Digital radiography is a form of X ray imaging technique involving usage of X-ray sensors in place of photographic films. The advantages of using digital radiography include:
Flat Panel Detectors are a class of solid state x ray digital radiography devices similar to image sensors used in digital photography and video and are further classified in two main categories:
1. Indirect FPDs: It has aluminium-silicon (A-Si) detector with a scintillator in the detector’s outer layer, which allows conversion of X-rays to light. Hence it is called indirect imaging device. The light is passed through a A-Si photo-diode layer where it is converted to a digital signal. The digital signal is then read out by thin transistors. The image data file is sent to a computer for display.
2. Direct FPDs: Amorphous selenium(a-se) FPDs are known as “direct” detectors because X-ray photons are converted directly into charge. X-ray photons create electron-hole pairs in a-Se, and the transit of these electrons and holes depends on the potential of the bias voltage charge. As the holes are replaced with electrons, the resultant charge pattern in the selenium layer is read out by an active matrix array, electrometer probes.
Principle of flat panel detectors:
The working principle for flat panel detectors include the passage of X rays through the subject used for imaging and go strike the detector. Due to the differences in the focusing x-rays, the sensors have exactly the same size as the image they capture. millions of 0.2mm pixels each with a thin film transistor forming a grid pattern behind the scintillator as a layer on the glass substrate, each pixel contains a photo-diode which generates an electrical signal in proportion to the light produced which are used to produce accurate and sensitive digital representation of the x-ray image.
Radiological examinations in dental
- Primarily it is time efficient.
- It is able to electronically trans and improve the quality of images.
- It uses less radiation to produce an image of same as against ordinary radipgraph.
The two major variants of digital image capture devices:
- Flat panel detectors (FPDs)
- High-density line-scan solid state detectors
Flat Panel Detectors are a class of solid state x ray digital radiography devices similar to image sensors used in digital photography and video and are further classified in two main categories:
1. Indirect FPDs: It has aluminium-silicon (A-Si) detector with a scintillator in the detector’s outer layer, which allows conversion of X-rays to light. Hence it is called indirect imaging device. The light is passed through a A-Si photo-diode layer where it is converted to a digital signal. The digital signal is then read out by thin transistors. The image data file is sent to a computer for display.
2. Direct FPDs: Amorphous selenium(a-se) FPDs are known as “direct” detectors because X-ray photons are converted directly into charge. X-ray photons create electron-hole pairs in a-Se, and the transit of these electrons and holes depends on the potential of the bias voltage charge. As the holes are replaced with electrons, the resultant charge pattern in the selenium layer is read out by an active matrix array, electrometer probes.
Principle of flat panel detectors:
The working principle for flat panel detectors include the passage of X rays through the subject used for imaging and go strike the detector. Due to the differences in the focusing x-rays, the sensors have exactly the same size as the image they capture. millions of 0.2mm pixels each with a thin film transistor forming a grid pattern behind the scintillator as a layer on the glass substrate, each pixel contains a photo-diode which generates an electrical signal in proportion to the light produced which are used to produce accurate and sensitive digital representation of the x-ray image.
Radiological examinations in dental
- In intraoral examination the film or sensor is placed in the mouth focusing the oralmaxillofacial region.
- In extraoral examination where the film or sensor is placed outside the mouth to visualize the entire oral maxillofacial region.
Benefits of flat panel detectors in digital radiography for dentistry
Digital radiography in dentistry provides the clinician with the ability to store their images on a computer. This provides two key advantages over film radiography :
Digital radiography in dentistry provides the clinician with the ability to store their images on a computer. This provides two key advantages over film radiography :
- Helps in aiding diagnostics and providing easier patient communication.
- To communicate images electronically
- No need of photographic films.
Hence the use of Flat-panel detectors are more sensitive and faster than film. They are lighter, more durable, smaller in volume, more accurate, and have less image distortion than other imaging methods.
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