NeuroCam™ 7T
MR Head Coil for Parallel Transmission with 64 Independent Receive Elements and 16 Field Probes for High Image Quality and Stability at 7T.
Related Applications: Diffusion Imaging, fMRI
Challenges
- Field fluctuations from system and physiological sources noticeably degrade image quality at ultra-high field strength
- High-performance scanners operating at the technical limit of the hardware inevitably exhibit some system non-linearities that influence image quality
- Non-Cartesian encoding schemes are attractive for advanced neuroimaging but require very accurate knowledge of the encoding fields
- Both, high SNR and spatial resolution are required to answer some of the most fundamental questions about the human brain
MRI has revolutionized our understanding of the human brain by providing non-invasive and detailed insights into its structure and function. The advent of ultra-high field (UHF) MRI scanners, operating at field strengths of 7 Tesla and beyond, has opened up new possibilities for exploring the complexities of the brain. However, along with the numerous advantages offered by UHF imaging, several challenges and considerations must be addressed to ensure optimal image quality and reliable data acquisition. The pursuit of answering fundamental questions about the human brain necessitates both high SNR and spatial resolution in UHF MRI. Achieving these requirements simultaneously presents a technical challenge due to various trade-offs and limitations inherent to UHF systems. Innovations in coil design, parallel imaging techniques, and image reconstruction methods are continuously evolving to strike a balance between SNR and resolution, enabling researchers to obtain the highest quality data for insightful brain investigations. Efforts to mitigate field fluctuations, correct system non-linearities, and optimize non-Cartesian encoding schemes are essential for improving image quality and ensuring reliable data acquisition.
About NeuroCamTM 7T
Head coil with integrated field monitoring for accurate neuroimaging at 7 Tesla
NeuroCamTM 7T with its 64 highly sensitive receive elements provides new opportunities for neuroimaging at 7 Tesla. The tight-fitting geometry ensures optimal coil-head coupling, maximizing sensitivity and minimizing signal loss. Additionally, it features an 8 or 16 channel transmit coil, enabling parallel transmission to achieve a homogeneous spin excitation. By elevating SNR and enabling finer spatial resolution, NeuroCamTM 7T captures subtle anatomical details and facilitates the detection of intricate brain activity.
Operator and Patient Comfort
Easy patient positioning
The transmit array and the anterior part of the receiver array can be shifted toward the service end of the magnet for easy subject positioning. The top part of the receiver has indentations on both sides to easily slide it over the subject.
Enhanced patient comfort
The detachable front-view mirror can be placed on top of the transmit coil to allow the subject to see the magnet room on the patient-side of the bore. The position on the coil can be adjusted via a sliding mechanism.
Easy handling
The compact design and the light weight (14 kg) of the coil assembly facilitates the handling of the coil by the operator.
Enhanced Image Quality
Superior signal-to-noise ratio
The tight-fitted receiver array, which comprises 64 independent elements, provides high SNR for neuroimaging applications.
The increase in SNR is particularly evident within cortical regions when compared to 7T head coils currently available on the market.
The NeuroCamTM 7T also supports higher acceleration factors than the default 7T head coil due to its higher encoding power.
Susceptibility-weighted imaging
Susceptibility Weighted Imaging (SWI) at ultra-high field strengths, such as 7T, offers exceptional detail and contrast, making it ideal for visualizing intricate structures. SWI is particularly useful for detecting microbleeds and hemorrhages, visualizing veins and venous structures, identifying calcifications, and assessing iron deposition. The NeuroCamTM 7T further enhances these advantages by providing excellent image quality with fine detail.
Acquisition parameters
- Patient-specific pTX shim
- Acquired in-plane resolution: 0.3 x 0.3 mm
- Field-of-view: 220 mm
- Matrix: 896 x 728
- Acceleration factor: 3
MPRAGE
The MPRAGE sequence provides great anatomical detail and contrast, making it ideal for visualizing fine structures in the brain and spinal cord. The shown sagittal image demonstrates the extensive coverage down to C6, showcasing the NeuroCamTM 7T's capability to capture detailed images of both the brain and upper cervical spine. The Universal pTX pulses enable uniform excitation and improved image quality across diverse populations without the need for individual patient B1 maps.
Acquisition parameters
- Universal pTX pulse designed for NeuroCam 7T
- Acquired voxel size: 0.75 mm isotropic
- Interpolated voxel size for display: 0.3 mm isotropic
- Acceleration factor: 5 (A-P direction)
- TR: 3000 ms
- TI: 1300 ms
- Acquisition time: 5:19 min
T2 Turbo Spin Echo imaging
The transverse Turbo Spin Echo (TSE) images acquired in Circular Polarized (CP) mode demonstrate excellent image quality, even without the use of advanced RF shimming techniques. Despite being Specific Absorption Rate (SAR) intensive, the efficiency of the coil ensures that it can still produce excellent images at ultra-high field strength.
Acquisition parameters
- Field-of-view: 230 x 173 mm
- Slices: 39
- In-plane resolution: 0.2 x 0.2 mm
- Slice thickness: 3 mm
- Acceleration factor PE: 2
- Acquisition time: 3:38
- CP mode
Improved Image Readability
Homogeneous excitation
The 8 or 16 independent transmit elements of NeuroCamTM 7T allow to homogenize the transmit field via parallel transmission. The coil version with 16 transmit elements does not comprise a front-view mirror due to the smaller size of the transmit elements, but it includes the same rear-view mirror for visual stimulation as the 8-channel version of the coil.
T2 Turbo Spin Echo
The coronal TSE image demonstrates excellent left-right symmetry, achieved through the use of parallel transmission to homogenize the transmit field. The image quality is excellent, showcasing fine anatomical details. Notably, on the patient's right side, the cochlea is clearly visible.
Acquisition parameters
- pTX excitation and refocusing
- Field-of-view: 80 x 161 mm
- Matrix: 320 x 208
- Voxel size: 0.25 x 0.38 mm
- Acceleration factor: 3
- Acquisition time: 5:24 min
MP2RAGE
MP2RAGE is used for obtaining high-quality T1-weighted images, providing superior contrast between white matter and grey matter. This sequence is particularly useful for visualizing sub-thalamic nuclei, deep grey matter structures, and cortical grey matter, as well as for applications such as segmentation and voxel-based morphometry. A patient-specific RF shim was used to further enhance image quality and uniformity.
Acquisition parameters
- Voxel size: 0.75 mm iso
- Field-of-view: 220 mm
- Acceleration factor: 3
T2 FLAIR fat-suppressed Turbo Spin Echo
FLAIR imaging at 7 Tesla (7T) presents unique challenges, primarily due to issues with magnetic field homogeneity and specific absorption rate (SAR) limitations. Enhancing image homogeneity can be achieved through efficient coil design and the use of parallel transmission techniques as demonstrated below.
Acquisition parameters
- Field-of-view: 220 x 220 mm
- In-plane resolution: 0.55 x 0.66 mm
- Slice thickness: 2 mm
- Acceleration factor PE: 3
- Acquisition time: 4:00
- pTX mode
Simplified Setup for Scientific Studies
Large visual field
A detachable rear-view mirror can be attached to the enclosure of the receiver array for visual stimulation.
Unobstructed rear-view
The enclosure of the receiver array is designed to minimally obstruct the visual field.
Functional imaging
The NeuroCamTM 7T is ideally suited for functional MRI (fMRI) applications. Its high cortical signal-to-noise ratio (SNR) and low g-factor penalty enable the acquisition of high-quality images with significantly reduced artifact levels compared to the standard 32-channel head coil.
Acquisition parameters
- Voxel size: 0.8 mm iso
- Acceleration factor: 4
Stable and Reproducible Imaging
Field monitoring
The NeuroCamTM 7T is available with a fully integrated array of 16 fluorine field probes for concurrent measurement of the encoding fields. The probes are located in the enclosure of the receiver array and distributed around the imaging volume to provide optimal conditioning for the spatial expansion of the spherical harmonics basis fields. The housing of the frontend electronics for the field probe array is attached to the back of the coil, where it does not obstruct the visual field of the rear-view mirror.
The field probe hardware of the NeuroCamTM 7T can be easily connected to NYOX, the field monitoring system, using the provided multiconnector cable. This cable is detachable on both ends. If the planned scan session does not include field monitoring, the cable does not need to be connected.
Flexible sampling schemes
Irrespective of the used encoding scheme (e.g. EPI, spiral, radial), the fully integrated field probe array allows to acquire images with enhanced stability and reproducibility.
Spiral diffusion-weighted imaging at 7 Tesla
Concurrent field monitoring enables the use of optimized sampling patterns for data acquisition. The technology facilitates applications that are particularly challenging at 7T, such as diffusion-weighted imaging. By continuously tracking the dynamic magnetic field variations, field monitoring ensures higher accuracy and consistency in the acquired data. This leads to improved image quality and resolution, making it possible to visualize fine structural details and subtle pathological changes that are critical for advanced neuroimaging studies.
Acquisition parameters
- FOV: 216 x 216 x 88.8 mm3
- Resolution: 1.2 mm iso
- Acquisition time: 21.5 min
- b-value/directions: 0 s/mm2 (11 repetitions), 1000 s/mm2 (61 directions), 2000 s/mm2 (61 directions)
- TE: 44 ms
Higher-order field terms
The example below demonstrates the influence of a diffusion preparation on a spiral readout (Courtesy of Sajjad Feizollah and Christine Tardif, McGill University, Montreal, Canada). The data was acquired with a Clip-on Camera on a 7T scanner. The animation on the left-hand side illustrates a field-monitored spiral trajectory that was not preceded by a diffusion gradient. Upon closer examination, distinct characteristics differentiate it from its counterpart on the right-hand side that is influenced by a preceding diffusion gradient. Particularly noteworthy is the considerable disparity observed in the zeroth order term (k0), which represents the fluctuation of the global magnetic field. Upon magnification, discernible amplification of higher order fields is observed beyond the zeroth term. These amplified higher-order fields can be attributed to eddy currents induced by the diffusion gradients. Higher-order terms can have a direct impact on image quality and geometric consistency, which makes their characterization very important.
The ability to simultaneously measure the actual encoding fields provides the opportunity to select more demanding yet efficient readout schemes. To illustrate this, intra-cellular volume fraction (ICVF) maps derived from diffusion-weighted data acquired using two different readout techniques are shown below: echo planar imaging (EPI) on the left and spiral imaging on the right. The usage of a spiral readout, which achieves higher SNR, directly translates into ICVF maps of superior quality.
Physiological fluctuations
By monitoring the magnetic field, real-time adjustments can be made to compensate for fluctuations caused by breathing or other factors, ensuring a more stable and uniform field throughout the imaging procedure. Alternatively, corrections can be applied during image reconstruction by incorporating the measured field data into the process. The figure below illustrates frequency fluctuations caused by a breathing subject in a 7T MR scanner, as measured by four field probes positioned at different locations within the scanner bore (Courtesy of DZNE Bonn, Germany).
Versions
Designed for tomorrow
NeuroCamTM 7T exists in three versions, each tailored to meet specific imaging needs. Choose from our Standard, Advanced, and Excellence versions, each offering unique features and capabilities for exceptional neuroimaging performance.
STANDARD
The Standard version of the NeuroCamTM 7T is a powerful and versatile option that delivers exceptional imaging capabilities. It includes a state-of-the-art MR head coil with 8 or 16 transmit and 64 receive channels. This configuration provides excellent signal reception and allows for precise imaging of the brain. With its advanced technology and reliable performance, the Standard version offers a comprehensive solution for a wide range of imaging needs.
ADVANCED
The Advanced version builds upon the Standard version’s capabilities. It includes the same MR head coil as the Standard version, ensuring high-quality image acquisition. The Advanced version provides the flexibility to upgrade to the Excellence version in the future, allowing you to expand the system’s capabilities as your needs evolve. With its exceptional imaging capabilities and upgrade potential, the Advanced version offers a reliable and future-proof solution.
EXCELLENCE
The Excellence version represents the pinnacle of our MR solution offerings, designed to deliver uncompromising image quality and advanced functionality. In addition to the MR head coil, the Excellence version features a 16-channel field probe array. This innovative array enables precise monitoring and compensation for field fluctuations, resulting in highly accurate and artifact-free imaging. With the Excellence version, you can achieve outstanding image quality and stability, especially for challenging imaging schemes. It offers the most comprehensive solution for cutting-edge research and advanced applications.
Compatible with head-only gradient systems
Supporting Material
Extensive documentation
The NeuroCamTM 7T users benefit from comprehensive technical documentation, providing them with substantial flexibility and the capability to conduct additional RF simulations. This documentation encompasses details on coil design, CAD models, bench and scanner test results, MR compatibility information, simulation reports, and more.
CAD Model
Technical Report
EM Coil Model
DICOM Viewer
Further Information & Images
Disclaimer
This product is developed in collaboration with MR CoilTech.
Some features of the product are still under development and not commercially available yet. Their future availability cannot be ensured. All data and information contained on this webpage are legally not binding and shall not create any warranties or liabilities whatsoever of Skope. CAUTION – Investigational device. Limited by Federal law to investigational use.
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