Cone-ray tomograph - obtaining 3D images.

In 1998, a cone-beam computed tomography scanner was shown at the Department of Medical Physics in Verona (Italy). After this event, bulky, inconvenient and highly expensive tunnel (or with a gantry frame) MRI and CT scanners are gone.

Cone-beam tomograph - advantages:
Compact size.
Software processing of images.
Operating time 10 - 20 seconds.

This means that tapered beam tomographs allow obtaining a natural image with a resolution of less than one tenth of a millimeter with a dozen times less x-ray dose and a shorter x-ray tube operation time dozens of times.

On cone beam tomographs can be obtained:
Panoramic 2D images.
Tomographic 3D images with holographic volume effect.
Image resolution is less than 0.1 mm.

The theoretical resolution is equal to the pixel value in 2D or voxel in 3D conversion.

The real resolution is equal to double the pixel value in 2D or voxel in 3D conversion.

For example, if the pixel is 0.8mm, then the resolution is 1.6mm. This is a noise correction.

Cone-ray tomograph - panoramic image.

A panoramic shot without a holographic effect of volume is made by rotating the frame by 180 degrees, and formed using the square window of the collimator flap.

Cone-ray tomograph - tomographic image.

A tomographic image with a gallographic effect is performed by rotating the arc 180 degrees. X-ray radiation passes through an iron-slot beam-forming gate, standing on the radiating window of the X-ray tube.

The gate can be called anything, for example, a curtain or a collimator.

Cone-ray tomograph - holographic image.

The holographic effect of volume is carried out by synchronization of mechanics and software.

This photograph shows the appearance of a rotating frame of a cone-ray tomograph, and in the lower corners there are inserted photographs of the nodes with the covers removed.

The photos show how the collimator beam valve moves along the output channel of the x-ray tube with 2D panorama and 3D tomography.

In this photo the slit valve - the collimator does not close the window of the x-ray tube, forming a circular cone beam. This is the operating position of the flap for panoramic images.

In the first samples of tomographs (2011, 2012), the square window for the tomographic mode was not closed by anything. On later models of 2014, 2015, the collimator window was closed with an aluminum X-ray diffuser for uniformity of the irradiated field.

This photograph shows a collimator with a diffusing aluminum plate.

In tomographic images, the shutter closes the window of the x-ray tube, forming a flat narrow tapered beam. Hence the name of the method of fluoroscopy - cone beam.

This photo shows a collimator with a slit iron plate. For mode - Tomography.

Cone-beam tomograph - detector array.

Tomographic 3D image.

This picture shows the receiving voxel detector array with an X-ray to light converter. Pixel is a 2D detector, voxel is a 3D detector.

Stripes are drawn on the matrix. This is an x-ray beam passing through a slit screen - a cone shaper.

The yellow color highlights the image detection area when rotating the scanner frame for a 3D tomographic image. The yellow area is motionless, like a slit valve on an x-ray tube.

Then the tomographic image is summed up from thin strips (slices).

Panoramic 2D shot.

Panoramic 2D image is formed by a wide conical beam, covering the entire shooting area. Without collimator. With this formation, the image is obtained in one plane (front view only).

Then a 2D image is formed by software addition of instant photographs of an object taken from all sides in a circular panorama.

The 2D tomography mode uses the entire receiving matrix.

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