Magnetic Resonance Imaging

Children examined in MRI without anaesthesia  


For the first time, Bochum clinicians have been able to show on the basis of a large sample, that it is possible to examine children’s heads in the MRI scanner without general anaesthesia or other medical sedation. In many cases it was sufficient to prepare the young patients for the examination in an age-appropriate manner in order to take away their fear of the tube. And the results speak for themselves: of the 2,461 image sequences recorded with 326 patients, the participating radiologists classified 97% as “diagnostically relevant”. At the same time, through his study, the associate professor Dr Christoph M. Heyer (BG Bergmannsheil University Hospital, Bochum) has been able to demonstrate for the first time the value of the so-called BLADE sequences for the comprehensive examination of children in the MRI scanner. The study is published in the November 2012 issue of the journal “RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren.”

Magnetic resonance imaging (MRI) as a radiation-free process plays a key role within paediatric diagnostic radiology imaging. It is indispensable when it comes to depicting the central nervous system of children. Although the advantages of MRI over other test methods are sufficiently well known, many institutions and practices shy away from using it with young children. On the one hand, they assume that the children will not keep still enough to achieve sufficient image quality for diagnosis. On the other hand, they shun the organisational effort and expense involved when they need to sedate or anesthetise the children in order to achieve an unimpeded workflow. For this, the young patients have to be admitted to the ward with a parent. They also have to have a peripheral venous indwelling cannula inserted and be administered sedatives or anaesthetics.

There is another way

Assistant professor Heyer and colleagues have shown that there is another way of doing things. They examined 326 patients with an average age of 7.2 years in the Paediatric Radiology Outpatient Clinic at the Department of Diagnostic Radiology, Interventional Radiology and Nuclear Medicine at the Bergmannsheil University Hospital without sedation or general anaesthesia. All the young patients were previously prepared for the MRI in an age-appropriate manner, given enough time to visit the scanner room, were allowed to take their cuddly toys into the MRI and their parents were with them. In addition, the Bochum clinicians recorded MRI sequences using the sotermed “BLADE” technique so as to exclude “blurring” as far as possible.

With this concept the doctors succeeded in examining 41% of the three year olds, 91% of the four-year olds and 98% of patients over the age of five without sedation. The in total 2,461 image sequences acquired were reviewed by two radiologists, and in a total of 97% of cases declared to be diagnostically usable. The Paediatric Radiology Outpatient Clinic at the BG University Hospital Bergmannsheil specialises in MRI and CT examinations of children and adolescents of all ages. It is headed by assistant professor Heyer, the double specialist for paediatrics and diagnostic radiology/paediatric radiology.

Reference: Dispensing with Sedation in Pediatric MR Imaging of the Brain: What is Feasible? Heyer CM, Lemburg SP, Sterl S, Holland-Letz T, Nicolas V, Fortschr Röntgenstr 2012, 184:1034-1042| doi: 10.1055/s-0032-1313065  

MRI study shows breastfed babies have enhanced brain development  

A new study by researchers from Brown University finds more evidence that breastfeeding is good for babies’ brains. The study made use of specialized, baby-friendly magnetic resonance imaging (MRI) to look at the brain growth in a sample of children under the age of 4. The research found that by age 2, babies who had been breastfed exclusively for at least three months had enhanced development in key parts of the brain compared to children who were fed formula exclusively or who were fed a combination of formula and breast milk. The extra growth was most pronounced in parts of the brain associated with language, emotional function, and cognition, the research showed.

This isn’t the first study to suggest that breastfeeding aids babies’ brain development. Behavioural studies have previously associated breastfeeding with better cognitive outcomes in older adolescents and adults. But this is the first imaging study that looked for differences associated with breastfeeding in the brains of very young and healthy children, said Sean Deoni, assistant professor of engineering at Brown and the study’s lead author.

“We wanted to see how early these changes in brain development actually occur,” Deoni said. “We show that they’re there almost right off the bat.”

Deoni leads Brown’s Advanced Baby Imaging Lab. He and his colleagues use quiet MRI machines that image babies’ brains as they sleep. The MRI technique Deoni has developed looks at the microstructure of the brain’s white matter, the tissue that contains long nerve fibres and helps different parts of the brain communicate with each other. Specifically, the technique looks for amounts of myelin, the fatty material that insulates nerve fibres and speeds electrical signals as they zip around the brain.

Deoni and his team looked at 133 babies ranging in ages from 10 months to four years. All of the babies had normal gestation times, and all came from families with similar socioeconomic statuses. The researchers split the babies into three groups: those whose mothers reported they exclusively breastfed for at least three months, those fed a combination of breast milk and formula, and those fed formula alone. The researchers compared the older kids to the younger kids to establish growth trajectories in white matter for each group.

The study showed that the exclusively breastfed group had the fastest growth in myelinated white matter of the three groups, with the increase in white matter volume becoming substantial by age 2. The group fed both breast milk and formula had more growth than the exclusively formula-fed group, but less than the breast milk-only group.

“We’re finding the difference [in white matter growth] is on the order of 20% to 30%, comparing the breastfed and the non-breastfed kids,” said Deoni. “I think it’s astounding that you could have that much difference so early.” Deoni and his team then backed up their imaging data with a set of basic cognitive tests on the older children. Those tests found increased language performance, visual reception, and motor control performance in the breastfed group.

The study also looked at the effects of the duration of breastfeeding. The researchers compared babies who were breastfed for more than a year with those breastfed less than a year, and found significantly enhanced brain growth in the babies who were breastfed longer – especially in areas of the brain dealing with motor function.

Deoni says the findings add to a substantial body of research that finds positive associations between breastfeeding and children’s brain health.

“I think I would argue that combined with all the other evidence, it seems like breastfeeding is absolutely beneficial,” he said. doi: 10.1016/j.neuroimage.2013.05.090    

MRI used to track cancer-beating nanoparticles   

Small particles loaded with medicine could be a future weapon for cancer treatment. A recently-published study shows how nanoparticles can be formed to efficiently carry cancer drugs to tumour cells. And because the particles can be seen in MRI images, they are traceable.

Both therapeutic and diagnostic in function, the so-called “theranostic” particles were developed by a team including KTH Professor Eva Malmström- Jonsson, from the School of Chemical Science, as well as researchers at Sweden’s Chalmer’s University and the Karolinska Institute in Stockholm.

Malmström-Jonsson says that the particles, which the team developed for breast cancer treatment, are biodegradable and non-toxic. Their research was published in the science journal Particle & Particle Systems Characterization.

The study resulted in a method to make nanoparticles spontaneously build themselves up with tailored macromolecules. The formation requires a balance between the particle’s hydrophilic (capable of dissolving in water) and hydrophobic (not dissolvable in water) parts. The hydrophobic portion makes it possible to fill the particle with the drug.

A relatively high concentration of the natural isotope 19F (fluorine) makes the particles clearly visible on high-resolution images taken by MRI (magnetic resonance imaging). By following the path of theranostic nanoparticles in the body, it is possible to obtain information about how the drug is taken up by the tumour and whether the treatment is working.

Scientists filled nanoparticles with the chemotherapy drug doxorubicin (known as chemo), which is used today to treat bladder, lung, ovarian and breast cancer. In experiments on cultured cells, they showed that the particles themselves are not harmful but can effectively kill cancer cells after being loaded with the drug. The next step is to develop the system to target tumours that are difficult to treat with chemotherapy, such as brain tumours, pancreatic cancer, and drug-resistant breast cancer tumours.

“By targeting groups on the surface, or by changing the size or introducing ionic groups on our nanoparticles, one can increase the selective uptake in these tumours,” says Andreas Nystrom, an associate professor of nanomedicine at the Swedish Medical Nanoscience Center and Department of Neuroscience, Karolinska - Institute.

In the long term, research can result in tailored chemotherapy treatments that seek out tumour cells. This would enable the toxic drug to be delivered more specifically to the tumour, making the treatment more effective while reducing side effects.

“What we want to do is try to give nanoparticles a homing function on the surface so that the drug is as effective as possible and can be transported to the right place,” Malmström-Jonsson says. doi: 10.1002/ppsc.201300018

 Date of upload: 18th Jul 2013


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