MRI stress-testing

Putting our scanners through their paces

Why are we stress-testing our MRI scanners?

patient safety

product reliability

sustainability

What if an MRI got hit by a magnetic object? Or the wrong settings were set before a scan? What if a patient-table got stuck during an emergency? There is an unlimited number of things that could go wrong, and still all our scanners have to fulfill specific criteria ensuring – no matter the scenario – their safety, reliability, and sustainability.
In short this is why we're testing - but certainly as important as the why is the how. So next question:

How are we stress-testing our MRI scanners?

The outside

Temperature, transport and other environmental influences

surfaces

tables

environments

The outer layer of an MRI must be able to withstand a lot. Not only environmental influences such as temperature and transport conditions, but also impact damage. MRIs generate a magnetic field that can strongly pull any magnetic object in the immediate surrounding area at high speed.

Ball impact test

To ensure that the surface of the MRI is strong enough to withstand unexpected impacts, they are simulated with a steel ball. This includes two tests: First, the resistance of the material under heat is tested. Shrinkage or deformation must not occur, even after cooling. Then the surface is tested for its strength, with the steel ball being dropped freely onto it. The test part is then examined for fine cracks or pressure marks.

Standard finger test

Not only the direct surface, but also any openings are inspected closely. A great many cables and wires run beneath the surface of an MRI. Essential pieces for the smooth functioning of the system but potential danger sources. A special, standardized finger is used to examine openings and recesses of an MRI to see if patients could get stuck or reach any electrical wire. This is to ensure both: the safety of the patient and the system. To detect these potential dangers at an early stage, the standard finger test is performed.

Patient table test

The product safety and reliability of an MRI scanner depends on all parts of the system. The patient table will move the patient during the exam, so it must of course pass highest safety requirements. Among other things, the following is checked on each individual table at the end of the table's production line:

A phantom of 270 Kilogram is placed on the table.
Then the functionality of the brakes is ensured.
Afterwards a laser is used to measure the table's position memory, meaning whether it stops automatically at the same preset marks every time.
Then follows an endurance test. Up and down...
...and in and out of the imitated scanner bore.

Phantom placement

Achieving specified image quality

An MRI scanner's product reliability is, among other, depending on the local environment. If, for example, the MRI department of a hospital is located at the third floor of a building, the vibrations caused by the floors above and below might have an impact on the system. Same with the vibrations coming from heavy traffic outside of the building, just to mention two examples. But how to test such a scenario? We have built a special room for that in which the floor starts shaking with just a push of a button. During the product development phase, our MRI systems are placed in this room to test its reactions to vibrations and to ensure it still runs smoothly.

Watch here

The inside

Interfaces, data transmission and processing

connectors

wires

signals

The inside of an MRI is where all the magic happens. Electrical signals are transmitted, processed and returned. Electromagnetic waves are recorded and translated into clinical images. And all this must run smoothly and reliably.

Plugging and unplugging

During an MRI scan, imaging data is generated, for example with the help of body coils, and then transmitted to the imaging software of the system. To ensure data processing runs properly, all plugs need to work, and all signals need to be recognized by the software. Therefore, a plug-test is part of each patient table production. Once the plugs have been checked for any defects, they are connected to the patient table and the software runs the testing program. A robotic arm helps the tester to reposition the plugs again and again, until the program gives green light to all sequences.

How does MRI work?

MRI technology is one of the great achievements of medical technology - discover 12 things that are barely known.

Volunteer release test

Before an MRI system can be safely tested with volunteers, Phantom Hugo must undergo several MRI scans. In this test phase, our colleagues check whether the system is safe for scans with volunteers: software parameters are checked, the system is manipulated, and error messages are deliberately provoked in order to subsequently evaluate the scanner's reaction. The task of the software is to ask back in case of wrong settings: is the body weight of the patient really 400 kilograms with a height of 130cm? Can these parameters be correct? See how the system reacts here:

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MRI technology is one of the great achievements of medical technology - discover 12 things that are barely known.

Only if the software detects and questions all of the operators manipulations, the system is ready for the last testing phase: actually scanning a human volunteer.

For more information on Magnetic Resonance Imaging, please click here.