches a predetermined threshold; and

a second signal interface for receiving other signals than the exposure control signals, the other signals being outputted from the radiographic image detector, which includes the sensor on a detection panel and outputs image data of a radiograph.

18. The source controller unit as recited in claim 17, wherein the other signals include a radiation admitting signal.