The Philips Intera Achieva 3T MRI scanners are state-of-the-art scanners with superior gradient performance (80 mT/m gradient strength, 200T/m/s slew-rate) and 16 independent digital receiver channels. The number and types of RF coils are constantly being expanded. Those currently available include:

• Quadrature Body Coil
• Quadrature T/R head coil
• 6-ch SENSE head coil
• 8-ch SENSE head coil
• 8-ch SENSE Knee coil
• 4-ch SENSE Breast coil
• 6-ch SENSE Torso Array
• 6-ch SENSE Cardiac Array
• 2-ch SENSE Flex Arrays (Small, Medium, Large)
• 6-ch Spine Coil Array
• 50mm id. Small Sample Solenoid Coil

Spectroscopy: A full array of proton spectroscopy methods are available, including: STEAM, PRESS, 2D and 3D CSI, including SENSE acceleration. Multinuclear spectroscopy (primarily 13C and 31P) is also available:

• 31P: a 14cm id surface coil, along with proton decoupling (via Quadrature Body Coil)
• 13C: a 20cm id, half-volume coil with integrated proton imaging/decoupling coil

For more information on the scanners and ancillary equipment, please see: http://wiki.vuiis.vanderbilt.edu/index.php/Human_Imaging (Vanderbilt access only).

The Philips Intera Achieva 3T MRI scanners are state-of-the-art scanners with superior gradient performance (80 mT/m gradient strength, 200T/m/s slew-rate) and 16 independent digital receiver channels. The number and types of RF coils are constantly being expanded. Those currently available include:

• Quadrature Body Coil
• Quadrature T/R head coil
• 6-ch SENSE head coil
• 8-ch SENSE head coil
• 8-ch SENSE Knee coil
• 4-ch SENSE Breast coil
• 6-ch SENSE Torso Array
• 6-ch SENSE Cardiac Array
• 2-ch SENSE Flex Arrays (Small, Medium, Large)
• 6-ch Spine Coil Array
• 50mm id. Small Sample Solenoid Coil

Spectroscopy: A full array of proton spectroscopy methods are available, including: STEAM, PRESS, 2D and 3D CSI, including SENSE acceleration. Multinuclear spectroscopy (primarily 13C and 31P) is also available:

• 31P: a 14cm id surface coil, along with proton decoupling (via Quadrature Body Coil)
• 13C: a 20cm id, half-volume coil with integrated proton imaging/decoupling coil

For more information on the scanners and ancillary equipment, please see: http://wiki.vuiis.vanderbilt.edu/index.php/Human_Imaging (Vanderbilt access only).

The instrument is a 7 Tesla human magnetic resonance (MR) scanner from Philips Medical Systems. The scanner is designed to take advantage of increased SNR and spectral separations, while providing the flexibility to address the challenges of imaging at high field strengths.

Magnet

The magnet, manufactured by Magnex Scientific Ltd, has a 7 Tesla central field strength and <5 ppm peak-to-peak field variation over a 45 cm spherical volume. The bore size is 900 mm. It is equipped with 13 cryoshims (passive shims are used as needed to cancel higher order field errors). The helium boil-off rate is 0.2 l/h, with greater than 100 days hold time. The mass of the magnet when filled with helium is approximately 32 tonnes. The magnet is installed in a 400 tonne shielded room that isolates the exterior from the magnet's static field and the interior from environmental radio frequency noise.

Room temperature shims

Room temperature shims include second order (Z2, ZX, ZY, XY, X2-Y2) and third order (X3, Y3, Z3, Z2X, Z2Y, Z[X2-Y2], ZXY) coils. The Z2 shim is self-shielded and programmable to allow fast switching (for dynamic shimming applications).

Gradient system

The gradient coils are self-shielded, force balanced, and water cooled, with a 58 cm patient aperture. They support imaging in a 40 cm field of view (FOV) in the X and Y directions, and 35 cm FOV in the Z direction. Maximum gradient strength is 40 mT/m with a slew rate of 200 mT/m/ms.

Radio frequency (RF) transmitters

There are two fully independent transmit channels, each capable of delivering 4 kW to radio frequency coils. Both channels are broadband. The two channels are combinable for a total of 8 kW at 300 MHz.

RF receivers

The receiver currently has 16 independent proton channels, plus 4 supporting quadrature detection at 1H, 19F, 31P, 13C, and 23Na frequencies. The system can be upgraded to more channels as required.

RF Coils

Current radio frequency coils available or in production include a volume transmit/receive head coil, a volume transmit head coil, and 16 channel receive-only SENSE coil for 1H. A transmit/receive volume head coil for 13C-1H is under development. The manufacturer also provides an interface box that allows user-built coils to be used. In the near future, the following proton and carbon-13 coils will be provided in addition to our current coils: a T/R 14 cm surface coil: a T/R 8 cm surface coil: a 12 cm quadrature surface 13C-1H dual coil.

Patient handling

The scanner has a moving bed and an intercom system for communication between the investigators and study subjects.

Pulse sequence capabilities

The system has the same system software, pulse programming environment, and pulse sequences as current 3T Philips scanners, although not all sequences have been optimized for 7T. Our familiarity with the 3T and ability to transfer protocols between the platforms will be a major advantage in performing studies at 7T.

NIR uses a newly developed near infrared optical encephalography system (Hitachi ETG-4000). The ETG-4000 system employs laser diodes in the wavelength range of about 700-900nm. The system uses class 1M laser products in accordance with IEC (International Electochemical Commission) guideline IEC825. Class 1M laser products are considered safe based on current medical knowledge. This class includes all lasers or laser systems that cannot emit levels of optical radiation above the exposure limits for the eye under any exposure conditions inherent in the design of the laser product. The maximum exposure limit for the human eye during prolonged exposure is typically 0.4 microwatts. The laser light is coupled to the subject via optical fibers on a pad laid out in 3 possible matrixes; 3x5, 4x4 or 2 3x3. There is no danger associated with this system. Subjects can perform cognitive tasks in a normal environment and thus there are no risks with the experimental protocol. The ETG-4000 system currently has FDA approval.

The Event Related Potential Laboratory (ERPL) is located in B164 adjacent to the 3T suite and is fully equipped with state of the art neurophysiology experimental research equipment. The goal of the ERPL is to afford researchers the ability to record electroencephalograms (EEGs) while simultaneously acquiring fMRI data. Currently, the ERPL utilizes the Compumedics Neuroscan Synamps2 amplifier in conjunction with either Neuroscan’s 64-channel QuickCap(non-MR compatible) or 64-channel MagLink Cap(MR compatible) to record EEGs for event related potential studies. In order to accommodate many head sizes, the ERPL has both small and medium sized QuickCaps and Maglink Caps. The ERPL utilizes two mobile Dell Optiplex Pentium IV PCs running Windows XP professional to run the data acquisition and stimulus presentation software packages. One of the PCs is solely dedicated to running Neuroscan’s Scan 4.3.3 software which is used for EEG data acquisition and analysis. The other PC is well equipped with a variety of stimulus presentation packages to allow maximum flexibility to the researchers. Some of the packages available include Neuroscan’s Stim and EPrime.

Experiment Room

Interview Room

Mock Scanner

The 3T suite is fully equipped with a range of audio and video presentation equipment. For video presentation, an inside-the-scanner-room XGA resolution Avotec projector (which projects to a screen placed just behind the subject's head), Epson DLP projector (for projection onto a screen at the front of the scanner) or a pair of XGA-compatible LCD goggles for video stimulus presentation can be used, depending on the experimenter’s preference. Headphones for audio stimulus presentation and a microphone for subject feedback are also available, as well as an infrared eye tracker (built in to the LCD goggles). a Macintosh G4 computer, a Dell Pentium IV PC are available for stimuli generation. Software packages available for use include E-Prime, RSVP, Psyscope and Matlab (with the Psychological Presentation toolbox) . Two five-button keypads (one for each hand) interfaced to the computers can be used to collect subject responses if desired (Rowland Institute of Science, Boston, MA). Galvanic Skin Response (GSR) can also be measured.