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https://en.wikipedia.org/wiki/Tomography
Tomography is imaging by sections or sectioning, through the use of any kind of penetrating wave. The method is used in radiology, archaeology, biology, atmospheric science, geophysics, oceanography, plasma physics, materials science, astrophysics, quantum information, and other areas of science. The word tomography is derived from Ancient Greek τόμος tomos, "slice, section" and γράφω graphō, "to write". A device used in tomography is called a tomograph, while the image produced is a tomogram.
In many cases, the production of these images is based on the mathematical procedure tomographic reconstruction, such as X-ray computed tomography technically being produced from multiple projectional radiographs. Many different reconstruction algorithms exist. Most algorithms fall into one of two categories: filtered back projection (FBP) and iterative reconstruction (IR). These procedures give inexact results: they represent a compromise between accuracy and computation time required. FBP demands fewer computational resources, while IR generally produces fewer artifacts (errors in the reconstruction) at a higher computing cost.[1]
Although MRI and ultrasound are transmission methods, they typically do not require movement of the transmitter to acquire data from different directions. In MRI, both projections and higher spatial harmonics are sampled by applying spatially-varying magnetic fields; no moving parts are necessary to generate an image. On the other hand, since ultrasound uses time-of-flight to spatially encode the received signal, it is not strictly a tomographic method and does not require multiple acquisitions at all.
https://en.wikipedia.org/wiki/Medical_imaging
As a discipline and in its widest sense, it is part of biological imaging and incorporates radiology, which uses the imaging technologies of X-ray radiography, magnetic resonance imaging, ultrasound, endoscopy, elastography, tactile imaging, thermography, medical photography, and nuclear medicine functional imaging techniques as positron emission tomography (PET) and single-photon emission computed tomography (SPECT).
Measurement and recording techniques that are not primarily designed to produce images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (ECG), and others, represent other technologies that produce data susceptible to representation as a parameter graph vs. time or maps that contain data about the measurement locations. In a limited comparison, these technologies can be considered forms of medical imaging in another discipline.
As of 2010, 5 billion medical imaging studies had been conducted worldwide.[1] Radiation exposure from medical imaging in 2006 made up about 50% of total ionizing radiation exposure in the United States
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Medical imaging equipment are manufactured using technology from the semiconductor industry, including CMOS integrated circuit chips, power semiconductor devices, sensors such as image sensors (particularly CMOS sensors) and biosensors, and processors such as microcontrollers, microprocessors, digital signal processors, media processors and system-on-chip devices. As of 2015, annual shipments of medical imaging chips amount to 46 million units and $1.1 billion.[3]
Medical imaging is often perceived to designate the set of techniques that noninvasively produce images of the internal aspect of the body. In this restricted sense, medical imaging can be seen as the solution of mathematical inverse problems
This means that cause (the properties of living tissue) is inferred from effect (the observed signal). In the case of medical ultrasound, the probe consists of ultrasonic pressure waves and echoes that go inside the tissue to show the internal structure. In the case of projectional radiography, the probe uses X-ray radiation, which is absorbed at different rates by different tissue types such as bone, muscle, and fat.
The term "noninvasive" is used to denote a procedure where no instrument is introduced into a patient's body, which is the case for most imaging techniques used.
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High Resolution X-ray-Induced Acoustic Tomography
Abstract
Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray.
X-ray-induced acoustic waves has been observed1,2, while tomographic imaging with X-ray induced computed tomography (XACT) has been investigated in our previous experiments3. To induce acoustic waves, X-rays are absorbed by the excitation of inner-shell electrons and generate photoelectrons4,5. The excited electrons decay either by electromagnetic radiation, which may be reabsorbed, or by an Auger process. Auger electrons and photoelectrons transfer part of their kinetic energy to the surrounding medium by the production of cascades of secondary electrons. After multiple collisions, these electrons reach thermal equilibrium. The transfer of energy from the system of thermalized excited electrons to the tissue is governed by the electron-phonon interaction, which increases the temperature of the atomic system. The increase of the temperature in the irradiated volume is typically less than a millikelvin6 and the generated pressure waves are X-ray-induced acoustic (XA) signals (Fig. 1a). The X-ray-induced effect process is intrinsically three-dimensional (3D), as the XA waves are spherical in nature and propagate in all directions from their point of generation (Fig. 1b). The use of XA signals for volumetric imaging is uniquely advantageous: a single projection X-ray exposure is sufficient to generate acoustic signals in 3D space (Fig. 1c).
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XACT reduces radiation dose required for imaging a 3D subject
We calculated the minimal required dose for imaging a 100 μm-diameter breast calcification in a 16 cm-diameter breast phantom with XACT. The minimal dose is defined as the amount of dose needed to generate enough pressure amplitude over detector’s noise level while maintaining the spatial resolution at 100 μm. In our calculation, 5MHz ultrasound detector was applied and its noise was calculated by the noise equivalent pressure (NEP) model. In XACT, noise mainly arises from three sources: thermal acoustic noise from the medium, thermal noise from the ultrasonic transducer and electronic noise from the amplifier
Liangzhong Xiang, Shanshan Tang, Moiz Ahmad & Lei Xing
Open Access
Published: 18 May 2016
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Noninvasive Assessment of Early Dental Lesion Using a Dual-Contrast Photoacoustic Tomography
https://www.nature.com/articles/srep21798
Abstract
Dental hard tissue lesions, including caries, cracked-tooth, etc., are the most prevalent diseases of people worldwide. Dental lesions and correlative diseases greatly decrease the life quality of patients throughout their lifetime. It is still hard to noninvasively detect these dental lesions in their early stages. Photoacoustic imaging is an emerging hybrid technology combining the high spatial resolution of ultrasound in deep tissue with the rich optical contrasts. In this study, a dual-contrast photoacoustic tomography is applied to detect the early dental lesions. One contrast, named B-mode, is related to the optical absorption. It is good at providing the sharp image about the morphological and macro-structural features of the teeth. Another contrast, named S-mode, is associated with the micro-structural and mechanical properties of the hard tissue. It is sensitive to the change of tissue properties induced by the early dental lesions. Experiments show that the comprehensive analysis of dual-contrast information can provide reliable information of the early dental lesions. Moreover, the imaging parameter of S-mode is device-independent and it could measure tissue properties quantitatively. We expect that the proposed scheme could be beneficial for improving safety, accuracy and sensitivity of the clinical diagnosis of the dental lesion.
According to up-to-date epidemiological investigation, there has been a remarkable increase in the prevalence of dental caries recently in all age range, including children, adults and elderly people1. Dental lesion will incur localized dissolution and destruction of calcified hard tissues and further cause oral pain, tooth loss through pulp and periapical tissue inflammation2. Therefore, the dental lesion and correlative diseases greatly decrease the life quality of patients throughout their lifetime2,3.
Diagnosis of the early dental lesion has important clinical significance for the prevention and treatment of such diseases. If the lesions could be diagnosed at an initial stage, the progress of dental diseases can be stopped through preventive treatment, such as diet modification, plaque control, appropriate usage of fluoride for early caries and occlusal adjustment, adhesive crown restoration for cracked tooth. Otherwise, as the lesion progressing, destroy of the hard tissue could not be repaired unless employing aggressive treatment, such as filling treatment, root canal treatment and post-crown restoration. Even more, the involved tooth could not be preserved as root fracture or mass destruction.
Visual and radiographic examinations are the most widely used methods for dental disease diagnosis currently. However, they are inefficient in assessing the hard tissue lesion at an initial stage. Visual examination, as a subjective method, has a low reproducibility in detecting early enamel lesions, due to the dependence of the knowledge and clinical experience of the examiner. Radiographic examination is highly accurate for cavitated proximal lesions, but is poorly sensitive for non-cavitated lesions, such as white spot caries and cracks, which commonly appear at the early stage of dental lesion3,4. Researchers are still looking for advanced utility methods that can significantly improve the sensitivity and specificity for objective assessment of early lesions in the teeth5,6,7,8.
Photoacoustic tomography (PAT)9 is a hybrid non-invasive imaging modality combining the rich optical contrast with high ultrasonic resolution in turbid tissue. By extracting different imaging parameters from the photoacoustic signals, the PAT can effectively reflect the biochemical information10,11,12,13,14, biomechanical properties15,16,17, microstructural characteristics18,19,20,21,22,23,24,25, blood velocity26,27, temperature distribution28,29 and so on. Besides, non-ionizing laser used in PAT is much safer than the ionizing radiation, e.g., X-ray which as the radiographic method is used for the dental examination in clinics. Generally, rich contrasts and biosecurity make PAT have the natural advantages in mapping the physiological structure and function of biological tissue, such as breast cancer detecting30,31,32,33,34,brain imaging35,36, vessel diseases monitoring28,37,38, joint imaging39,40, etcAccording to up-to-date epidemiological investigation, there has been a remarkable increase in the prevalence of dental caries recently in all age range, including children, adults and elderly people1. Dental lesion will incur localized dissolution and destruction of calcified hard tissues and further cause oral pain, tooth loss through pulp and periapical tissue inflammation2. Therefore, the dental lesion and correlative diseases greatly decrease the life quality of patients throughout their lifetime2,3.
Diagnosis of the early dental lesion has important clinical significance for the prevention and treatment of such diseases. If the lesions could be diagnosed at an initial stage, the progress of dental diseases can be stopped through preventive treatment, such as diet modification, plaque control, appropriate usage of fluoride for early caries and occlusal adjustment, adhesive crown restoration for cracked tooth. Otherwise, as the lesion progressing, destroy of the hard tissue could not be repaired unless employing aggressive treatment, such as filling treatment, root canal treatment and post-crown restoration. Even more, the involved tooth could not be preserved as root fracture or mass destruction.
Visual and radiographic examinations are the most widely used methods for dental disease diagnosis currently. However, they are inefficient in assessing the hard tissue lesion at an initial stage. Visual examination, as a subjective method, has a low reproducibility in detecting early enamel lesions, due to the dependence of the knowledge and clinical experience of the examiner. Radiographic examination is highly accurate for cavitated proximal lesions, but is poorly sensitive for non-cavitated lesions, such as white spot caries and cracks, which commonly appear at the early stage of dental lesion3,4. Researchers are still looking for advanced utility methods that can significantly improve the sensitivity and specificity for objective assessment of early lesions in the teeth5,6,7,8.
Photoacoustic tomography (PAT)9 is a hybrid non-invasive imaging modality combining the rich optical contrast with high ultrasonic resolution in turbid tissue. By extracting different imaging parameters from the photoacoustic signals, the PAT can effectively reflect the biochemical information10,11,12,13,14, biomechanical properties15,16,17, microstructural characteristics18,19,20,21,22,23,24,25, blood velocity26,27, temperature distribution28,29 and so on. Besides, non-ionizing laser used in PAT is much safer than the ionizing radiation, e.g., X-ray which as the radiographic method is used for the dental examination in clinics. Generally, rich contrasts and biosecurity make PAT have the natural advantages in mapping the physiological structure and function of biological tissue,
such as breast cancer detecting, brain imaging, vessel diseases monitoring, joint imaging etc
"...PAT could non-invasively image the teeth structure and detect the early dental lesion. However, the current studies mostly focused on the soft tissue. Seldom applications have been done to the hard tissue, such as tooth. In this study, we devoted to imaging the human tooth cross-section and detecting the early lesion in the dental hard tissue by a dual-contrast PAT system. Two different parameters, intensity and spectral slope, have been extracted from the photoacoustic signals to form images, respectively. Intensity of photoacoustic signals is used as the imaging parameter in conventional PAT. Its brightness indicates the relative optical absorption in tissue, which is similar to the classic B-mode ultrasound imaging.
23 February 2016
Renxiang Cheng, Jiaojiao Shao, Xiaoxiang Gao, Chao Tao, Jiuyu Ge & Xiaojun Liu
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The Use of Optical Coherence Tomography in Dental Diagnostics: A State-of-the-Art Review
Academic Editor: João Manuel R.S. Tavares
Optical coherence tomography provides sections of tissues in a noncontact and noninvasive manner. The device measures the time delay and intensity of the light scattered or reflected from biological tissues, which results in tomographic imaging of their internal structure. This is achieved by scanning tissues at a resolution ranging from 1 to 15 μm. OCT enables real-time in situ imaging of tissues without the need for biopsy, histological procedures, or the use of X-rays, so it can be used in many fields of medicine. Its properties are not only particularly used in ophthalmology, in the diagnosis of all layers of the retina, but also increasingly in cardiology, gastroenterology, pulmonology, oncology, and dermatology. The basic properties of OCT, that is, noninvasiveness and low wattage of the used light, have also been appreciated in analytical technology by conservators, who use it to identify the quality and age of paintings, ceramics, or glass. Recently, the OCT technique of visualization is being tested in different fields of dentistry, which is depicted in the article.
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Medical imaging is the basis of effective medical diagnosis and is now the mainstream of a dynamically developing branch of science, which is biomedical engineering. Its development started after an accidental discovery of Wilhelm Conrad Roentgen, a professor of physics, who in 1895 observed little fluorescence during his research on electrical discharges and cathode rays. X-radiation turned out to be a fundamental discovery which is still used in medicine today.
Another milestone was the development of the first computed tomography (CT) device by Godfrey Newbold Hounsfield in 1967. The concept of tomography refers to a method that provides images showing sections of the tested structure. The first CT scanner initiated rapid development of medical imaging techniques. A common feature of different types of CT devices is noninvasive imaging of tissue structures and internal organs, as well as their functional parameters. The desire to minimize invasiveness of methods such as biopsy or exploratory surgery, which are painful and may cause deterioration in the patient’s condition, was an impetus for the improvement of computed tomography equipment. As a result, completely new technologies were developed, such as magnetic resonance imaging (MRI), ultrasonography (USG), positron emission tomography (PET), single photon emission computed tomography (SPECT), and the latest and more widely used optical coherence tomography (OCT).
The method of optical coherence tomography using interferometry with partially coherent light was first presented in 1991 at the Institute of Technology of the University of Massachusetts [1]. The first in vivo measurements of the section of the human retina were made two years later in Vienna [2]. The first commercial optical tomography device was produced in 1996 by Zeiss-Humphrey [3].
Optical coherence tomography (OCT) uses a beam of partially coherent light to create tomographic images. Currently, there are two basic types of optical coherence tomography: time domain optical coherence tomography (TdOCT) and Fourier domain optical coherence tomography (FdOCT). The former technique was developed in 1991 by the abovementioned group of researchers from the Massachusetts Institute of Technology in the United States [1] for use in ophthalmic diagnosis. It can produce tomographic images of relatively low quality, resulting from long time of measurement, but it does not allow for three-dimensional imaging of objects [4]. Modern optical tomography with detection in the frequency domain (Fourier domain optical coherence tomography) reduces the capture time by more than a hundred times and creates three-dimensional images of the test object.
The Short History of OCT in Dentistry
Attempts to use optical coherence tomography in dentistry were first made in 1998 by researchers from the Laboratory of Medical Technology of Livermore, California, in collaboration with researchers from the University of Connecticut. In their work, they presented a prototype of dental optical coherence tomography and its in vivo application [15].
The device designed by them scanned hard tissues to a depth of 3 mm and soft tissues to a depth of 1.5 mm, which even now, 14 years after the creation of this sample design, is comparable to the possibilities of the latest generation apparatus. Two years later, the same group of researchers presented the first intraoral scans not only of the hard tissues but also soft tissues of the oral cavity, using another specifically designed CT prototype. In the published work, they demonstrated the possibility of imaging the gum margin, periodontal pockets, and attachments, both epithelial and connective, using an infrared beam of light [16]. The usefulness of optical coherence tomography in the recognition of lesions in the structure of both soft and hard tissues of the oral cavity was also presented in the same year 1998 by experimental and clinical studies conducted by Feldchtein et al. [17], which was actually the first mention of the possibility of OCT examination of hard tissue. In 2000, the same scientific center compared two OCT prototypes having different wavelengths of light: 850 and 1310 nm. Analysis of the quality of scans from individual devices and the evaluation of the possibility of reflecting the anatomical details of the oral cavity showed greater effectiveness of the apparatus using longer wavelengths of light [18]. Five years later, as an experiment, twenty-one dentists were asked to analyze fissure sealants, composite fillings, or tissue enamel based on OCT scans. Despite the lack of knowledge of the techniques of OCT scan interpretation, the dentists who took part in the study obtained clinically acceptable results, which proved the potential clinical application of OCT [19]. The possibility of assessing caries developing under fissure sealants, which is difficult to diagnose, was subject to similar verification. After 90-minute training, doctors assessed the correctness of the enamel structure under 5 different types of sealing materials. When analysing OCT scans, the doctors detected caries more frequently compared with clinical or radiological assessment [20].
In the following years, a leading center dealing with optical tomography became the University of California in San Francisco. A series of articles was published, broadening the knowledge on the aspects of OCT application in conservative dentistry. The described issues were related to imaging of caries incipiens, their remineralization, and monitoring of the progressing or stopped demineralization of the enamel surface or tooth structure underneath fillings [21–29]. The issue of enamel remineralization is still continued [12]. In 2010, an innovative work was presented on attempts of enamel remineralization with chitosan. The penetration depth of chitosan into the enamel structure was evaluated by optical tomography.
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The next studies described the effectiveness of optical coherence tomography in monitoring the range and efficiency of infrared and fractional CO2 lasers in caries removal [32–37]. The effectiveness of a diode laser and Nd-YAG laser in the development of root canals during endodontic treatment was also verified [38]. An attempt was also made to use OCT in endodontic in vitro studies [39]. The results of studies evaluating the errors in prosthetic treatment were also published: defects in the structure of the materials used in prosthetic restoration and microleakage at the contact surface of the reconstruction and the tooth as well as the appropriateness of using OCT to control the internal structure of the prosthetic restoration without the need for its removal [34, 40].
Attempts were also made to visualize and measure the length of periodontal ligaments before and during orthodontic tooth movement. Incisors of rats were moved by applying successively varying sizes of forces and then the teeth were removed. The condition of the ligaments was imaged using optical coherence tomography and X-rays. OCT scans showed differences in periodontal ligament arrangement depending on the size of the applied force and their significant twist when using the greatest forces
Another application of OCT was an attempt to evaluate the salivary pellicle. In order to compare the results and to improve the resolution and specificity of images, an optical coherence microscope (OCM) was used. Salivary pellicle islands were visible in the samples incubated in saliva, which grow into complexes completely covering the enamel surface [43]. The aim of the next study was to evaluate the retention of the biofilm around orthodontic hooks depending on the ligaturing method using OCT and microbiological samples. Both microbiological and optical (OCT) analysis showed a significant difference in biofilm formation depending on the ligaturing method. The hooks ligaturated with elastic elements showed a greater amount of cariogenic Streptococcus mutans, whereas metal ligatures showed much less biofilm retention. The study found that optical coherence tomography may also be treated as a full-fledged quantitative indicator of bacterial plaque, which can be quickly and reliably visualized around orthodontic hooks
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Another direction of research using the OCT technique has become the assessment of restorations with composite fillings in conservative dentistry. The study demonstrated, based on analysis of OCT scans, the leakage of composite restorations of enamel defects. The fissures were on average 50 μm. The results were confirmed by X-ray images and optical microscopy. The study resulted in the development of their own spectral CT scanner, which was based on the Michelson interferometer. The created device, as well as the modern optical tomography instrument, divides monochromatic light into two beams, allowing for the reflection of the beams from semi-transparent mirrors and their subsequent interference. Using such a device, the researchers revealed the errors of composite reconstruction in the form of visible pits and fissures at the border between the filling and the cavity wall [47]. Enamel cracks at the border between the enamel and the composite filling reinforced with glass fibre were evaluated in a similar manner [48].The subject of evaluation was also the tightness of three selected composite fillings, cracks of composite reconstruction reinforced with glass fibre, which were imaged using optical coherence tomography (OCT), scanning electron microscopy (SEM), and optical microscopy (OM) [49]. The results enabled to describe the internal cracks of composites, which were not accessible during SEM or OM imaging. It was also observed that the assessment by means of optical coherent tomography required no special sample preparation, making it less expensive compared with the assessment in the scanning electron microscope [50]. In a further step, the efficiency of optical coherence tomography and confocal microscope in the evaluation of composite materials was compared [51].
There are also publications extending the above issue and evaluating marginal adaptation, porosity, and internal integrity of composite fillings. The potential of OCT and high resolution scans, allowing for critical assessment of the structure of fillings, previously inaccessible using common diagnostic methods, has thus been proven [52]. Similar studies evaluating polymerization shrinkage showed significant differences in its size depending on the tested materials [53]. Composite fillings restoring bovine enamel defects and their marginal adaptation with the use of self-etching techniques were also studied. The findings confirmed the thesis that optical coherence tomography is an effective tool in the accurate assessment of tightness of composite fillings [54]. The study of Senawongse et al. [55] made it possible to visualize the adhesive connection between the bonding system and the dentin, analyse carious lesions within the crown and root of the tooth, and assess secondary caries [56, 57]. From a clinical point of view, the studies identifying the relationship between the quality of OCT scans and the level of tooth hydration are very important [58, 59]. It directly affects the strength of the enamel prisms to injuries and the colour of the tissue, which is to be reproduced during conservative or prosthetic restorations. The use of OCT for educational purposes was also presented. The mistakes in the fillings made by dental students were discussed based on performed scans
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OCT was also used to evaluate enamel cracks. The results were verified using a stereomicroscope and histological samples of individual enamel layers. Enamel cracks were identified by CT as intensified signals appearing in exactly the same places where damage to the histological samples and stereomicroscopic images was visible. The results showed that OCT very accurately identified cracks and their size, so measurements of the scanned teeth yielded results that were equally reliable to those obtained from stereomicroscopy and histological examination of subsequent enamel layers [62].
In order to improve the quality of OCT scans and facilitate their interpretation, gold nanoparticles were applied. They are normally used as contrast in SEM imaging to visualize the hybrid layer and dentin tubules [63]. This was a significant advancement in dentin imaging because until then only a qualitative and quantitative evaluation of tooth decay had been possible, without distinguishing histological structures [64].
Attempts were also made to use optical coherence tomography in maxillofacial surgery for separating normal and dysplastic fragments of oral epithelium and distinguishing between solid and bullous lesions [65, 66].
The latest studies continue to focus primarily on early diagnosis of caries, assessment of the quality and thickness of dentin, and assessment of dental fillings [67–74]. The precise topics and conclusions of the articles from the last 5 years, according to field of dentistry are summarized in Tables 1, 2, 3, 4, 5, 6, 7, and 8. In the first table, there is set of publications [61, 75–94] that are exposing the facilities of OCT and the possibility of diagnostics in dentistry.
https://new.hindawi.com/journals/jhe/2017/7560645/
Open Access
Volume 2017 |Article ID 7560645 | 31 pages | https://doi.org/10.1155/2017/7560645
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http://merkel.co.il/microct-dental-medicine
MILabs image
micro Computed Tomography (uCT): Dental Medicine
3D modeling by the MiLabs high-resolution microCT facilitates research and development in dental medicine, by both in-vivo and ex-vivo imaging of samples such as teeth, jaw or dental implants.
http://merkel.co.il/technologies/in-vivo-imaging/msot-ithera-medical
Listen to light, listen to molecules.
The innovative nature of the MSOT technology (Multispectral Optoacoustic Tomography) is its capability for volumetric, quantitative differentiation of tissue, in vivo and in real time, with and without the application of contrast agents.
The method operates through several millimeters to centimeters of tissue enabling tomographic three-dimensional imaging with optical contrast, significantly deeper than even the most advanced forms of modern microscopy. The video-rate image acquisition facilitates visualization of dynamic phenomena over time, avoiding delays through imaging and long scan times. No other technology can currently compete with such performance.
MSOT allows safe power delivery in tissue by operating in the near-infrared (NIR) spectral region, where low light attenuation allows deep penetration in tissue. High detection specificity is achieved by resolving multiple spectral signatures through tissues and accurately decomposing the biodistribution of relevant molecules from non-specific background contributions
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Principle of MSOT operation
Pulsed light of time-shared multiple wavelengths illuminates the tissue of interest and establishes transient photon fields in tissue.
In response to the fast absorption transients by tissue elements, acoustic responses are generated via the photoacoustic phenomenon, which are then detected with acoustic detectors. By modeling photon and acoustic propagation in tissues and using inversion methods, images can then be generated and spectrally unmixed to yield the biodistribution of reporter molecules and tissue biomarkers.
Light of different wavelengths is selected to target the absorption transient of the chromophore or fluorochrome, as selected for spectral differentiation.
Learn about a new development of this technology: the RSOM: high-resolution raster scanning optoacoustic mesoscopy
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High-resolution optoacoustic imaging from iThera Medical
High-resolution visualization of superficial microvasculature is critical for diagnosis and treatment monitoring of diseases like skin cancers, tumor angiogenesis and vascular disease.
Conventional imaging modalities are able to assess microvasculature only with the help of contrast agents or invasive techniques. RSOM utilizes laser excitation and high-frequency acoustic detection,
thereby providing intrinsic optical tissue contrast, with up to 10 μm resolution, at several millimeters depth.
iThera Medical has developed RSOM imaging systems for explorative preclinical and clinical use. Clinically, RSOM can be utilized to detect diseases in which irregular accumulation of hemoglobin or melanin is involved,
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photoacustic, audio tomography, x-ray radiation alternatives current and emerging technology for dental
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