The Center’s magnetic resonance imaging (MRI) facilities include the following.
Large-bore MRI Systems
* All subject bays are equipped with Blu-ray/DVD players for subject entertainment
Bay 1: Siemens 3T MRI Skyra with 128ch receive capabilities and 2ch pTx
This is a Siemens 3T Skyra with 128-channel receive capabilities and 2-channel parallel transmit. The system comes with 128 RF channels, 40mT/m gradients and a 70cm patient bore for improved subject comfort (and mandatory for fetal imaging) and stimulus access. The scanner provides Siemens 32- and 64-channel head coils as well as an assortment of body arrays. Bay 1 also contains an assortment of audio, visual, and sensory stimuli equipment for fMRI studies, including digital high-definition rear projection, audio stimulation, and a subject response device. The stimulus equipment is set up to be run from a PC, a Macintosh, or the user’s laptop computer. Stimuli can trigger or be triggered by the scanner. Bay 1 is also equipped with a state-of-the-art power injector. Furthermore, the system is configured for simultaneous TMS/MRI operation, including a video navigation system for the TMS stimulator.
Bay 2: Siemens 7T Terra.X MRI
This is a 7T MAGNETOM Terra.X system with a 60-cm bore which has CE and 510(k) approval for clinical use. This upgraded system has a gradient strength of 130 mT/m and slew rate of 250 T/m/s, provides passive and active shimming up to 3rd order, and is equipped with up to 64 receive channels and 16-channel parallel transmit (in research mode), including an 8-channel Tx Nova 32-channel receive head coil. The increased SNR allows for 0.2 mm in-plane resolution to visualize previously unseen structures, 0.14 cm³ voxel sizes for metabolic brain mapping (in research mode) and submillimeter BOLD fMRI precision to visualize sub-cortical activations. Bay 2 also contains an assortment of audio, visual, and sensory stimulus equipment for fMRI studies and rear projection, audio stimulation, and a subject response device setup. Stimuli can trigger or be triggered by the scanner. The user may operate the stimulus equipment from a personal laptop computer. Bay 2 is also equipped with a Siemens Syngo workstation for 3D image processing, cardiac evaluation, and quantitative image analysis.
Bay 3: Siemens 7T Terra.X MRI Impulse edition
This project will leverage a next-generation 7T human head MRI scanner currently under construction at the Martinos Center. The system features the exclusive Impulse high-performance head-only gradient platform, developed by Siemens Healthineers in close collaboration with Martinos Center investigators and designed to be the most powerful 7T gradient system available for human research. Upon completion, this installation will be one of only three Impulse systems nationally (alongside UC Berkeley and Stanford), positioning the Martinos Center as an international leader in ultra-high-field MRI performance.
The Impulse gradient coil is purpose-built for 7T imaging and delivers exceptional performance, with a maximum gradient strength of 200 mT/m and a maximum slew rate of 900 T/m/s—significantly greater than the most advanced whole-body gradient systems in routine use. This performance substantially increases encoding speed while reducing distortion and blurring, directly addressing key limitations of ultra-high-field MRI. These capabilities will significantly enhance echo-planar imaging (EPI)–based techniques, including fMRI, diffusion MRI, and perfusion imaging. In fMRI, improved encoding efficiency enables spatial resolutions beyond current encoding-limited constraints, allowing full exploitation of 7T sensitivity for submillimeter functional mapping. In diffusion imaging, high gradient strength and rapid slew rates shorten diffusion encoding times, reduce T2-related signal loss, and enable more robust microstructural characterization.
The scanner bay will be equipped with advanced RF hardware, including a 64-channel receive / 8-channel transmit coil from MR CoilTech, an in-house–developed 64-channel receive / 8-channel transmit coil, and a 24-channel visual cortex coil. The bay will also include a Skope NYOX field camera for real-time monitoring and correction of gradient-induced field perturbations, as well as integrated audiovisual and sensory stimulation systems for fMRI, including rear projection, audio delivery, and subject response devices.
As of January 2026, construction is underway, with completion and readiness for human scanning anticipated in summer 2026.
Bay 4: Siemens 3T Prisma MRI
This is a 3T Siemens Prisma fit, 128-channel whole-body MRI with a two-channel transmit system. The system features the Siemens XR200 gradient system with 80 mT/m gradient strength and 200 T/m/s maximum slew rate. Bay 4 is equipped with a full assortment of body imaging coils as well as Siemens 32-channel and 64-channel head-neck coils. Bay 4 is also multi-nuclear capable and an MGH-built 8-channel 31P head array is available. In addition, it contains an assortment of audio, visual, and sensory stimulus equipment for fMRI studies including rear projection, audio stimulation, and a subject response device. Bay 4 has also been configured to allow simultaneous TMS stimulation as well as recording of simultaneous EEG.
Bay 5: Siemens 3T Cima.X MRI
The Siemens 3T Cima.X whole-body MRI scanner provides state-of-the-art gradient performance and advanced acquisition/reconstruction capabilities. The features and benefits provided by this state-of-the-art platform are summarized as follows: (1) next-generation whole-body Gemini gradient technology featuring maximum gradient strength of 200 mT/m and high slew rate of 200 T/m/s that significantly boosts signal-to-noise ratio and enables higher resolution and faster imaging across a range of applications; (2) streamlined and standardized workflows for greater ease of use, enabling a broader user base as well as robustness and consistency across sessions using the newest Numaris X Syngo software platform; (3) standardized hardware and software for compatibility with other sites, enabling the Martinos Center’s technological developments to be readily translated to the newest platform and integrated into new, collaborative multi-site trials; (4) enhanced system performance including 128 RF receiver channels, local BioMatrix shims, integrated BioMatrix high-temporal-resolution physiological monitoring, a faster image reconstruction computer, a new Open Recon platform for on-scanner integration of research and third-party image reconstruction algorithms, and new sequence and application packages compatible with the latest Siemens platform; and (5) an up-to-date testbed for the unique instrumentation and technology research and development performed at the Martinos Center, including advanced imaging sequences and reconstruction, higher-density receive coil arrays, and shim-RF multi-coil arrays to be shared with our collaborators and freely disseminated to the MRI community.
Bay 6: Martinos 3T MR/PET (head-only)
The combined MR-PET system consists of a 3T Siemens TIM Trio with a 60 cm (RF coil ID) 32-channel whole-body MRI (Siemens Healthineers, Erlangen, Germany) and a BrainPET head camera (Cubresa Inc., Winnipeg, Canada) insert for simultaneous MR-PET acquisitions. The BrainPET has an axial FOV of 200 mm and incorporates an ergonomic head holder, which allows the insert to slide into place over the patient for imaging. The PET detector modules consist of dual-layer offset LYSO scintillator arrays (bottom layer 26 ´ 12 crystals, 2.35 ´ 2.35 ´ 12 mm3; top layer 25 ´ 11 crystals, 2.35 ´ 2.35 ´ 8 mm3) coupled to SiPMs. The performance characteristics for the Cubresa BrainPET include sub-2 mm spatial resolution and 8% sensitivity. The BrainPET contains an actively decoupled quadrature-polarized transmit coil and a helmet-shaped 32-channel receive array.
This MR system has EPI, second-order shimming, CINE, MR angiography, diffusion, perfusion, and spectroscopy capabilities for both neuro and body applications. It uses the same gradients as the 1.5 T Avanto (Bay 2; 45 mT/m strength, 200T/m/s slew rate).
Bay 6 also contains an assortment of audio, visual, and sensory stimulus equipment for fMRI studies, including rear projection, audio stimulation, and a subject response device. The system is located adjacent to the research cyclotron.
Bay 7: Siemens 3T mMR MR/PET (whole-body)
The Biograph mMR scanner (Siemens Healthcare Inc.) consists of a 3T whole-body superconductive magnet with active shielding and external interference shielding and a whole-body PET scanner. It is equipped with a gradient system with a maximum gradient amplitude of 45 mT/m and a maximal slew rate of 200 T/m/s. Separate cooling channels that simultaneously cool primary and secondary coils allow the application of extremely gradient intensive techniques. This scanner is equipped with the “TIM” RF coils that were custom designed to minimize the 511 keV photons attenuation. The fully-integrated PET detectors use APD technology and LSO crystals (eight rings with 56 detectors blocks per ring, each consisting of 8×8 arrays of 4×4×20 mm3 crystals read out by a 3×3 array of APDs). The PET scanner’s transaxial and axial fields of view are 594 mm and 25.8 cm, respectively. The Biograph mMR scanner is also located adjacent to the research cyclotron.
Bay 7 also contains an assortment of audio, visual, and sensory stimulus equipment for fMRI studies including rear projection, audio stimulation, and a subject response device.
Bay 8: Human Connectome Scanner
The Connectome 2.0 scanner is the one-of-a-kind next-generation human connectomics MRI scanner, engineered as a joint collaborative effort between the Martinos Center and Siemens Healthineers and funded by the NIH BRAIN Initiative. The system replaces the original Connectome 3T MRI system (MAGNETOM Connectom, Siemens Healthineers), which was installed at MGH from 2011-2023 and featured a whole-body gradient (AS302) equipped with maximum gradient strength of 300 mT/m and slew rate of 200 T/m/s.
The Connectome 2.0 MRI system (MAGNETOM Connectom.X, Siemens Healthineers) is built on the Siemens Vida platform incorporating the latest 3T wide-bore magnet design with excellent magnetic field homogeneity. This next-generation system is equipped with a high-performance asymmetric head gradient featuring a maximum gradient amplitude of 500 mT/m and high slew rate of 600 T/m/s. This powerful gradient has a maximum effective amplitude of 866 mT/m (vector addition of all 3 gradient axes) and maximum effective slew rate of 1039 T/m/s. The gradient coil incorporates the latest high-efficiency technology including direct liquid cooled conductors to enable high current density without incurring excessive heating. The gradient system is driven by two high-performance gradient power amplifiers (GPA’s) with peak current of 1200 A and peak voltage of 2250 V per axis and features sophisticated dual-GPA control, allowing the system to achieve full gradient strength for maximum duty cycle on diffusion imaging and other imaging sequences using fast readouts. The head gradient has a novel three-layer coil geometry that incorporated detailed peripheral nerve stimulation modeling in the design phase to maximize the usable parameter space for in vivo human brain imaging. The three-layer gradient coil geometry consists of a narrow inner cylinder, wider middle cylinder with shoulder cut-outs, and spacious outer cylinder to allow a typical range of adult subjects to be scanned. The resulting design achieved the target specifications of <10% nonlinearity in a 22 cm region of linearity and a relatively large inner diameter of 44 cm.
The system comes with two transmit channels, 96 RF receive channels and a custom-built tune-up coil, as well as a dedicated 72-channel receive coil for head/neck imaging and a 64-channel ex vivo whole brain receive array, each of which has 16 clip-on field probes from Skope embedded into the 3D-printed array scaffolds to enable real-time magnetic field monitoring. The system allows for up to second order shimming and dynamic and concurrent field monitoring to minimize image distortions and artifacts from eddy currents induced by the strong gradients. As a MAGNETOM 3T system, the instrument is equipped with the highest performance compute option for the fastest image reconstruction available with modern accelerated imaging techniques. It comes with the latest state-of-the-art Numaris X software platform and a suite of software packages required for high-end neuroimaging, including advanced diffusion, fMRI, ASL, and quantitative imaging applications. The system also enables new research capabilities through the recently introduced Open Recon interface, which enables third-party image reconstruction and post-processing solutions to be integrated directly in the reconstruction pipeline. The system electronics include a modern 4G DaVinci generation console and a high-end “MARS” image reconstruction computer equipped with a high-capacity RAID for temporary data storage and multiple GPU accelerators for fast image reconstruction. Bay 8 also contains visual (rear projection) and auditory stimulation setups as well as a triggering interface to enable high-quality functional MRI measurements.
This one-of-a-kind system represents the ultimate diffusion MRI instrument capable of capturing the complex multi-scale organization of the human brain.
Bay 9: uMI Panorama GS PET/CT system
The uMI Panorama GS (United Imaging Healthcare, Houston, TX) is a state-of-the-art long axial field-of-view (LAFOV) digital PET/CT system designed to provide simultaneous high sensitivity and high spatial resolution imaging across the entire body. The PET component features LYSO crystals (2.76 × 2.76 × 18.1 mm³) coupled to advanced digital silicon photomultiplier (SiPM) detectors, providing a 148 cm axial field of view that enables true whole-body coverage in a single bed position. This configuration allows ultra-fast time-of-flight imaging, dynamic total-body studies, and quantitative whole-body parametric mapping with exceptional signal-to-noise performance.
The CT subsystem supports up to 160-slice acquisitions, rapid gantry rotation, low-dose imaging protocols, and dual-energy capabilities for accurate anatomical localization and attenuation correction.
The system is optimized for both clinical and research applications, including oncology, cardiopulmonary, and neuroimaging studies, and is particularly well-suited for advanced protocols such as dynamic tracer distribution, kinetic modeling, and systems-level investigations of physiology and disease.
Bay 9 is equipped with subject monitoring and audiovisual systems to ensure participant comfort and is located on the same floor as the radiochemistry facility, providing immediate access to a broad array of PET tracers.
The Low-field MRI and Hyperpolarized Media Laboratory
A custom-made 6.5-mT scanner in this laboratory is enabling novel research on spin-polarized materials and their use as magnetic tracers in vivo. The lab is working to develop orientation-variable imaging of human lung function with inhaled hyperpolarized noble gas (3He). This novel open geometry MR technology allows imaging in a variety of orientations (i.e., subject may be standing, sitting, or lying down) and without the limitations of high-field imaging, which exclude subjects with implants, pacemakers, etc. By the process of hyperpolarization, which increases the atomic nuclear spin polarization, the NMR signal of noble gases such as 3He and 129Xe can be increased by four to five orders of magnitude, allowing their detection by low-field MRI scanners. Current research applications include studies of pulmonary physiology, e.g., to map ventilation and pulmonary oxygen concentration as a function of body orientation in the gravitational field.
Mock Magnet
The mock magnet is used to acclimate normal and clinical populations (children and adults) to the MRI environment in preparation for participation in MRI studies. The mock scanner is modeled after the Siemens 3T Allegra system in both structure and dimensions. Its parts include an original Siemens patient table, funnel and head coil. Transducers and recordings of scanner noise from the Siemens 1.5T (Sonata) and 3T are used to simulate the vibrations and pulse sequence noises associated with the actual scanning experience. Stimuli may be presented using headphones or a rear projection system; a mirror is mounted on the head coil (as also found in Bays 2, 3 and 4), and a button box is available for responding to stimuli. Potential subjects who are anxious about participating in MRI studies are gradually desensitized to the confined space of an MRI magnet tunnel through a series of training steps. A feedback system to help train subjects to remain still when in the scanner is being developed. The mock scanner is located near the Behavioral Testing Suite, and in close proximity to the 1.5T and 3T magnets.
Small-bore MRI Systems
9.4T MRI
The 9.4 Tesla (400 MHz proton frequency) 21-cm diameter horizontal bore magnet (Magnex Scientific) uses a Bruker Avance III console with ParaVision 6.0 operating software for MR imaging and is capable of imaging small animals (rats and mice). The scanner is equipped with 4 radio-frequency (RF) receive channels allowing for the use of phased array receive coils. Capabilities include high-quality, high resolution, anatomical and functional imaging using a wide variety of contrast mechanisms (T1, T2, diffusion, perfusion), together with multi-shot 2D and 3D sequences, single-shot EPI, Chemical Exchange Saturation Transfer (CEST) sequences, Ultrashort Echo Time (UTE) sequences, and localized multinuclear NMR spectroscopy and spectroscopic imaging. The dual gradient system comprises a Bruker gradient coil capable of 44 G/cm, and a Resonance Research (Billerica, MA) gradient insert capable of 150 G/cm.
4.7T MR-PET
The 4.7 Tesla (200 MHz proton frequency) MR-PET scanner consists of a 40 cm diameter horizontal bore magnet (Bruker Biospin) interfaced to a Bruker Avance III console with ParaVision 7.0 operating software for MR imaging, and a PET insert (Bruker Biospin) with Paravision 360 operating software for PET imaging. The system is capable of multinuclear MR imaging, MR spectroscopy, and simultaneous PET-MR imaging of small animals (rabbits, rats and mice). The scanner is equipped with 4 radio-frequency (RF) receive channels allowing for the use of phased array receive coils. Capabilities include high-quality, high resolution, anatomical and functional imaging using a wide variety of contrast mechanisms (T1, T2, diffusion, perfusion), together with multi-shot 2D and 3D sequences, single-shot EPI, Chemical Exchange Saturation Transfer (CEST) sequences, Ultrashort Echo Time (UTE) sequences, localized multinuclear NMR spectroscopy and spectroscopic imaging, and simultaneous PET-MR. The scanner has three different Bruker gradient coils available for different imaging applications including a 20-cm i.d. BGA-20S-HP gradient with maximum field strength of 30 G/cm, 12-cm i.d. BGA-12S-HP gradient with maximum field strength of 66 G/cm, and a BGA-06 gradient with maximum field strength of 100 G/cm. The PET insert fits into the BGA-20S-HP gradient and has 0.7 mm resolution with Full Field Accuracy (FFA) and 12% sensitivity.
11.7T Spectroscopy
The 11.7 Tesla laboratory includes a 54 mm i.d. vertical bore, actively screened magnet interfaced to a JEOL 500 MHz NMR console with variable temperature capability. This instrument has 3 RF channels, each with complete waveform shaping capability. Channel 1 is highband, with 1H/19F observe, spinlock and decouple capability (100 W, 455-535 MHz). Channel 2 has broadband observe, spinlock and decouple capability (10-210 MHz, 300 W). Channel 3 is highband, with 1H/19F observe, spinlock and decouple capability (100 W, 455-535 MHz). The probe consists of a 5mm ROYAL HFX, triple-channel NMR probe (1H,19F, and X) with 3G/A*cm Z gradient, and BB range from 31P to 109Ag. The probe is auto tune/matched and has VT capabilities for operation between -170 to +250°C.
14T Spectroscopy/Microscopy
The 14.1 Tesla (600MHz) laboratory consists of a 8.9-cm wide bore, actively screened, vertical bore Magnex magnet interfaced to a Bruker Avance III HD spectrometer console. Capabilities include dual RF channels and deuterium lock; 5-mm and 10-mm direct and indirect observation high-resolution (0.7 ppb) multinuclear multidimensional liquid state spectroscopy; high-resolution (1.6 ppb) 1H and 13C MAS spectroscopy (including gradient spectroscopy); high-power multinuclear cross polarization/magic angle spinning (CP/MAS) spectroscopy; an automated MAS sample changer; multinuclear (31P/1H, 19F/1H, and 13C/1H) micro-imaging and in vivo spectroscopy; actively screened gradients with up to 150 G/cm; and variable controlled temperature from –100 to +150 °C with stability approaching 0.1 °C.
14T MR Microscopy
This system comprises a 14.1T (600 MHz) Magnex 130-mm diameter horizontal magnet and Resonance Research gradient and shim coils interfaced to a Bruker Avance Neo console with 4 receiver channels; installation of the system is currently ongoing, and is nearing completion. A quadrature birdcage coil and surface transmit/receive coils are available for use.