IBM team boosts MRI resolution

The technique could resolve objects on the nanometre scale

The resolution of magnetic resonance imaging (MRI) has been given a massive boost by a team at computer giant IBM.

MRI is used as an imaging technique in medicine to visualise the internal structure of the human body.

The researchers demonstrated this imaging at a resolution 100 million times finer than current MRI.

The advance could lead to important medical applications and is powerful enough to see bacteria, viruses and proteins, say the researchers.

The researchers said it offered the ability to study complex 3D structures at the "nano" scale.

The step forward was made possible by a technique called magnetic resonance force microscopy (MRFM), which relies on detecting very small magnetic forces.

In addition to its high resolution, MRFM has the further advantage that it is chemically specific, can "see" below surfaces and, unlike electron microscopy, does not destroy delicate biological materials.

Now, the IBM-led team has dramatically boosted the sensitivity of MRFM and combined it with an advanced 3D image reconstruction technique.

This allowed them to demonstrate, for the first time, MRI on biological objects at the nanometre scale.

The technique was applied to a sample of tobacco mosaic virus and achieved resolution down to four nanometres (one nanometre is one billionth of a metre; a tobacco mosaic virus is 18 nanometres across).

"MRI is well known as a powerful tool for medical imaging, but its capability for microscopy has always been very limited," said Dan Rugar, manager of nanoscale studies at IBM Research.

"Our hope is that nano MRI will eventually allow us to directly image the internal structure of individual protein molecules and molecular complexes, which is key to understanding biological function."