Flat Panel Detector

Flat Panel Detector

Digital Imaging


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:


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.