Slice Views Research Articles

Digital "flipbooks" for enhanced visual assessment of simple and complex brain tumors.

Typical longitudinal radiographic assessment of brain tumors relies on side-by-side qualitative visualization of serial magnetic resonance images (MRIs) aided by quantitative measurements of tumor size. However, when assessing slowly growing tumors and/or complex tumors, side-by-side visualization and quantification may be difficult or unreliable. Whole-brain, patient-specific "digital flipbooks" of longitudinal scans are a potential method to augment radiographic side-by-side reads in clinical settings by enhancing the visual perception of changes in tumor size, mass effect, and infiltration across multiple slices over time. In this approach, co-registered, consecutive MRI scans are displayed in a slide deck, where one slide displays multiple brain slices of a single timepoint in an array (eg, 3 × 5 "mosaic" view of slices). The flipbooks are viewed similarly to an animated flipbook of cartoons/photos so that subtle radiographic changes are visualized via perceived motion when scrolling through the slides. Importantly, flipbooks can be created easily with free, open-source software. This article describes the step-by-step methodology for creating flipbooks and discusses clinical scenarios for which flipbooks are particularly useful. Example flipbooks are provided in Supplementary Material.

Clinical trainee performance on task-based AR/VR-guided surgical simulation is correlated with their 3D image spatial reasoning scores.

This paper describes a methodology for the assessment of training simulator-based computer-assisted intervention skills on an AR/VR-guided procedure making use of CT axial slice views for a neurosurgical procedure: external ventricular drain (EVD) placement. The task requires that trainees scroll through a stack of axial slices and form a mental representation of the anatomical structures in order to subsequently target the ventricles to insert an EVD. The process of observing the 2D CT image slices in order to build a mental representation of the 3D anatomical structures is the skill being taught, along with the cognitive control of the subsequent targeting, by planned motor actions, of the EVD tip to the ventricular system to drain cerebrospinal fluid (CSF). Convergence is established towards the validity of this assessment methodology by examining two objective measures of spatial reasoning, along with one subjective expert ranking methodology, and comparing these to AR/VR guidance. These measures have two components: the speed and accuracy of the targeting, which are used to derive the performance metric. Results of these correlations are presented for a population of PGY1 residents attending the Canadian Neurosurgical "Rookie Bootcamp" in2019.

Development of 3D tomosynthesis technique for nondestructive technology application using vertically aligned carbon nanotube-based high-resolution cold cathode electron beam

Nondestructive technology (NDT) is the most popular method for detecting defects inside an object without harming it. A 3D tomography algorithm toolbox and an x-ray imaging system are the essential components of NDT. We fabricated a high-resolution cold cathode electron beam (HRC-beam) based on vertically aligned carbon nanotubes to accomplish this objective. Using an HRC-beam, multiple angle projection images were captured in an x-ray imaging system. This x-ray source's horizontal and vertical focal spot sizes were 0.57 and 0.49 mm, respectively. Using the homemade 3D tomography algorithm toolbox, all the multiple projection images were recreated in a 3D volume. This toolbox employs algorithms such as the radon transform and the inverse radon transform to generate the 3D volume. The matlab r2022b program was used to execute the algorithm. This study explains the development of a three-dimensional volume and the inspection of the 3D volume in a slice view using a high-resolution cold cathode electron beam and the 3D tomography algorithm toolbox. A large phantom cable was used to evaluate 3D reconstruction and void inspection inside the large phantom cable.

GPR antennas geometry and its impact over detection of near-surface water contamination through AVO Data analysis at laboratory site

Polarization is an important technique for ground penetrating radar (GPR) surveys, particularly when determining the shape, orientation, size, and precise location of any buried material. A linearly-polarized incident GPR wave experiences polarization change upon scattering from the host medium, which highly depends upon the technique and antenna orientation used for the acquisition of the GPR data. This paper focuses on the polarization of GPR data acquired at a laboratory test site. We kept the GPR antenna orientation and geometry in mind to understand how they impact the results while detecting subsurface contamination. Because of its direct indication ability, amplitude variation with offset (AVO) has been widely used to detect subsurface contamination; however, a technique to evaluate the distribution of subsurface contamination is not yet available; thus, in this study, we will also discuss the distribution of contamination using polarization of GPR data. Two major phenomena have been studied: the polarity of the data acquired and slice view with and without contamination in the testing tank, as well as trace, frequency, and amplitude plot during data analysis to determine the difference of plot with and without contamination. Our findings suggest that using the polarization geometry technique to obtain an accurate view of the subsurface contamination will not only improve the GPR AVO analysis but will also provide a clear distribution of contamination in the subsurface.

Performance Analysis of Low-Resolution Electroencephalogram Source Localization Techniques

Brain source localization has attained significant fascination over the last few decades. Source localization in the human brain is a prospective complication that is derived in the multifaceted real-world complications because of the brain’s practical and biological density, other than medical precincts of assembling Electroencephalogram (EEG) from enormously various subjects. It is validated that the electromagnetic signal recorded on the top of the scalp is owing to the collective actions of neurons inside the brain. Any impulsive action of the brain, sensory stimulus, cognitive action, or the generation of motor yield possibly will offer intensification to such neuronal actions. Source- localization in the human brain implicates the localization and detection of such primary neuronal originators into the brain. Although renowned and different research in the area, the complications remnants to be a mysterious inverse problem in the brain signal processing research. The performance of EEG source localization techniques based on standardized Low-Resolution Brain Electromagnetic Tomography (sLORETA) and exact Low-Resolution Brain Electromagnetic Tomography (eLORETA) is highlighted in this research. The Event-Related Potential (ERP) records with chromatic stimulus are considered for analysis at diverse time intervals for both techniques and final results are discussed in reports of scalp map, slice view, and, cortex map and proposed the optimum techniques for EEG source localization.

Seismic sedimentology analysis of fluvial-deltaic systems in a complex strike-slip fault zone, Bohai Bay Basin, China: Implications for reservoir prediction

The Miocene fluvial-deltaic system in the Bohai Bay Basin exhibits difficulties in favourable reservoir prediction in a complex strike-slip fault zone in the Tanlu fault system. On the basis of 3D seismic data and 12 wells, we utilize two different RGB colour-blending methods from various datasets. The first method is derived from the 3D stacked, −90° phase seismic volume, and the second method is generated from the root mean square (RMS) volume attribute, which is extracted from −90° phase seismic data. Combined with the linear combination analysis of user control, we attempt to better quantify reservoir thickness and evolution of the fluvial-deltaic system in the Guantao Formation. The results show that stratal slices of the second RGB colour-blending method have a much greater ability to characterize sedimentary facies evolution and to analyse sand-thickness variations, which can effectively decrease the disadvantageous influence of multiple fault blocks on stratal slice views. In the vertical section, the linear combination analysis and the first RGB colour-blending method, however, have greater utility and resolution, which can be used to characterize the sand body by the width of seismic events or display the various sand thicknesses in different colours. The high-resolution anatomy of the fluvial-deltaic system in the Bohai Bay Basin not only explains current exploration effects but also effectively predicts thick sandstones with the most production potential in this complex region. This study may also have great significance for other complex areas or strata.

A Multi-Modular System for the Visualization and Classification of MER Data During Neurostimulation Procedures.

This paper proposes an interactive analysis and visualization tool for the accuracy improvement of electrode placement during neurostimulation therapy surgery. During the procedure, the presented system assists the surgeon in the crucial tissue type detection by providing a fused visualization of the current electrode location and the microelectrode recordings (MER). The system processes the MER in real-time and utilizes a convolutional neural network (CNN) to classify the targeted tissue type. In addition to presenting the MER in its raw waveform, the system also offers the visualization of the frequency domain and the result of the neural network. To further assist the decision-making process, additional visualization methods are integrated into the system. Using the pre-operative taken CT and MRI scans, the system offers 3D visualization in the form of direct volume rendering (DVR) and axis-aligned slice views in 2D. Both domains are enriched by the MER readings and the result of the machine learning classifier.

Hierarchical alignment of 3D print with tool path based on microstructure

ABSTRACT Using a 3D scanner to inspect a 3D print is becoming more significant as the spectrum of applications for fused filament fabrication expands. We use the tool path, which describes the 3D printing process, as the nominal data to evaluate the manufacturing errors. However, since the 3D print’s coordinate system in the scan data is unknown, the 3D print must be aligned with the tool path before the nominal-actual comparison. Therefore, we present a novel alignment based on the 3D print’s microstructure. The proposed method first estimates the build direction and then aligns the 3D print with the tool path along the build direction. Finally, each layer of the 3D print is aligned with its corresponding layer of the tool path in the horizontal direction. The alignment result can be confirmed through the slice view. In addition, the performance, extension, and applications of the proposed method are discussed.

Sequence application of Brain mri with orthodontic bracket

Magnetic Resonance Imaging (MRI) examination of the brain at high resolution will be able to detect abnormalities in the brain that are not detected before. The MRI machine is equipped with a very strong magnetic force, therefore metal objects can interfere with the workings of the machine . Some patients, there may be a magnet in the body unnoticed, for example: orthodontic bracket. The purpose of this study was to analyze the effectiveness of sequences to reduce metal artifacts due to the installation of the Orthodontic Bracket. This type of research is a quantitative analytic with a quasi-experimental research design. The research design used was a one group pretest-posttest design to determine the optimization of the application of the Slice Encoding Metal Artifact Correction (SEMAC) and View Angle Tilting (VAT) sequences on Brain MRI with Orthodontic Bracket. The results showed that the SEMAC sequence combined with T2 TSE was able to reduce metal artifacts well. VAT sequences combined with T2 TSE were able to reduce metal artifacts quite well. A more optimal sequence to reduce metal artifacts is T2 TSE SEMAC, where the sequence is able to reveal thin structures that are not visible in the T2 TSE or T2 TSE VAT sequences.

Understanding predictive factors for merge conflicts

Abstract Context: Merge conflicts often occur when developers change the same code artifacts. Such conflicts might be frequent in practice, and resolving them might be costly and is an error-prone activity. Objective: To minimize these problems by reducing merge conflicts, it is important to better understand how conflict occurrence is affected by technical and organizational factors. Method: With that aim, we investigate seven factors related to modularity, size, and timing of developers contributions. To do so, we reproduce and analyze 73504 merge scenarios in GitHub repositories of Ruby and Python MVC projects. Results: We find evidence that the likelihood of merge conflict occurrence significantly increases when contributions to be merged are not modular in the sense that they involve files from the same MVC slice (related model, view, and controller files). We also find bigger contributions involving more developers, commits, and changed files are more likely associated with merge conflicts. Regarding the timing factors, we observe contributions developed over longer periods of time are more likely associated with conflicts. No evaluated factor shows predictive power concerning both the number of merge conflicts and the number of files with conflicts. Conclusion: Our results could be used to derive recommendations for development teams and merge conflict prediction models. Project management and assistive tools could benefit from these models.

Implementation of a modified quality assurance protocol for CBCT machines within UT health San Antonio School of Dentistry.

To implement the quality control assurance protocol (including the re-establishment of baseline data from 2016) to monitor the stability of image quality of CBCT machines located within the UT Health San Antonio School of Dentistry. Five CBCT machines ProMax 3D Mid® (Planmeca Oy, Helsinki, Finland), 3D Accuitomo XYZ Slice View Tomograph® (Model MCT-1, Type EX-1F8; Fushimi-ku, Kyoto: J. Morita Mfg. Corp), Veraviewepocs 3D (Model R100; Fushimi-ku, Kyoto: J. Morita Mfg. Corp), PreXion3D Excelsior® (PreXion, San Mateo, CA), and i-CAT FLX Series® (Imaging Sciences International, Hatfield, PA) were tested for Artifact, Contrast-to-Noise Ratio, Noise, Spatial Resolution, and Contrast Resolution using a custom insert configuration in the SEDENTEXCT IQ phantom. Four-scan benchmark mean values for Artifact, Contrast-to-Noise, Noise, Spatial Resolution, and Contrast Resolution were determined for the five machines tested with associated alert and action level thresholds calculated. This newly developed QA protocol established image quality baseline values. Recommended tests, frequency, and actions levels have been updated and control charts established for future trend analysis to enable proper implementation of a QA protocol monitoring CBCT machines at UT health San Antonio.

Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b

Context. Of the presently known ≈3900 exoplanets, sparse spectral observations are available for ≈100. Ultra-hot Jupiters have recently attracted interest from observers and theoreticians alike, as they provide observationally accessible test cases. Confronting detailed theoretical models with observations is of preeminent importance in preparation for upcoming space-based telescopes. Aims. We aim to study cloud formation on the ultra-hot Jupiter HAT-P-7b, the resulting composition of the local gas phase, and how their global changes affect wavelength-dependent observations utilised to derive fundamental properties of the planet. Methods. We apply a hierarchical modelling approach as a virtual laboratory to study cloud formation and gas-phase chemistry. We utilise 97 vertical 1D profiles of a 3D GCM for HAT-P-7b to evaluate our kinetic cloud formation model consistently with the local equilibrium gas-phase composition. We use maps and slice views to provide a global understanding of the cloud and gas chemistry. Results. The day/night temperature difference on HAT-P-7b (ΔT ≈ 2500 K) causes clouds to form on the nightside (dominated by H2/He) while the dayside (dominated by H/He) retains cloud-free equatorial regions. The cloud particles vary in composition and size throughout the vertical extension of the cloud, but also globally. TiO2[s]/Al2O3[s]/CaTiO3[s]-particles of cm-sized radii occur in the higher dayside-latitudes, resulting in a dayside dominated by gas-phase opacity. The opacity on the nightside, however, is dominated by 0.01…0.1μm particles made of a material mix dominated by silicates. The gas pressure at which the atmosphere becomes optically thick is ~10−4 bar in cloudy regions, and ~0.1 bar in cloud-free regions. Conclusions. HAT-P-7b features strong morning/evening terminator asymmetries, providing an example of patchy clouds and azimuthally-inhomogeneous chemistry. Variable terminator properties may be accessible by ingress/egress transmission photometry (e.g., CHEOPS and PLATO) or spectroscopy. The large temperature differences of ≈2500 K result in an increasing geometrical extension from the night- to the dayside. The H2O abundance at the terminator changes by <1 dex with altitude and ≲0.3 dex (a factor of 2) across the terminator for a given pressure, indicating that H2O abundances derived from transmission spectra can be representative of the well-mixed metallicity at P ≳ 10 bar. We suggest the atmospheric C/O as an important tool to trace the presence and location of clouds in exoplanet atmospheres. The atmospheric C/O can be sub- and supersolar due to cloud formation. Phase curve variability of HAT-P-7b is unlikely to be caused by dayside clouds.

Immersive Virtual Colonoscopy.

Virtual colonoscopy (VC) is a non-invasive screening tool for colorectal polyps which employs volume visualization of a colon model reconstructed from a CT scan of the patient's abdomen. We present an immersive analytics system for VC which enhances and improves the traditional desktop VC through the use of VR technologies. Our system, using a head-mounted display (HMD), includes all of the standard VC features, such as the volume rendered endoluminal fly-through, measurement tool, bookmark modes, electronic biopsy, and slice views. The use of VR immersion, stereo, and wider field of view and field of regard has a positive effect on polyp search and analysis tasks in our immersive VC system, a volumetric-based immersive analytics application. Navigation includes enhanced automatic speed and direction controls, based on the user's head orientation, in conjunction with physical navigation for exploration of local proximity. In order to accommodate the resolution and frame rate requirements for HMDs, new rendering techniques have been developed, including mesh-assisted volume raycasting and a novel lighting paradigm. Feedback and further suggestions from expert radiologists show the promise of our system for immersive analysis for VC and encourage new avenues for exploring the use of VR in visualization systems for medical diagnosis.

Visual analysis of void and reinforcement characteristics in X-ray computed tomography dataset series of fiber-reinforced polymers

Fiber-reinforced polymers (FRPs) are of great importance in various industries because of their superior properties as compared to conventional materials, their versatile processing, and their wide application possibilities. To fulfil the high-quality standards in its respective applications, industrial 3D X-ray computed tomography (XCT) is increasingly used. It enables an accurate, non-destructive characterization of material features such as inclusions, voids, fibers, or other reinforcements, which is of core importance for material and component design. In this work we present FeatureAnalyzer, a generalization of the previously introduced PorosityAnalyzer tool, which allows to analyze dataset series as generated for exploring the parameter space of image processing workflows (including pre-filtering, segmentation, postprocessing or quantification) applied to XCT datasets of fiber-reinforced polymers. With a scatter plot matrix (SPLOM), the characteristics of the features of interest may be examined in more detail regarding the used input and output parameters. Individual results may be selected in the SPLOM and analyzed using 2D slice views and 3D renderings. For this work, three different samples (sample #1 - #3) were scanned by means of XCT and were evaluated by using FeatureAnalyzer. The samples #1 and #2 have a porosity value of approximately 1.7 vol. %. By using the FeatureAnalyzer in combination with SPLOM, the threshold parameters could be analyzed before the over-segmentation of voids occurs. Additional evaluations by parallel coordinates clearly show, that sample #2 has a higher number of spherical voids in the center of the specimen compared to sample #1. By evaluating the resin content of sample #3, the individual layer thickness could be measured. The source code of the tool is available on Github: https://github.com/3dct/open_iA/

Use of high resolution computed tomography to diagnose ante-mortem dental root fractures in archaeological samples

Dental root fractures are rarely documented in past human populations, but when they are observed, diagnosing ante-mortem events as causal factors can be difficult due to postmortem alteration. Can high resolution X-ray computed tomography (CT) improve our ability to diagnose if a dental fracture was caused ante- or post-mortem? To test this, a case study of two individuals with previously diagnosed dental root fractures were re-examined with high resolution CT to confirm or refute the original diagnoses. For individual 4170, use of high resolution CT supported the original diagnosis of an ante-mortem root fracture on the right mandibular central incisor that was made based on planar X-ray. With the new analyses, the root fracture was found to be associated with evidence of calcification, and with radicular and alveolar bone resorption, which are positive correlates of an ante-mortem origin. Resolving this level of detail of bone modification was not possible without using high resolution CT. For individual 4172, the use of high resolution CT enabled visualisation of fracturing and cracking throughout several molars and crowns of other teeth that were not evident in planar X-ray, suggesting that these fractures were likely produced by post-mortem taphonomic processes rather than ante-mortem events as originally diagnosed. In this case study, high resolution CT offered critical advantages compared to a planar X-ray approach, such as using 3D multiple slice views without superimposing alveolar bone and teeth as in planar X-ray imaging. This study demonstrates the potential of high resolution CT in confirming and refuting ante-mortem processes, and that visualisation of 3D structures is crucial for arriving at definitive diagnoses.

Decreased postoperative gluteus medius muscle cross-sectional area measured by computed tomography scan in patients with intertrochanteric fractures nailing.

In patients with femoral intertrochanteric fractures treated by cephalomedullary (CM) nailing, abduction force reportedly decreased by 25-30% during the postoperative follow-up period. The purpose of the current study is to evaluate the cross-sectional area (CSA) and adipose tissue ratio (ATR) of the gluteus medius muscle on the postoperative computed tomography (CT) view, expecting this graphic study will support clinical results. A total of 27 patients with femoral intertrochanteric fractures treated by CM femoral nail implants completed the study. The mean age at osteosynthesis was 83 years (range: 72-94 years). The mean postoperative follow-up period was 23 months. The three CT axial slice views were defined as slices A, B, and C corresponding to proximal, midway, and distal part of gluteus medius, respectively. The CSA and ATR were assessed bilaterally. The mean and standard deviation of CSA values (mm2) between the nonoperated/ operated side were as follows: slice A: 2225.8 ± 621.2/1984.5 ± 425.8; slice B: 2145.1 ± 538.3/1854.9 ± 383.9; and slice C: 1711.0 ± 459.0/1434.5 ± 396.9 ( p < 0.01 in slices A, B, and C). The mean and standard deviation of ATR values (%) from the nonoperative/ operative side were as follows: slice A: 2.8 ± 1.7/5.2 ± 3.5; slice B: 2.7 ± 1.9/4.6 ± 3.2; and slice C: 3.6 ± 3.0/4.8 ± 3.2 ( p < 0.01 in slices A and B and p < 0.05 in slice C). Our image findings documented that gluteus medius is significantly changed in CSA and ATR. The damage possibly triggers decrease in muscular strength of hip abduction in the postoperative follow-up period. This measurement is objective, and needed no patient's endurance and cooperation.

Effects of positioning upon the vertical dimension on cone beam computed tomography

Aims: The present study was performed to investigate the effects of different positioning modalities on vertical dimensional measurements of potential implant sites in cone beam computed tomography (CBCT) images. Methods: Twenty-eight implant shaped stainless steel pins were placed in every tooth location in a dry skull and CBCT images of these pins were obtained with the skull in different positions in lateral and forward-backward planes. The following angles were used in both planes: –10°, –5°, 0°, +5° and +10°. The CBCT images were obtained with the Kodak 9000 CBCT imaging system (Carestream Health Inc, Rochester NY, USA). Panoramic slice views were used for measurement allowing all pins to be viewed on the same slice. The measurements of vertical dimensions of the pins were performed twice on the obtained images by the same observer according to tooth regions and the data was statistically analyzed. Results: Statistical analysis revealed that for forward-backward movements measurement differences were statistically significant in maxillary anterior, mandibular anterior and mandibular premolar regions and for lateral position changes statistically significant differences were observed in the maxillary premolar and maxillary molar regions for imaging modalities changing between the angles of –10° and +10°. Conclusion: Changing the skull position reduces the accuracy of vertical dimensions on CBCT scans. The results of the present study showed that skull movements between –10o and +10o effects the anterior regions significantly, but for other regions of the jaws the measurements are within a clinically acceptable range.

Visualizing Tensor Normal Distributions at Multiple Levels of Detail.

Despite the widely recognized importance of symmetric second order tensor fields in medicine and engineering, the visualization of data uncertainty in tensor fields is still in its infancy. A recently proposed tensorial normal distribution, involving a fourth order covariance tensor, provides a mathematical description of how different aspects of the tensor field, such as trace, anisotropy, or orientation, vary and covary at each point. However, this wealth of information is far too rich for a human analyst to take in at a single glance, and no suitable visualization tools are available. We propose a novel approach that facilitates visual analysis of tensor covariance at multiple levels of detail. We start with a visual abstraction that uses slice views and direct volume rendering to indicate large-scale changes in the covariance structure, and locations with high overall variance. We then provide tools for interactive exploration, making it possible to drill down into different types of variability, such as in shape or orientation. Finally, we allow the analyst to focus on specific locations of the field, and provide tensor glyph animations and overlays that intuitively depict confidence intervals at those points. Our system is demonstrated by investigating the effects of measurement noise on diffusion tensor MRI, and by analyzing two ensembles of stress tensor fields from solid mechanics.

Ultrasonic Phased Array 3D Imaging for the Steel Butt Weld Defects

Ultrasonic phased array imaging detection technology combinating the focused beam and array probe movement can get powerful test information. It has been widely used in the steel butt weld detection. For making up the limitations of 2D view, in this paper,we used one-dimensional linear array probe, got 2D slice view data obtained by phased array ultrasonic S-scan, through software programming algorithm to realize 3D reconstruction of steel butt weld typical defects. Experiment shows that it can display more intuitive performance of the defects in space. Revealing a better shape, size and orientation information. Providing a reference for the final evaluation of the defect.

Acute LTE electromagnetic field exposure modulates the human resting-state functional connectivity

We designed a controllable near-field LTE EMF exposure environment (figure 1) [4]. 21 right-handed healthy subjects were enrolled to participate in a double, crossover, randomized and counterbalanced experiment including two sessions In each session, the EMF exposure (real or sham) lasted for 30 min. The structural and resting state fMRI signals were collected before and after the exposure. The head structural images were segmented interactively to identify 24 tissues with iSeg. Then we performed the Finite-Difference TimeDomain (FDTD) simulation [5] to estimate the specific absorption rate (SAR) power distribution induced in different head tissues. We examined the amplitude of low frequency fluctuation (ALFF) of brain activity [6], and found three brain regions showing significantly decreased ALFF values after real exposure [4]. Then we selected these three regions as seed volumes for the functional connectivity analyses. Data preprocessing included slice time correction, head motion correction, spatially normalization, linear detrend, Gaussian smoothing (FWHM = 4 mm), and temporal band-pass filter with 0.01 ~ 0.1 Hz. Then the mean time series of each seed volume were computed for each condition. Cross-correlation analysis was performed between the mean signals and the time series of all other brain voxels. After performing a Fisher's on correlation coefficients, we used paired t-test to generate the maps of statistical difference between pre-and post-exposure (P < 0.05, corrected with Monte Carlo simulation method). Figure 1. Experimental setup for LTE EMF exposure Figure 2. Slice views for estimated SAR power distribution in two subjects. SAR maps are colored according to the bar on the right, and 0 dB equals 2.36 W/kg for a specific voxel.