The scientists at the University of Cambridge have developed a new technique that uses ultra-powerful 7T MRI scanners to detect minute brain differences in patients with treatment-resistant epilepsy.
The new technique has allowed doctors at Addenbrooke’s Hospital, Cambridge, to offer surgical interventions to patients, potentially curing their condition.
The approach addresses the previous limitations of 7T MRI scanners, which suffered from signal blackspots in critical brain areas.
The new technique significantly enhances the resolution of brain scans, doubling the chances of seizure freedom post-surgery.
The introduction of the ‘parallel transmit’ technique, developed by researchers at the University of Cambridge’s Wolfson Brain Imaging Centre and Université Paris-Saclay, involves using eight transmitters around the brain.
The method overcomes the signal dropouts common in 7T MRI scans, particularly in the temporal lobes where most epilepsy cases originate.
University of Cambridge professor of biomedical Imaging Chris Rodgers said: “It used to be the case that MRI scanners used a single radio transmitter, but in a similar way to how single Wi-Fi routers leave areas where you will struggle to get a signal, so these scanners would tend to leave blackspots on brain scans where it was hard to make out the relevant tissue.
“Now, by using multiple radio transmitters positioned around the patients’ head – like having a Wi-Fi mesh around your home – we can get much clearer images with fewer blackspots. This is important for epilepsy scans because we need to see very precisely which part of the brain is misbehaving.
“The Paris group’s plug-and-play sequences avoid the need to calibrate the scanner at every visit, making it practical to use these scans for scanning patients.”
The study, published in Epilepsia, demonstrates the effectiveness of this approach.
In a trial involving 31 drug-resistant epilepsy patients at Addenbrooke’s Hospital, the parallel transmits 7T scanner identified previously unseen structural lesions in nine patients.
It confirmed suspected lesions in four patients and ruled out suspected lesions in the other four, and the parallel transmit images were clearer than conventional 7T images in 57% of cases.
The findings led to significant changes in epilepsy management for over half of the patients.
Nine patients were offered surgery to remove lesions, while one patient received laser interstitial thermal therapy.
Three patients had complex lesions that precluded surgery, and five patients were offered stereotactic electroencephalography (sEEG) to pinpoint lesions using electrodes.
Patient feedback indicated that the parallel transmit 7T MRI was generally well-tolerated, with minor side effects such as dizziness and claustrophobia.
The study suggests that the technique is acceptable to patients and represents a significant advancement in the treatment of drug-resistant epilepsy.
