Parallel transmit 7T MRI for adult epilepsy pre-surgical evaluation

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Drug-resistant focal epilepsy requires precise pre-surgical evaluation.
• Conventional 3T MRI can be insufficient in identifying epileptogenic lesions.
• Advanced 7T MRI offers higher resolution but requires optimized techniques.

Purpose of the Study:

• To implement parallel transmit (pTx) 7T MRI for pre-surgical evaluation in epilepsy patients with negative or equivocal 3T MRI findings.
• To compare the image quality and diagnostic performance of pTx 7T MRI against conventional single transmit (CP) 7T MRI.
• To assess the impact of pTx 7T MRI on clinical management and surgical decision-making.

Main Methods:

• A comparative protocol using both pTx and CP 7T MRI was implemented in 31 epilepsy surgery candidates.
• Standard MRI sequences (T1, T2, FLAIR, EDGE) were acquired in 3D 0.8mm isotropic space.
• Independent blinded ratings by neuroradiologists, a neurologist, and a neurosurgeon assessed image quality, with quantitative analysis for signal dropout.

Main Results:

• 7T MRI identified previously unseen lesions in 29% of patients and confirmed or disproved 3T-equivocal lesions.
• pTx 7T MRI provided better lesion visualization than CP 7T MRI in 57% of cases.
• Clinical management was altered in 58% of patients, with 10 patients offered surgical intervention (resection or LITT) and others reconsidered for surgery or sEEG.

Conclusions:

• Parallel transmit 7T MRI is implementable in a clinical setting for epilepsy pre-surgical evaluation.
• pTx 7T MRI demonstrates superior image quality and diagnostic utility compared to single transmit 7T MRI.
• This advanced imaging technique significantly impacts clinical management and surgical planning for drug-resistant focal epilepsy.