Magnetic Resonance: Siemens Prisma 3T MRI Scanner
Siemens Prisma 3T: actively shielded, whole body 3 Tesla magnet, 80mT/m gradients with a slew rate of 200 T/m/s. The MR system is equipped with a 20 channels RF coil and a 64 channels RF coil for experimental neuroimaging applications.
- 32” LCD for visual stimuli (NNL);
- projector EPSON EMP-7900;
- optic fiber digital microphone with noise cancellation for vocal registration during imaging;
- on-board Audio system (Siemens pneumatic headphones and earplugs);
- 2 x 4 button response pads (Cedrus LP-400 Response pad and Cedrus Lumina LSC-400B Controller);
- MR compatible glass frames (adult and pediatric, max -6 and +6);
- tactile piezoelectric stimulator (2 x 5 fingers) (QuaeroSys);
- Eye Tracker (Eyelink1000);
- MR-compatible EEG (Brainamp, 64 channels);
- galvanic skin responses (Brainamp GSR);
- physiological data monitoring and recording (ECG, pOx, respiration pulses);
- other equipment can be made available upon request, after feasibility study (physiologic monitoring , communication PC , docking station...)
MRI Lab provides the researchers with:
- a stimulation pc located in control room , connected to the Peripheral Equipment within the Scanner room and equipped with a stimulation software. The Stimulation PC can receive triggers from the scanner and responses from the NNL ButtonBox systems;
- a training pc, clone of the stimulation PC, can be found in the MRI area and used to test paradigms and to train subjects outside the scanner.
- Matlab R2017b with PsychToolbox 3 - 2018-04-14v3.0.14 and ASF as stimulation framework
- E-Prime (v.2.0 10.242)
- Presentation (v. 20.1 Build 12.04.17)
- Labview complete runtime environment (National Instruments)
- GStreamer 1.14.1
- Processor: Intel Xeon CPU E5 - 1620 v30 @3.50GHz - 4 core, 8 GB RAM
- Video Card: NVIDIA GeForce GTX 1050 Ti - 1 GB dedicated Video RAM
The stimulation PC is permanently connected to the projector connected to the stimulation PC with a VGA port (see Figure below), to be used to present stimuli and register subjects responses. Images are projected on a removable acrylic screen seen by the subject through a mirror put on the MR coil.
VGA connection of the graphic card of the stimulation PC and the projector
Instructions for users
- Accession: the password is printed on LCD monitor. Log in locally (PC offline).
- Connection: use a portable device for your script.
In case a laptop is needed to present stimuli, the VGA connector (labeled with "projector input") and the Serial port have to be unplugged from the stimulation PC and plugged to the laptop. After the session the normal default configuration of all connections has to be restored for the following user; this is very important because all equipment is shared among all research projects .
Updates and Development
The descripted hardware and software equipment is the standard configuration of the Stim-PC. Updates made by MRI Lab will be announced in advance and described to the users. Potential specific configurations should be requested by sending an email to MRI Lab staff. The staff will discuss if and how implement requested changes in the lab environment.
Nordic Neurolab Box
Signals coming from Scanner Room are managed by Nordic Neurolab Box (NNL Box), which is connected to the button boxes through a optic fiber cable and to the scanner through a BNC cable.
NNL Box is in turn connected to the Stim-PC through USB. Stim - PC collect signal from the scanner room as if it was an external USB keyboard.
This means that whenever a signal is sent from within scanner room, numbers appear on the Stim-PC. Keep this in mind when you need to collect responses within your matlab code.
The scanner, during functional acquisitions, sends a 50 us "pulse" every TR, marking in this way the "volumes" of your MRI experiment. Synchronization with the scanner trigger is provided through a BNC cable connected to the NordicNeuroLab box, attached to Stim-PC via a USB Port. Stim-PC collect triggers as if someone was systematically pressing "5" key (the one located in the alphanumeric part of the keyboard) at the beginning of each volume acquisition. This means that in debugging, you can test your scripts by simply accepting "5" key
MRI Lab provides two 4- button boxes for the participant to send responses while performing inside the scanner. Buttons are arranged in a linear way. They are marked as right and left through a duct tape. They send, respectively, "1","2","3","4" and "6","7","8","9" keys to Stim-PC.
You can check the responses by focusing on NNL Box during the experiments. Specific green leds light up when a button is pressed.
For the visual stimuli presentation MR-Lab provides a compatible Nordic NeuroLab LCD monitor positioned at the back of the magnet bore.
Basic monitor specs include: 878 mm horizontal x 485 mm vertical; 3840 x 2160 pixels; surface luminance 350 c/m2; contrast ratio 5000:1 typ, refresh rate 60Hz @ UHD, 120Hz@FHD
Current setup includes very basic auditory capabilities. Participants can hear auditory stimuli sent from Stim - PC through earplugs. Currently there is no possibility to work with different channels, fine-tune the equalisation or record participants' voice.
You can always send an email to MRI Lab staff asking generic questions. In this way the whole staff will notice your request and specific staff memebers would combine their efforts to provide you an answer.
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