Mātai News

Leading revolution in MRI contrast weighting

The Gisborne Herald, 30 July 2022

Comparison of a standard MRI (image A) and MASDIR MRI image (image B). No abnormality is seen on the standard MRI. A focal lesion is seen on the MASDIR image (long arrow) and other abnormalities are seen in the corticospinal tracts (short arrows) as well as elsewhere in the white matter. Eighty percent or more of the white matter is abnormal on the MASDIR image. The only normal white matter appears black. High signal ‘etched’ lines are also seen (arrowhead). These precisely define the boundaries between white matter and cortical grey matter. These boundaries are poorly seen on the standard MRI.

Gisborne researchers recently got the call-up to the medical science equivalent of the All Blacks. Andrew Ashton takes a look at why the recent publication of their latest project is such a big deal . . .


Gisborne-based Mātai Medical Research Institute has teamed up with the “godfather” of medical imaging research to publish a new study that hopes to make it easier to spot conditions like multiple sclerosis and long Covid.


If you have ever had an MRI scan, you will have come into contact with work by Kiwi medical imaging pioneer Graeme Bydder.


Much of the content of present-day clinical MR examinations is derived from his early work. At age 78, Mātai scientific advisory board member and Emeritus Professor at the University of California San Diego, Bydder is still a major influencer in imaging advancements.


A new paper headed by Professor Bydder, and involving the Mātai team from Gisborne, has recently been published in the medical journal Quantitative Imaging in Medicine and Surgery. It changes the way clinicians think about MR image contrast and has the potential to transform the way neuro-inflammatory diseases of the brain and other conditions are imaged.


The paper, with the scholarly title “Improving the Understanding and Performance of Clinical MRI using Tissue Property Filters (TP-filters) and the Central Contrast Theorem, MASDIR (Multiplied, Added, Subtracted and/or Divided Inversion Recovery) Pulse Sequences and Synergistic Contrast MRI (scMRI)” provides a mathematical framework for increasing the sensitivity of MRI to subtle signs of disease.


The concepts in the paper evolved from work by Prof Bydder and Professor Ian Young, both pioneers in the development of clinical MRI.


Mātai clinical lead Dr Daniel Cornfeld and Mātai MRI charge technologist Paul Condron contributed to the work by applying and refining many of the concepts in the manuscript and producing proof-of-concept images based on the new framework.


“It is hoped that this new framework will make it easier for physicians to understand what they are seeing on images,” Dr Cornfeld said.


“This is important because many of the concepts historically taught to radiologists and scientists about why things look the way they do are misleading and in some cases incorrect. Better understanding of why the images look the way they do also makes it easier to develop new and improved image types for detecting disease.”


The mathematical framework explains the dark/light image contrast seen on the images, and makes it possible to design sequences that will detect very subtle abnormalities. While there are always new MRI techniques being described in the literature, most depend on state-of-the-art hardware and software only available at top research institutions. The concepts in this paper can be applied to images that can be obtained on regular clinical scanners.


The new techniques, called MASDIR pulse sequences, which multiply, add, subtract and/or divide existing inversion recovery clinical images acquired with certain settings input by the user, improve tissue contrast by 5-15 times compared to current “gold standard” techniques.


This makes subtle changes due to disease far easier to see. These techniques dramatically improve the visualisation of subtle disease in multiple sclerosis, the archetypal neuro-inflammatory disease of the brain.


There is increasing evidence that neuroinflammation is a major contributor to a wide range of diseases in the nervous system besides multiple sclerosis, including traumatic brain injury, myalgic encephalitis/chronic fatigue syndrome, long Covid, Alzheimer’s and Parkinson’s disease.


These diseases are also likely to show much more abnormality with the new techniques.


It is also hoped that the techniques will be useful in other parts of the body. For example, Mātai plans to see if MASDIR techniques can increase the sensitivity of MRI to prostate cancer.


The new technique needs precise targeting at the transition between different tissues, and this has been achieved by Paul Condron, charge technologist, using an advanced MRI system installed at the Mātai Medical Research Institute in Gisborne.

Prof Bydder a pioneer of new MRI methods

To put the work into perspective, Galileo’s first use of the telescope in astronomy during the months of December 1609 through to March 1610 had an optical magnification of eight to nine times and saw craters on the moon, separate stars in the Milky Way and four of Jupiter’s moons, all for the first time.

“We have an amplification of image contrast of 5-15 times and see MS lesions not shown with present day MRI, extensive changes due to diffuse disease in white matter and highly resolved white-grey matter boundaries also for the first time,” Dr Condron said.


Prof Bydder is a pioneer of new MRI methods. He is a graduate of Otago Medical School and is emeritus professor of radiology at the University of California, San Diego.


He worked on the world’s first commercial whole-body CT machine at Northwick Park Hospital in London from 1978-80, and the world’s first commercial cryomagnet-based MRI system (1981-1990) at Hammersmith Hospital in London. He has published over 300 peer-reviewed journal articles on MRI techniques, clinical applications of MRI, image interpretation and related subjects, and has over 26,000 citations. Much of the content of present-day clinical MR examinations is derived from his early work.


“Graeme Bydder is one of the godfathers of MRI,” said Paul Condron “In my career I have quoted his work countless times and we use his sequences daily. Having the opportunity to work alongside GB (as he is known) on this project is like being asked if I want to have a game of rugby with the All Blacks.

“He is revolutionising the way we think about contrast weighting in MRI and addressing the central contrast problem, something that has not changed since the early days. Graeme is able to take something so complex and break it down to a level that everyone can understand. The initial images acquired at Matai clearly depict changes that are not seen on current ‘gold standard’ imaging, which may lead to improvements in treatment of diseases in the future.”

Mātai chief executive and director of research Dr Samantha Holdsworth agreed.


“It was pretty neat to see Graeme’s maths and physics in action — seeing how applying it can light up inflammatory brain lesions.”


The new research tops off a busy month for Mātai researchers.


Earlier in July, Mātai announced it was ready to launch a “game-changing” public pathway in the diagnosis of prostate cancer.


The pathway will address issues of accuracy and equity when it comes to the most commonly diagnosed cancer in New Zealand.


One in six of all cancers diagnosed is prostate cancer, with Māori, Pasifika and rural men identified as more vulnerable.


The Mātai pathway is a three-year New Zealand-first project that Dr Daniel Cornfield said would address “deficiencies in current biopsy techniques”.


With a generous donation from the Hugh Green Foundation, Mātai will be bringing in a new biopsy machine next month which is essential to the project.


Mātai is a not-for-profit research centre focused on enhancing the capabilities of medical imaging using new and advanced software, post-processing and artificial intelligence.