MRI at 7 Tesla and above: demonstrated and potential capabilities

Specific absorption rate implications of within-scan patient head motion for ultra-high field MRI

PURPOSE

This study investigates the implications of all degrees of freedom of within-scan patient head motion on patient safety.

METHODS

Electromagnetic simulations were performed by displacing and/or rotating a virtual body model inside an 8-channel transmit array to simulate 6 degrees of freedom of motion. Rotations of up to 20° and displacements of up to 20 mm including off-axis axial/coronal translations were investigated, yielding 104 head positions. Quadrature excitation, RF shimming, and multi-spoke parallel-transmit excitation pulses were designed for axial slice-selection at 7T, for seven slices across the head. Variation of whole-head specific absorption rate (SAR) and 10-g averaged local SAR of the designed pulses, as well as the change in the maximum eigenvalue (worst-case pulse) were investigated by comparing off-center positions to the central position.

RESULTS

In their respective worst-cases, patient motion increased the eigenvalue-based local SAR by 42%, whole-head SAR by 60%, and the 10-g averaged local SAR by 210%. Local SAR was observed to be more sensitive to displacements along right-left and anterior-posterior directions than displacement in the superior-inferior direction and rotation.

CONCLUSION

This is the first study to investigate the effect of all 6 degrees of freedom of motion on safety of practical pulses. Although the results agree with the literature for overlapping cases, the results demonstrate higher increases (up to 3.1-fold) in local SAR for off-axis displacement in the axial plane, which had received less attention in the literature. This increase in local SAR could potentially affect the local SAR compliance of subjects, unless realistic within-scan patient motion is taken into account during pulse design.

A field-monitoring-based approach for correcting eddy-current-induced artifacts of up to the 2nd spatial order in human-connectome-project-style multiband diffusion MRI experiment at 7T: A pilot study

Over the recent years, significant advances in Spin-Echo (SE) Echo-Planar (EP) Diffusion MRI (dMRI) have enabled improved fiber tracking conspicuity in the human brain. At the same time, pushing the spatial resolution and using higher b-values inherently expose the acquired images to further eddy-current-induced distortion and blurring. Recently developed data-driven correction techniques, capable of significantly mitigating these defects, are included in the reconstruction pipelines developed for the Human Connectome Project (HCP) driven by the NIH BRAIN initiative. In this case, however, corrections are derived from the original diffusion-weighted (DW) magnitude images affected by distortion and blurring. Considering the complexity of k-space deviations in the presence of time varying high spatial order eddy currents, distortion and blurring may not be fully reversed when relying on magnitude DW images only. An alternative approach, consisting of iteratively reconstructing DW images based on the actual magnetic field spatiotemporal evolution measured with a magnetic field monitoring camera, has been successfully implemented at 3T in single band dMRI (Wilm et al., 2017, 2015). In this study, we aim to demonstrate the efficacy of this eddy current correction method in the challenging context of HCP-style multiband (MB ​= ​2) dMRI protocol. The magnetic field evolution was measured during the EP-dMRI readout echo train with a field monitoring camera equipped with 16 ¹⁹F NMR probes. The time variation of 0^th, 1^st and 2^nd order spherical field harmonics were used to reconstruct DW images. Individual DW images reconstructed with and without field correction were compared. The impact of eddy current correction was evaluated by comparing the corresponding direction-averaged DW images and fractional anisotropy (FA) maps. ¹⁹F field monitoring data confirmed the existence of significant field deviations induced by the diffusion-encoding gradients, with variations depending on diffusion gradient amplitude and direction. In DW images reconstructed with the field correction, residual aliasing artifacts were reduced or eliminated, and when high b-values were applied, better gray/white matter delineation and sharper gyri contours were observed, indicating reduced signal blurring. The improvement in image quality further contributed to sharper contours and better gray/white matter delineation in mean DW images and FA maps. In conclusion, we demonstrate that up-to-2^nd-order-eddy-current-induced field perturbation in multiband, in-plane accelerated HCP-style dMRI acquisition at 7T can be corrected by integrating the measured field evolution in image reconstruction.

Efficient de-noising of high-resolution fMRI using local and sub-band information

BACKGROUND

High-resolution fMRI, useful for accurate brain mapping, suffers from low functional sensitivity at a reasonable acquisition time. Conventional smoothing techniques although reduce the noise and boost the sensitivity, but degrade the spatial resolution of fMRI.

NEW METHODS

We propose a novel spatial de-noising technique to increase sensitivity while preserving the boundaries of active regions in the high-resolution fMRI. A modified version of PCA that utilizes adjacent voxels information (LPCA) is first suggested for de-noising. This technique is then further empowered by its application to wavelet sub-bands (WLPCA).

RESULTS

Proposed techniques were assessed on both simulated and experimental data. Identifiablity index was calculated for evaluation of the denoising on the simulated data. Maximum and mean z-scores along with LAE and SSIM were reported on experimental data for two presented techniques as well as Guassian smoothing. WLPCA outperformed other techniques in Identifiablity index, for simulation, and in preserving maximum z-score, for experimental study.

COMPARISON WITH EXISTING METHODS

The presented technique was developed to simultaneously suppress the noise and preserve the boundaries of active areas against leakage. For first aim, its achievable mean z-score was compared to conventional Gaussian. For second aim, its maximum z-score was compared to that of no-smoothing. While Gaussian and no-smoothing can work fine with only one measure, WLPCA was able to improve both measures concurrently.

CONCLUSIONS

The local PCA based methods, and in particular WLPCA, is an effective noise reduction step that preserves the spatial resolution by preventing activity leakage of high-resolution fMRI data.

The "Loopole" Antenna: A Hybrid Coil Combining Loop and Electric Dipole Properties for Ultra-High-Field MRI

PURPOSE

To revisit the "loopole," an unusual coil topology whose unbalanced current distribution captures both loop and electric dipole properties, which can be advantageous in ultra-high-field MRI.

METHODS

Loopole coils were built by deliberately breaking the capacitor symmetry of traditional loop coils. The corresponding current distribution, transmit efficiency, and signal-to-noise ratio (SNR) were evaluated in simulation and experiments in comparison to those of loops and electric dipoles at 7 T (297 MHz).

RESULTS

The loopole coil exhibited a hybrid current pattern, comprising features of both loops and electric dipole current patterns. Depending on the orientation relative to B₀, the loopole demonstrated significant performance boost in either the transmit efficiency or SNR at the center of a dielectric sample when compared to a traditional loop. Modest improvements were observed when compared to an electric dipole.

CONCLUSION

The loopole can achieve high performance by supporting both divergence-free and curl-free current patterns, which are both significant contributors to the ultimate intrinsic performance at ultra-high field. While electric dipoles exhibit similar hybrid properties, loopoles maintain the engineering advantages of loops, such as geometric decoupling and reduced resonance frequency dependence on sample loading.

Beyond T2 and 3T: New MRI techniques for clinicians

Technological advances in Magnetic Resonance Imaging (MRI) in terms of field strength and hybrid MR systems have led to improvements in tumor imaging in terms of anatomy and functionality. This review paper discusses the applications of such advances in the field of radiation oncology with regards to treatment planning, therapy guidance and monitoring tumor response and predicting outcome.

The Transition from Metal-Based to Metal-Free Contrast Agents for T1 Magnetic Resonance Imaging Enhancement

Magnetic resonance imaging (MRI) has received significant attention as the noninvasive diagnostic technique for complex diseases. Image-guided therapeutic strategy for diseases such as cancer has also been at the front line of biomedical research, thanks to the innovative MRI, enhanced by the prior delivery of contrast agents (CAs) into patients' bodies through injection. These CAs have contributed a great deal to the clinical utility of MRI but have been based on metal-containing compounds such as gadolinium, manganese, and iron oxide. Some of these CAs have led to cytotoxicities such as the incurable Nephrogenic Systemic Fibrosis (NSF), resulting in their removal from the market. On the other hand, CAs based on organic nitroxide radicals, by virtue of their structural composition, are metal free and without the aforementioned drawbacks. They also have improved biocompatibility, ease of functionalization, and long blood circulation times, and have been proven to offer tissue contrast enhancement with longitudinal relaxivities comparable with those for the metal-containing CAs. Thus, this Review highlights the recent progress in metal-based CAs and their shortcomings. In addition, the remarkable goals achieved by the organic nitroxide radical CAs in the enhancement of MR images have also been discussed extensively. The focal point of this Review is to emphasize or demonstrate the crucial need for transition into the use of organic nitroxide radicals-metal-free CAs-as against the metal-containing CAs, with the aim of achieving safer application of MRI for early disease diagnosis and image-guided therapy.

High resolution time-of-flight MR-angiography at 7 T exploiting VERSE saturation, compressed sensing and segmentation

BACKGROUND

3D Time-of-Flight (TOF) MR-angiography (MRA) substantially benefits from ultra-high magnetic field strengths (≥7 T) due to increased Signal-to-Noise ratio and improved contrast. However, high-resolution TOF-MRA usually requires long acquisition times. In addition, specific absorption rate constraints limit the choice of optimal pulse sequence parameters, especially if venous saturation is employed.

PURPOSE

To implement and evaluate an arterial TOF-MRA for accelerated high-resolution angiography at ultra-high magnetic field strength.

FIELD STRENGTHS/SEQUENCE

7 T modified gradient-echo TOF sequence including venous saturation using Variable-Rate Selective Excitation (VERSE), Compressed Sensing (CS) and sparse application of saturation pulses, called segmentation, were included for acceleration.

ASSESSMENT

To analyze the acceleration techniques all volunteers were examined with the same protocols. CS with different sampling patterns and regularization factors as well as segmentation were applied for acceleration. For comparison, conventional acceleration techniques were applied (GRAPPA PAT 3 and Partial Fourier (6/8 in slice/phase encoding)). Images were co-registered and 40 mm thick transversal maximum intensity projections were created to calculate the relative number of vessels. To analyze the visibility of small vessels, the lenticulostriate arteries (LSA) were examined. This was done via multiscale vessel enhancement filtering in a VOI and quantification via Fiji ImageJ as well as qualitatively evaluation by two radiologists. Additionally, the venous/arterial vessel-to-background ratios (vVBR/aVBR) were calculated for chosen protocols.

RESULTS

For the acceleration of a high resolution TOF-MRA (0.31 mm isotropic), under-sampling of 9.6 showed aliasing artifacts, whereas 7.2 showed no aliasing. The regularization factor R had a strong impact on the image quality according to smoothing (R = 0.01 to R = 0.005) and noise (R = 0.0005 to R = 0.00005). With the alternating sampling patterns it was shown that the k-space center should not be under-sampled too much. Additionally segmentation could be verified to be feasible for stronger acceleration with sufficient venous suppression.

CONCLUSION

The combination of several independent techniques (VERSE, CS with acceleration factor 7.2, R = 0.001, Poisson disc radius of 80%, 3 segments) enables the application of high-resolution (0.31 mm isotropic) TOF-MRA with venous saturation at 7 T in clinical time settings (TA ≈ 5 min) and within the SAR limits.

Measurement of T1 and T2 relaxation times of the pancreas at 7 T using a multi-transmit system

Objective

To determine T₁ and T₂ relaxation times of healthy pancreas parenchyma at 7 T using a multi-transmit system.

Materials and methods

Twenty-six healthy subjects were scanned with a 7 T MR system using eight parallel transceiver antennas, each with two additional receive loops. A Look-Locker sequence was used to obtain images for T₁ determination, while T₂ was obtained from spin-echo images and magnetic resonance spectroscopy measurements with different echo times. T₁ and T₂ times were calculated using a mono-exponential fit of the average magnitude signal from a region of interest in the pancreas and were tested for correlation with age.

Results

The age range of the included subjects was 21–72 years. Average T₁ and T₂ relaxation times in healthy pancreas were 896 ± 149 ms, and 26.7 ± 5.3 ms, respectively. No correlation with age was found.

Conclusion

T₁ and T₂ relaxation times of the healthy pancreas were reported for 7 T, which can be used for image acquisition optimization. No significant correlations were found between age and T₁ or T₂ relaxation times of the pancreas. Considering their low standard deviation and no observable age dependence, these values may be used as a baseline to study potentially pancreatic tissue affected by disease.

Dual-domain convolutional neural networks for improving structural information in 3 T MRI

We propose a novel dual-domain convolutional neural network framework to improve structural information of routine 3 T images. We introduce a parameter-efficient butterfly network that involves two complementary domains: a spatial domain and a frequency domain. The butterfly network allows the interaction of these two domains in learning the complex mapping from 3 T to 7 T images. We verified the efficacy of the dual-domain strategy and butterfly network using 3 T and 7 T image pairs. Experimental results demonstrate that the proposed framework generates synthetic 7 T-like images and achieves performance superior to state-of-the-art methods.

Multinuclear MRI at Ultrahigh Fields

In this article, an overview of the current developments and research applications for non-proton magnetic resonance imaging (MRI) at ultrahigh magnetic fields (UHFs) is given. Due to technical and methodical advances, efficient MRI of physiologically relevant nuclei, such as Na, Cl, Cl, K, O, or P has become feasible and is of interest to obtain spatially and temporally resolved information that can be used for biomedical and diagnostic applications. Sodium (Na) MRI is the most widespread multinuclear imaging method with applications ranging over all regions of the human body. Na MRI yields the second largest in vivo NMR signal after the clinically used proton signal (H). However, other nuclei such as O and P (energy metabolism) or Cl and K (cell viability) are used in an increasing number of MRI studies at UHF. One major advancement has been the increased availability of whole-body MR scanners with UHFs (B0 ≥7T) expanding the range of detectable nuclei. Nevertheless, efforts in terms of pulse sequence and post-processing developments as well as hardware designs must be made to obtain valuable information in clinically feasible measurement times. This review summarizes the available methods in the field of non-proton UHF MRI, especially for Na MRI, as well as introduces potential applications in clinical research.

A dual-tuned multichannel bilateral RF coil for 1 H/23 Na breast MRI at 7 T

PURPOSE

Sodium MRI has shown promise for monitoring neoadjuvant chemotherapy response in breast cancer. The purpose of this work was to build a dual-tuned bilateral proton/sodium breast coil for 7T MRI that provides sufficient SNR to enable sodium breast imaging in less than 10 minutes.

METHODS

The proton/sodium coil consists of 2 shielded unilateral units: 1 for each breast. Each unit consists of 3 nested layers: (1) a 3-loop solenoid for sodium excitation, (2) a 3-loop solenoid for proton excitation and signal reception, and (3) a 4-channel receive array for sodium signal reception. Benchmark measurements were performed in phantoms with and without the sodium receive array insert. In vivo images were acquired on a healthy volunteer.

RESULTS

The sodium receive array boosted 1.5 to 3 times the SNR compared with the solenoid. Proton SNR loss due to residual interaction with the sodium array was less than 10%. The coil enabled sodium imaging in vivo with 2.8-mm isotropic nominal resolution (~5-mm real resolution) in 9:36 minutes.

CONCLUSION

The coil design that we propose addresses challenges associated with sodium's low SNR from a hardware perspective and offers the opportunity to investigate noninvasively breast tumor metabolism as a function of sodium concentration in patients undergoing neoadjuvant chemotherapy.

Potential of Sodium MRI as a Biomarker for Neurodegeneration and Neuroinflammation in Multiple Sclerosis

In multiple sclerosis (MS), experimental and ex vivo studies indicate that pathologic intra- and extracellular sodium accumulation may play a pivotal role in inflammatory as well as neurodegenerative processes. Yet, in vivo assessment of sodium in the microenvironment is hard to achieve. Here, sodium magnetic resonance imaging (²³NaMRI) with its non-invasive properties offers a unique opportunity to further elucidate the effects of sodium disequilibrium in MS pathology in vivo in addition to regular proton based MRI. However, unfavorable physical properties and low in vivo concentrations of sodium ions resulting in low signal-to-noise-ratio (SNR) as well as low spatial resolution resulting in partial volume effects limited the application of ²³NaMRI. With the recent advent of high-field MRI scanners and more sophisticated sodium MRI acquisition techniques enabling better resolution and higher SNR, ²³NaMRI revived. These studies revealed pathologic total sodium concentrations in MS brains now even allowing for the (partial) differentiation of intra- and extracellular sodium accumulation. Within this review we (1) demonstrate the physical basis and imaging techniques of ²³NaMRI and (2) analyze the present and future clinical application of ²³NaMRI focusing on the field of MS thus highlighting its potential as biomarker for neuroinflammation and -degeneration.

Reproducibility of brain MRS in older healthy adults at 7T

To date, the majority of MRS reproducibility studies have been conducted in healthy younger adults, with only a few conducted in older adults at 3 T. With the growing interest in applying MRS methods to study the longitudinal course and effects of treatments in neurodegenerative disease, it is important to establish reproducibility in age-matched controls, especially in older individuals. In this study, spectroscopic data were acquired using a stimulated echo acquisition mode (STEAM) localization technique in two regions (anterior and posterior cingulate cortices-ACC, PCC, respectively) in 10 healthy, cognitively normal older adults (64 ± 8.1 years). Reproducibility was assessed via mean coefficients of variation (CVs) and relative differences (RDs) calculated across two visits performed 2-3 months apart. Metabolites with high signal-to-noise ratio (SNR) such as NAA, tCho, and Glu had mean CVs of 10% or less and mean RDs of 15% or less across both regions. Metabolites with lower SNR such as GABA and Gln had slightly higher mean CVs of 22% or less and mean RDs of 27% or less across both regions. These results demonstrate the feasibility of acquiring MRS data at 7 T in older subjects, and establish that the spectroscopic data are reproducible in both the ACC and PCC in older, healthy subjects to the same extent as in previous studies in young subjects.

Computational and experimental evaluation of the Tic-Tac-Toe RF coil for 7 Tesla MRI

A variety of 7 Tesla RF coil systems have been proposed to produce spin excitation (B1+ field) and MR image acquisition. Different groups have attempted to mitigate the challenges at high and ultra-high field MRI by proposing novel hardware and software solutions to obtain uniformly high spin excitation at acceptable RF absorption levels. In this study, we extensively compare the designs of two distributed-circuit based RF coils: the Tic-Tac-Toe (TTT) head coil and TEM head coil on multiple anatomically detailed head models and in-vivo. Bench measurements of s-parameters and experimental B1+ field distribution were obtained in volunteers and compared with numerical simulations. RF absorption, quantified by both average and peak SAR, and B1+ field intensity and homogeneity, calculated/measured in terms of maximum over minimum and coefficient of variation (CV) in the region of interest (ROI), are presented for both coils. A study of the RF consistency of both coils across multiple head models for different RF excitation strategies is also presented.

Characterizing geometrical accuracy in clinically optimised 7T and 3T magnetic resonance images for high-precision radiation treatment of brain tumours

Background and purpose

In neuro-oncology, high spatial accuracy is needed for clinically acceptable high-precision radiation treatment planning (RTP). In this study, the clinical applicability of anatomically optimised 7-Tesla (7T) MR images for reliable RTP is assessed with respect to standard clinical imaging modalities.

Materials and methods

System- and phantom-related geometrical distortion (GD) were quantified on clinically-relevant MR sequences at 7T and 3T, and on CT images using a dedicated anthropomorphic head phantom incorporating a 3D grid-structure, creating 436 points-of-interest. Global GD was assessed by mean absolute deviation (MAD_Global). Local GD relative to the magnetic isocentre was assessed by MAD_Local. Using 3D displacement vectors of individual points-of-interest, GD maps were created. For clinically acceptable radiotherapy, 7T images need to meet the criteria for accurate dose delivery (GD < 1 mm) and present comparable GD as tolerated in clinically standard 3T MR/CT-based RTP.

Results

MAD_Global in 7T and 3T images ranged from 0.3 to 2.2 mm and 0.2-0.8 mm, respectively. MAD_Local increased with increasing distance from the isocentre, showed an anisotropic distribution, and was significantly larger in 7T MR sequences (MAD_Local = 0.2-1.2 mm) than in 3T (MAD_Local = 0.1-0.7 mm) (p < 0.05). Significant differences in GD were detected between 7T images (p < 0.001). However, maximum MAD_Local remained ≤1 mm within 68.7 mm diameter spherical volume. No significant differences in GD were found between 7T and 3T protocols near the isocentre.

Conclusions

System- and phantom-related GD remained ≤1 mm in central brain regions, suggesting that 7T MR images could be implemented in radiotherapy with clinically acceptable spatial accuracy and equally tolerated GD as in 3T MR/CT-based RTP. For peripheral regions, GD should be incorporated in safety margins for treatment uncertainties. Moreover, the effects of sequence-related factors on GD needs further investigation to obtain RTP-specific MR protocols.

Post mortem high resolution diffusion MRI for large specimen imaging at 11.7 T with 3D segmented echo-planar imaging

BACKGROUND

Diffusion weighted imaging (DWI) is the only in vivo technique allowing for the mapping of tissue fiber architecture. Post mortem DWI is an increasingly popular method, since longer acquisition times (compared to in vivo) allow higher spatial and angular resolutions to be achieved. However, DWI protocols must be adapted to post mortem tissue (e.g., tuning acquisition parameters to account for changes in T1/T2). New method: In this work, we developed a framework to obtain high quality diffusion weighted images on post mortem large samples by using a combination of fast imaging with 3D diffusion-weighted segmented EPI (3D-DW seg-EPI), Gadolinium soaking and data denoising. Analyses including tractography were used to check the quality of the acquired data, including a comparison with 3D-DW SE acquisitions. Comparison with existing method: Effects on diffusion data of each of the components of the framework were tested: 3D-DW seg-EPI versus 3D-DW SE EPI; with and without data denoising; with and without Gd-soaking.

CONCLUSIONS

Our study demonstrated the feasibility of analysing anatomical connectivity using diffusion imaging of a post mortem macaque brain with a 3D-DW seg-EPI sequence acquired at ultra-high field. The combination of high angular and spatial resolution DWI with Gd-soaking and denoising provided data allowing us to perform diffusion tractography with results very similar to those obtained with a 3D-DW SE acquisition (with shorter acquisition times: 222 h versus 37 h for 3D-DW seg-EPI).

Pros and cons of ultra-high-field MRI/MRS for human application

Magnetic resonance imaging and spectroscopic techniques are widely used in humans both for clinical diagnostic applications and in basic research areas such as cognitive neuroimaging. In recent years, new human MR systems have become available operating at static magnetic fields of 7 T or higher (≥300 MHz proton frequency). Imaging human-sized objects at such high frequencies presents several challenges including non-uniform radiofrequency fields, enhanced susceptibility artifacts, and higher radiofrequency energy deposition in the tissue. On the other side of the scale are gains in signal-to-noise or contrast-to-noise ratio that allow finer structures to be visualized and smaller physiological effects to be detected. This review presents an overview of some of the latest methodological developments in human ultra-high field MRI/MRS as well as associated clinical and scientific applications. Emphasis is given to techniques that particularly benefit from the changing physical characteristics at high magnetic fields, including susceptibility-weighted imaging and phase-contrast techniques, imaging with X-nuclei, MR spectroscopy, CEST imaging, as well as functional MRI. In addition, more general methodological developments such as parallel transmission and motion correction will be discussed that are required to leverage the full potential of higher magnetic fields, and an overview of relevant physiological considerations of human high magnetic field exposure is provided.

Clinical 7 T MRI: Are we there yet? A review about magnetic resonance imaging at ultra-high field

In recent years, ultra-high field MRI (7 T and above) has received more interest for clinical imaging. Indeed, a number of studies have shown the benefits from the application of this powerful tool not only for research purposes, but also in realms of improved diagnostics and patient management. The increased signal-to-noise ratio and higher spatial resolution compared with conventional and high-field clinical scanners allow imaging of small anatomical detail and subtle pathological findings. Furthermore, greater spectral resolution achieved at ultra-high field allows the resolution of metabolites for MR spectroscopic imaging. All these advantages have a significant impact on many neurological diseases, including multiple sclerosis, cerebrovascular disease, brain tumors, epilepsy and neurodegenerative diseases, in part because the pathology can be subtle and lesions small in these diseases, therefore having higher signal and resolution will help lesion detection. In this review, we discuss the main clinical neurological applications and some technical challenges which remain with ultra-high field MRI.

In vivo 13C-MRI using SAMBADENA

Magnetic Resonance Imaging (MRI) is a powerful imaging tool but suffers from a low sensitivity that severely limits its use for detecting metabolism in vivo. Hyperpolarization (HP) methods have demonstrated MRI signal enhancement by several orders of magnitude, enabling the detection of metabolism with a sensitivity that was hitherto inaccessible. While it holds great promise, HP is typically relatively slow (hours), expensive (million $, €) and requires a dedicated device (“polarizer”). Recently, we introduced a new method that creates HP tracers without an external polarizer but within the MR-system itself based on parahydrogen induced polarization (PHIP): Synthesis Amid the Magnet Bore Allows Dramatically Enhanced Nuclear Alignment (SAMBADENA). To date, this method is the simplest and least cost-intensive method for hyperpolarized ¹³C-MRI. HP of P_13C > 20% was demonstrated for 5mM tracer solutions previously. Here, we present a setup and procedure that enabled the first in vivo application of SAMBADENA: Within seconds, a hyperpolarized angiography tracer was produced and injected into an adult mouse. Subsequently, fast ¹³C-MRI was acquired which exhibited the vena cava, aorta and femoral arteries of the rodent. This first SAMBADENA in vivo¹³C-angiography demonstrates the potential of the method as a fast, simple, low-cost alternative to produce HP-tracers to unlock the vast but hidden powers of MRI.

Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging

With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the subcortex are also discussed.

Investigation of lateral geniculate nucleus volume and diffusion tensor imaging in patients with normal tension glaucoma using 7 tesla magnetic resonance imaging

Background

There is evidence that glaucoma is a neurodegenerative disease involving the whole visual pathway. We prospectively examined potential benefits of volumetry of the lateral geniculate nucleus (LGN) and diffusion tensor imaging (DTI) using a new 7T scanner.

Methods

20 patients with normal tension glaucoma and 16 control individuals were examined. LGN volume and fractional anisotropy (FA) of the optic tract (OT) and the optic radiation (OR) and their correlation with RNFL (retinal nerve fiber layer) thickness were analyzed.

Results

LGN volume was significantly reduced in NTG (60.9 vs 88.3; p < 0.05). FA of the OT (right: 0.35 vs 0.66, left: 0.36 vs 0.67; p < 0.05) and of the OR (right: 0.41 vs 0.70, left: 0.41 vs 0.69; p < 0.05) was also significantly reduced. Nasal RNFL thickness correlated with the volume of the contralateral LGN (r = 0.471, p = 0.05). Temporal RNFL thickness correlated with the volume of the ipsilateral LGN (r = 0.603, p = 0.015).

Conclusion

NTG leads to significant atrophy of the LGN compared to controls. FA of the optic tract and the optic radiation is reduced in NTG as sign of axonal degeneration. RNFL thickness but not FA correlates with LGN volume.

Smart-Dust-Nanorice for Enhancement of Endogenous Raman Signal, Contrast in Photoacoustic Imaging, and T2-Shortening in Magnetic Resonance Imaging

Raman microspectroscopy provides chemo-selective image contrast, sub-micrometer resolution, and multiplexing capabilities. However, it suffers from weak signals resulting in image-acquisition times of up to several hours. Surface-enhanced Raman scattering (SERS) can dramatically enhance signals of molecules in close vicinity of metallic surfaces and overcome this limitation. Multimodal, SERS-active nanoparticles are usually labeled with Raman marker molecules, limiting SERS to the coating material. In order to realize multimodal imaging while acquiring the rich endogenous vibronic information of the specimen, a core-shell particle based on "Nanorice", where a spindle-shaped iron oxide core is encapsulated by a closed gold shell, is developed. An ultrathin layer of silica prevents agglomeration and unwanted chemical interaction with the specimen. This approach provides Raman signal enhancement due to plasmon resonance effects of the shell while the optical absorption in the near-infrared spectral region provides contrast in photoacoustic tomography. Finally, T2-relaxation of a magnetic resonance imaging (MRI) experiment is altered by taking advantage of the iron oxide core. The feasibility for Raman imaging is evaluated by nearfield simulations and experimental studies on the primate cell line COS1. MRI and photoacoustics are demonstrated in agarose phantoms illustrating the promising translational nature of this strategy for clinical applications in radiology.

Distribution of brain sodium long and short relaxation times and concentrations: a multi-echo ultra-high field 23Na MRI study

Sodium (²³Na) MRI proffers the possibility of novel information for neurological research but also particular challenges. Uncertainty can arise in in vivo ²³Na estimates from signal losses given the rapidity of T2* decay due to biexponential relaxation with both short (T₂*_short) and long (T₂*_long) components. We build on previous work by characterising the decay curve directly via multi-echo imaging at 7 T in 13 controls with the requisite number, distribution and range to assess the distribution of both in vivo T₂*_short and T₂*_long and in variation between grey and white matter, and subregions. By modelling the relationship between signal and reference concentration and applying it to in vivo ²³Na-MRI signal, ²³Na concentrations and apparent transverse relaxation times of different brain regions were measured for the first time. Relaxation components and concentrations differed substantially between regions of differing tissue composition, suggesting sensitivity of multi-echo ²³Na-MRI toward features of tissue composition. As such, these results raise the prospect of multi-echo ²³Na-MRI as an adjunct source of information on biochemical mechanisms in both physiological and pathophysiological states.

Nuclear magnetic relaxation dispersion of murine tissue for development of T1 (R1 ) dispersion contrast imaging

This study quantified the spin-lattice relaxation rate (R₁ ) dispersion of murine tissues from 0.24 mT to 3 T. A combination of ex vivo and in vivo spin-lattice relaxation rate measurements were acquired for murine tissue. Selected brain, liver, kidney, muscle, and fat tissues were excised and R₁ dispersion profiles were acquired from 0.24 mT to 1.0 T at 37 °C, using a fast field-cycling MR (FFC-MR) relaxometer. In vivo R₁ dispersion profiles of mice were acquired from 1.26 T to 1.74 T at 37 °C, using FFC-MRI on a 1.5 T scanner outfitted with a field-cycling insert electromagnet to dynamically control B₀ prior to imaging. Images at five field strengths (1.26, 1.39, 1.5, 1.61, 1.74 T) were acquired using a field-cycling pulse sequence, where B₀ was modulated for varying relaxation durations prior to imaging. R₁ maps and R₁ dispersion (ΔR₁ /ΔB₀ ) were calculated at 1.5 T on a pixel-by-pixel basis. In addition, in vivo R₁ maps of mice were acquired at 3 T. At fields less than 1 T, a large R₁ magnetic field dependence was observed for tissues. ROI analysis of the tissues showed little relaxation dispersion for magnetic fields from 1.26 T to 3 T. Our tissue measurements show strong R₁ dispersion at field strengths less than 1 T and limited R₁ dispersion at field strengths greater than 1 T. These findings emphasize the inherent weak R₁ magnetic field dependence of healthy tissues at clinical field strengths. This characteristic of tissues can be exploited by a combination of FFC-MRI and T₁ contrast agents that exhibit strong relaxivity magnetic field dependences (inherent or by binding to a protein), thereby increasing the agents' specificity and sensitivity. This development can provide potential insights into protein-based biomarkers using FFC-MRI to assess early changes in tumour development, which are not easily measureable with conventional MRI.

1.5 versus 3 versus 7 Tesla in abdominal MRI: A comparative study

Objectives

The aim of this study was to investigate and compare the feasibility as well as potential impact of altered magnetic field properties on image quality and potential artifacts of 1.5 Tesla, 3 Tesla and 7 Tesla non-enhanced abdominal MRI.

Materials and methods

Magnetic Resonance (MR) imaging of the upper abdomen was performed in 10 healthy volunteers on a 1.5 Tesla, a 3 Tesla and a 7 Tesla MR system. The study protocol comprised a (1) T1-weighted fat-saturated spoiled gradient-echo sequence (2D FLASH), (2) T1-weighted fat-saturated volumetric interpolated breath hold examination sequence (3D VIBE), (3) T1-weighted 2D in and opposed phase sequence, (4) True fast imaging with steady-state precession sequence (TrueFISP) and (5) T2-weighted turbo spin-echo (TSE) sequence. For comparison reasons field of view and acquisition times were kept comparable for each correlating sequence at all three field strengths, while trying to achieve the highest possible spatial resolution. Qualitative and quantitative analyses were tested for significant differences.

Results

While 1.5 and 3 Tesla MRI revealed comparable results in all assessed features and sequences, 7 Tesla MRI yielded considerable differences in T1 and T2 weighted imaging. Benefits of 7 Tesla MRI encompassed an increased higher spatial resolution and a non-enhanced hyperintense vessel signal at 7 Tesla, potentially offering a more accurate diagnosis of abdominal parenchymatous and vasculature disease. 7 Tesla MRI was also shown to be more impaired by artifacts, including residual B₁ inhomogeneities, susceptibility and chemical shift artifacts, resulting in reduced overall image quality and overall image impairment ratings. While 1.5 and 3 Tesla T2w imaging showed equivalently high image quality, 7 Tesla revealed strong impairments in its diagnostic value.

Conclusions

Our results demonstrate the feasibility and overall comparable imaging ability of T1-weighted 7 Tesla abdominal MRI towards 3 Tesla and 1.5 Tesla MRI, yielding a promising diagnostic potential for non-enhanced Magnetic Resonance Angiography (MRA). 1.5 Tesla and 3 Tesla offer comparably high-quality T2w imaging, showing superior diagnostic quality over 7 Tesla MRI.

Ultra-high-field magnetic resonance spectroscopy in non-alcoholic fatty liver disease: Novel mechanistic and diagnostic insights of energy metabolism in non-alcoholic steatohepatitis and advanced fibrosis

BACKGROUND & AIMS

With the rising prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) non-invasive tools obtaining pathomechanistic insights to improve risk stratification are urgently needed. We therefore explored high- and ultra-high-field magnetic resonance spectroscopy (MRS) to obtain novel mechanistic and diagnostic insights into alterations of hepatic lipid, cell membrane and energy metabolism across the spectrum of NAFLD.

METHODS

MRS and liver biopsy were performed in 30 NAFLD patients with NAFL (n=8) or NASH (n=22). Hepatic lipid content and composition were measured using 3-Tesla proton (¹ H)-MRS. 7-Tesla phosphorus (³¹ P)-MRS was applied to determine phosphomonoester (PME) including phosphoethanolamine (PE), phosphodiester (PDE) including glycerophosphocholine (GPC), phosphocreatine (PCr), nicotinamide adenine dinucleotide phosphate (NADPH), inorganic phosphate (Pi), γ-ATP and total phosphorus (TP). Saturation transfer technique was used to quantify hepatic ATP flux.

RESULTS

Hepatic steatosis in ¹ H-MRS highly correlated with histology (P<.001) showing higher values in NASH than NAFL (P<.001) without differences in saturated or unsaturated fatty acid indices. PE/TP ratio increased with advanced fibrosis (F3/4) (P=.002) whereas GPC/PME+PDE decreased (P=.05) compared to no/mild fibrosis (F0-2). γ-ATP/TP was lower in advanced fibrosis (P=.049), while PCr/TP increased (P=.01). NADPH/TP increased with higher grades of ballooning (P=.02). Pi-to-ATP exchange rate constant (P=.003) and ATP flux (P=.001) were lower in NASH than NAFL.

CONCLUSIONS

Ultra-high-field MRS, especially saturation transfer technique uncovers changes in energy metabolism including dynamic ATP flux in inflammation and fibrosis in NASH. Non-invasive profiling by MRS appears feasible and may assist further mechanistic and therapeutic studies in NAFLD/NASH.

Advances in High-Field MRI

MRI techniques and systems have evolved dramatically over recent years. These advances include higher field strengths, new techniques, faster gradients, improved coil technology, and more robust sequence protocols. This article reviews the most commonly used advanced MRI techniques, including diffusion-weighted imaging, magnetic resonance spectrography, diffusion tensor imaging, and cerebrospinal fluid flow tracking.

First Application of 7-T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors

BACKGROUND

Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7-T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of the skull base. In this study, we apply a 7-T imaging protocol to patients with skull base tumors and compare the images with clinical standard of care.

METHODS

Images were acquired at 7 T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5-, 3-, and 7-T scans for detection of intracavernous cranial nerves and internal carotid artery (ICA) branches. Detection rates were compared. Images were used for surgical planning and uploaded to a neuronavigation platform and used to guide surgery.

RESULTS

Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7 T. The 7-T images were successfully incorporated into preoperative planning and intraoperative neuronavigation.

CONCLUSIONS

Our study represents the first application of 7-T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7-T MRI compared with 3- and 1.5-T MRI, and found that integration of 7 T into surgical planning and guidance was feasible. These results suggest a potential for 7-T MRI to reduce surgical complications. Future studies comparing standardized 7-, 3-, and 1.5-T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7-T MRI for endonasal endoscopic surgical efficacy.

Hippocampal subfields at ultra high field MRI: An overview of segmentation and measurement methods

The hippocampus is one of the most interesting and studied brain regions because of its involvement in memory functions and its vulnerability in pathological conditions, such as neurodegenerative processes. In the recent years, the increasing availability of Magnetic Resonance Imaging (MRI) scanners that operate at ultra‐high field (UHF), that is, with static magnetic field strength ≥7T, has opened new research perspectives. Compared to conventional high‐field scanners, these systems can provide new contrasts, increased signal‐to‐noise ratio and higher spatial resolution, thus they may improve the visualization of very small structures of the brain, such as the hippocampal subfields. Studying the morphometry of the hippocampus is crucial in neuroimaging research because changes in volume and thickness of hippocampal subregions may be relevant in the early assessment of pathological cognitive decline and Alzheimer's Disease (AD). The present review provides an overview of the manual, semi‐automated and fully automated methods that allow the assessment of hippocampal subfield morphometry at UHF MRI, focusing on the different hippocampal segmentation produced. © 2017 The Authors Hippocampus Published by Wiley Periodicals, Inc.

Safety issues and updates under MR environments

Magnetic resonance (MR) imaging is a useful imaging tool with superior soft tissue contrast for diagnostic evaluation. The MR environments poses unique risks to patients and employees differently from ionizing radiation exposure originated from computed tomography and plain x-ray films. The technology associated with MR system has evolved continuously since its introduction in the late 1970s. MR systems have advanced with static magnetic fields, faster and stronger gradient magnetic fields and more powerful radiofrequency transmission coils. Higher field strengths of MR offers greater signal to noise capability and better spatial resolution, resulting in better visualization of anatomic detail, with a reduction in scan time. With the rapid evolution of technology associated with MR, we encounter new MR-related circumstances and unexpected dangerous conditions. A comprehensive update of our knowledge about MR safety is necessary to prevent MR-related accidents and to ensure safety for patients and staff associated with MR. This review presents an overview about MR-related safety issues and updates.

MR imaging of the temporomandibular joint: comparison between acquisitions at 7.0 T using dielectric pads and 3.0 T

OBJECTIVES

To qualitatively and quantitatively compare MRI of the temporomandibular joint (TMJ) at 7.0 T using high-permittivity dielectric pads and 3.0 T using a clinical high-resolution protocol.

METHODS

Institutional review board-approved study with written informed consent. 12 asymptomatic volunteers were imaged at 7.0 and 3.0 T using 32-channel head coils. High-permittivity dielectric pads consisting of barium titanate in deuterated suspension were used for imaging at 7.0 T. Imaging protocol consisted of oblique sagittal proton density weighted turbo spin echo sequences. For quantitative analysis, pixelwise signal-to-noise ratio maps of the TMJ were calculated. For qualitative analysis, images were evaluated by two independent readers using 5-point Likert scales. Quantitative and qualitative results were compared using t-tests and Wilcoxon signed-rank tests, respectively.

RESULTS

TMJ imaging at 7.0 T using high-permittivity dielectric pads was feasible in all volunteers. Quantitative analysis showed similar signal-to-noise ratio for both field strengths (mean ± SD; 7.0 T, 13.02 ± 3.92; 3.0 T, 14.02 ± 3.41; two-sample t-tests, p = 0.188). At 7.0 T, qualitative analysis yielded better visibility of all anatomical subregions of the temporomandibular disc (anterior band, intermediate zone and posterior band) than 3.0 T (Wilcoxon signed-rank tests, p < 0.05, corrected for multiple comparisons).

CONCLUSIONS

MRI of the TMJ at 7.0 T using high-permittivity dielectric pads yields superior visibility of the temporomandibular disc compared with 3.0 T.

Design and implementation of a simple multinuclear MRI system for ultra high-field imaging of animals

Non-proton MRI has recently garnered gathering interest with the increased availability of ultra high-field MRI system. Assuming the availability of a broadband RF amplifier, performing multinuclear MR experiments essentially requires additional hardware, such as an RF resonator and a T/R switch for each nucleus. A double- or triple-resonant RF probe is typically constructed using traps or PIN-diode circuits, but this approach degrades the signal-to-noise ratio (SNR) and image quality compared to a single-resonant coil and this is a limiting factor. In this work, we have designed the required hardware for multinuclear MR imaging experiments employing six single-resonant coil sets and a purpose-built animal bed; these have been implemented into a home-integrated 9.4T preclinical MRI scanner. System capabilities are demonstrated by distinguishing concentration differences and sensitivity of X-nuclei imaging and spectroscopy without SNR penalty for any nuclei, no subject interruption and no degradation of the static shim conditions.

Toward imaging the body at 10.5 tesla

PURPOSE

To explore the potential of performing body imaging at 10.5 Tesla (T) compared with 7.0T through evaluating the transmit/receive performance of similarly configured dipole antenna arrays.

METHODS

Fractionated dipole antenna elements for 10.5T body imaging were designed and evaluated using numerical simulations. Transmit performance of antenna arrays inside the prostate, kidneys and heart were investigated and compared with those at 7.0T using both phase-only radiofrequency (RF) shimming and multi-spoke pulses. Signal-to-noise ratio (SNR) comparisons were also performed. A 10-channel antenna array was constructed to image the abdomen of a swine at 10.5T. Numerical methods were validated with phantom studies at both field strengths.

RESULTS

Similar power efficiencies were observed inside target organs with phase-only shimming, but RF nonuniformity was significantly higher at 10.5T. Spokes RF pulses allowed similar transmit performance with accompanying local specific absorption rate increases of 25-90% compared with 7.0T. Relative SNR gains inside the target anatomies were calculated to be >two-fold higher at 10.5T, and 2.2-fold SNR gain was measured in a phantom. Gradient echo and fast spin echo imaging demonstrated the feasibility of body imaging at 10.5T with the designed array.

CONCLUSION

While comparable power efficiencies can be achieved using dipole antenna arrays with static shimming at 10.5T; increasing RF nonuniformities underscore the need for efficient, robust, and safe parallel transmission methods. Magn Reson Med 77:434-443, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

The technological future of 7 T MRI hardware

In this article we present our projections of future hardware developments on 7 T human MRI systems. These include compact cryogen-light magnets, improved gradient performance, integrated RF-receive and direct current shimming coil arrays, new RF technology with adaptive impedance matching, patient-specific specific absorption rate estimation and monitoring, and increased integration of physiological monitoring systems. Copyright © 2015 John Wiley & Sons, Ltd.

W(h)ither human cardiac and body magnetic resonance at ultrahigh fields? technical advances, practical considerations, applications, and clinical opportunities

The objective of this study was to document and review advances and groundbreaking progress in cardiac and body MR at ultrahigh fields (UHF, B0 ≥ 7.0 T) with the goal to attract talent, clinical adopters, collaborations and resources to the biomedical and diagnostic imaging communities. This review surveys traits, advantages and challenges of cardiac and body MR at 7.0 T. The considerations run the gamut from technical advances to clinical opportunities. Key concepts, emerging technologies, practical considerations, frontier applications and future directions of UHF body and cardiac MR are provided. Examples of UHF cardiac and body imaging strategies are demonstrated. Their added value over the kindred counterparts at lower fields is explored along with an outline of research promises. The achievements of cardiac and body UHF-MR are powerful motivators and enablers, since extra speed, signal and imaging capabilities may be invested to overcome the fundamental constraints that continue to hamper traditional cardiac and body MR applications. If practical obstacles, concomitant physics effects and technical impediments can be overcome in equal measure, sophisticated cardiac and body UHF-MR will help to open the door to new MRI and MRS approaches for basic research and clinical science, with the lessons learned at 7.0 T being transferred into broad clinical use including diagnostics and therapy guiding at lower fields. Copyright © 2015 John Wiley & Sons, Ltd.

(39) K and (23) Na relaxation times and MRI of rat head at 21.1 T

At ultrahigh magnetic field strengths (B0  ≥ 7.0 T), potassium ((39) K) MRI might evolve into an interesting tool for biomedical research. However, (39) K MRI is still challenging because of the low NMR sensitivity and short relaxation times. In this work, we demonstrated the feasibility of (39) K MRI at 21.1 T, determined in vivo relaxation times of the rat head at 21.1 T, and compared (39) K and sodium ((23) Na) relaxation times of model solutions containing different agarose gel concentrations at 7.0 and 21.1 T. (39) K relaxation times were markedly shorter than those of (23) Na. Compared with the lower field strength, (39) K relaxation times were up to 1.9- (T1 ), 1.4- (T2S ) and 1.9-fold (T2L ) longer at 21.1 T. The increase in the (23) Na relaxation times was less pronounced (up to 1.2-fold). Mono-exponential fits of the (39) K longitudinal relaxation time at 21.1 T revealed T1  = 14.2 ± 0.1 ms for the healthy rat head. The (39) K transverse relaxation times were 1.8 ± 0.2 ms and 14.3 ± 0.3 ms for the short (T2S ) and long (T2L ) components, respectively. (23) Na relaxation times were markedly longer (T1  = 41.6 ± 0.4 ms; T2S  = 4.9 ± 0.2 ms; T2L  = 33.2 ± 0.2 ms). (39) K MRI of the healthy rat head could be performed with a nominal spatial resolution of 1 × 1 × 1 mm(3) within an acquisition time of 75 min. The increase in the relaxation times with magnetic field strength is beneficial for (23) Na and (39) K MRI at ultrahigh magnetic field strength. Our results demonstrate that (39) K MRI at 21.1 T enables acceptable image quality for preclinical research. Copyright © 2016 John Wiley & Sons, Ltd.

Improving peak local SAR prediction in parallel transmit using in situ S-matrix measurements

PURPOSE

Peak local specific absorption rate (pSAR10g) is an important parameter used to determine patient safety during radiofrequency transmission. pSAR10g predictions for parallel transmit MRI are affected by the level of coupling exhibited by a modeled array in the simulation environment. However, simulated array coupling is rarely equal to the physical array coupling. Accurately simulating the physical array coupling may improve the accuracy of predicted SAR levels.

METHODS

The scattering parameter matrix (S-matrix) of a prototype 4-channel array was measured in situ using directional couplers installed on a 7T scanner. Agreement between the simulated and measured S-matrix was achieved by using network co-simulation with a modified cost function. B1+ maps acquired in a phantom were compared to B1+ distributions determined from simulations.

RESULTS

The modified co-simulation technique forces the simulations to have S-matrices similar to the measured values. A comparison of realistically versus ideally simulated coupling conditions shows that ideally simulated coupling can result in large ( > 40%) error in pSAR10g predictions, even when the array is reasonably tuned. The simulated B1+ distributions match the measured B1+ distributions better when the coupling is accurately simulated.

CONCLUSION

Considering the measured array coupling matrix in numerical simulations eliminates a potential confound in pSAR10g prediction. Magn Reson Med 77:2040-2047, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Correlation of the venous angioarchitecture of multiple cerebral cavernous malformations with familial or sporadic disease: a susceptibility-weighted imaging study with 7-Tesla MRI

OBJECTIVE Multiple cerebral cavernous malformations (CCMs) are rare lesions that occur in sporadic or familial form. Depending on the disease form, the natural history and treatment of the lesions strongly vary. Molecular analysis of an underlying germline mutation (CCM1-3) is the most sensitive screening method to distinguish between sporadic and familial cases. However, based on the different pathomechanisms that are believed to be involved in either form, significant distinctions in the CCM-associated cerebral venous angioarchitecture should be detectable. This has not been systematically studied. METHODS A consecutive series of 28 patients with multiple CCMs (681 total) diagnosed on 1.5-T MRI underwent genetic screening for CCM1-3 mutations and high-resolution susceptibility-weighted imaging (SWI) of the cerebral venous angioarchitecture with 7-T MRI. Imaging data were analyzed to examine the CCM-associated venous angioarchitecture. Results were correlated with findings of molecular analysis for CCM1-3 mutations. RESULTS Two different SWI patterns (sporadic and familial) were found. The presence of associated developmental venous anomalies correlated with negative screening for germline mutations (11 sporadic) in all cases. All patients with confirmed familial disease showed normal underlying venous angioarchitecture. Additionally, a very unusual case of a probable somatic mutation is presented. CONCLUSIONS The SWI results of the venous angioarchitecture of multiple CCMs correlate with sporadic or familial disease. These results are consistent with the theory that venous anomalies are causative for the sporadic form of multiple CCMs.