X-ray diagnostic apparatus for tomosynthesis having a detector that detects positional relationships

• US 5,828,722 A
• Filed: 05/14/1997
• Issued: 10/27/1998
• Est. Priority Date: 05/17/1996
• Status: Expired due to Fees

• Current Assignee: Sirona Dental Systems GmbH (Sirona Dental Systems Incorporated)
• Original Assignee: Sirona Dental Systems GmbH & Co. KG.
• Inventors: Ploetz, Josef, Franetzki, Manfred
• Primary Examiner(s): Porta, David P.
• Application Number:
  US08/856,147
• Time in Patent Office: 531 Days
• Field of Search: 378/38, 378/39, 378/21, 378/22, 378/25, 378/24, 378/23, 378/168, 378/170, 378/205, 378/204
• US Class Current: 378/38
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 6/08 Auxiliary means for directing the radiation beam to a particular spot, e.g. using light beams
• CPC Class Codes: A61B 6/51 for dentistry
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device
• CPC Class Codes: A61B 6/587 Alignment of source unit to detector unit

Abstract

An diagnostic apparatus for generating X-ray exposures for tomosynthesis includes a position detector (2, 4) for registering the mutual positional relationship between the radiation transmitter (1) and/or the radiation receiver (3) and/or the object (7) under examination. The position detector (2, 4) can be arranged in part or in whole on the radiation transmitter (1), on the radiation receiver (3) or on the object (7) under examination. An evaluation device (11) evaluates the signals from the position detector (2, 4) and generates correction signals if the relative position between the radiation transmitter (1) and/or the radiation receiver (3) and/or the object (7) under examination deviates from the home position. The correction signals are then fed to an image-generating device (12) for use in the image processing.

Claims

1. An X-ray diagnostic apparatus for generating a tomosynthesis recording, comprising:

a radiation transmitter that transilluminates an object under examination from a plurality of different directions;

a radiation receiver that is adjustably mounted relative to said radiation transmitter and that produces radiation signals for generating the tomosynthesis recording of the object under examination;

an image-generating device that receives the radiation signals for each of the plurality of different directions and computes the tomosynthesis recording of the object under examination;

at least one position detector that produces position signals in accordance with a positional relationship between at least any two of (i) said radiation transmitter, (ii) said radiation receiver, and (iii) the object under examination, wherein said position detector is mounted on at least any one of said radiation transmitter, said radiation receiver, or the object under examination; and

an evaluation device that (i) evaluates the position signals to determine a deviation between the positional relationship and a desired relationship, (ii) generates correction signals in accordance with the evaluated deviation, and (iii) outputs the correction signals to said image-generating device.

2. The X-ray diagnostic apparatus as claimed in claim 1, wherein said image-generating device computes the tomosynthesis recording of the object under examination on the basis of at least the radiation signals and the correction signals.

3. The X-ray diagnostic apparatus as claimed in claim 1, wherein:

said position detector is implemented as at least any one of a magnetic, electromagnetic, optical, acoustic or mechanical device;

said position detector comprises a transmitter and a receiver;

said transmitter of said position detector is mounted on at least one of said radiation receiver or the object under examination; and

said receiver of said position detector is arranged on said radiation transmitter.

4. The X-ray diagnostic apparatus as claimed in claim 1, wherein:

said position detector is implemented as at least any one of a magnetic, electromagnetic, optical, acoustic or mechanical device;

said position detector comprises a transmitter and a receiver;

said transmitter of said position detector is arranged on said radiation transmitter; and

said receiver of said position detector is mounted on at least one of said radiation receiver or the object under examination.

5. The X-ray diagnostic apparatus as claimed in claim 1, further comprising:

a holding device for holding the object to be examined;

wherein;

said position detector is implemented as at least any one of a magnetic, electromagnetic, optical, acoustic or mechanical device;

said position detector comprises a transmitter and a receiver;

said transmitter of said position detector is mounted on said holding device; and

said receiver of said position detector is arranged on said radiation transmitter.

6. The X-ray diagnostic apparatus as claimed in claim 1, further comprising:

a holding device for holding the object to be examined;

wherein;

said position detector is implemented as at least any one of a magnetic, electromagnetic, optical, acoustic or mechanical device;

said position detector comprises a transmitter and a receiver;

said transmitter of said position detector is arranged on said radiation transmitter; and

said receiver of said position detector is mounted on said holding device.

7. The X-ray diagnostic apparatus as claimed in claim 1, further comprising:

a coupling between said radiation transmitter and a coupled object, the coupled object including at least one of said radiation receiver and the object under examination, wherein said coupling limits a relative displacement between said radiation transmitter and the coupled object.

8. The X-ray diagnostic apparatus as claimed in claim 7, wherein said coupling is an elastic coupling that exhibits a restoring force substantially proportional to the deviation from the desired relationship.

9. The X-ray diagnostic apparatus as claimed in claim 7, wherein said coupling is an elastic coupling that exhibits a small restoring torque in response to a small deviation from the desired relationship and exhibits a large restoring torque in response to a large deviation from the desired relationship.

10. The X-ray diagnostic apparatus as claimed in claim 1, wherein said evaluation device (iv) evaluates whether or not the correction signals exceed prescribed limits.

11. The X-ray diagnostic apparatus as claimed in claim 10, wherein, if the correction signals are within the prescribed limits, said evaluation device (v) enables said radiation transmitter to be stimulated to emit radiation.

12. The X-ray diagnostic apparatus as claimed in claim 10, further comprising:

an indicator connected to said evaluation device for providing an indication if the correction signals exceed the prescribed limits.

13. The X-ray diagnostic apparatus as claimed in claim 1, wherein said evaluation device comprises:

a processor that evaluates, from the position signals received from said position detector, a deviation between the positional relationship and the desired relationship, and produces an evaluation result;

a signal generator that generates the correction signals based on the evaluation result.

14. The X-ray diagnostic apparatus as claimed in claim 13, wherein said evaluation device further comprises:

a comparator that determines whether the deviation is within a prescribed limit, and that produces a comparison result.

15. The X-ray diagnostic apparatus as claimed in claim 14, further comprising:

an actuator controlled by the comparison result of said comparator to stimulate said radiation transmitter to emit radiation only if the deviation lies within the prescribed limit.

16. The X-ray diagnostic apparatus as claimed in claim 14, further comprising:

an indicator controlled by the comparison result of said comparator to output a signal if the deviation exceeds the prescribed limit.

17. An X-ray diagnostic apparatus for tomosynthesis, comprising:

a radiation transmitter and a radiation receiver provided for generating tomosynthesis recordings of an object under examination, said radiation transmitter and said radiation receiver being adjustably mounted such that, when the object under examination is transilluminated from different directions, signals are derived at said radiation receiver for each of the directions;

an image-generating device receiving the signals in order to calculate a tomosynthesis recording of the object under examination;

at least one position detector provided for registering, as position signals, a positional relationship between at least one of (i) said radiation transmitter and said radiation receiver, (ii) said radiation transmitter and the object under examination, and (iii) said radiation receiver and the object under examination, said position detector being arranged on at least one of said radiation transmitter, said radiation receiver, and the object under examination; and

an evaluation device provided for evaluating the position signals from said position detector, and for generating correction signals if the positional relationship deviates from a desired relationship;

whereby the correction signals are supplied from said evaluation device to said image-generating device.