In the medical community, nondestructive testing, or NDT services provide the world with a plethora of new scans and services. For example, the x-ray computed tomography , also known as a computerized axial tomography, or CAT, was a major breakthrough. A CAT scan uses a computer that takes data from several X-ray images of structures inside a human’s or animal’s body and converts them into pictures on a monitor. Tomography is the process of generating a 2-dimensional image of a slice or section through a 3-dimensional object. The very first CT scanners were installed between 1974 and 1976. In the beginning, only head imaging was available. In 1976 whole body imaging became available to patients. By 1980, CT scans were widely available. Currently, there are approximately 6,000 CT scanners installed in the United States and approximately 30,000 installed worldwide thanks to NDT services.
What does the CT scan provide?
NDT services provide this technology, but it was invented in 1972 by Godfrey Housefield of EMI Laboratories, a British engineer, and Allan Cormack of Tufts University, Massachusetts, born of England and South African blood. Both men would later receive the Nobel Peace Prize for their medical and scientific contributions. The first CT scanner developed by Hounsfield in his lab at EMI took several hours to acquire the raw data for a single scan or “slice” and took days to reconstruct a single image from this raw data. The latest multi-slice CT systems can collect up to 4 slices of data in about 350 ms and reconstruct a 512 x 512-matrix image from millions of data points in less than a second. Industrial CT technology is improving very quickly. While a few single CT slices would take hours to generate years ago, it is now possible to reconstruct complete 3D models with billions of voxels in just seconds. This opens the door for numerous new applications like 3D reverse engineering, rapid prototyping, 3D metrology and more.
This specific invention offered by NDT services, the industrial CT scanning process, allows customers to reduce their new product inspection costs and failure analysis costs between 25 and 75 percent when compared to existing technology. A micro-CT scan yields resolutions in microns because the focal spot of a micro focus tube is only a few microns in size. For comparison, micro-CT resolution is about 100 times better than the best CAT scan in the medical field.
More Perks Offered by NDT Services
Numerous predetermined GDandT (geometric dimensioning and tolerance) points can be analyzed at once to meet PPAP (production part approval process) requirements. The accuracy of the industrial CT scanning equipment?s metrology, which is dependent on part size and density, ranges from 5-200 microns. Part size is not an issue. Parts ranging from as small as .5mm in length to parts as large as 660mm in diameter x1m in length can be digitally x-rayed. X-rays can be taken as fast as 30 frames per second.
Using digital radiography, whether the image is produced by a digital radiography panel or computed radiography imaging plate, the radioactive source power and exposure time is substantially reduced (usually by 30% to 50%) and, in the case of computed radiography, image transfer by means of electronic processing is at least five times faster than chemical film processing. Focal spot sizes below 1 mm are used for radiography of light metal castings, mainly for automotive industry. Focal spots which are smaller than 0.4mm at tube power of < 1kW are used for aerospace castings and weld inspection. Finally micron-focus tubes have focal spots below 0.1 mm. Its industrial use is mainly in the field of inspection of thin welds or in the semiconductor industry.
A resolution of over 2.88 line pairs per mm was considered essential to maintain diagnostic accuracy in a receiver operating characteristic analysis with regards to undisplaced or minimally displaced fractures of the extremities. Resolution size corresponds to a pixel size of 0.16 mm and the pixel size is directly related to spatial resolution.
As you can see, NDT services has made incredible bounds for the medical community and all patients who utilize the technology offered to them. Now we are able to keep better track of our bodies and what’s going on inside them.
