scholarly journals Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Radiation Dose ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Optical Coherence ◽  
X Rays ◽  
High Quality ◽  
X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

Abstract WP1: High-Frequency Optical Coherence Tomography for Cerebrovascular Disease

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Ajit S Puri ◽  
Giovanni Ughi ◽  
Robert M King ◽  
Matthew Gounis
Keyword(s):  
Optical Coherence Tomography ◽  
Cerebrovascular Disease ◽  
High Frequency ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Image Resolution ◽  
Patient Specific ◽  
Optical Coherence

Introduction: Optical coherence tomography (OCT) has played an important role in the diagnosis and treatment guidance in coronary artery disease. However, existing OCT systems are not suitable for routine neurovascular applications due to the size and tortuosity of the arteries. Hypothesis: We seek to demonstrate a prototype high-frequency OCT (HF-OCT) capable of high-resolution imaging in simulated cerebrovascular anatomy. Methods: A low-profile HF-OCT system was constructed with an image resolution approaching 10μm. Using an in vitro, patient-specific model of the circle of Willis with circulating porcine blood, we characterized the delivery of the device and ability to image in a tortuous path. Also, human cadaver intracranial atherosclerosis plaques were imaged with HF-OCT and assessed by an expert imager. Finally, neurovascular devices were implanted in 8 pigs (Fig 1) and HF-OCT imaging was compared with gold-standard DSA and CT. Results: In the phantom, optimal blood clearance was achieved through an intermediate catheter (5 Fr Navien) with infusion of contrast at 5 ml/s in the internal carotid and basilar artery, and 3 ml/sec in the MCA. The in vivo study demonstrated that both malapposition of devices or thrombus formation along the device surface could be reliably diagnosed among 3 reviewers (Fleiss’s kappa of 0.87 and 0.9, respectively). This agreement was superior to DSA and CT. Imaging in tortuous swine brachial showed in all cases imaging free of artifacts, uniform illumination and ability to visualize vessel wall layers. Plaque types including ‘lipid pools’, fibrotic, and calcific tissue from cadaver specimens of ICAD could be adequately depicted by HF-OCT. Conclusion: In vitro, in vivo and ex vivo characterization of a novel HF-OCT device has shown it is capable of imaging in the tortuous intracranial vascular anatomy. This technology has to potential to aid in the diagnosis of cerebrovascular disease and guide optimal endovascular treatment.

scholarly journals High speed rotary system for catheter based 3-D imaging with optical coherence tomography (OCT)

2021 ◽  
Author(s):  
Antonio Mauro
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Optical Coherence ◽  
X Rays ◽  
Sound Waves ◽  
Acquisition Rate

Optical Coherence Tomography (OCT) is an addition to the other tomographic imaging techniques of x-ray computed tomography, magnetic resonance imaging, and ultrasound imaging. OCT uses optical reflections of biological tissues as opposed to x-rays, RF fields, and sound waves to obtain images. A rotary and pullback system has been developed for use with OCT. The system was developed to facilitate the three dimensional imaging of various lumens in humans and animals. The system is capable of rotating at a rate of 200 Hz. At this rate the rotary system will allow for a frame acquisition rate of 200 fps which is significantly higher than the highest published acquisition rate to date of 108 fps. The probes used with the system were modeled after the Intravascular Ultrasound (IVUS) miniature torque cable design. The probes can be sealed and sterilized between subjects without being damaged; unlike the single use IVUS probes. The rotary system was used to image the outer ear of a mouse in vivo. A lateral slice from the resulting three dimensional image was compared to the general histology of a mouse ear. The image compared well to the general anatomy as found on the histology.

scholarly journals Dental Diagnosis and Treatment Assessments: Between X-rays Radiography and Optical Coherence Tomography

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4825
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging Techniques ◽  
Correct Diagnosis ◽  
Three Dimensional ◽  
Daily Basis ◽  
Image Resolution ◽  
Imaging Method ◽  
Optical Coherence ◽  
X Rays ◽  
Swept Source

A correct diagnosis in dental medicine is typically provided only after clinical and radiological evaluations. They are also required for treatment assessments. The aim of this study is to establish the boundaries from which a modern, although established, imaging technique, Optical Coherence Tomography (OCT), is more suitable than the common X-ray radiography to assess dental issues and treatments. The most common methods for daily-basis clinical imaging are utilized in this study for extracted teeth (but also for other dental samples and materials), i.e., panoramic, intraoral radiography, and three-dimensional (3D) cone beam computed tomography (CBCT). The advantages of using OCT as an imaging method in dentistry are discussed, with a focus on its superior image resolution. Drawbacks related to its limited penetration depth and Field-of-View (FOV) are pointed out. High-quality radiological investigations are performed, measurements are done, and data collected. The same teeth and samples are also imaged (mostly) with an in-house developed Swept Source (SS)-OCT system, Master-Slave enhanced. Some of the OCT investigations employed two other in-house developed OCT systems, Spectral Domain (SD) and Time Domain (TD). Dedicated toolbars from Romexis software (Planmeca, Helsinki, Finland) are used to perform measurements using both radiography and OCT. Clinical conclusions are drawn from the investigations. Upsides and downsides of the two medical imaging techniques are concluded for each type of considered diagnosis. For treatment assessments, it is concluded that OCT is more appropriate than radiography in all applications, except bone-related investigations and periodontitis that demand data from higher-penetration depths than possible with the current level of OCT technology.

scholarly journals High speed rotary system for catheter based 3-D imaging with optical coherence tomography (OCT)

2021 ◽  
Author(s):  
Antonio Mauro
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Optical Coherence ◽  
X Rays ◽  
Sound Waves ◽  
Acquisition Rate

Optical Coherence Tomography (OCT) is an addition to the other tomographic imaging techniques of x-ray computed tomography, magnetic resonance imaging, and ultrasound imaging. OCT uses optical reflections of biological tissues as opposed to x-rays, RF fields, and sound waves to obtain images. A rotary and pullback system has been developed for use with OCT. The system was developed to facilitate the three dimensional imaging of various lumens in humans and animals. The system is capable of rotating at a rate of 200 Hz. At this rate the rotary system will allow for a frame acquisition rate of 200 fps which is significantly higher than the highest published acquisition rate to date of 108 fps. The probes used with the system were modeled after the Intravascular Ultrasound (IVUS) miniature torque cable design. The probes can be sealed and sterilized between subjects without being damaged; unlike the single use IVUS probes. The rotary system was used to image the outer ear of a mouse in vivo. A lateral slice from the resulting three dimensional image was compared to the general histology of a mouse ear. The image compared well to the general anatomy as found on the histology.

scholarly journals Modern Trends in Imaging V: Optical Coherence Tomography for Rapid Tissue Screening and Directed Histological Sectioning

2012 ◽  
Vol 35 (3) ◽  
pp. 129-143 ◽  
Author(s):  
Woonggyu Jung ◽  
Stephen A. Boppart
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Image Guidance ◽  
Diagnostic Yield ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Optical Coherence ◽  
Sampling Errors ◽  
Cross Sectional

In pathology, histological examination of the “gold standard” to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack ofin vivoobservation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.

scholarly journals Evaluation of Single-Impact-Induced Cartilage Degeneration by Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Florence de Bont ◽  
Nicolai Brill ◽  
Robert Schmitt ◽  
Markus Tingart ◽  
Björn Rath ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Cartilage Degeneration ◽  
High Energy ◽  
Optical Coherence ◽  
Human Cartilage ◽  
Irregularity Index ◽  
Impact Area ◽  
Impact Energies

Posttraumatic osteoarthritis constitutes a major cause of disability in our increasingly elderly population. Unfortunately, current imaging modalities are too insensitive to detect early degenerative changes of this disease. Optical coherence tomography (OCT) is a promising nondestructive imaging technique that allows surface and subsurface imaging of cartilage, at near-histological resolution, and is principally applicablein vivoduring arthroscopy. Thirty-four macroscopically normal human cartilage-bone samples obtained from total joint replacements were subjected to standardized single impactsin vitro(range: 0.25 J to 0.98 J). 3D OCT measurements of impact area and adjacent tissue were performed prior to impaction, directly after impaction, and 1, 4, and 8 days later. OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections. WhileOAIandOHIscores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) andOIIscores. In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

In vivo and in vitro diagnostics using Full Field Optical Coherence Tomography

2012 ◽  
Author(s):  
Osnath Assayag ◽  
Fabrice Harms ◽  
Eugénie Dalimier ◽  
Bertrand de Poly ◽  
Claude Boccara
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
In Vitro Diagnostics ◽  
Full Field
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