CT scans machine also known as computed tomography machine, is a result of X-ray tomography. The machine allows the user to look inside the object without cutting or opening it. The machine combines numerous X-ray scans that taken from different angles and produces a homographic image.
After collecting two-dimensional radiographic images, it further proceeds with generating a three-dimensional virtual image of the object that can be seen and inspected on a computer.
X-ray CT is commonly and widely used in medical imaging. These cross-sectional images are used in medical institutions for the purpose of diagnosing.
Working of X-ray tomography instrument
An X-ray source, detectors to measure X-ray intensity from multiple beam paths and a rotational geometry to capture the image are the major elements of X-ray tomography. Different configurations can be optimized according to the composition and size of the imagine objects.
Tomography can also be performed with the help of a synchrotron or gamma-ray emitter but X-ray tubes are used in majority of CT systems. Peak X-ray energy and the target material are major characteristics of tube. Current determines X-ray intensity that impacts and spatial resolution is impacted by the focal spot size.
Usually to get better image resolution it uses smaller detectors, but because of the reduced area as it small, count rates also get reduced. Now, to reduce noise level it uses longer acquisition to compensate with count rates. Sodium metatungstate, cesium iodide and gadolinium oxysulfide are common materials for scintillation.
Strengths of X-ray tomography: The image that comes in result is completely non-destructive 3 dimensional image. There is no requirement of any sample preparation. Reconstruction is easy due to attenuation conservation and the sub-voxel levels can be extracted.
Limitations of X-ray tomography: To capture high resolution image the objects should be smaller. Resolution capacity is limited to 1000-2000x cross section diameter of an object. Limiting the resolution may cause blurry spots on the boundaries of the object. Polychromatic X-rays may complicate the determination of gray levels. Low-energy X-rays cannot penetrate large geological specimens. Beam hardening can cause interpretation and complicated data acquisition. Computers with giant data storage capacity are needed in order to obtain large data volumes and their visualization as well as analysis.
Although, the machine is widely used in medical hospitality sector and got a very essential place and value in diagnosing the majority of health issues and problems in human body.
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