How radioactive isotopes are created and used for medical diagnostics

Learn about the applications of radioactivity in medical, academic, and industrial settings

Besides their use for radiometric dating by archaeologists and researchers at museums and universities, radioactive materials are used in sensors that help track ocean currents and analyze pollution, soil, and petroleum products. Radioisotope-based sensors also help measure air in ice cream and prevent spillovers when soda bottles are filled in factories.

Particle beams can be used to alter the surface properties of artificial joints

Surface hardening and embedding specific elements or coatings can improve the biocompatibility and bone tissue integration of these implants. Particle accelerators are significant sources of the radioisotopes needed in medical diagnostics, and microwave linear accelerators are used in the majority of cancer irradiation treatments.

Learn about the 'Goldilocks' of radioisotopes, which can help attack hard-to-treat cancers

Actinium-225 can be attached to a molecule that binds to cancer antigens, helping it target specific cancers in the body. It emits alpha particles that can damage DNA but do not penetrate deeply, confining the damage to nearby cancer cells. However, annual global production of actinium-225 is less than a grain of sand.

More than 97% of the world's particle accelerators are used for commercial purposes

Only a few hundred of the over 30,000 particle accelerators worldwide are used for research. Most are involved in medical imaging and treatment, food sterilization, semiconductor processing, cargo screening, and radioisotope production. They're also used to modify the properties of polymers.

Particle accelerators allow physicists to create controlled nuclear experiments

Before the 1930s, scientists relied on naturally radioactive substances to learn about atomic nuclei. The first atom was split in 1932 when John Cockcroft and Ernest Walton fired a beam of accelerated protons at a lithium atom, producing alpha radiation.

Radiometric dating uses radioactive isotopes to determine the age of objects

By comparing the amounts of parent and daughter isotopes and knowing how long it takes a sample of the former to become the latter, scientists can estimate when an organism was alive or when rocks formed.

A list of five everyday products that rely on radioactivity, including exit signs and gemstones

Like some glow-in-the-dark wristwatches, some exit signs contain sealed tubes of tritium—radioactive hydrogen gas—which emit low-energy beta particles that react with surrounding elements to produce light, making them visible without batteries. In smoke detectors, smoke particles disrupt the steady flow of ions generated by americium-241.

View the periodic table of radioactive elements, and a list of each's most stable isotopes

Technetium is the lightest artificial radioactive element, which is produced primarily as a byproduct of nuclear fission. Several unstable isotopes are commercially available to medical professionals and scientists, despite their radioactivity risks.

Cyclotrons move particles in spiral paths of increasing radius

After particles are injected into the center of the device, an alternating electric field and a constant magnetic field energize the particles as they spiral outward toward a target. Cyclotrons are common in hospitals that perform molecular imaging, which relies on radioactive components that decay within hours.

Particle accelerators detect subatomic particles using millions of sensors

Calorimeters measure the energy of particles. Tracking devices can measure momentum and charge from the trajectory of particles, which is determined by recording tiny electrical signals. Time-of-flight detectors provide particle velocities directly and particle mass indirectly, giving physicists a suite of properties to compare with those of known matter.

The Curies developed a way to measure radioactivity in an old medical dissecting room

Despite lacking proper laboratory conditions, Marie and Pierre built an ionization chamber and a piezoelectric quartz electrometer to measure the amount of charged particles released by radiation, with a sensitivity of ten-trillionth of an ampere. Substances with different emission rates indicated different elements.

Less common types of radioactive decay include emitting neutrons and antimatter

Through neutron emission, one or more neutrons are ejected from atoms that have far fewer protons. Neutrons can also be released by artificially inducing the fission, or separation, of a large atomic nucleus into smaller ones. During beta-plus decay, a positron—the antimatter version of an electron—is produced when a proton turns into a neutron.

Radioactive waste solutions include glass smelting and dumping into graphite blocks

Since radioactive materials can take seconds to millions of years to decay, their disposal or storage requires creative solutions. Besides turning liquid waste into glass or storing medical waste in lead-lined rooms, spent nuclear rods are stored in deep-water pools.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Cathode-ray tube televisions are examples of electron accelerators

CRT TVs work by converting electricity into heat, which causes electrons to be emitted from the rear of the device in three beams responsible for the colors red, green, and blue. Electromagnets direct electrons to phosphor molecules on the screen, which emit light and illuminate the pixels.

It may be possible to create dark matter in particle accelerators

In high-energy collisions, exotic forms of matter can be produced by directly converting energy into mass according to *E = mc*². Even though a dark matter particle would not be directly observable, its creation would result in unaccounted-for mass, which can be compared to potential dark matter candidates for indirect detection.

How helium enables MRI machines to look inside organisms

By cooling the machine's magnets with liquid helium to extremely low temperatures, they can generate and maintain powerful magnetic fields that align the hydrogen atoms in living things to point toward a patient's head or feet. A radio pulse nudges these atoms, which realign and induce a measurable signal in nearby electrical coils. These signals are captured in slices and then stacked into a 3D reconstruction.

Gamma Knife surgery uses incredibly precise, high-energy light to treat patients

A form of brain stereotactic radiosurgery, this non-invasive technology concentrates beams of light onto specific tumors to damage the DNA of malignant cells, killing them. The gamma rays used are in the same part of the electromagnetic spectrum as those produced in nuclear reactions, cosmic ray collisions, and radioactive decay.

Synchrotron radiation has revealed the fur color of creatures millions of years old

When electrons are accelerated in the loop, they produce intense X-rays that can reveal properties of a sample struck by them, just as X-rays can be used to show bone structure in humans. Studying the reflected light from fossils can uncover the presence of known pigmentation compounds.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

RTGs convert heat generated by the decay of radioactive plutonium into electricity

Radioisotope thermoelectric generators use a thermocouple—two plates of different metals joined at two junctions to make a closed circuit. When heating one junction while keeping the other cool, a voltage and an electric current are created.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

What are pulsars?

Pulsars are neutron stars created as part of stellar evolution and emit radiation beams visible from Earth. These beams pulse like a lighthouse's light due to the star's rotation, creating periodic high-energy emissions. Pulsars were first discovered as radio sources; it was also discovered they emit gamma rays. NASA uses its Fermi Gamma-ray Space Telescope to retrieve and analyze data from pulsars.

Can brain scans help with processing trauma?

MRIs and brain monitoring therapies are becoming increasingly popular for those looking to process trauma and address mental health conditions, including PTSD and depression. This article details how these therapies quantify mental health, giving users another way to measure and manage their mental and emotional needs through brain mapping and other methods.

CT scanners at airports take images across energy bands to identify baggage contents

Old X-ray scanners' inability to distinguish between water and explosives has driven strict liquid bans and longer wait times through airport security. New scanners combine multi-angle images across the energy spectrum to determine an object's density and atomic composition for improved threat detection.

How the number of subatomic particles helps identify different types of atoms

Different elements, such as oxygen and nitrogen, can be distinguished by the number of protons in each, since all atoms of the same element have the same number of protons. Isotopes of a given element have the same number of protons but different numbers of neutrons, while ions are atoms possessing different numbers of electrons than protons.

Early peptide research focused on isolating the substances from animal tissue

In the first half of the 20th century, peptides including insulin and adrenocorticotropic hormone were isolated from animals to provide life-saving medicines. ACTH was isolated from the pituitary glands of cows and pigs and insulin was isolated from the pancreas of dogs and cows.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'