High-field Imaging Research Articles

A novel approach for 3D morphological characterization of silica nanoparticle population through HAADF-STEM

The morphology of amorphous silica NPs in three dimensions (3D) of space is analysed using a single technique: the transmission electron microscope in Scanning Transmission Electron Microscopy with High Angle Annular Dark Field (HAADF-STEM) imaging mode. For this purpose, a method consisting in adjusting the HAADF-STEM signal by a function describing the thickness of material in a sphere has been developed to determine the height of the nano-object and tested on particles having quasi-spherical shape. This approach is suitable only in the case of a nanomaterial chemically homogeneous. A reference present in the image is required for calibrating the signal strength. This reference can be either a particle of known shape or a particle whose height was previously measured with another technique (i.e. Atomic Force Microscopy). Thus, the study of the small silica particles by HAADF-STEM highlighted their spheroidal shape but also their preferential orientation on the substrate.

Dynamic strain ageing induced by Suzuki segregation in a Ni alloy

The state-of-the-art energy dispersive X-ray spectroscopy and high angle angular dark field imaging have been conducted with the transmission electron microscopy to investigate the dynamic strain ageing in a Ni alloy. Enrichment of Cr and Co atoms at the stacking faults is found in the sample, indicating Suzuki segregation is responsible for the observed dynamic strain ageing at 923 K. The calculated diffusion distances of solute species along the stacking faults using the bulk diffusion coefficients suggest that the pipe diffusion along partial dislocation core is intimately involved during the tensile process.

Argon bubble formation in tantalum oxide-based films for gravitational wave interferometer mirrors

The argon content of titanium dioxide doped tantalum pentoxide thin films was quantified in a spatially resolved way using high angle annular dark field (HAADF) images and DualEELS (a form of electron energy loss spectroscopy (EELS) that takes two spectra in quick succession from the highs and low-loss region). Films annealed at 300 °C, 400 °C, and 600 °C were investigated to see if there was a relationship between annealing temperature and bubble formation. It was shown using HAADF imaging that argon is present in most of these films and that bubbles of argon start to form after annealing at 400 °C and coarsen after annealing at 600 °C. A semi-empirical standard was created for the quantification using argon data from the EELS Atlas and experimental data scaled using a Hartree Slater cross-section. The density and pressure of argon within the bubbles were calculated for 35 bubbles in the 600 °C sample. The bubbles had a mean diameter, density, and pressure of 22 Å, 870 kg/m3 and 400 MPa, respectively. The pressure was calculated using the Van der Waals equation. The bubbles may affect the properties of the films, which are used as optical coatings for mirrors in gravitational wave detectors. This spatially resolved quantification technique can be readily applied to other small noble gas bubbles in a range of materials.

Perceptual Learning: How Does the Visual Circuit Change through Experience?

New research establishes that high-field functional imaging in humans can distinguish laminar specificity of visual circuit plasticity in humans. By simultaneously imaging fine-scale brain circuitry while measuring large-scale brain connectivity we can further unravel the mechanisms of perceptual learning.

Temperature-dependent interfacial behaviour of Au@SiO2 core shell nanoparticles on Si3N4 support film

Structural, chemical, and thermodynamic behaviours of metallic nanostructures surrounded by a variety of ceramic/refractory materials play a crucial role in their high-temperature applications. In this work, we report the effect of high-temperature annealing on a system of Au@SiO2 core-shell nanoparticles dispersed on Si3N4 grids. The thermal degradation of the Au–SiO2–Si3N4 system has been explained using minute compositional changes at different interfaces involving Au–SiO2, SiO2–Si3N4 and Au–Si3N4. High Angle Annular Dark Field Imaging coupled with Energy Dispersive X-ray Spectroscopy elemental mapping technique has been used for the same. Possible reactions among SiO2 and Si3N4 substrate with the aid of Au at high temperature leading to thermal decomposition of the system have been explained using High-Resolution Transmission Electron Microscopy and Selected Area Electron Diffraction analysis.

Feasibility of head-tilted brain scan to reduce susceptibility-induced signal loss in the prefrontal cortex in gradient echo-based imaging

Susceptibility-induced static field (B0) inhomogeneity near the nasal cavity degrades high-field MRI image quality. Many studies have addressed this problem by hardware- or sequence-based methods to improve local B0 shimming or minimize the impact of inhomogeneity. Here, we investigate the feasibility of the head-tilted brain scan as an easily accessible way to reduce B0 inhomogeneity and associated gradient echo signal loss in the prefrontal cortex (PFC). We exploit the fact that the region of intense local B0 gradient can be steered away from the PFC by head reorientation with respect to the main magnetic field. We found that the required chin-up head tilting by a substantial angle (> 30°) can be readily achieved for a group of healthy subjects when their back was raised by about 10 cm. Eleven subjects were scanned at 3T, using a standard 20 channel head-neck coil, for whole-head B0 mapping and gradient-echo EPI-based functional MRI (fMRI) performing a reward-punishment task in normal and tilted head orientations. Additionally, multi-echo gradient echo and resting-state fMRI scans were performed on six subjects in both orientations. Head-tilted sessions, which lasted for at least 20 min, were well-tolerated by all subjects and demonstrated a marked reduction of localized signal loss in the gradient echo-based images and EPI images in the PFC compared to normal orientation scans. Imaging in tilted orientation reduced the group-averaged B0 standard deviation and peak B0 gradient in the orbital gyrus beyond what was possible with simulated 3rd order shimming. The behavioral performance in the head-tilted fMRI scans indicated that the subjects were able to perform a cognitive task with little difficulty, and the tilted fMRI scans successfully produced a robust whole-brain functional activation map consistent with the literature. Our study proposes that the back-raised, head-tilted imaging can benefit the shimming of the prefrontal brain regions while being compatible with moderate-length neuroimaging scans on healthy, cooperating subjects.

The effect of the Mo/W ratio on the catalytic properties of alumina supported hydrotreating catalysts prepared from mixed SiMo6W6 and SiMo9W3 heteropolyacids

New mixed H4[SiMonWn-12O40] (n = 6 and 9) Keggin type heteropolyacids (HPAs) have been successfully synthesized, as confirmed by single-crystal XRD, Raman and IR spectroscopy analysis. The resulting polyoxometallates were used for preparation of hydrotreatment catalysts. Mo(W)/Al2O3 catalysts were synthesized by incipient wetness impregnation of alumina support with water solutions of prepared mixed Keggin HPAs and corresponding counterparts based on mixture of monometallic H4[SiMo12O40] and H4[SiW12O40] HPAs. Oxidic catalysts were analyzed by Raman spectroscopy to determine the precursor structure after deposition. Catalysts in sulfided state were characterized by high-resolution transmission electron microscopy (HRTEM), high angle annular dark field imaging (HAADF) and X-ray photoelectron spectroscopy (XPS) and were tested in co-hydrotreating of dibenzothiophene (DBT) and naphthalene. The use of new mixed Keggin HPAs made it possible to obtain catalysts with mixed MoWS2 active centers, which was confirmed by HAADF. Moreover, the Mo/(Mo + W) ratio has a direct effect on the structure of the active phase species. An ordered core-shell structure with Mo atoms in the core is maintained until the fraction of molybdenum in mixed MoW/Al2O3 catalyst exceeds 50 %, where a more disordered structure is observed. Moreover, this Mo/(Mo + W) ratio of 0.5 is optimal to achieve a maximum catalytic activity. Indeed, the turnover frequencies (TOF) of the MoWS2 edge centers with random atoms distribution in a cluster as in Mo9W3/Al2O3, was lower compared to that of Mo6W6/Al2O3 with core-shell structure.

Optical and structural analysis of ultra-long GaAs nanowires after nitrogen-plasma passivation

The structural and optical properties of individual ultra-long GaAs nanowires (NWs) were studied after different nitrogen passivation process conditions. The surface morphology of the NWs after passivation was characterized by high resolution transmission electron microscopy (HRTEM) and high angle annular dark field (HAADF) imaging. Electron energy loss spectroscopy (EELS) confirmed the presence of nitrogen on the NW surface. Micro-photoluminescence (μ-PL) on single NWs indicated an increase of the luminescence intensity upon passivation. This work reveals the efficacy of a plasma passivation process on complex nanometer-scale morphologies.

α-Synuclein Induces Progressive Changes in Brain Microstructure and Sensory-Evoked Brain Function That Precedes Locomotor Decline.

In vivo functional and structural brain imaging of synucleinopathies in humans have provided a rich new understanding of the affected networks across the cortex and subcortex. Despite this progress, the temporal relationship between α-synuclein (α-syn) pathology and the functional and structural changes occurring in the brain is not well understood. Here, we examine the temporal relationship between locomotor ability, brain microstructure, functional brain activity, and α-syn pathology by longitudinally conducting rotarod, diffusion magnetic resonance imaging (MRI), resting-state functional MRI (fMRI), and sensory-evoked fMRI on 20 mice injected with α-syn fibrils and 20 PBS-injected mice at three timepoints (10 males and 10 females per group). Intramuscular injection of α-syn fibrils in the hindlimb of M83+/- mice leads to progressive α-syn pathology along the spinal cord, brainstem, and midbrain by 16 weeks post-injection. Our results suggest that peripheral injection of α-syn has acute systemic effects on the central nervous system such that structural and resting-state functional activity changes occur in the brain by four weeks post-injection, well before α-syn pathology reaches the brain. At 12 weeks post-injection, a separate and distinct pattern of structural and sensory-evoked functional brain activity changes was observed that are co-localized with previously reported regions of α-syn pathology and immune activation. Microstructural changes in the pons at 12 weeks post-injection were found to predict survival time and preceded measurable locomotor deficits. This study provides preliminary evidence for diffusion and fMRI markers linked to the progression of synuclein pathology and has translational importance for understanding synucleinopathies in humans.SIGNIFICANCE STATEMENT α-Synuclein (α-syn) pathology plays a critical role in neurodegenerative diseases such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. The longitudinal effects of α-syn pathology on locomotion, brain microstructure, and functional brain activity are not well understood. Using high field imaging, we show preliminary evidence that peripheral injection of α-syn fibrils induces unique patterns of functional and structural changes that occur at different temporal stages of α-syn pathology progression. Our results challenge existing assumptions that α-syn pathology must precede changes in brain structure and function. Additionally, we show preliminary evidence that diffusion and functional magnetic resonance imaging (fMRI) are capable of resolving such changes and thus should be explored further as markers of disease progression.

The design of power supply for HF MRI superconducting magnet

High-field (HF) magnet resonance imaging (MRI) is designed as a large aperture human body imaging system. The superconducting magnet provides magnetic field B0 for HF MRI. The power supply is a key component, provides excitation and demagnetization functions for superconducting magnet. According to the requirements, the superconducting magnet power supply needs to be designed and developed with small volume and high reliability and bidirectional energy flow. A combination topology is proposed, including a pulse-width-modulation (PWM) rectifier, a dual-active-bridge (DAB), and a H-bridge. In this paper, the principle of the combination topology is introduced briefly. Meanwhile, the analysis and test results of a PWM rectifier based on hybrid active-neutral-point-clamped (ANPC) three-level are given.

Nanoscale constraints on the in situ transformation of Ru–Os–Ir sulfides to alloys at low temperature

We report new results of a combined focused ion beam high-resolution transmission electron microscopy (FIB/HRTEM) investigation of two grains of platinum-group minerals (PGM) corresponding to the laurite (RuS2)-erlichmanite (OsS2) solid solution series. The grains are included within unaltered chromite and the serpentine-dominant matrix of the mantle-hosted chromitite body of Monte Bueno in eastern Cuba. At the micron-scale, the grain hosted in unaltered chromite preserves magmatic features including a complex oscillatory zoning defined by a core of erlichmanite surrounded by alternating bands of Os-rich/Os-poor laurite, revealed by conventional field emission scanning electron microscopy (FE-SEM) and X-ray mapping by electron microprobe analyzer (EPMA). Combining high-magnification (HMEM), high angle-annular dark field (HAADF) images and the corresponding Energy Dispersive Spectra (EDS), the elemental mappings acquired using HRTEM showed that the oscillatory zoning occurs at both the micron and nano scales. A specific feature highlighted by HRTEM observations is the rather complex structure of the erlichmanite core, consisting of an aggregation of much smaller cores (<1 µm) characterized by an oscillatory zoning linked to bands thinner than 10 nm that are not detectable when the whole grain is imaged using conventional FE–SEM and X–ray EPMA elemental mapping. The nanotextural features identified in this study suggest: (1) formation of the PGM grains characterized by the coalescence of laurite/erlichmanite nuclei that originally formed independently and coalesced in the silicate magma, (2) growth and crystal zoning of compositionally different bands as a result of sudden changes in T, fS2, fO2 and composition of the melt. These thermodynamic and chemical changes also allowed the segregation of nano-sized Fe–Ni–S solid particles/droplets from the silicate magma, which are now found within the PGM grain as nanoparticles of pentlandite of <100 nm in size and had potential implications for laurite nucleation. On the other hand, backscattered FESEM images and X-ray EPMA mapping of the altered PGM grain associated with the silicate matrix of the chromitite revealed a magmatic sector zoned core, which is surrounded by a rim of S-deficient laurite (i.e., desulfurized laurite) that hosts Ru-Os-Ir alloys. The FIB/HRTEM observations on the rim of desulfurized laurite ± Os–Ir–Ru alloys revealed an intergrowth of nano-sized (<5 nm) laurite with ad Ru-Os-Ir-(S-As) and Ru-Os-Ir alloys (50–100 nm) within a Fe-Mn oxide/hydroxide matrix. This microstructure and the coexistence of these nanoparticles within the Fe-Mn oxide/hydroxide matrix illustrates an alteration sequence whereby magmatic laurite was desulfurized and decomposed into smaller laurite nanoparticles, which in turn were progressively transformed to Ru-Os-Ir-(S-As) particles and, finally, to Ru-Os-Ir nanoalloys. Self-reorganization (coarsening) of the desulfurizing laurite within a matrix transforming to Fe-Mn oxide/hydroxide matrix resulted in the formation of nanoscale intergrowths of Ru-Os-Ir-(S-As) particles and Ru-Os-Ir alloys with the Fe-Mn oxide/hydroxide . This took place concomitant to incorporation/oxidation of Fe and Mn by relatively more oxidizing fluids. These alteration fluids were generated during to serpentinization/ocean-floor metamorphism that affected the chromitite body. The observations provided here are relevant to the current debate about the platinum-group element (PGE) mobilization and the possible existence of PGE oxides and hydroxides minerals

Investigation of anisotropic π plasmon induced by the intrinsic crystallographic defects in topological crystalline insulator material—tin-substitutional lead selenide (Pb1−xSnxSe)

The presence of intrinsic defects in topological crystalline insulator materials has been predicted to improve the thermoelectric figure-of-merit values in the literature. Performing atomic-resolved high angle annular dark field imaging, momentum-resolved electron energy loss spectroscopy, and electron spectroscopic diffraction, we observed those intrinsic defects, including interstitial Se atoms and Se vacancies, to cause localized mirror symmetry breaking and further result in the anisotropic π-plasmon dispersion along the ΓX¯ and ΓM¯ directions in single-crystal Pb1−xSnxSe (x = 0 and 0.34). In addition to the anisotropic π plasmon dispersion, the splitting lines along the ΓX¯ direction were revealed with selected π plasmon energy in the electron spectroscopic diffraction pattern.

Design of a nanoprobe for high field magnetic resonance imaging, dual energy X-ray computed tomography and luminescent imaging

The combination of different bioimaging techniques, mainly in the field of oncology, allows circumventing the defects associated with the individual imaging modalities, thus providing a more reliable diagnosis. The development of multimodal endogenous probes that are simultaneously suitable for various imaging modalities, such as magnetic resonance imaging (MRI), X-ray computed tomography (CT) and luminescent imaging (LI) is, therefore, highly recommended. Such probes should operate in the conditions imposed by the newest imaging equipment, such as MRI operating at high magnetic fields and dual-energy CT. They should show, as well, high photoluminescence emission intensity for their use in optical imaging and present good biocompatibility. In this context, we have designed a single nanoprobe, based on a core-shell architecture, composed of a luminescent Eu3+:Ba0.3Lu0.7F2.7 core surrounded by an external HoF3 shell that confers the probe with very high magnetic transverse relaxivity at high field. An intermediate, optically inert Ba0.3Lu0.7F2.7 layer was interposed between the core and the shell to hinder Eu3+–Ho3+ cross-relaxation and avoid luminescence quenching. The presence of Ba and Lu, with different K-edges, allows for good X-ray attenuation at high and low voltages. The core-shell nanoparticles synthesized are good potential candidates as trimodal bioprobes for MRI at high field, dual-energy CT and luminescent imaging.

In situ metal-organic chemical vapour deposition growth of III–V semiconductor nanowires in the Lund environmental transmission electron microscope

A new environmental transmission electron microscope has been installed in Lund in order to investigate the growth of III–V semiconductor nanowires by metal-organic chemical vapour deposition. We report here on the concepts behind the design of the facility and on details of the operation, and we refer to early results to highlight the new information that can be accessed from in situ studies. The installation includes a gas handling system that delivers the precursors to III–V semiconductor growth under controlled conditions. The core microscope is a Hitachi HF-3300S 300 kV transmission electron microscope with additional pumping that can handle up to 6 Pa of gas injected into the specimen area, or up to 400 Pa if an apertured lid is fitted to the holder. Various custom specimen holders incorporate precursor gas lines, a heating chip or a double tilt mechanism. The polepiece gap has been expanded to accommodate the holders, while the combination of an imaging aberration corrector and a cold field emission gun delivers a point resolution of 86 pm. Single images with atomic level detail are collected by one camera while another camera provides real-time video recording. A scanning unit offers high angle annular dark field and secondary electron images, and compositional microanalysis is performed with energy dispersive spectroscopy. In summary, III–V nanowires have been grown successfully in situ across a range of controlled conditions such as substrate temperature and precursor partial pressures. Atomic resolution images and movies, and spectroscopy data taken during this growth allow detailed measurements of structures, compositions and growth rates—data that are otherwise hard or impossible to obtain from ex situ studies—and further our understanding of the mechanisms of crystal growth.

High-field spatial imaging of charge transport in silicon at low temperature

We present direct imaging measurements of charge transport across a 1 cm × 1 cm × 4 mm-thick crystal of high purity silicon (∼15 kΩ-cm) at temperatures of 5 K and 500 mK. We use these data to measure lateral diffusion of electrons and holes as a function of the electric field applied along the [111] crystal axis and to verify our low-temperature Monte Carlo software. The range of field strengths in this paper exceed those used in our previous study [R. A. Moffatt et al., Appl. Phys. Lett. 114, 032104 (2019)] by a factor of 10 and now encompass the region in which some recent silicon dark matter detectors operate [R. Agnese et al., Phys. Rev. Lett. 121, 051301 (2018)]. We also report on a phenomenon of surface charge trapping, which can reduce expected charge collection.

The formation kinetics of Cr2O3dispersed Cu synthesized by Cryo-milling

AbstractNano-crystalline (nc) Cu with Cr2O3dispersoid (~4 vol.%) was successfully made by reactive-milling at 210 K with a mixture of pure Cu, Cu2O, and Cr powder. The vacuum hot pressing (HP) was performed at 1123 K and 50 MPa for 2h to consolidate the milled powder for further analysis. TEM (Transmission Electron Microscopy) work revealed that the HPed materials were comprised with a mixture of the nc-Cu and a homogeneous distribution of Cr2O3dispersoids. The microstructure and Vickers hardness of the as-milled powder and the HPed materials were characterized by standard metallographic techniques. The grain size of the Cu was measured using Scherrer’s formula (XRD) and TEM observation; the Cr2O3dispersoid size was estimated from the HADDF (High Angle Annular Dark Field) images and element mapping by STEM-EDS (Scanning Transmission Electron Microscopy-Energy Dispersive Spectroscopy) works. The formation kinetics and coarsening of the Cr2O3dispersoids in Cu matrix were discussed based on the calculations with thermodynamic parameters in comparison with those of Al2O3.

SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging.

Scanning nanoscale superconducting quantum interference devices (nanoSQUIDs) are of growing interest for highly sensitive quantitative imaging of magnetic, spintronic, and transport properties of low-dimensional systems. Utilizing specifically designed grooved quartz capillaries pulled into a sharp pipette, we have fabricated the smallest SQUID-on-tip (SOT) devices with effective diameters down to 39 nm. Integration of a resistive shunt in close proximity to the pipette apex combined with self-aligned deposition of In and Sn, has resulted in SOTs with a flux noise of 42 nΦ0 Hz-1/2, yielding a record low spin noise of 0.29 μB Hz-1/2. In addition, the new SOTs function at sub-Kelvin temperatures and in high magnetic fields of over 2.5 T. Integrating the SOTs into a scanning probe microscope allowed us to image the stray field of a single Fe3O4 nanocube at 300 mK. Our results show that the easy magnetization axis direction undergoes a transition from the 〈111〉 direction at room temperature to an in-plane orientation, which could be attributed to the Verwey phase transition in Fe3O4.

Microstructural characteristic of the 24Cr2SiMn super ferritic stainless steel synthesized using local Indonesian materials

Precipitation is a key factor for the mechanical properties of material at high temperature application. It is important to study the formation and stability of precipitates in order to optimize the material properties. In this article, the author presents the preliminary results of the microstructure including precipitates formation in Fe-24Cr-2Si-0.8Mn (wt%) super ferritic stainless steel. Both the X-ray and the HRPD neutron diffraction pattern characterizations showed the first four characteristic reflections intensity with Miller indices corresponding to the (110), (200), (211), (220) diffraction planes that are typical for diffracting plan ( hkl ) of bcc system. The Scanning Transmission Electron Microscopy (STEM)-High Angle Angular Dark Field (HAADF) images and semi-quantitative Energy-Dispersive X-ray Spectroscopy (EDS) revealed the presence of chromium-carbide and chromium rich precipitates in rod-like shape with the size of about 700 nm in length and 250 nm in width. EDX semi-quantification results showed that the precipitate in the ferritic sample typically consists of 55.04 wt%C, 0.78 wt%Si, 35.42 wt%Cr, 0.68 wt%Mn, and 8.37 wt%Fe. Moreover, Selected Area Electron Diffraction (SAED) analysis revealed (Fe,Cr)7C3 as one of the chromium-carbide formed as precipitates. Finally, HRTEM images showed atomic structure of matrix and precipitates at dendrite boundaries at atomic level.

Microstructural characteristic of the 24Cr2SiMn super ferritic stainless steel synthesized using local Indonesian materials

Precipitation is a key factor for the mechanical properties of material at high temperature application. It is important to study the formation and stability of precipitates in order to optimize the material properties. In this article, the author presents the preliminary results of the microstructure including precipitates formation in Fe-24Cr-2Si-0.8Mn (wt%) super ferritic stainless steel. Both the X-ray and the HRPD neutron diffraction pattern characterizations showed the first four characteristic reflections intensity with Miller indices corresponding to the (110), (200), (211), (220) diffraction planes that are typical for diffracting plan ( hkl ) of bcc system. The Scanning Transmission Electron Microscopy (STEM)-High Angle Angular Dark Field (HAADF) images and semi-quantitative Energy-Dispersive X-ray Spectroscopy (EDS) revealed the presence of chromium-carbide and chromium rich precipitates in rod-like shape with the size of about 700 nm in length and 250 nm in width. EDX semi-quantification results showed that the precipitate in the ferritic sample typically consists of 55.04 wt%C, 0.78 wt%Si, 35.42 wt%Cr, 0.68 wt%Mn, and 8.37 wt%Fe. Moreover, Selected Area Electron Diffraction (SAED) analysis revealed (Fe,Cr)7C3 as one of the chromium-carbide formed as precipitates. Finally, HRTEM images showed atomic structure of matrix and precipitates at dendrite boundaries at atomic level.

Contemporary and emerging magnetic resonance imaging methods for evaluation of moyamoya disease.

Numerous recent technological advances offer the potential to substantially enhance the MRI evaluation of moyamoya disease (MMD). These include high-resolution volumetric imaging, high-resolution vessel wall characterization, improved cerebral angiographic and perfusion techniques, high-field imaging, fast scanning methods, and artificial intelligence. This review discusses the current state-of-the-art MRI applications in these realms, emphasizing key imaging findings, clinical utility, and areas that will benefit from further investigation. Although these techniques may apply to imaging of a wide array of neurovascular or other neurological conditions, consideration of their application to MMD is useful given the comprehensive multidimensional MRI assessment used to evaluate MMD. These MRI techniques span from basic cross-sectional to advanced functional sequences, both qualitative and quantitative.The aim of this review was to provide a comprehensive summary and analysis of current key relevant literature of advanced MRI techniques for the evaluation of MMD with image-rich case examples. These imaging methods can aid clinical characterization, help direct treatment, assist in the evaluation of treatment response, and potentially improve the understanding of the pathophysiology of MMD.