Diseases, Conditions, Syndromes

Radiologists find chest X-rays highly predictive of COVID-19

A team of LSU Health New Orleans radiologists investigated the usefulness of chest X-rays in COVID-19 and found they could aid in a rapid diagnosis of the disease, especially in areas with limited testing capacity or delayed ...

Sports medicine & Kinesiology

Mayo Clinic Q&A: Understanding 'golfer's elbow

Dear Mayo Clinic: About a month ago, I began experiencing pain in my elbow. I experience this almost constantly, but it is worst whenever I try to lift anything, no matter how heavy. The pain moves from my elbow down my inner ...

Diseases, Conditions, Syndromes

AI helps doctors fight COVID-19 in Brazil

Doctors in Brazil, the country with the second-highest number of cases and deaths in the coronavirus pandemic, have a new tool in their fight against COVID-19: artificial intelligence to detect infections.

Sports medicine & Kinesiology

Thirty-five-second scan could pick the next sporting champion

How hard is it to pick the next Usain Bolt, Ian Thorpe or Anna Meares? Finding a world champion often falls to talent scouts and involves years of hard work, but could it be as simple as a 35-second body scan?


Tooth tech could help dentists diagnose problems more quickly

Imagine that your dentist's office has a new cyber assistant. This virtual aide can look for troublesome signs on your X-rays while your dentist conducts your exam. The X-ray analysis might be cheaper and more precise—and ...

Radiology & Imaging

New CT scan method lowers radiation exposure

A CT scan technique that splits a full X-ray beam into thin beamlets can deliver the same quality of image at a much reduced radiation dose, according to a new UCL study.

Health informatics

Using lung X-rays to diagnose COVID-19

Researchers from the Department of Computer Architecture and Technology at the University of Seville's School of Computer Engineering (ETSII) are working on a system that uses X-ray images of patients' lungs to help diagnose ...

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X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays. In many languages, X-radiation is called Röntgen radiation after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had called them X-rays to signify an unknown type of radiation.:1-2

X-rays are primarily used for diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. X-rays are a form of ionizing radiation and as such can be dangerous.

X-rays from about 0.12 to 12 keV are classified as soft X-rays, and from about 12 to 120 keV as hard X-rays, due to their penetrating abilities.

The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). So older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually defined by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.

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