3 tesla system

Patients underwent MRI scans using a GE 3-Tesla system and a 3D CT scan. Initial target coordinates of the ventral intermediate nucleus (VIM) were at 25% of the AC-PC distance anterior to the PC and 14 mm lateral to the AC-PC line. VIM thalamotomy was performed contralateral to the more disabling side and according to the preference of the patient.
On the day of the procedure, the patient's head was shaven completely. A stereotactic frame (CRW Integra Plainsboro, NJ) was fixed to the skull and an elastic silicone diaphragm affixed. The patient's head was attached to the focused ultrasound 1024 US transducers helmet. A T2 weighted MRI scan was performed for planning reassessment.
MRgFUS sonications were performed using a 3-Tesla MRI (GE) and a focused ultrasound system (ExAblate Neuro, Insightec).
Treatment included a gradual increase in total energy either by an increased intensity or by longer sonication durations. Sonications were stopped when adequate control of tremor was achieved, with the temperature reaching no more than 59°C.

Scanning was performed on a GE 3-Tesla System (GE, 12-channel head coil). For image guidance and prescription of voxels of interest, axial T1 images were obtained using three-dimensional magnetization-prepared rapid gradient-echo with settings of time to repetition (TR) = 2,000 (ms), time to echo (TE) = 30 ms, time following inversion pulse (TI) = 1,100 ms, flip angle = 8° and voxel size 1 × 1 × 1 mm³. ¹H-MRS was acquired using the standard PRESS sequence with the following parameters: TR = 2,000 ms, TE = 30 ms. See Figure 1 for our voxel of interest.