AUTO DETECTION OF POTENTIAL ACCIDENTAL RADIATION OCCURRENCES (ARO) BY CHECKING COLLIMATOR BLADE POSITION
Publication Date: 2014-Nov-05
The IP.com Prior Art Database
The invention proposes a technique to alarm a user to prevent accidental radiation occurrence (ARO) in an interventional radiology system. The technique includes an automatic detection of misalignment of a detector and a tube to alarm or warn the user. The technique detects collimator blades on the image acquired during examination to detect whether primary beam is fully intercepted at the detector or not. Full interception at the detector ensures that the collimator blades images are present on all four sides. Full interception at the detector checks extent of the collimator blade area on each edge against the reported positions by positioner. Full interception at the detector also checks symmetry between opposing collimator edges. Blade edge detection algorithm is run on the recorded image during each procedure or as a part of the real time acquisition chain.
FIELD OF INVENTION
The invention generally relates to an interventional radiology system and more particularly to a technique that alarms a user to prevent accidental radiation occurrence (ARO) in the interventional radiology system.
BACKGROUND OF THE INVENTION
A modern interventional radiology system includes a C-shaped gantry with X-ray tube on one side and a flat panel detector on other side. Both the detector and the tube are provided with X-Y linear and rotational adjustments for proper alignment during installation.
The radiology system includes a primary protective barrier which is placed behind the detector. The barrier captures stray X-ray. Stray X-ray falls outside the detector and does not contribute to image. Further, stray X-ray is harmful to an operator and doctor. In clinical scenario, an interventional system is surrounded by multiple third party accessories, such as, monitor suspensions, life support system, ECGs, patient stretcher and instrument trolleys. Though the interventional system is equipped with collision detection for internal and patient collisions, however, collision with such third party accessories is inevitable. Collisions result in drift of the detector or tube and affect alignment. Misalignment provides X-ray to fall outside detector and sometime outside a primary barrier. When X-ray falls outside the primary barrier, there is serious radiation hazard to the doctor and operator, which is termed as accidental radiation occurrence (ARO). FIG. 1 depicts unused portion of the beam.
There is no detection mechanism available to warn the operator or user or doctor of such radiation threat. The user only notices collimator blades out of field of view (FOV) and continues to utilize the system unaware of the radiation risk. The operator manually captures user warnings to be cautious while moving gantry to avoid collision with third party components.
A conventional technique includes mechanically strengthening of the tube and detector mounting to reduce drift. However, the conventional technique becomes complex, as both the tubes and detector assembly require X-Y linear and rotational adjustments.
Another conventional technique includes detecting shutter area to eliminate from original image and allow storing, transmission and processing of useful data.
Another conventional technique includes detecting misalignment of the detector or tube personally for calibration purpose.
Yet another conventional technique includes drift in design simulations to predict Z-direction and addition of a correction factor to collimator blade to avoid image misalignment.
However, the conventional techniques do not allow auto detection of misalignment of the detector or tube.
It would be desirable to have an efficient technique to utilize the interventional radiology system intelligence to detect ARO.
BRIEF DESCRIPTION OF THE INVE...