Imaging Of Hard Tissues Research Articles

Neck lumps: Early Detection with Dental Magnetic Resonance Imaging?

Cervical lymphadenopathy can indicate a range of diseases, including infections, inflammation, and neoplastic processes. Accurate diagnosis is crucial for identifying the underlying cause and determining appropriate treatment. Diagnostic procedures include clinical examination, ultrasound, fine needle aspiration, biopsy, and imaging techniques. While conventional imaging methods such as X-ray and computed tomography (CT) have proven useful, they exhibit limitations in sensitivity and specificity, especially for soft tissue structures. Magnetic resonance imaging (MRI) provides superior soft tissue contrast, offering additional critical information for differential diagnosis. This article presents a case study of a 29-year-old male with a cervical mass. Advanced dental MRI protocols, including DESS, SPACE-SPAIR, and SPACE-STIR sequences, have significantly enhanced the imaging capabilities of the den-tomaxillofacial region, enabling the generation of high-resolution images of both hard and soft tissues. Especially, MR OPGs have demonstrated the capacity to identify early signs of potential pathology. These protocols have the potential to enhance early detection, thereby con-tributing to accurate diagnosis and effective treatment planning.

3D X-ray microscope acts as an accurate and effective equipment of pathological diagnosis in craniofacial imaging

Craniofacial structure and dental hard tissue used to be researched on by traditional imaging tools such as light microscope, electron microscope and micro-CT. Due to the limitations of imaging principle, resolution and 3D rendering reconstruction technique, traditional imaging tools are constrained for presenting fine structure and precise measurements. Here a brand-new imaging equipment–3D X-ray microscope is introduced to realize a more efficient scanning by demonstrating the comparison of the craniofacial structures and dental hard tissue of diabetes and normal DBA mouse. To explore a higher resolution, more efficient imaging measurement and 3D reconstruction method on craniofacial structure and dental hard tissue. The study included 12 DBA mice which were divided into two groups (control group and diabetes group). The heads were separated and scanned by 3D X-ray microscope, after which regions of interest were selected, followed by measurement and 3D reconstruction based on microscope attached software Dragonfly pro©. Hemi-mandibles were collected for enamel mineral density assessment supported by QRM-MicroCT-HA phantom. Data was submitted to paired t-tests at a 95% confidence level. The automatic assessed enamel thickness of diabetes mice decreased on average, whereas the rest of manual measurements and automatic assessed density showed no statistical difference. We constructed HA phantom assisted enamel density procedure in Dragonfly software. Craniofacial structure and dental hard tissue were well-presented both in 2D slide and 3D reconstruction viewport by 3D X-ray microscope which can be routinely used as craniofacial structure and dental hard tissue imaging tool.

Comparative Evaluation of Laser System to Conventional Surgical Approaches in Periodontal Healing Using Optical Coherence Tomography

Background: Optical coherence tomography (OCT) is an emerging, radiation-free diagnostic tool in dentistry, providing high-resolution, real-time imaging of both hard and soft tissues, including periodontal areas, for more accurate postoperative evaluations. This study aims to investigate the efficacy of OCT on periodontal tissues in animals by comparing the healing effects of laser therapy with those of conventional surgical instruments. Methods: Six rabbits underwent periodontal surgery using a laser, scalpel, and punch to perform an apically positioned flap on the mandibular anterior incisors and to create a tongue ulcer on the dorsal surface of the tongue. Visual and OCT evaluations were conducted on days 1, 2, 3, 7, and 14. Results: In periodontal surgery, the laser exhibited slightly faster healing compared to other methods. In tongue ulcer formation, the scalpel and punch groups demonstrated slightly faster healing than that of the laser. However, both methods ultimately showed similar healing outcomes. Conclusions: In the dental field, OCT is emerging as a valuable tool for assessing healing, including early stages of healing, in periodontal therapy.

Application of Reciprocity Principle in Ultrasound Bone Tomography

Abstract Full-matrix synthetic aperture imaging (FMSA) is a well-established and widely used modality for ultrasound imaging Nevertheless, the accompanying relatively large amount of data acquisition, storage, and process results in heavy costs of computation and memory, which further hinders FMSA from real-time implementation. Moreover, the most existing FMSAs employed the hypothesis uniform sound velocity to reconstruct the soft tissues, which is not suitable for hard tissue imaging, irrespective of the high acoustic impedance contrast (i.e., the difference of sound velocity) between the bone and soft tissues. To overcome these limitations, a half-matrix ultrasound bone tomography method combining the reciprocity principle and sound velocity estimation was proposed for cortical cross-section imaging. The travel-time inversion was firstly utilized for sound velocity prediction, and then half-matrix synthetic aperture (HMSA) with ray-tracing was conducted to image the cortical cross-section. An ex-vivo bovine femur was used to validate the effectiveness of the method. Compared to the full-matrix capture method, the proposed method was demonstrated to be an accurate and cost-effective modality for cortical bone tomography.

Detection and Imaging of Exposure-Related Metabolites and Xenobiotics in Hard Tissues by Laser Sampling and Mass Spectrometry.

The utility of two novel laser-based methods, laser ablation electrospray ionization (LAESI) and laser desorption ionization (LDI) from silicon nanopost array (NAPA), is explored via local analysis and mass spectrometry imaging (MSI) of hard tissues (tooth and hair) for the detection and mapping of organic components. Complex mass spectra are recorded in local analysis mode from tooth dentin and scalp hair samples. Nicotine and its metabolites (cotinine, hydroxycotinine, norcotinine, and nicotine) are detected by LAESI-MS in the teeth of rats exposed to tobacco smoke. The intensities of the detected metabolite peaks are proportional to the degree of exposure. Incorporating ion mobility separation in the LAESI-MS analysis of scalp hair enables the detection of cotinine in smoker hair along with other common molecular species, including endogenous steroid hormones and some lipids. Single hair strands are imaged by MALDI-MSI and NAPA-LDI-MSI to explore longitudinal variations in the level of small molecules. Comparing spectra integrated from NAPA-LDI-MSI and MALDI-MSI images reveals that the two techniques provide complementary information. There were 105 and 82 sample-related peaks for MALDI and NAPA, respectively, with an overlap of only 16 peaks, indicating a high degree of complementarity. Enhanced molecular coverage and spatial resolution offered by LAESI-MS and NAPA-LDI-MSI can reveal the distributions of known and potential biomarkers in hard tissues, facilitating exposome research.

Low field slice-selective ZTE imaging of ultra-short T_2 tissues based on spin-locking

Magnetic Resonance Imaging of hard biological tissues is very challenging due to small proton abundance and ultra-short T_2 decay times, especially at low magnetic fields, where sample magnetization is weak. While several pulse sequences, such as Ultra-short Echo Time (UTE), Zero Echo Time (ZTE) and SWeep Imaging with Fourier Transformation (SWIFT), have been developed to cope with ultra-short lived MR signals, only the latter two hold promise of imaging tissues with sub-millisecond T_2 times at low fields. All these sequences are intrinsically volumetric, thus 3D, because standard slice selection using a long soft radio-frequency pulse is incompatible with ultra-short lived signals. The exception is UTE, where double half pulses can perform slice selection, although at the cost of doubling the acquisition time. Here we demonstrate that spin-locking is a versatile and robust method for slice selection for ultra-short lived signals, and present three ways of combining this pulse sequence with ZTE imaging of the selected slice. With these tools, we demonstrate slice-selected 2D ex vivo imaging of the hardest tissues in the body at low field (260 mT) within clinically acceptable times.

A combination of scanning electron microscopy and broad argon ion beam milling provides intact structure of secondary tissues in woody plants

The secondary tissues of woody plants consist of fragile cells and rigid cell walls. However, the structures are easily damaged during mechanical cross-sectioning for electron microscopy analysis. Broad argon ion beam (BIB) milling is commonly employed for scanning electron microscopy (SEM) of hard materials to generate a large and distortion-free cross-section. However, BIB milling has rarely been used in plant science. In the present study, SEM combined with BIB milling was validated as an accurate tool for structural observation of secondary woody tissues of two samples, living pine (Pinus densiflora) and high-density oak wood (Quercus phillyraeoides), and compared with classical microtome cross-sectioning. The BIB milling method does not require epoxy resin embedding because of prior chemical fixation and critical point drying of the sample, thus producing a three-dimensional image. The results showed that xylem structures were well-preserved in their natural state in the BIB-milled cross-section compared with the microtome cross-section. The observations using SEM combined with BIB milling were useful for wide-area imaging of both hard and soft plant tissues, which are difficult to observe with transmitted electron microscopy because it is difficult to obtain sections of such tissues, particularly those of fragile reaction woods.

X-ray microtomography imaging of craniofacial hard tissues in selected reptile species with different types of dentition.

BackgroundReptiles exhibit a large heterogeneity in teeth morphology. The main variability comprises the different tooth shape, the type of tooth attachment to the underlying bone, or the ability to replace the teeth.FindingsHere, we provide full datasets of microtomography scans and 3D models of reptilian dentitions and skulls. We selected representative species for each of 9 reptilian families on the basis of their characteristic dental features. Because there are ≥4 different types of tooth-bone attachments, ranging from the mammalian-like thecodont attachment found in crocodilians to the simple acrodont implantation observed in some lizards, we aimed to evaluate species with different types of tooth-bone attachments. Moreover, another interesting feature varying in reptilian species is the complexity of tooth shape or the number of tooth generations, which can be associated with the type of tooth attachment to the jawbone. Therefore, selected model species also include animals with distinct tooth morphology along the jaw or different number of tooth generations. The development of tooth attachment and relationship of the tooth to the jaw can be further analysed in detail on a large collection of pre-hatching stages of chameleon. Next, we introduce different possibilities for how these datasets can be further used to study tooth-bone relationships or tooth morphology in 3D space. Moreover, these datasets can be valuable for additional morphological and morphometric analyses of reptilian skulls or their individually segmented skeletal elements.ConclusionsOur collection of microcomputed tomography scans can bring new insight into dental or skeletal research. The broad selection of reptilian species, together with their unique dental features and high quality of these scans including complete series of developmental stages of our model species and provide large opportunities for their reuse. Scans can be further used for virtual reality, 3D printing, or in education.

3D visualization and morphometric analysis of spinal motion segments and vascular networks: A synchrotron radiation-based micro-CT study in mice.

The structure of spinal motion segments and spinal vasculature is complicated. Visualizing the three-dimensional (3D) structure of the spine may provide guidance for spine surgery. However, conventional imaging techniques fail to simultaneously obtain 3D images of soft and hard tissues, and achieving such coimaging states of the spine and its vascular networks remains a challenge. Synchrotron radiation micro-CT (SRμCT) provides a relatively effective and novel method of acquiring detailed 3D information. In this study, specimens of the thoracic spine were obtained from six mice. SRμCT was employed to acquire 3D images of the structure, and histologic staining was performed for comparisons with the SRμCT images. The whole spinal motion segments and the spinal vascular network were simultaneously explored at high resolution. The mean thickness of the cartilaginous end plates (CEPs) and the volume of the intervertebral discs (IVDs) were calculated. The surface of the CEPs and the facet joint cartilage (FJC) were presented as heat maps, which allowed for direct visualization of the thickness distribution. Regional division revealed heterogeneity among the ventral, central, and dorsal parts of the CEPs and between the superior and inferior parts of the facet processes. Moreover, the connections and spatial morphology of the spinal vascular network were visualized. Our study indicates that SRμCT imaging is an ideal method for high-resolution visualization and 3D morphometric analysis of the whole spinal motion segments and spinal vascular network.

A guide for optimal iodine staining and high-throughput diceCT scanning in snakes.

Diffusible iodine‐based contrast‐enhanced computed tomography (diceCT) visualizes soft tissue from micro‐CT (µCT) scans of specimens to uncover internal features and natural history information without incurring physical damage via dissection. Unlike hard‐tissue imaging, taxonomic sampling within diceCT datasets is currently limited. To initiate best practices for diceCT in a nonmodel group, we outline a guide for staining and high‐throughput µCT scanning in snakes. We scanned the entire body and one region of interest (i.e., head) for 23 specimens representing 23 species from the clades Aniliidae, Dipsadinae, Colubrinae, Elapidae, Lamprophiidae, and Viperidae. We generated 82 scans that include 1.25% Lugol's iodine stained (soft tissue) and unstained (skeletal) data for each specimen. We found that duration of optimal staining time increased linearly with body size; head radius was the best indicator. Postreconstruction of scans, optimal staining was evident by evenly distributed grayscale values and clear differentiation among soft‐tissue anatomy. Under and over stained specimens produced poor contrast among soft tissues, which was often exacerbated by user bias during “digital dissections” (i.e., segmentation). Regardless, all scans produced usable data from which we assessed a range of downstream analytical applications within ecology and evolution (e.g., predator‐prey interactions, life history, and morphological evolution). Ethanol destaining reversed the known effects of iodine on the exterior appearance of physical specimens, but required substantially more time than reported for other destaining methods. We discuss the feasibility of implementing diceCT techniques for a new user, including approximate financial and temporal commitments, required facilities, and potential effects of staining on specimens. We present the first high‐throughput workflow for full‐body skeletal and diceCT scanning in snakes, which can be generalized to any elongate vertebrates, and increases publicly available diceCT scans for reptiles by an order of magnitude.

Simultaneous imaging of hard and soft biological tissues in a low-field dental MRI scanner

Magnetic Resonance Imaging (MRI) of hard biological tissues is challenging due to the fleeting lifetime and low strength of their response to resonant stimuli, especially at low magnetic fields. Consequently, the impact of MRI on some medical applications, such as dentistry, continues to be limited. Here, we present three-dimensional reconstructions of ex-vivo human teeth, as well as a rabbit head and part of a cow femur, all obtained at a field strength of 260 mT. These images are the first featuring soft and hard tissues simultaneously at sub-Tesla fields, and they have been acquired in a home-made, special-purpose, pre-medical MRI scanner designed with the goal of demonstrating dental imaging at low field settings. We encode spatial information with two pulse sequences: Pointwise-Encoding Time reduction with Radial Acquisition and a new sequence we have called Double Radial Non-Stop Spin Echo, which we find to perform better than the former. For image reconstruction we employ Algebraic Reconstruction Techniques (ART) as well as standard Fourier methods. An analysis of the resulting images shows that ART reconstructions exhibit a higher signal-to-noise ratio with a more homogeneous noise distribution.

An Intraoral OCT Probe to Enhanced Detection of Approximal Carious Lesions and Assessment of Restorations.

Caries, the world’s most common chronic disease, remains a major cause of invasive restorative dental treatment. To take advantage of the diagnostic potential of optical coherence tomography (OCT) in contemporary dental prevention and treatment, an intraorally applicable spectral-domain OCT probe has been developed based on an OCT hand-held scanner equipped with a rigid 90°-optics endoscope. The probe was verified in vitro. In vivo, all tooth surfaces could be imaged with the OCT probe, except the vestibular surfaces of third molars and the proximal surface sections of molars within a "blind spot" at a distance greater than 2.5 mm from the tooth surface. Proximal surfaces of 64 posterior teeth of four volunteers were assessed by intraoral OCT, visual-tactile inspection, bitewing radiography and fiber-optic transillumination. The agreement in detecting healthy and carious surfaces varied greatly between OCT and established methods (18.2–94.7%), whereby the established methods could always be supplemented by OCT. Direct and indirect composite and ceramic restorations with inherent imperfections and failures of the tooth-restoration bond were imaged and qualitatively evaluated. The intraoral OCT probe proved to be a powerful technological approach for the non-invasive imaging of healthy and carious hard tooth tissues and gingiva as well as tooth-colored restorations.

Bimodal magnetic resonance imaging-computed tomography nanoprobes: A Review

Bimodal imaging combines two imaging modalities in order to benefit from their advantages and compensate the limitations of each modality. This technique could accurately detect diseases for diagnostic purposes. Nanoparticles simultaneously offer diagnostic data via various imaging modalities owing to their unique properties. Moreover, bimodal nanoprobes could be incorporated into theranostic systems for the design of multifunctional agents. Magnetic resonance imaging (MRI) and computed tomography (CT) are frequently used as noninvasive imaging modalities. These powerful, noninvasive diagnostic techniques used for the imaging of soft and hard tissues, respectively. However, MRI has low sensitivity and is not suitable for the imaging of bony structures. On the other hand, low soft tissue contrast is a major limitation of CT. Therefore, the development of various contrast agents that are proper for bimodal MRI/CT nanoprobes could largely influence modern medicine. This review aimed to specifically focus on the imaging properties of bimodal MRI/CT nanoprobes and their biomedical applications.

Magnetic Resonance Imaging of Hard Tissues and Hard Tissue Engineered Bio-substitutes

Magnetic resonance imaging (MRI) is a non-invasive diagnostic imaging tool based on the detection of protons into the tissues. This imaging technique is remarkable because of high spatial resolution, strong soft tissue contrast and specificity, and good depth penetration. However, MR imaging of hard tissues, such as bone and teeth, remains challenging due to low proton content in such tissues as well as to very short transverse relaxation times (T2). To overcome these issues, new MRI techniques, such as sweep imaging with Fourier transformation (SWIFT), ultrashort echo time (UTE) imaging, and zero echo time (ZTE) imaging, have been developed for hard tissues imaging with promising results reported. Within this article, MRI techniques developed for the detection of hard tissues, such as bone and dental tissues, have been reviewed. The main goal was thus to give a comprehensive overview on the corresponding (pre-) clinical applications and on the potential future directions with such techniques applied. In addition, a section dedicated to MR imaging of novel biomaterials developed for hard tissue applications was given as well.

تلوين صورة الأشعة السينية الصدرية الأمامية باستخدام معادلات رياضية تجريبية متنوعة

Chest x-ray medical images are widely used for diagnostic purposes for several reasons including it available, attainable and excellent imaging of hard tissues like bones, but there is difficulty in imaging of the soft tissues, moreover the saturated colour of the x-ray image causing intricacy to read it, therefore, turned attention to the colorization process which can be used to transform the grayscale medical images to the colour medical images. In this paper, a new pseudo-coloring method proposed for colorizing the frontal chest x-ray medical images which are very important for disease detection and recognition. The key idea of this method is applying different and various experimental mathematical equations on the proposed medical sample image, which it belongs to the patient with Hydatid cyst parasite disease in the lung. The counterfeit coloring had intense contribute in enhancing of the visual attractiveness of medical images, the output colored images have a better visual description, it has a possibility to describe hidden information better than a conventional monochromatic image, this is an excellent indicator of the algorithm's suitability for the purpose for which it was formulated.

Soft tissue changes after anterior maxillary osteotomy by using 3D CBCT scanning.

The objective of this study was to evaluate the soft tissue changes after anterior maxillary osteotomy using cone beam computed tomography. The study included twelve patients diagnosed as suffering from an excess of the anterior part of maxilla and required surgical correction by anterior maxillary osteotomy. Assessment of Cone beam computed tomography in evaluation the soft tissue changes. All cases subjected to anterior maxillary osteotomy using modified Cuper technique. Follow up of cases was does clinically and radio- graphically by cone beam computed tomography. The results of the study proved that the statistically significant increase in mean Nasolabial angle after 6 months was 5.2 degrees, the mean value of nasal width after 6 months was 0,9mm. The mean value of Philtrum length was 3.3mm. In conclusion, Cone Beam Computed Tomography can be used to obtain dimensionally accurate linear and angular measurement from bony maxillofacial structure and landmarks and allows accurate, three-dimensional imaging of hard and soft tissues.

Effect of Shortened Dental Arch on Temporomandibular Joint Intra-articular Disorders.

To investigate whether a shortened dental arch (SDA), as identified by reduced posterior occlusal contacts, is a risk factor for the progression of temporomandibular joint (TMJ) intra-articular disorders (ID), as identified using imaging techniques. This multisite, prospective observational study with a mean follow-up period of 7.9 years had a sample of 345 participants with at least 1 temporomandibular disorder (TMD) diagnosis at baseline. SDA was defined as reduced occlusal posterior support due to lack of occlusal intercuspal contacts in the molar region on the left and/or right side. SDA was assessed at baseline and at follow-up with metalized Mylar Tape. The presence or absence of a TMJ ID and the specific TMJ ID diagnoses for baseline and follow-up images were established by a calibrated, blinded radiologist at each of three sites by using bilateral magnetic resonance imaging for soft tissue imaging for disc displacement and by bilateral multidetector computed tomography or cone beam computed tomography for hard tissue imaging for degenerative joint diseases. Wilcoxon rank sum test and linear regression analyses were used to test for an impact of SDA on TMJ ID status. At baseline, TMJ ID status of either side was not significantly affected by the presence of SDA on the ipsilateral or contralateral side of the jaw (all P > .05). Furthermore, the presence or absence of SDA at baseline was also not a significant predictor for progression of the TMJ ID status between baseline and follow-up (all P > .05). The findings of this study suggest that there is no significant effect of SDA on progression of TMJ ID.

In vivo imaging of human oral hard and soft tissues by polarization-sensitive optical coherence tomography.

Since optical coherence tomography (OCT) provides three-dimensional high-resolution images of biological tissue, the benefit of polarization contrast in the field of dentistry is highlighted in this study. Polarization-sensitive OCT (PS OCT) with phase-sensitive recording is used for imaging dental and mucosal tissues in the human oral cavity in vivo. An enhanced polarization contrast of oral structures is reached by analyzing the signals of the co- and crosspolarized channels of the swept source PS OCT system quantitatively with respect to reflectivity, retardation, optic axis orientation, and depolarization. The calculation of these polarization parameters enables a high tissue-specific contrast imaging for the detailed physical interpretation of human oral hard and soft tissues. For the proof-of-principle, imaging of composite restorations and mineralization defects at premolars as well as gingival, lingual, and labial oral mucosa was performed in vivo within the anterior oral cavity. The achieved contrast-enhanced results of the investigated human oral tissues by means of polarization-sensitive imaging are evaluated by the comparison with conventional intensity-based OCT.

Three-dimensional imaging of soft and hard facial tissues in patients with craniofacial syndromes: a systematic review of methodological quality.

To systematically review the methodological quality of three-dimensional imaging studies of patients with craniofacial syndromes and to propose recommendations for future research. PubMed, Embase and Cochrane databases as well as Grey literature were electronically searched. Inclusion criteria were patients with genetic syndromes with craniofacial manifestations and three-dimensional imaging of facial soft and/or hard tissues. Exclusion criteria consisted of non-syndromic conditions or conditions owing to environmental causes, injury or trauma, facial soft and hard tissues not included in the image analysis, case reports, reviews, opinion articles. No restrictions were made for patients' ethnicity nor age, publication language or publication date. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS). The search yielded 2228 citations of which 116 were assessed in detail and 60 were eventually included in this review. Studies showed a large heterogeneity in study design, sample size and patient age. An increase was observed in the amount of studies with time, and the imaging method most often used was CT. The most studied craniofacial syndromes were Treacher Collins, Crouzon and Apert syndrome. The articles could be divided into three main groups: diagnostic studies (34/60, 57%), evaluation of surgical outcomes (21/60, 35%) and evaluation of imaging techniques (5/60, 8%). For comparative studies, the median MINORS score was 13 (12-15, 25-75th percentile), and for non-comparative studies, the median MINORS score was 8 (7-9, 25-75th percentile). The median MINORS scores were only 50 and 54% of the maximum scores and there was a lack of prospective, controlled trials with sufficiently large study groups. To improve the quality of future studies in this domain and given the low incidence of craniofacial syndromes, more prospective multicentre controlled trials should be set up.

Three-dimensional hard and soft tissue imaging of the human cochlea by scanning laser optical tomography (SLOT)

The present study focuses on the application of scanning laser optical tomography (SLOT) for visualization of anatomical structures inside the human cochlea ex vivo. SLOT is a laser-based highly efficient microscopy technique which allows for tomographic imaging of the internal structure of transparent specimens. Thus, in the field of otology this technique is best convenient for an ex vivo study of the inner ear anatomy. For this purpose, the preparation before imaging comprises decalcification, dehydration as well as optical clearing of the cochlea samples in toto. Here, we demonstrate results of SLOT imaging visualizing hard and soft tissue structures with an optical resolution of down to 15 μm using extinction and autofluorescence as contrast mechanisms. Furthermore, the internal structure can be analyzed nondestructively and quantitatively in detail by sectioning of the three-dimensional datasets. The method of X-ray Micro Computed Tomography (μCT) has been previously applied to explanted cochlea and is solely based on absorption contrast. An advantage of SLOT is that it uses visible light for image formation and thus provides a variety of contrast mechanisms known from other light microscopy techniques, such as fluorescence or scattering. We show that SLOT data is consistent with μCT anatomical data and provides additional information by using fluorescence. We demonstrate that SLOT is applicable for cochlea with metallic cochlear implants (CI) that would lead to significant artifacts in μCT imaging. In conclusion, the present study demonstrates the capability of SLOT for resolution visualization of cleared human cochleae ex vivo using multiple contrast mechanisms and lays the foundation for a broad variety of additional studies.