Intera 1.5 t pulsar system

Ours was an observational retrospective, single‐center, case series study conducted by searching electronic records between 2010 and 2021. Search terms included: bruxism, teeth grinding, and jaw clenching. Inclusion criteria consisted of (a) complete medical records, (b) episodic AB as a presenting complaint or observed during physical or neurological examination or hospitalization, and (c) magnetic resonance imaging (MRI) or computed tomography (CT) of the brain. Exclusion criteria consisted of oroalimentary automatisms during epileptic seizures. As electroencephalography was not performed, the criteria of exclusion for oroalimentary automatisms such as teeth grinding, chewing movements or teeth chattering included (a) nondistractible episodes, (b) impaired consciousness, (c) concurrent autonomic signs, (d) evolution into a generalized tonic‐clonic seizure and (e) pre‐ or postictal signs. Diagnostic imaging was performed using a high‐field MRI scanner (Philips Intera 1.5‐T Pulsar System, Philips Medical Systems, Guildford, England) and a 64‐slice helical CT scanner (Somatom Definition AS Siemens, Erlangen, Germany).

MRI was used to track MION‐labeled cells. Isolated forelimbs were scanned from the distal aspect of the digits to the mid metacarpal region with a 1.5 T MR scanner (Philips Intera 1.5 T Pulsar System; Philips Medical Systems, Guildford, UK). Images were acquired in the transverse plane with a 61 × 61 mm field of view, 0.55 mm slice thickness, and 0.51 × 0.51 × 0.55 mm voxel size. Gradient echo sequences (Flip angle 15°, TR = 30 ms) were chosen over turbo spin echo sequences in order to maximize sensitivity to the susceptibility artifact generated by MION particles, resulting in signal void. In order to differentiate the hypointense signal generated by MION particles from other causes of signal void, such as scar tissue (or other fibrous tissue such as tendons), a dual echo technique (short TE = 7.2 ms and long TE2 = 17.4 ms) was used. This provided spatially matching image series, in which the susceptibility artifact associated with MION would increase in size in the long TE images when compared with the short TE images, while the size of other causes of signal void would not be affected.