How We Make Benchtop Coil Interfaces for Other MRI Labs  


By Pawel Slabiak • April 2, 2024

Center for Advanced Imaging Innovation and Research

The device emulates communication between an MRI machine and coil elements, allowing engineers to diagnose and troubleshoot issues.

A benchtop interface is a laboratory instrument for building, testing, and debugging radiofrequency (RF) coils used in magnetic resonance imaging (MRI).

The Center for Advanced Imaging Innovation and Research is sharing the devices with other research groups that build advanced MRI hardware. 

Imaging hardware engineers at NYU Langone Health have created an interface compatible with Siemens Tim 4G systems.

See how a team in NYU Langone’s RF lab puts together the first unit that will ship to another institution. 

From left: Ryan Brown, PhD, associate professor of radiology; Jerzy Walczyk, instrument design and repair specialist; Bili Wang, research engineer, seen in NYU Langone's RF laboratory.

“This is a test box that mimics what the MRI system puts out—like the signals it gives to the coil,” said Bili Wang, research engineer who led the development of the interface.

“This way we can test coils that we develop on the bench before taking them to the actual MRI scanner,” Wang said. 

Tim 4G is a new standard on Siemens MRI machines that allows one connector at the scanner to handle 24 coil channels—up from 8 on the previous system—reducing the number of cables that technologists must route around a patient during an imaging exam.

Diagram of a breakout PCB used in the interface.

To simplify the hardware, they used a single Siemens Tim 4G cable.

Around 2020, researchers at NYU Langone were developing a 24-channel flexible glove coil for dynamic MRI of the hand and wrist.

A prototype of a 24-channel flexible glove coil.

The engineers had to “daisy-chain the power supply for all the preamplifiers,” Wang said, “which was very tedious.”

However, the team did not initially have a suitable benchtop interface.

Fabric prototypes of the flexible glove coil.

The inconvenience prompted Wang to construct a prototype that made the coil development much easier, she said.

A new interface seen during assembly in NYU Langone's RF laboratory.

After the proof of concept —“a mumbo jumbo of cables”—Wang created a second, better organized iteration.

When the team realized that other advanced MRI research groups would likely face the same need, “we decided to make a [third] version that is more shareable, more manufacturable.”

...and a box made of aluminum panels that could be ordered in precut pieces.

To streamline the device, the team designed printed circuit boards (PCBs) that could be made by a PCB house in small batches... 

Bili Wang holds a made-to-order PCB (green) and an earlier version built in the lab (copper).

The parts are assembled, mounted, and enclosed on site. 

A time-lapse compresses several hours of work in the RF laboratory into a 30-second clip.

Assembling the enclosure, mounting the PCBs and connectors, soldering the remaining components, and testing the unit takes a few days.

Another 30-second clip shows the team working over multiple hours to complete the interface unit.

The box includes several safety features.

Regulator circuits disallow high currents, ensuring correct voltage. Indicator lights show whether power is flowing to preamplifiers and alert users to potential wiring faults.

Diagram of a power-regulating PCB.

The interface is available upon request, at cost. The first unit for an outside research lab is going to Polytechnique Montréal.

“We’re also interested in improving this design even more,” said Wang. “It would be interesting to hear back from other people what features would be nice.”

Bili Wang in NYU Langone's RF lab with a pickup loop and a 24-channel flexible glove coil connected to the Tim 4G interface and a network analyzer.

The interface “was my first project" after joining the team in 2018, Wang said. "I was building this box simultaneously with building my first coil.”

Prototype circuit boards built in the RF lab (copper) and a made-to-order PCB that ships with the interface (green).

Building the interface "taught me how the scanner is communicating with the coils,” said Wang.

“This way, I learned both sides of the story.”

Credits: PCB renderings courtesy of Douglas Brantner. Photo, video, text, and production by Pawel Slabiak.

Tim 4G is a Siemens Healthineers trademark not affiliated with or endorsed by the Center for Advanced Imaging Innovation and Research, NYU Langone Health, or New York University. For more information about Tim 4G, see

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