Non-invasive Imaging Systems Research Articles

Multi-parametric Photoacoustic Imaging Combined with Acoustic Radiation Force Impulse Imaging for Applications in Tissue Engineering.

Tissue engineering is a dynamic field focusing on the creation of advanced scaffolds for tissue and organ regeneration. These scaffolds are customized to their specific applications and are often designed to be complex, large structures to mimic tissues and organs. This study addresses the critical challenge of effectively characterizing these thick, optically opaque scaffolds that traditional imaging methods fail to fully image due to their optical limitations. We introduce a novel multi-modal imaging approach combining ultrasound, photoacoustic, and acoustic radiation force impulse imaging. This combination leverages its acoustic-based detection to overcome the limitations posed by optical imaging techniques. Ultrasound imaging is employed to monitor the scaffold structure, photoacoustic imaging is employed to monitor cell proliferation, and acoustic radiation force impulse imaging is employed to evaluate the homogeneity of scaffold stiffness. We applied this integrated imaging system to analyze melanoma cell growth within silk fibroin protein scaffolds with varying pore sizes and therefore stiffness over different cell incubation periods. Among various materials, silk fibroin was chosen for its unique combination of features including biocompatibility, tunable mechanical properties, and structural porosity which supports extensive cell proliferation. The results provide a detailed mesoscale view of the scaffolds' internal structure, including cell penetration depth and biomechanical properties. Our findings demonstrate that the developed multimodal imaging technique offers comprehensive insights into the physical and biological dynamics of tissue-engineered scaffolds. As the field of tissue engineering continues to advance, the importance of non-ionizing and non-invasive imaging systems becomes increasingly evident, and by facilitating a deeper understanding and better characterization of scaffold architectures, such imaging systems are pivotal in driving the success of future tissue-engineering solutions.

Design and analysis of ultra-wideband microstrip patch antenna with various conductive materials for terahertz gap

The paper explores the design and analysis of a wideband microstrip patch antenna with a metallic patch and a 3 × 3 split ring resonator (SRR) array operating in the 0.1–5 THz frequency range. The antenna's structure incorporates different conductive materials such as gold, silver, and graphene as a metallic patch. The dimensions of the metallic patch and SRR are calculated to achieve wideband operation within the desired THz range. The SRR array enhances electromagnetic resonance, thereby improving bandwidth and radiation characteristics for medical imaging. The study discusses the equivalent circuit and design equations for the microstrip patch antenna and SRR unit cell. For designing and analyzing the proposed antenna, CST Microwave Studio 2019 software have been used. Performance parameters such as return loss, bandwidth, gain, efficiency, directivity, VSWR, and radiation pattern have been evaluated. The advantages and limitations of each conductive material are evaluated to determine their suitability for THz-based medical imaging applications. The goal is to maximize the antenna's bandwidth, gain, and image resolution for medical imaging purposes. The findings highlight the performance characteristics of gold, silver, and graphene as conductive materials for medical imaging applications, facilitating the development of high-resolution, non-invasive imaging systems with improved diagnostic capabilities.

Monitoring the effectiveness of nanosecond laser for the treatment of port-wine stain patients using non-invasive imaging systems

A variety of lasers have been used to treat port-wine stain (PWS) birthmarks, however, all of them carry the risk of adverse effects. Our objective was to assess the effectiveness and safety of nanosecond (ns) laser treatment for PWS patients using non-invasive images. This study included 20 PWS patients, whose ages ranged from one to sixteen years. A nanosecond laser (λ=595 nm; τp=2 ns), with a spot size of 5 mm, and parameters of 0.2-0.3 J/cm2, 5 Hz, was used in three passes. The infrared thermal imager aided in determining the optimal laser dosage and preventing side effects. The primary efficiency was evaluated using a DermaSpectrometer, and patients were followed up after one week, four weeks, three months, and twelve months. The infrared thermal images of skin surface temperature assessment in the first ten seconds were recorded after the maximal energy density 0.3 J/cm2 treatment. The thermal wave equation and Penne’s bioheat transfer equation ranged from 32.4±0.1 to 33.8±0.2°C, 32.6±0.1 to 34.7±0.3°C (baseline skin surface temperature - 32.4±0.3°C) respectively. Transient hyperpigmentation appeared in 5% (n=1) of the 20 patients, but it resolved spontaneously within three months. There was no evidence of permanent hypopigmentation or scarring. The DermaSpectrometer revealed a 30% reduction in Hb-index three months after a single treatment. The infrared image instrument is helpful in determining the optimum laser dosage. For the treatment of PWS patients, a nanosecond pulsed laser at 595nm was effective and safe.

Analysis of good and bad fingerprint for identification of NIR based optical frameworks using Monte Carlo method

NIR-based optical materials are widely used in bio-imaging, photodynamic treatment, optoelectronics, sensing and anti-counterfeiting applications. Their advancement has significantly increased the potential for non-invasive imaging, targeted therapy and optical communication systems. Medicine, biology, material science, and telecommunications have all benefited from this progress. Considering this, we herein developed QSAR models using absorption maxima of 292 organic compounds to identify molecular features that can be utilized to shift their λmax towards NIR region. Four splits were developed using Monte Carlo Optimization and index of ideality of correlation (TF2) with CORAL software. Predictability of four models created by these splits was carried out by numerous validation metrics. Model built from second split was observed to be the best with R2validation = 0.8252 and IIC = 0.8423. Mechanistic interpretation was also performed by extracting structural attributes that are responsible for increase and decrease of λmax using correlation weights. Positive structural attributes have been utilized for designing new organic chromophores with red shifted λmax ranging between 791 and 936 nm. The present study offers new horizons for the development of NIR based chromophores.

Evaluation ofTopical Off-the-Shelf Therapies to Reduce the Need to Evacuate Battlefield-Injured Warfighters.

Immediate evacuation of burn casualties can be challenging in austere environments, and it is predicted to be even more difficult in future multi-domain battlespaces against near-peer foes. Therefore, a need exists to treat burn wounds at the point of injury to protect the exposed injury for an extended period. In this study, we compare two commercially available FDA-approved therapies to the current gold standard of care (GSOC), excisional debridement followed by the application of split-thickness skin graft, and the standard for prolonged field care, silver sulfadiazine (SSD) cream. The shelf-stable therapies evaluated were irradiated human skin (IHS) allograft and polylactic acid (PLA). Our objective was to study whether they have the potential capability to reduce the need for evacuation to a burn center for surgical intervention so that the combat power can be preserved in the field. Sixteen burns (50 cm2) were created on the dorsum of four anesthetized swine. All materials were sterile, but a sterile field was not utilized in order to simulate the prolonged field care setting. The wounds were then treated with PLA, IHS, and SSD cream, and the remaining wounds (designated GSOC) were also treated with SSD cream. On post-operative day (POD) 3, sterile surgical debridement and skin grafting (1:4) were performed on the GSOC wounds. Burn healing was followed for either PODs 10, 14, 21, or 28, wherein one animal was humanely euthanized at each time point; each represented a time point of the healing process. A full-thickness excisional biopsy was taken from each wound immediately after euthanasia to give a cross-section view of the wound edge to edge. Wound healing was determined by the histological analysis of wound re-epithelialization, epidermal thickness, rete ridges, and scar elevation index and macroscopically using noninvasive imaging systems. The PLA and IHS treatments did not need to be reapplied to the wounds during the course of the experiment, unlike SSD, which was reapplied at each assessment time point. In terms of re-epithelialization, on POD 10, IHS and SSD were similar to the GSOC; on POD 14, all treatments were similar; on POD 21, PLA and IHS were similar to SSD; finally, on POD 28, re-epithelialization was similar in all groups. On POD 28, scar elevation index and rete ridges/mm were similar to all groups, and epidermal and dermal thickness for PLA and IHS were similar to GSOC. This preclinical study demonstrated that the use of the PLA and the IHS dressings resulted in similar outcomes to the GSOC-treated burns in several key metrics of wound healing. These therapies represent a potentially useful tool in current and future battlespaces, where surgical intervention is not possible. The products are lightweight and, more importantly, stable at room temperature for their entire shelf lives. This would allow for easy storage and transport by medical practitioners in the field.

Non-invasive in vivo imaging of human corneal microstructures with optical coherence microscopy.

Non-invasive imaging systems with cellular-level resolution offer the opportunity to identify biomarkers of the early stage of corneal diseases, enabling early intervention, monitoring of disease progression, and evaluating treatment efficacy. In this study, a non-contact polarization-dependent optical coherence microscope (POCM) was developed to enable non-invasive in vivo imaging of human corneal microstructures. The system integrated quarter-wave plates into the sample and reference arms of the interferometer to enable deeper penetration of light in tissues as well as mitigate the strong specular reflection from the corneal surface. A common-path approach was adopted to enable control over the polarization in a free space configuration, thus alleviating the need for a broadband polarization-maintained fiber. The POCM achieved volumetric imaging of corneal microstructures, including endothelial cells over a field of view 0.5 × 0.5 mm2 with an almost isotropic resolution of ∼2.2 µm and a volume (500 × 500 × 2048 voxels) rate of 1 Hz. A self-interference approach between the corneal surface and underlying layers was also developed to lessen the corneal curvature and axial motion artifacts, thus enabling high-resolution imaging of microstructures in the anterior cornea, including squamous epithelial cells, wing epithelial cells, basal epithelial cells, sub-basal nerve plexus, and stromal keratocytes.

Recent Trends and Opportunities for the Targeted Immuno-Nanomaterials for Cancer Theranostics Applications.

The targeted delivery of cancer immunotherapies has increased noticeably in recent years. Recent advancements in immunotherapy, particularly in blocking the immune checkpoints (ICs) axis, have shown favorable treatment outcomes for multiple types of cancer including melanoma and non-small-cell lung cancer (NSLC). Engineered micromachines, including microparticles, and nanoplatforms (organic and inorganic), functionalized with immune agonists can effectively deliver immune-targeting molecules to solid tumors. This review focuses on the nanomaterial-based strategies that have shown promise in identifying and targeting various immunological markers in the tumor microenvironment (TME) for cancer diagnosis and therapy. Nanomaterials-based cancer immunotherapy has improved treatment outcomes by triggering an immune response in the TME. Evaluating the expression levels of ICs in the TME also could potentially aid in diagnosing patients who would respond to IC blockade therapy. Detecting immunological checkpoints in the TME using noninvasive imaging systems via tailored nanosensors improves the identification of patient outcomes in immuno-oncology (IO). To enhance patient-specific analysis, lab-on-chip (LOC) technology is a rapid, cost-effective, and accurate way of recapitulating the TME. Such novel nanomaterial-based technologies have been of great interest for testing immunotherapies and assessing biomarkers. Finally, we provide a perspective on the developments in artificial intelligence tools to facilitate ICs-based nano theranostics toward cancer immunotherapy.

A Preliminary Study of Liver Fat Quantification Using Reported Ultrasound Speed of Sound and Attenuation Parameters.

The quantification of liver fat as a diagnostic assessment of steatosis remains an important priority for non-invasive imaging systems. We derive a framework in which the unknown fat volume percentage can be estimated from a pair of ultrasound measurements. The precise estimation of ultrasound speed of sound and attenuation within the liver is found to be sufficient for estimating fat volume assuming a classic model of the properties of a composite elastic material. In this model, steatosis is represented as a random dispersion of spherical fat vacuoles with acoustic properties similar to those of edible oils. Using values of speed of sound and attenuation from the literature in which normal and steatotic livers were studied near 3.5 MHz, we describe agreement of the new estimation method with independent measures of fat. This framework holds the potential for translation to clinical scanners with which the two ultrasound measurements can be made and used for improved quantitative assessment of steatosis.

Tumor-homing peptide and its utility for advanced cancer medicine.

Cell‐penetrating peptides, such as antibodies, have gained great attention as tools for the development of specific delivery systems for payloads, which might be applied as non‐invasive carriers in vivo. Among these, tumor‐homing peptides recently have been studied for use in tumor medicine. Tumor‐homing peptides are oligopeptides, usually consisting of 30 or fewer amino acids that are efficiently and specifically incorporated into tumor cells, suggesting their potential use in establishing novel non‐invasive tumor imaging systems for diagnostic and therapeutic applications. Here, we briefly introduce the biological characteristics of our tumor‐homing peptides, focusing especially on those developed using a random peptide library constructed using mRNA display technology. The advantage of the tumor‐homing peptides is their biological safety, given that these molecules do not show significant cytotoxicity against non‐neoplastic cells; lack serious antigenicity, which alternatively might evoke unfavorable immune responses and inflammation in vivo; and are rapidly incorporated into target cells/tissues, with rates exceeding those seen for antibodies. Given their small size, tumor‐homing peptides also are easy to modify and redesign. Based on these merits, tumor‐homing peptides are expected to find wide application in various aspects of tumor medicine, including imaging diagnostics (eg, with dye‐conjugated probes for direct visualization of invasive/metastatic tumor lesions in vivo) and therapeutics (eg, using peptide‐drug conjugates [PDCs] for tumor targeting). Although further evidence will be required to demonstrate their practical utility, tumor‐homing peptides are expected to show great potential as a next‐generation bio‐tool contributing to precision medicine for cancer patients.

Holistic description of new deep sea megafauna (Cephalopoda: Cirrata) using a minimally invasive approach

BackgroundIn zoology, species descriptions conventionally rely on invasive morphological techniques, frequently leading to damage of the specimens and thus only a partial understanding of their structural complexity. More recently, non-destructive imaging techniques have successfully been used to describe smaller fauna, but this approach has so far not been applied to identify or describe larger animal species. Here, we present a combination of entirely non-invasive as well as minimally invasive methods that permit taxonomic descriptions of large zoological specimens in a more comprehensive manner.ResultsUsing the single available representative of an allegedly novel species of deep-sea cephalopod (Mollusca: Cephalopoda), digital photography, standardized external measurements, high-field magnetic resonance imaging, micro-computed tomography, and DNA barcoding were combined to gather all morphological and molecular characters relevant for a full species description. The results show that this specimen belongs to the cirrate octopod (Octopoda: Cirrata) genus Grimpoteuthis Robson, 1932. Based on the number of suckers, position of web nodules, cirrus length, presence of a radula, and various shell characters, the specimen is designated as the holotype of a new species of dumbo octopus, G. imperator sp. nov. The digital nature of the acquired data permits a seamless online deposition of raw as well as derived morphological and molecular datasets in publicly accessible repositories.ConclusionsUsing high-resolution, non-invasive imaging systems intended for the analysis of larger biological objects, all external as well as internal morphological character states relevant for the identification of a new megafaunal species were obtained. Potentially harmful effects on this unique deep-sea cephalopod specimen were avoided by scanning the fixed animal without admixture of a contrast agent. Additional support for the taxonomic placement of the new dumbo octopus species was obtained through DNA barcoding, further underlining the importance of combining morphological and molecular datasets for a holistic description of zoological specimens.

Chitosan Nanococktails Containing Both Ceria and Superparamagnetic Iron Oxide Nanoparticles for Reactive Oxygen Species-Related Theranostics

Reactive oxygen species (ROS) play an essential role in the progression of many chronic diseases like atherosclerosis and rheumatoid arthritis. For decades, antioxidant compounds have always been considered as potential treatments for these ROS-related diseases. Concomitantly, noninvasive imaging systems such as magnetic resonance imaging (MRI) have also been widely used in the diagnosis of diseases, especially atherosclerosis. In this study, we investigated the feasibility to develop chitosan nanococktails containing both nanoceria and superparamagnetic iron oxide nanoparticles for ROS-related theranostics. Nanoceria utilized as therapeutic modules capable of ROS scavenging and iron-oxide nanoparticles utilized as imaging agents for MRI have been synthesized separately. Subsequently, two versions of theranostic chitosan nanococktails containing both nanoceria and iron oxide nanoparticles (Chit-IOCO and Chit-TPP-IOCO) were successfully synthesized via two different mechanisms, electrostatic self-assembly, and ionic gelation. In vitro studies such as cytotoxicity, MRI, and ROS scavenging were performed. These theranostic nanococktails demonstrated effective ROS scavenging and MRI contrast as a potential platform for treatment and diagnosis of ROS-related diseases. Results indicated that both Chit-IOCO and Chit-TPP-IOCO can reduce the ROS level of the lipopolysaccharide-stimulated macrophage J774A.1 to the baseline level. Chit-IOCO was less toxic to the cells than Chit-TPP-IOCO. In addition, Chit-IOCO exhibited higher MRI relaxivity than Chi-TPP-IOCO (308 and 150 mM-1 s-1, respectively), indicating that Chi-IOCO was more effective than Chit-TPP-IOCO as an MRI contrast agent in macrophages. Taken together, Chit-IOCO nanococktail demonstrates outstanding potential for treatment and diagnosis of ROS-related diseases. Potentially, this nanococktail can be easily modified to include new modules, allowing future application of personalized medicine.

Non-invasive spectroscopic and imaging systems for prediction of beef quality in a meat processing pilot plant

This study evaluated a range of diffuse reflectance spectroscopic (Vis-NIR spectrophotometers) and imaging (Hyperspectral imaging cameras) instruments for predicting pH, IMF and shear force values of beef in a meat processing pilot plant. A total of 364 beef striploin samples were evaluated and prediction models were developed using PLSR. Models for pH and IMF (except Vis snapshot camera) showed good fit with high Rcv2 (0.29–0.92) and low SECV values. Good prediction accuracy with high Rp2 (0.44–0.90), RPD and low SEP values was also observed. While low values of Rp2 for shear force was observed, the expected curvilinear relationship between predicted values of shear force and predicted values of pH was observed suggesting that spectroscopic measurements were able detect biophysical factors associated to these two attributes. Overall, it can be concluded that diffuse reflectance spectroscopy combined with chemometrics has a great potential to be used as an on/in-line quality monitoring system for the meat processing industry.

Video-Speed Graphene Modulator Arrays for Terahertz Imaging Applications

Electrically tuneable high mobility charges on graphene yield an efficient electro-optical platform to control and manipulate terahertz (THz) waves. Real-world applications require a multiplex THz device with efficient modulation over a large active area. The trade-off between the efficient gating and switching speed, however, hinders the realization of these applications. Here, we demonstrate a large-format 256-pixel THz modulator which provides high-frame-rate reconfigurable transmission patterns. The time-domain and frequency-domain THz characterizations of graphene devices reveal the relaxation pathways of gate-induced charges and ion packing at graphene-electrolyte interface. The fundamental understanding of these limiting factors enables us to break the trade-off permitting switching frequencies up to 1 kHz. To show the promises of these devices, we demonstrate a single-pixel THz camera which allows spatial and spectroscopic imaging of large-area objects without any moving components. These results provide a significant advancement towards the achievement of non-invasive THz imaging systems using graphene-based platforms.

Noninvasive Monitoring of Allogeneic Stem Cell Delivery with Dual-Modality Imaging-Visible Microcapsules in a Rabbit Model of Peripheral Arterial Disease.

Stem cell therapies, although promising for treating peripheral arterial disease (PAD), often suffer from low engraftment rates and the inability to confirm the delivery success and track cell distribution and engraftment. Stem cell microencapsulation combined with imaging contrast agents may provide a means to simultaneously enhance cell survival and enable cell tracking with noninvasive imaging. Here, we have evaluated a novel MRI- and X-ray-visible microcapsule formulation for allogeneic mesenchymal stem cell (MSC) delivery and tracking in a large animal model. Bone marrow-derived MSCs from male New Zealand White rabbits were encapsulated using a modified cell encapsulation method to incorporate a dual-modality imaging contrast agent, perfluorooctyl bromide (PFOB). PFOB microcapsules (PFOBCaps) were then transplanted into the medial thigh of normal or PAD female rabbits. In vitro MSC viability remained high (79 ± 5% at 4 weeks of postencapsulation), and as few as two and ten PFOBCaps could be detected in phantoms using clinical C-arm CT and 19F MRI, respectively. Successful injections of PFOBCaps in the medial thigh of normal (n = 15) and PAD (n = 16) rabbits were demonstrated on C-arm CT at 1-14 days of postinjection. Using 19F MRI, transplanted PFOBCaps were clearly identified as “hot spots” and showed one-to-one correspondence to the radiopacities on C-arm CT. Concordance of 19F MRI and C-arm CT locations of PFOBCaps with postmortem locations was high (95%). Immunohistological analysis revealed high MSC survival in PFOBCaps (>56%) two weeks after transplantation while naked MSCs were no longer viable beyond three days after delivery. These findings demonstrate that PFOBCaps could maintain cell viability even in the ischemic tissue and provide a means to monitor cell delivery and track engraftment using clinical noninvasive imaging systems.

Noninvasive imaging systems for gametes and embryo selection in IVF programs: a review.

Optimizing the efficiency of the in vitro fertilization procedure by improving pregnancy rates and reducing the risks of multiple pregnancies simultaneously are the primary goals of the current assisted reproductive technology program. With the move to single embryo transfers, the need for more cost-effective and noninvasive methods for embryo selection prior to transfer is paramount. These aims require advancement in a more acquire gametes/embryo testing and selection procedures using high-tech devices. Therefore, the aim of the present review is to evaluate the efficacy of noninvasive imaging systems in the current literatures, focusing on the potential clinical application in infertile patients undergoing assisted reproductive technology treatments. In this regards, three advanced imaging systems of motile sperm organelle morphology examination, polarization microscopy and time-lapse monitoring for the best selection of the gametes and preimplantation embryos are introduced in full.

Intracranial Volume Quantification from 3D Photography.

3D photography offers non-invasive, radiation-free, and anesthetic-free evaluation of craniofacial morphology. However, intracranial volume (ICV) quantification is not possible with current non-invasive imaging systems in order to evaluate brain development in children with cranial pathology. The aim of this study is to develop an automated, radiation-free framework to estimate ICV. Pairs of computed tomography (CT) images and 3D photographs were aligned using registration. We used the real ICV calculated from the CTs and the head volumes from their corresponding 3D photographs to create a regression model. Then, a template 3D photograph was selected as a reference from the data, and a set of landmarks defining the cranial vault were detected automatically on that template. Given the 3D photograph of a new patient, it was registered to the template to estimate the cranial vault area. After obtaining the head volume, the regression model was then used to estimate the ICV. Experiments showed that our volume regression model predicted ICV from head volumes with an average error of 5.81 ± 3.07% and a correlation (R2) of 0.96. We also demonstrated that our automated framework quantified ICV from 3D photography with an average error of 7.02 ± 7.76%, a correlation (R2) of 0.94, and an average estimation error for the position of the cranial base landmarks of 11.39 ± 4.3mm.

Applying hyperspectral imaging to explore natural plant diversity towards improving salt stress tolerance

Salinity represents an abiotic stress constraint affecting growth and productivity of plants in many regions of the world. One of the possible solutions is to improve the level of salt resistance using natural genetic variability within crop species. In the context of recent knowledge on salt stress effects and mechanisms of salt tolerance, this review present useful phenomic approach employing different non-invasive imaging systems for detection of quantitative and qualitative changes caused by salt stress at the plant and canopy level. The focus is put on hyperspectral imaging technique, which provides unique opportunities for fast and reliable estimate of numerous characteristics associated both with various structural, biochemical and physiological traits. The method also provides possibilities to combine plant and canopy analyses with a direct determination of salinity in soil. The future perspectives in salt stress applications as well as some limits of the method are also identified.

Non-invasive in vivo tracking of fibrin degradation by fluorescence imaging.

Fibrin-based sealants consist of natural coagulation factors involved in the final phase of blood coagulation, during which fibrinogen is enzymatically converted by thrombin to form a solid-phase fibrin clot. For applications in tissue regeneration, a controlled process of matrix degradation within a certain period of time is essential for optimal wound healing. Hence, it is desirable to follow the kinetics of fibrinolysis at the application site. Non-invasive molecular imaging systems enable real-time tracking of processes in the living animal. In this study, a non-invasive fluorescence based imaging system was applied to follow and quantify site-specific degradation of fibrin sealant. To enable non-invasive tracking of fibrin in vivo, fibrin-matrix was labelled by incorporation of a fluorophore-conjugated fibrinogen component. Protein degradation and release of fluorescence were, in a first step, correlated in vitro. In vivo, fluorophore-labelled fibrin was subcutaneously implanted in mice and followed throughout the experiment using a multispectral imaging system. For the fluorescent fibrin, degradation correlated with the release of fluorescence from the clots in vitro. In vivo it was possible to follow and quantify implanted fibrin clots throughout the experiment, demonstrating degradation kinetics of approximately 16 days in the subcutaneous compartment, which was further confirmed by histological evaluation of the application site.

A Vision System for Robotic Ultrasound Guided Orthopaedic Surgery

Surgical navigation is a crucial concept in computer assisted surgery. The use of robots in the surgery room largely benefits from this concept's recent developments, namely with the use of non-invasive and radiation free imaging systems, like ultrasound (US). This paper presents the algorithms and software tools developed for US based orthopaedic surgery navigation. In the second part of the paper are presented the algorithms and software tools developed for controlling a robotic manipulator, that can be used both in simulation and in a real scenario. The paper also presents the developed simulation scenario, for a surgical procedure in Hip Resurfacing, e.g., the first drill of the femur head. For navigation, the system, during surgery, acquires a 3D US bone surface from a sequence of US images. This bone surface will then be registered to the pre-operative bone model, for a precise knowledge of the bone position and orientation. This registration is performed in two steps. The first, a global registration before the surgical procedure, to exactly register the bone. The second is to locally register the femur, which is faster and more suitable for tracking the bone movements. The measured bone movement is used by the robot manipulator to update its drilling position and orientation.

In vivo Monitoring of microRNA Biogenesis Using Reporter Gene Imaging

MicroRNAs are small noncoding RNAs regulating gene expression, through base paring with their target mRNAs, which have been actively investigated as key regulators in a wide range of biological processes. Conventional methods such as Northern blot are generally time-consuming, non-repeatable, and cannot be applied in vivo due to the requirement for cell fixation. Therefore, a noninvasive imaging system is required for the monitoring of microRNA biogenesis to understand the versatile functions of microRNAs in vivo as well as in vitro and to accelerate the clinical application of microRNA-based therapy. In this paper, we reviewed noninvasive molecular imaging systems for the monitoring of the biogenesis of microRNAs and post-transcriptional regulation of genes by microRNAs and the roles of microRNAs in various biological processes.