Magnetic resonance imaging of tuberous sclerosis complex with or without epilepsy at 7 T

This study was conducted to determine the benefit of magnetic resonance imaging (MRI) at 7 T in detecting structural lesions and previously unidentified abnormalities in patients with tuberous sclerosis complex (TSC). Thirteen patients with TSC (8-36 years, seven males) previously diagnosed by 3 T MRI underwent additional imaging at 7 T, which included T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE), T2-weighted turbo spin echo (TSE), SPACE fluid attenuated inversion recovery (FLAIR), susceptibility weighted imaging (SWI), white matter suppressed (WM-suppressed), and gray-white matter tissue border enhancement (GW-TBE) MPRAGE sequences. Subtle lesions, tuberal morphology, and perituberal cortex abnormalities were examined and compared to those observed at 3 T MRI using standard sequences. Improved visualization of TSC lesions was achieved in all subjects at 7 T compared to 3 T imaging, and three subjects received resective surgery. The 7 T T1- and T2-weighted images had high spatial resolution and provided a clear delineation of the perituberal cortex. SWI revealed abnormal blood vessel morphology. WM-suppressed and GW-TBE protocols, adjusted specifically for TSC imaging, aided in visualizing lesions and uncovered more extensive subtle lesions and abnormalities beyond the conventionally detected tubers. Due to its high spatial resolution and powerful new imaging protocols, 7 T MRI provided a better evaluation of subtle lesions and perituberal details compared with conventional MRI at 3 T, with potential implications for diagnosis and operative treatment of TSC and its related epilepsy. (orig.)