Application Field

Imaging Diagnosis

Field Introduction

Computer tomography (CT) is an X-ray computed tomography scanner that performs multiple cross-sectional scans around a certain part of the human body by using precisely collimated X-ray beams along with extremely high-sensitivity detectors. It provides fast scanning times and clear images and can be used to examine a variety of diseases, accurately identify lesions, and help doctors make diagnoses.

CT consists of X-ray tube, filter, collimator, detector and frame. Of these, the X-ray tube, detection system and reconstruction algorithm are the CT components with the greatest impact on image quality. As the number of detectors increases and scanning time decreases, CT equipment technology has continued to improve, putting forward ever higher requirements for X-ray tubes, front collimators and detector collimators. This also demands higher requirements for the tungsten and molybdenum material technology used in the core components of the tube, and for the manufacturing of front collimators and detector collimators (post-collimators).

Front collimator: installed in front of the CT tube. The X-rays emitted from the tube are cone-shaped rays, which can be transformed into sheet-shaped beams after passing through the narrow gap of the tungsten-molybdenum device. The beam is used to select the slice thickness of the X-ray, and controls the scanning slice thickness by controlling the width of the X-ray constraint in the direction parallel to the long axis of the human body.

Rear collimator: The slits on the device are separately aligned with each detector, so that the detectors only receive rays that enter the detector vertically. This minimizes the interference of scattered rays coming from other directions.

X-ray tube: X-ray source. The performance of a CT machine largely depends on the quality of the tube, a key part of which is the anode target. This affects the emission intensity of the X-rays and the service life of the tube.

The tube anode mainly consists of an anode target, which receives electron bombardment radiation and dissipates heat. The greater the heat capacity, the larger the anode target required. The target surface tends to be rhenium-tungsten alloy mounted on a molybdenum or graphite base. Compared with a pure tungsten target surface, rhenium-tungsten alloy has better thermal expansion resistance and higher heat capacity, and its X-ray radiation rate decreases slowly.





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■    Broad experience in cooperative R&D.
■    Specializing in refractory metal materials for more than 60 years.