X-ray Micro-computed Tomography Imaging Research Articles

A Technique for In-Situ Displacement and Strain Measurement with Laboratory-Scale X-Ray Computed Tomography

Abstract Purpose: Establish a technique for simultaneous interrupted volumetric imaging of internal structure and time-resolved full-field surface strain measurements during in-situ X-ray micro-computed tomography (XCT) experiments. This enables in-situ testing of stiff materials with large forces relative to the compliance of the in-situ load frame, which might exhibit localization (e.g., necking, compaction banding) and other inhomogeneous behaviors.Methods: The system utilizes a combination of in-situ XCT, 2D X-ray imaging, and particle tracking to conduct volumetric imaging of the internal structure of a specimen with interrupted loading and surface strain mapping during loading. Critically, prior to the laboratory-scale XCT experiments, specimens are speckled with a high-X-ray-contrast powder that is bonded the surface. During in-situ loading, the XCT system is programmed to capture sequential 2D X-ray images orthogonal to the speckled specimen surface. A single particle tracking (SPT) or digital image correlation (DIC) algorithm is used to measure full-field surface strain evolution throughout the time-sequence of images. At specified crosshead displacements, the motion and 2D image sequence is paused for volumetric XCT image collection. Results: We show example results on a micro-tensile demonstration specimen additive manufactured from Inconel 718 nickel-chrome alloy. Results include XCT volume reconstructions, crosshead-based engineering stress, and full-field strain maps. Conclusion: We demonstrate an in-situ technique to obtain surface strain evolution during laboratory-scale XCT testing and interrupted volumetric imaging. This allows closer investigation of, for example, the effect of micro-pores on the strain localization behavior of additive manufactured metal alloys. In addition to describing the method using a representative test piece, the dataset and code are published as open-source resources for the community. Graphical abstract

Surface Wetting Characterization in Pore-scale Multiphase Flow Simulations: A Ketton Carbonate Case Study

Direct numerical simulations are commonly applied to X-ray computed microtomography images of porous rocks to measure petrophysical properties, such as relative permeability. To complement and/or expand laboratory data with useful simulations, such simulations need to reflect the true wetting condition of reservoir rock. It is therefore important to investigate approaches for assigning surface wetting conditions in pore-scale multiphase flow simulations. Two-phase Lattice-Boltzmann simulations are conducted on a Ketton carbonate image using different effective wetting models and then compared to pore-scale experimental data on the same rock, which is published elsewhere in (Scanziani et al., 2018). Two different wetting models are established based on the aging of the Ketton sample with crude oil at connate water saturation. Model 1 provides uniform wetting on all oil treated surfaces. Model 2 attempts to capture the multiscale nature of carbonate by allowing for spatially varying wetting conditions on oil treated surfaces based on local microporosity. Assessment criteria are based on pore-scale morphological measures, which include oil surface area coverage, oil phase topology, fluid/fluid curvatures, and contact angles. Overall, Model 1 with an assigned contact angle of greater than +10° above the geometrically measured contact angle from the experimental data provided the best results based on our assessment criteria.

Monoliths for gas storage manufactured with precision pore engineering using 3D-printed templates

A fast, customizable, and systematic route for producing activated carbon monoliths for gas storage with low interparticle porosity (9 % to 24 %) containing tailored macro channels is disclosed. The production uses a three-dimensional (3D)-printed polymeric lattice, rich in oxygen, as a sacrificial template. Its interstitial voids are filled with a phenolic resin that is carbonized and activated at 1173 K under carbon dioxide (CO2). Sequential pyrolysis occurs via thermal treatment with the 3D-printed lattice removed first, rendering macro channels with the same shape as the template in accurately placed positions. Resulting in adsorbents with interparticle porosities ranging from 10 % to 23 %, calculated from X-ray micro-computed tomography (micro-CT) images. The axial resolution of these macro channels was similar to the SLA printing layer thickness used of 100 µm. Making it the best resolution attained to date in fabricating monoliths via a 3D-printed sacrificial templating method. Breakthrough experiments indicated healthy macro channel connectivity due to the reduced mass transfer zone. Moreover, excellent mechanical integrity was displayed, with a monolith withstanding 900 N before excessive fracturing occurred despite the presence of macro channels. Therefore, this method emphasizes its use for gas storage applications by enabling the adsorbent material to efficiently utilize the volumetric space while allowing a fast rate of adsorption over the entire structure.

In situ three-dimensional visualization of Bursaphelenchus xylophilus inoculated in Pinus thunbergii using X-ray micro-computed tomography

Pine wilt disease, a devastating infectious disease of pine trees, is caused by the pinewood nematode, Bursaphelenchus xylophilus. It is important to understand the spatial dispersal processes of B. xylophilus within host-tree tissues to assess its pathogenic mechanism. However, this is not feasible with conventional microscopy-imaging techniques. In this study, we showed that X-ray micro-computed tomography (micro-CT) imaging can be a powerful tool for visualizing infected nematodes within host-tree tissues. We visualized 161 nematodes and 11 eggs within a Pinus thunbergii stem section, 47.3 mm3 in volume, using an appropriate segmentation of the micro-CT images. Quantitative measurements of the segmented region corresponding to the nematodes allowed for the calculation of the longitudinal length and a-value, which were similar to previous morphological descriptions of B. xylophilus. The technique adopted in this study can aid in understanding the behavior of and obtaining quantitative information on B. xylophilus within tree tissues.

Electro-Mechanical Characterisation and Damage Monitoring by Acoustic Emission of 3D-Printed CB/PLA.

Even though the influence of the printing direction on the mechanical properties of 3D-printed samples by fused filament fabrication is established in the literature, very little is known about mechanical and electrical coupling. In this study, electrically conductive polylactic acid filled with carbon black particles undergoes monotonic and repeated progressive tensile loading to better understand the influence of the printing direction on the electro-mechanical properties of three-dimensional-printed samples. The objective is to analyse the electro-mechanical behaviour of this composite for its potential application as an actuator. The classical laminate theory is also applied to evaluate the relevance of this theory in predicting the mechanical characteristics of this material. In addition, a comprehensive damage analysis is performed using acoustic emission, infrared thermography, scanning electron microscopy, and X-ray microcomputed tomography imaging. Results show that the degradation of the mechanical and electrical properties is highly influenced by the printing direction. The appearance and development of crazes in 0° filaments are highlighted and quantified. The conclusions drawn by this study underline the interest in using longitudinal and unidirectional printing directions to improve the conductive path within the samples. Furthermore, the evolution of the resistance throughout the experiments emphasizes the need to control the implemented voltage in the design of future electro-thermally triggered actuators.

Xylem-dwelling pathogen unaffected by local xylem vessel network properties in grapevines (Vitis spp.).

Xylella fastidiosa (Xf) is the xylem-dwelling bacterium associated with Pierce's disease (PD), which causes mortality in agriculturally important species, such as grapevine (Vitis vinifera). The development of PD symptoms in grapevines depends on the ability of Xf to produce cell-wall-degrading enzymes to break up intervessel pit membranes and systematically spread through the xylem vessel network. Our objective here was to investigate whether PD resistance could be mechanistically linked to xylem vessel network local connectivity. We used high-resolution X-ray micro-computed tomography (microCT) imaging to identify and describe the type, area and spatial distribution of intervessel connections for six different grapevine genotypes from three genetic backgrounds, with varying resistance to PD (four PD resistant and two PD susceptible). Our results suggest that PD resistance is unlikely to derive from local xylem network connectivity. The intervessel pit area (Ai) varied from 0.07 ± 0.01 mm2 mm-3 in Lenoir to 0.17 ± 0.03 mm2 mm-3 in Blanc do Bois, both PD resistant. Intervessel contact fraction (Cp) was not statically significant, but the two PD-susceptible genotypes, Syrah (0.056 ± 0.015) and Chardonnay (0.041 ± 0.013), were among the most highly connected vessel networks. Neither Ai nor Cp explained differences in PD resistance among the six genotypes. Bayesian re-analysis of our data shows moderate evidence against the effects of the traits analysed: Ai (BF01 = 4.88), mean vessel density (4.86), relay diameter (4.30), relay density (3.31) and solitary vessel proportion (3.19). Our results show that radial and tangential xylem network connectivity is highly conserved within the six different Vitis genotypes we sampled. The way that Xf traverses the vessel network may limit the importance of local network properties to its spread and may confer greater importance on host biochemical responses.

3D Quantification of Pore Networks and Anthropogenic Carbon Mineralization in Stacked Basalt Reservoirs.

Basalt formations are promising candidates for the geologic storage of anthropogenic CO2 due to their storage capacity, porosity, permeability, and reactive geochemical trapping ability. The Wallula Basalt Carbon Storage Pilot Project demonstrated that supercritical CO2 injected into >800 m deep Columbia River Basalt Group stacked reservoir flow tops mineralizes to ankerite-siderite-aragonite on month-year time scales, with 60% of the 977 metric tons of CO2 converted within 2 years. The potential impacts of mineral precipitation and consequent changes in the rock porosity, pore structure, pore size, and pore size distributions have likely been underestimated hitherto. Herein, we address these knowledge gaps using X-ray microcomputed tomography (XMT) to evaluate the pore network architecture of sidewall cores recovered 2 years after CO2 injection. In this study, we performed a detailed quantitative analysis of the CO2-reacted basalt cores by XMT imaging. Reconstructed 3D images were analyzed to determine the distribution and volumetric details of porosity and anthropogenic carbonate nodules in the cores. Additional mineralogic quantification provided insight into the overall paragenesis and carbonate growth mechanisms, including mineralogic/chemical zonation. These findings are being used to parametrize multiphase reactive transport models to predict the fate and transport of subsurface CO2, enabling scale-up to commercial-scale geologic carbon storage in basalts and other reactive mafic-ultramafic formations.

Advanced analysis of disintegrating pharmaceutical compacts using deep learning-based segmentation of time-resolved micro-tomography images

The mechanism governing pharmaceutical tablet disintegration is far from fully understood. Despite the importance of controlling a formulation's disintegration process to maximize the active pharmaceutical ingredient's bioavailability and ensure predictable and consistent release profiles, the current understanding of the process is based on indirect or superficial measurements. Formulation science could, therefore, additionally deepen the understanding of the fundamental physical principles governing disintegration based on direct observations of the process. We aim to help bridge the gap by generating a series of time-resolved X-ray micro-computed tomography (μCT) images capturing volumetric images of a broad range of mini-tablet formulations undergoing disintegration. Automated image segmentation was a prerequisite to overcoming the challenges of analyzing multiple time series of heterogeneous tomographic images at high magnification. We devised and trained a convolutional neural network (CNN) based on the U-Net architecture for autonomous, rapid, and consistent image segmentation. We created our own μCT data reconstruction pipeline and parameterized it to deliver image quality optimal for our CNN-based segmentation. Our approach enabled us to visualize the internal microstructures of the tablets during disintegration and to extract parameters of disintegration kinetics from the time-resolved data. We determine by factor analysis the influence of the different formulation components on the disintegration process in terms of both qualitative and quantitative experimental responses. We relate our findings to known formulation component properties and established experimental results. Our direct imaging approach, enabled by deep learning-based image processing, delivers new insights into the disintegration mechanism of pharmaceutical tablets.

Unsupervised texture classification of 3D X-ray Micro-computed Tomography images

Characterizing rock proprieties is crucial in the oilfield to evaluate hydrocarbon reserves. Several studies showed a high correlation between rock properties and textures. Therefore, we propose integrating texture information in the images to identify precisely the most representative textures in highly heterogeneous rocks to estimate their properties. First, we implemented a steerable pyramid decomposition to extract the texture features. Then, those parameters were used as input for the Self-organizing map to classify the textures. Finally, by applying several models and comparing their results, we suggested the best approach to implement for texture classification.

3D Texture Segmentation using Supervised Methods

Supervised learning methods have been widely used for image classification in various fields, including medical and industrial sectors. Some of these methods are traditional and possess certain limitations when addressing complex problems. The most common and effective approaches involve Convolutional Neural Networks (CNNs), such as U-Net. However, most studies employ CNNs in their 2D structures, which can impose limitations in classifying 3D objects. The purpose of this paper is to propose the utilization of 3D CNNs to potentially enhance the classification of 3D data, particularly X-ray micro-computed tomography images of reservoir rock samples. Our focus is on examining the performance of the 3D U-Net architecture, a supervised classification approach, in segmenting various 3D rock textures.

Multiscale fusion of tight sandstone digital rocks using attention-guided generative adversarial network

Tight sandstone exhibits heterogeneity due to its multiple mineral compositions and multiscale pore structures, presenting significant challenges for digital rock modeling. To capture the multiscale information inherent in heterogeneous rocks, we utilized an attention-guided generative adversarial network (AttentionGAN) to combine X-ray micro-computed tomography (micro-CT) and scanning electron microscope (SEM) images of tight sandstone, thereby producing large-scale, high-precision rock images. The reconstructed digital rock images comprehensively showcase the multiscale pore structures, including intergranular and clay micropores, as well as the distribution of minerals. Mineral content, two-point correlation functions, representative volume elements, and pore radius distributions were calculated for both the real and reconstructed images to confirm the efficacy of the proposed AttentionGAN. The results demonstrate that AttentionGAN is capable of generating high-precision rock images with a wide field of view. This offers a beneficial methodology for characterizing heterogeneous rocks and numerically simulating rock physics processes.

Matching of crushed highly decomposed granite particles using 3D SHOT descriptors

Owing to the complex morphology and the fragility of highly decomposed granite (HDG), it is still a challenge to track the breakage process of HDG particles within a deformed sample in geomechanics research. An HDG particle matching method is proposed in this paper for the first time to track and match HDG fragments with their mother particles from which they break off. First, the X-ray micro-computed tomography (μCT) images of HDG particles were acquired from a one-dimensional compression test and a certain number of HDG particles and fragments were selected and reconstructed. Second, the original and fracture surfaces of the fragments were identified and segmented. Then, the essential morphological features of the particles and fragments were represented with the key points. The neighbourhood information around the key points was encoded by the three-dimensional (3D) feature descriptor. Next, the mismatches were filtered out by the random sample consensus (RANSAC) algorithm based on the similarity of the local neighbourhood information. Finally, the influences of several parameters on the matching results were investigated. The capability and efficiency of the HDG particle matching method were demonstrated using the μCT data of ten HDG particles and 32 fragments that resulted from the crushing of these particles.

A Pore-Scale Model for Electrokinetic In situ Recovery of Copper: The Influence of Mineral Occurrence, Zeta Potential, and Electric Potential

Electrokinetic in-situ recovery is an alternative to conventional mining, relying on the application of an electric potential to enhance the subsurface flow of ions. Understanding the pore-scale flow and ion transport under electric potential is essential for petrophysical properties estimation and flow behavior characterization. The governing physics of electrokinetic transport is electromigration and electroosmotic flow, which depend on the electric potential gradient, mineral occurrence, domain morphology (tortuosity and porosity, grain size and distribution, etc.), and electrolyte properties (local pH distribution and lixiviant type and concentration, etc.). Herein, mineral occurrence and its associated zeta potential are investigated for EK transport. The new Ek model which is designed to solve the EK flow in complex porous media in a highly parallelizable manner includes three coupled equations: (1) Poisson equation, (2) Nernst–Planck equation, and (3) Navier–Stokes equation. These equations were solved using the lattice Boltzmann method within X-ray computed microtomography images. The proposed model is validated against COMSOL multiphysics in a two-dimensional microchannel in terms of fluid flow behavior when the electrical double layer is both resolvable and unresolvable. A more complex chalcopyrite-silica system is then obtained by micro-CT scanning to evaluate the model performance. The effects of mineral occurrence, zeta potential, and electric potential on the three-dimensional chalcopyrite-silica system were evaluated. Although the positive zeta potential of chalcopyrite can induce a flow of ferric ion counter to the direction of electromigration, the net effect is dependent on the occurrence of chalcopyrite. However, the ion flux induced by electromigration was the dominant transport mechanism, whereas advection induced by electroosmosis made a lower contribution. Overall, a pore-scale EK model is proposed for direct simulation on pore-scale images. The proposed model can be coupled with other geochemical models for full physicochemical transport simulations. Meanwhile, electrokinetic transport shows promise as a human-controllable technique because the electromigration of ions and the applied electric potential can be easily controlled externally.Graphical abstract

In situ X-ray computed micro-tomography imaging of failure processes in Cr-coated Zircaloy nuclear fuel cladding materials

Chromium (Cr)-coated Zircaloy fuel cladding has been considered a promising candidate materials system for accident tolerant fuels. In this work, two types of Cr coatings produced by cold sprayed (CS) and physical vapour deposited (PVD) methods were studied. In particular, a novel combination of C-ring compression tests at room temperature (RT) and 345 °C in an inert gas environment and real-time X-ray micro-computed tomography (XCT) imaging was adopted to investigate the failure processes. Before testing, the crystal structure and local properties were fully characterized; post testing, ex situ scanning electron microscope (SEM) imaging were conducted to complement the XCT measurements in crack density. It was found that the failure processes in both coatings vary with temperature, as discussed in detail. The hoop strength of first coating cracks’ formation of CS materials were higher than the PVD materials due to their higher interfacial roughness and distribution of splatted grains in CS coating. Based on a calculation of the first Dundurs’ parameter from the measured local properties and observed crack arrest/deflection at coating/substrate interface, it was found that the cold sprayed coating-cladding material system has a higher interfacial toughness in terms of critical strain energy release rate due to its interlocking interfacial structure.

Natural gas desorption versus laboratory gas adsorption with pore shrinkage

To perform hydro-mechanical experiments on sorptive geomaterials, the gas is injected into bulk of the specimen to re-saturate it representing its in-situ state, and adsorption is monitored until gas equilibrium is reached. We show in this study that this experimental procedure does not reflect the in-situ state of the sample leading to potentially significant errors. We measured the carbon dioxide (CO2) adsorption capacity of the coal specimen (free of gas) and its powder with different particle sizes and compared the results with field desorption data. Experimental results indicate an increase in coal adsorption capacity with decrease in coal particle size. Interestingly, the field data exhibits much higher desorbed gas amount compared to laboratory-measured adsorption capacity of coal powder with smallest measurable particle size under the same gas pressure. To shed light on the observation of field desorption – laboratory adsorption hysteresis, the micro-scale gas adsorption experiments combined with X-ray micro-Computed Tomography (XRCT) measurements were conducted where an intact specimen was imaged before (dry state) and after Krypton injection. The analysis of the XRCT images indicates that the Krypton adsorption closes/reduces the aperture of pre-existing fractures in the specimen. In addition, the Krypton diffuses only in a small region near pre-existing fractures despite its adsorption measurement indicating gas equilibrium and specimen saturation. This observation proposes that significant portion of pores exposed to Krypton experienced a size reduction by swelling resulting in partial saturation of the specimen. This patrial saturation at laboratory conditions evidently cannot resemble the in-situ state of gas sorption capacity.

Characterization of Channeling Effects Applied to Extended-Release Matrix Tablets Containing Pirfenidone.

Pirfenidone (PRF) is an anti-fibrotic agent that has been approved by the Food and Drug Administration (FDA) for the treatment of mild to moderate idiopathic pulmonary fibrosis. However, the current oral administration dosing regimen of PRF is complex and requires high doses. Patients are instructed to take PRF three times daily, with each dose consisting of up to three capsules or tablets (600 mg/d or 1.8 g/d of PRF) taken with food. To improve the dosing regimen, efforts are being made to develop an extended-release tablet with a zero-order release pattern. In this study, two types of extended-release matrix tablets were compared: non-channeled extended-release matrix tablets (NChMT) and channeled extended-release matrix tablets (ChMT). In vitro release tests, swelling and erosion index, rheology studies, and X-ray microcomputed tomography (XRCT), were conducted. The results indicated that ChMT maintained a zero-order release pattern with a constant release rate, while NChMT exhibited a decreased release rate in the latter half of the dissolution. ChMT exhibited accelerated swelling and erosion compared to other formulations, and this was made possible by the presence of channels within the tablet. These channels allowed for thorough wetting and swelling throughout the entire depth of the tablet. The formation of channels was confirmed through XRCT images. In conclusion, the presence of channels in ChMT tablets increased the rate of swelling and erosion, resulting in a zero-order release pattern. This development offers the potential to improve the dosage of PRF and reduce its associated side effects.

Starch depletion in the xylem and phloem ray parenchyma of grapevine stems under drought.

While nonstructural carbohydrate (NSC) storage can support long-lived woody plants during abiotic stress, the timing and extent of their use are less understood, as are the thresholds for cell mortality as NSCs and water supplies are consumed. Here, we combine physiological and imaging tools to study the response of Vitis riparia to a 6-week experimental drought. We focused on the spatial and temporal dynamics of starch consumption and cell viability in the xylem and phloem of the stem. Starch dynamics were further corroborated with enzymatic starch digestion and X-ray microcomputed tomography imaging. Starch depletion in the stems of droughted plants was detected after 2 weeks and continued over time. We observed distinct differences in starch content and cell viability in the xylem and phloem. By the end of the drought, nearly all the starch was consumed in the phloem ray parenchyma (98 % decrease), and there were almost no metabolically active cells in the phloem. In contrast, less starch was consumed in the xylem ray parenchyma (30 % decrease), and metabolically active cells remained in the ray and vessel-associated parenchyma in the xylem. Our data suggest that the higher proportion of living cells in the phloem and cambium, combined with smaller potential NSC storage area, rapidly depleted starch, which led to cell death. In contrast, the larger cross-sectional area of the xylem ray parenchyma with higher NSC storage and lower metabolically active cell populations depleted starch at a slower pace. Why NSC source-sink relationships between xylem and phloem do not allow for a more uniform depletion of starch in ray parenchyma over time is unclear. Our data help to pinpoint the proximate and ultimate causes of plant death during prolonged drought exposure and highlight the need to consider the influence of within-organ starch dynamics and cell mortality on abiotic stress response.

The use of three-dimensional uCT imaging technique in the description of a new species ofStenopusLatreille, 1819 (Decapoda: Stenopodidea: Stenopodidae), with a revised key to the species ofStenopus

AbstractMembers of the shrimp genus StenopusLatreille, 1819 generally inhabit shallow-water coral reefs. Individuals are colorful, with many of them highly sought in the aquarium trade. A recent biodiversity cruise to the Saya de Malha Banks in the western Indian Ocean collected a new species of Stenopus from rather deep waters, at 192–216 m depth. This species is unusual in having a long rostrum overreaching the scaphocerite and a red and white color pattern, unique for Stenopus. A badly damaged specimen from French Polynesia likely belongs to the new species. The characteristics of the new species are illustrated by X-ray microcomputed tomography images (uCT imaging), line drawings, and color photographs. A key is also provided for the 12 known species of Stenopus.

Study of the pore structure and calculation of macroscopic characteristics of rocks based on X-ray microcomputed tomography images

Background: Absolute and relative phase permeability and capillary pressure are important parameters in predicting oil and gas production from reservoirs, especially when acidizing the bottomhole zone of a well. They are mainly determined during long and resource-intensive laboratory experiments. Thus, additional approaches are required for the operational determination of the above parameters. The pore-network modeling based on microcomputed tomography data allows, firstly, to study the pore space of rock samples taking into account rock dissolution, secondly, to calculate the main macroscopic properties of rock samples without destroying them, and thirdly, to create a database of digital cores for further research
 Aim: Study of the pore space of two carbonate rock samples and the flow of fluids in them using the General Electric V|tome|X S240 MT and using the Avizo and PNFLOW software package.
 Materials and methods: This article uses microcomputed tomography with a spatial resolution of ~19 m and pore-network modeling of fluid flow in porous media to study the pore space of carbonate rock samples and determine absolute and phase permeabilities, as well as capillary pressure.
 Results: It is shown that an increase in the value of the Marker Extent parameter leads to a decrease in the number of pores and an overestimated absolute permeability due to improper pore separation, while a decrease in the value of this parameter made it possible to identify smaller pores. It is also shown that absolute permeability and porosity have different relationships before and after rock dissolution with high correlation coefficients that range from 0.62 to 0.81. It has been shown that rock dissolution will significantly affect the relative phase permeability of the samples.
 Conclusion: The dissolution of the rock led to a decrease in the residual oil saturation in both samples. In the case of oil displacement by water, as a result of rock dissolution, the residual oil saturation decreased from 38% to 22% and from 53% to 43% for the two samples under study. These results are important for understanding the flow of fluids in carbonate samples.

Micro-CT imaging in species description: exploring beyond sclerotized structures in lichen moths (Lepidoptera: Erebidae, Arctiinae, Lithosiini).

X-ray micro-computed tomography imaging (micro-CT) is valuable for systematic research since it permits the non-destructive scanning and imaging of internal structures of very rare species and/or type specimens. Additionally, micro-CT allows to view the morphology and the functional anatomy of structures in their natural anatomical position, without deformations that typically occur using classical dissection protocols. In this study we provide the description of two new species of lichen moths (Lepidoptera: Erebidae, Lithosiini) from the Atlantic Forest in eastern Brazil: Nodozana heliae Moraes sp. nov. from Rio de Janeiro state and Epeiromulona pataxo Moraes & Aguiar sp. nov. from Bahia state. The male and female genitalia as well as the wing morphology were examined by means of non-destructive micro-CT, subsequent 3D model reconstruction, 360 degree spinning animations, 2D images from different angles, and those were compared against classical genitalia dissections from the same specimens. We conclude that techniques complement each other, micro-CT being particularly useful to study wing venation, sclerotized internal structures and muscles, while classical dissection is useful to study membranous structures, particularly in the female genitalia, abdominal skin and specialised scales on the male 8th sternite.