Radiography is an imaging technique that produces high quality anatomical images with X-rays. General radiography is currently a major part of hospital imaging classes, abdominal, chest and limb examination.
The use of digital radiography has increased rapidly in recent years. Computing X-rays using conventional conventional X-ray equipment provided a cost-effective transition from traditional film (1895) to direct digital radiography (DDR). Direct Digital X-ray is a cassette-free imaging system and is ideal for applications where high transmission power is of primary importance. The direct digital X-ray system should allow all general radiographic diagnostic applications.
The main components of the digital radiographic system are:
1. X-ray generator
2. X-ray assembly
3. Desktop carriage or other device for patient support
4. Support for X-ray tube assembly
] 5. The sensor that converts x-rays into images
6. Workstation for image processing and image display
There are a number of technologies based on direct digital X-ray:
1) Indirect conversion detector : The x-rays are transformed into light scintillation and transformed into electrical signals.
2) Direct conversion sensor: transforms x-rays directly into electrical signals.
3) Linear Scanning Detectors: The X-ray fan opening scans the test area synchronously with the sensor aperture.
Because of the structure of the sensors, indirect and direct X-ray transformers are often referred to as flat panel detectors (FPDs). There are also portable digital cassettes that are sold as part of a system or can be retrofitted to an existing CR or film / screen room. Portable sensors can be used with an X-ray mobile unit. Such sensors can be connected to a review workstation via a wireless or radio connection.
Most digital detectors will need some level of environmental control. This can be the operating temperature range, temperature and / or relative humidity ratio.
Since the original image of the sensor is probably not suitable for operation; image processing should be used. Generally, a flat field correction is applied to the raw image to take into account changes in sensor sensitivity across the entire area. Many individual pixels can also be defective.
The majority of direct digital X-ray units are equipped with automatic exposure control (AEC) to provide the selected dose to the detector. This can determine the appropriate dose level with the usual AEC detector or the actual image sensor. It is essential that AEC operates reliably and consistently and is set correctly for the exposure sensor.
Optimization is the necessary process that determines the level of radiation required to provide adequate clinical information for a particular study. Optimization depends on many clinical and technical factors.
The modern digital X-ray systems have a built-in detector dose indicator. The Dose Indicator (DDI) of the sensor indicates the level of radiation received by the sensor. This is useful for checking if exposure is within the proper range for optimal image quality and QA for your company.
Source by sbobet