Intraoral computed radiography (CR) Intraoral computed radiography (CR)

Intraoral computed radiography (CR)

X-ray image acquisition using photostimulable phosphor plate

Computed radiography (CR) is a digital imaging technique widely used for dental, medical, and veterinary diagnostics. Instead of a conventional X-ray film, CR uses a special X-ray sensitive, photo-stimulable phosphor plate also known as an imaging plate (IP). CR reader or IP reader machines are typically designed to process and digitize X-ray images in a short time with high image quality.


When X-rays are irradiated onto the imaging plate, electrons are released within the storage phosphor material and stored in higher energy states. A laser beam then scans the plate creating an image from the blue fluorescent light emitted by the plate in proportion to the input amount of X-ray exposure. A high sensitivity, wide dynamic range photomultiplier tube (PMT) is then used to convert the emitted weak visible light into electronic signals. These signals are then digitally processed to reconstruct a high contrast image of the original object that was exposed to X-rays.


For intraoral dental imaging, smaller format imaging plates are often used, such as size 0, 1, 2, 3, and 4 imaging plates. Below is a table of dental size imaging plates. For intraoral dental CR readers, designers often employ a large diameter fast (low f/#) lens to collect emitted light from the entire imaging plate to one PMT.


Intraoral size imaging plates:
Size 0: 22 mm x 35 mm
Size 1: 24 mm x 40 mm
Size 2: 31 mm x 41 mm
Size 3: 27 mm x 54 mm
Size 4: 57 mm x 76 mm


PMTs employed in CR reader machines should have a large active area, high sensitivity to blue light, excellent linearity over a wide operating range, and good uniformity in order to produce the highest quality images. Our PMTs incorporate all of these features, and Hamamatsu has the widest selection of PMTs available on the market today. Please see the recommended products section below for more details.

Recommended products

PMTs for CR

These PMTs have high sensitivity at the phosphor's emission wavelength.

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Disclaimer: The products are intended exclusively for sale to manufacturers, for further processing and for incorporation into their products. The provided information is intended for discussion, development and design. Due to the suitability of the products for medical applications, a technical and regulatory review of the purchaser by Hamamatsu is required prior to sale. The promoted products are neither finished devices nor medical devices or ready for use and are not intended for distribution to distributors, dentists or medical practitioners.

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