Mumbai: A man carrying a liquid oxygen cylinder was killed when he was yanked into the jaws of an MRI machine and inhaled the gas that leaked out of the container.

Magnetic resonance imaging (MRI) is considered one of the safest ways to look deeply inside the human body, since it doesn't carry the risk of X-ray radiation or positron emission tomography scans.

Also read: Man dies after getting sucked in MRI machine Mumbai hospital; 2 arrested

Nonetheless, as MRI uses a powerful magnetic field to produce images, it bears the potential for accidents - such as in the case of the deceased Rajesh Maru, who was holding a metal oxygen cylinder when he accompanied a relative into the MRI room.

The powerful magnetic pull of the MRI sucked Maru in. According to reports, Maru's hand got trapped in the machine while the opening of the oxygen cylinder snapped. After hearing this commotion, we all rushed inside the room and pulled him out of the machine.

MRI scanners are particularly well suited to image the non-bony parts or soft tissues of the body. They differ from computed tomography (CT), in that they do not use the damaging ionizing radiation of x-rays. The brain, spinal cord and nerves, as well as muscles, ligaments, and tendons are seen much more clearly with MRI than with regular x-rays and CT; for this reason MRI is often used to image knee and shoulder injuries.

MRIs employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field. When the radiofrequency field is turned off, the MRI sensors are able to detect the energy released as the protons realign with the magnetic field.

During the process, the patient is placed inside the MRI machine and must stay very still to prevent the image from blurring.

What happened to Maru is a freak accident, as those who enter an MRI room are made to remove all objects that can be magnetised.

This is because anyone entering the room will be exposed to the strong magnetic field, which can turn these objects into dangerous projectiles that fly towards the machine.

If someone is being scanned when these devices fly into a machine, they could face serious injuries. A child in New York was killed in 2001 when the MRI machine sucked an oxygen canister into the machine where he was being scanned.

Even larger objects such as an office chair, for instance, can be sucked into an MRI machine with great force.