Parallel transmit (pTx) 7T MRI for drug-resistant focal epilepsy

Motivation: In one third of patients diagnosed with drug-resistant focal epilepsy 3T MRI cannot identify the causative lesion. Single transmit (1Tx) 7T MRI is more sensitive, but signal dropouts obscure temporal lobes where lesions often occur. Goal(s): Show feasibility of parallel transmit (pTx) 7T MRI to identify epileptogenic lesions and compare with circularly polarized (CP) 7T MRI. Approach: 10 patients with drug-resistant focal epilepsy and normal 3T were scanned with pTx and CP 7T MRI. Results: : pTx images were more uniform than CP. In three cases epileptogenic lesions (focal cortical dysplasia and encephalocele) that had not been visible at 3T were revealed. Impact: Parallel transmit (pTx) 7T MRI improves lesion detection in drug-resistant focal epilepsy patients. With further validation, this could contribute to surgical decision making, potentially without requiring invasive depth electrodes tests. This would widen access to curative epilepsy surgery.