FLAT PANEL DETECTOR
Flat-panel detectors (FPDs) are used in
digital radiography (DR) to convert X-rays into light (indirect conversion) or
electric charge (direct conversion) and read them out using thin-film
transistor (TFT) arrays.
Types of flat panel detector
ü Indirect flat panel display
Indirect detectors contain a layer of scintillator material,
usually gadolinium oxysulfide or cesium iodide, that converts X-rays into
light. Immediately behind the scintillator layer is an array of amorphous
silicon detectors that are fabricated in a process very similar to that used to
make LCD TVs and computer monitors. Like a TFT-LCD display, millions of pixels
about 0.2 mm each, each containing a thin-film transistor, form a grid of
amorphous silicon patterns on a glass substrate. Unlike LCDs, but like image
sensor chips in digital cameras, each pixel also contains a photodiode that
produces an electrical signal proportional to the light produced by the portion
of the scintillator layer in front of the pixel. The signal from the photodiode
is amplified and encoded by additional electronics located at the edge or
behind the sensor array to produce an accurate and sensitive digital
representation of the X-ray image.
ü Direct flat panel display
Direct conversion imagers utilize photoconductors, such as
amorphous selenium (a-Se), to capture incoming X-ray photons and convert them
directly into electrical charges.
X-ray photons incident on the a-Se layer generate electron-hole
pairs through the internal photoelectric effect. The bias voltage applied to
the depth of the selenium layer attracts electrons and holes to the
corresponding electrodes; thus, the resulting current is proportional to the
irradiation intensity. The signal is then read out using underlying readout
electronics, usually through an array of thin-film transistors (TFTs).
Why to Choose right flat panel detector:
Longevity
It is important that the flat panel detector can withstand
different forms of use and abuse, from very mild to very harsh, without
damaging its function or any of its components. Durability ensures that the
tablet can withstand these different uses and is durable, reducing the cost of
repairs, maintenance and replacement while ensuring funds are available for
other areas of productivity.
High replacement costs
Every flat panel
detector will require maintenance or repairs at some point, and maintenance or
parts replacement costs are not expensive. Even if the initial purchase cost of
a flat panel detector is cheap, the high cost of replacement parts can make it
less cost-effective in the long run.
Faster imaging processing time
The time required to process and develop test sample images
after X-ray beam projection is critical for fast analysis and results.
Therefore, careful consideration should be given to obtaining a flat panel
detector that can process and generate images.
Better Image Quality
The image quality produced by flat panel detectors is
critical for accurate analysis and results. Therefore, finding a flat panel
detector with high resolution and magnification is always the best option for
better image quality.
Improves Technician Productivity
The choice of flat panel detector can affect technician
productivity as they are often faced with slow processing and low image quality
shortcomings that affect their ability to analyze and produce accurate results.
Long service life
If the flat panel detector has a short service life, it will
result in increased long-term costs and is not suitable for its cost-benefit
ratio. However, guaranteeing a long lifetime for flat panel detectors means
lower long-term costs for new detectors and more money for productivity
improvements in other areas.
How to choose flat panel detector?
Choose a flat panel detector instead of an image intensifier.
When looking for flat panel detectors, most people usually
choose image intensifiers because they feel they are the same and they have the
same function. However, the two devices are completely different, and most
importantly, they have different capabilities in X-ray image processing. The
main difference between the two devices is that the image intensifier works by
using analog technology and converting X-rays into photons. In contrast, flat panel
detectors use digital technology for better image quality and greater accuracy.
Choose amorphous silicon-based detectors (a-Si) instead of CMOS
flat panel detectors.
Another key decision you need to make is to choose an
amorphous silicon based flat panel detector over a CMOS (complementary metal
oxide semiconductor) flat panel detector. One of the reasons is the
shortcomings of CMOS technology, namely its limited radiation hardness and
limited size, which makes amorphous silicon detectors more advantageous.
Research how solid the flat panel detector brand is
After successfully considering the specific type of tablet
you should choose, next comes the choice of a specific brand based on factors
including:
Market Share
A brand's market share indicates its strength, reputation,
and customer preference. A high market share is a powerful indicator of how
well a brand is performing on the other metrics mentioned earlier. A company's
market share also indicates its level of competitiveness, which indicates its
ability to offer you lower prices while remaining competitive to attract more
customers. Therefore, it is better to choose a flat panel detector brand with a
high market share.
Production and Sales History
A brand's production and sales records are also a strong
indicator of the brand's success or failure rate. It also shows how they can
meet your specific X-ray imaging requirements, such as panel size, pixel
requirements and image quality. Additionally, a manufacturer's production
history can help you view its commitment to R&D as a tool to improve the
quality of current production. Therefore, the history of the flat panel
detector manufacturer must be examined to find this critical information to
make the right decision.
Real customer reviews
Actual customer reviews often reveal a company's Customer
Satisfaction Index because it shows how well the company can deliver on its
promises to customers. It also shows how they address customer pain points and
address customer dissatisfaction. It can reveal both technical grievances such
as probe failures, component failures, and non-technical grievances such as
late or unresponsive responses to customer queries. All reviews will help you
make better decisions.