who are phantoms??? are they scared of light????
Answers
Explanation:
The word “phantom” may conjure up scary ideas, like ghosts, delusions or fake bank accounts.
But phantoms are also useful scientific devices. In the biomedical research community, medical imaging phantoms are objects used as stand-ins for human tissues to ensure that systems and methods for imaging the human body are operating correctly.
NIST develops and disseminates phantoms as part of an ongoing effort to help ensure that medical images provide reliable and quantitative (measurable) information, not just nice pictures. NIST’s specialty is phantoms used to make measurements that are directly traceable, or linked, to national or international technical standards. Traceability means an unbroken chain of comparisons to generally accepted references. This ensures that the phantoms can provide the confidence needed to compare images taken on different scanning machines, or on the same machine at different times.
NIST phantoms are often commercialized and used to calibrate—or compare to standard scales—imaging systems used in real-world settings, including major clinical trials.
By developing phantoms to meet identified needs, NIST helps to ensure the accurate evaluation of cancers, brain injury and disease, medical implants and other conditions. NIST’s work helps the companies that make phantoms, and provides great benefits to the medical professionals and technicians who use them, and patients who receive better care because of them.
How Do Phantoms Work?
Each NIST phantom is customized to fit a specific type of imaging system and measure relevant values for that system.
NIST staff create phantoms out of hard, soft and digital materials that mimic the responses of human tissues under specific conditions. Materials are selected based on their similarity to human tissues in terms of properties such as density, stretching strength and hardness, as well as the material’s availability, cost and toxicity level.
The materials include plastics, salt solutions, silicones, epoxy, polyurethane foams, carbon powder, water, disposable diapers and radioactive substances—whatever works best for a particular application.
NIST staff test the relevant properties of candidate materials and use the best-performing ones to design and fabricate prototype phantoms. NIST either produces the phantoms, or transfers these models to companies, which manufacture and sell their own versions. Commercial phantoms are then purchased by medical facilities and manufacturers to compare scanner performance with respect to standards and other machines at different clinics.