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Not being wired properly?

Rinckside 2022; 33,1: 1-2.

or some time, new developments in MR imag­ing have been mostly apps and gadgets playing with the data acquired. Seldom the actual usefulness of these appendages is being validated. Such out­come research is neither trendy nor attractive — nor does it fill pockets with ready cash. It is more work to milk a cow and make cheese than watch it digesting.

The development of MRI during the last five decades has been ac­com­pani­ed by paradigm shifts and changes in basic as­sumpt­ions of what was regarded as conventional wisdom and predictable com­mercial reward. The new move to low and medium field equipment follows this rule [1].

At present the question for potential buyers of low-field equipment is: Do I want the latest but ap­parently still immature technology or established and functioning technology that is not that sexy [2]?

   When one studies the recent scientific developments one finds that the research branch of the Japa­nese company Hitachi recently presented an MRI machine that can be switched on and off rapidly, so that it could be used in operation theaters. It is an open 1.1-m-diameter system based on a super­conducting magnet made with company-produced high-temperature superconducting magnesium di­boride (MgB₂) wire. Its length is 5.6 kilometers.

Hitachi stated that it will proceed with the development of vari­ous superconducting magnets that use magnesium di­boride wires and aim to be refrigerant-free and reduce power consumption.

To date, in most cases these wires are very brittle and the connection of one wire to the next seems to be a major problem. The specialists in the field claim that the high stability of the magnetic field necessary to create high-quality MR images cannot be guaranteed and might deteriorate over time. From this point of view the excitement at the prospect of novel wire technologies for superconduc­tive nearly helium-free magnetic resonance imaging equipment seems to be a little premature [3, 4 ].

With their technology the Japanese are one step ahead of an Italian company that already tries to market magnesium diboride superconducting magnets.

A detailed internal scientific memorandum pointed out some difficult steps not yet overcome in the development of a reliable long-term solution, among them the best composition of the kilometers-long wires for the magnets’ coils. Apparently the magnet is not operated in the persistent mode due to a lack of reliable superconducting joining technique of reacted magnesium di­boride conductors. Therefore, the magnet is continuously charged using a precise power supply during imaging and has a relatively high power consumption, which is perhaps one of the reasons for the limited deployment of this MRI system in hospitals and private practices. Another setback is the weight of the system: 28 tons. Users also complain that the sophisticated multi-position patient examination couch is difficult to clean and disinfect. However, a great advantage of this MR system is the option that patients can be moved from a supine, lying down, to a standing position, allowing imaging under the effects of gravity.

In this, the magnesium diboride manufacturer competes with a well-established company producing MRI equipment in the same Italian city. They also have a tilting weight-bearing MRI system per­mitting multi-position imaging for instance for musculoskeletal applications. It has a proven con­ventional “old-fashioned” permanent magnet that doesn’t suck much energy, doesn’t need helium, and its weight is only 7.9 tons.

   For decades the euphoria over new offspring techniques of MRI has been reliably followed by disil­lusionment. Exaggerations are and were widespread. There has been progress but much of the trust of the people who actually count on the developers and researchers was lost. They were taken on a constant roller coaster ride into nowhere.

Many patients, politicians and, to some extent, physicians believe that higher medical performance and novel medical equipment are a sign of higher quality in care. Very often new diagnostic tech­nologies are claimed to be more cost efficient and faster — but then early adopters are annoyed by malfunctioning or badly thought-out equipment. We do not know yet what the outcome in this case will be. It’s another wait-and-see situation.

By the way, both manufacturers compete also with pictures of healthy-looking young female pa­tients in their commercials … I know which one I prefer.

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References

1. Rinck PA. Smashing the magnetic field strength dogma. MRI: an unexpected change. Rinckside 2021; 32,1: 1-3.
2. Rinck PA. New, improved radiology demands better analysis. Rinckside 2002; 13,3: 9-11.
3. Patel D, Matsumoto H, Kumakura H, Maeda M, Kim S, Hossain SA, Choi S, Kim JH. MgB2 for MRI application: Dual sintering induced performance variation in in situ and IMD processed MgB2 conductors. J Mater Chem C (Royal Society of Chem­istry). 2020, DOI: 10.1039/C9TC06114B.
4. Ballarino A, Flükiger R. Status of MgB2 wire and cable applications in Europe. J Phys: Conf Ser 2017. 871 012098.

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Citation: Rinck PA. Not being wired properly?
Rinckside 2022; 33,1: 1-2.

A digest version of this column was published as:
What to make of the latest rumblings in the fast-changing MRI sector.
Aunt Minnie Europe. Maverinck. 18 January 2022.

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