Trio 3 tesla scanner

All participants smoked one of their own cigarettes immediately following signing the informed consent to standardize the time since a cigarette was last smoked. MRI scanning began approximately 1.5 h after smoking this cigarette. Scans were acquired on a Siemens Trio 3 Tesla scanner (Erlangen, Germany) with a 32-channel head coil. Multiecho multiplanar rapidly acquired gradient-echo (ME-MPRAGE) structural images were acquired with the following parameters (TR  =  2.1 s, TE 3.3 ms, slices  =  128, matrix  =  256×256, flip angle  =  7°, resolution  =  1.0 mm×1.0 mm×1.33 mm), and gradient echo echo-planar images were acquired using the following parameters (TR  =  2.5 s, TE  =  30 ms, flip angle  =  90°, slices  =  42, voxel size  =  3.5 mm isotropic). Slices were acquired aligned to the anterior and posterior commissure and the phase encode direction was set to acquire from the posterior to anterior direction to prevent prefrontal signal loss. During the 6-minute resting state fMRI scans participants were asked to remain awake with their eyes open. Two resting state scans were acquired approximately 1 h apart.

All the subjects were scanned on a Siemens Trio 3-Tesla scanner with a 32-channel head coil. T1-weighted images were obtained using a sagittal 3D magnetization prepared rapid gradient echo (MP-RAGE) sequence: slice number = 144, time repetition (TR) = 2530 ms, time echo (TE) = 3.39 ms, flip angle (FA) = 7°, slice thickness = 1.33 mm, field of view (FOV) = 256 × 256 mm², in-plane resolution = 256 × 256, time to inversion (TI) = 1100 ms, voxel size = 1 × 1 × 1.33 mm³. The resting-state functional images were obtained using an echo-planar imaging (EPI) sequence (8 min): slice number = 33, thickness/gap = 3.5/0.6 mm, TR = 2000 ms, TE = 30 ms, FOV = 200 × 200 mm², in-plane resolution = 64 × 64, FA = 90°, and 200 volumes.