Investigation of sputtering target re-deposits by Optical Coherence Tomography and grazing incident X-ray diffraction

2020 ◽  
Vol 695 ◽  
pp. 137757
Author(s):  
S. Maidul Haque ◽  
Rajnarayan De ◽  
D.D. Shinde ◽  
C. Prathap ◽  
J.S. Misal ◽  
...  
Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  

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.


2021 ◽  
Vol 127 (4) ◽  
Author(s):  
S. Skruszewicz ◽  
S. Fuchs ◽  
J. J. Abel ◽  
J. Nathanael ◽  
J. Reinhard ◽  
...  

AbstractWe present an overview of recent results on optical coherence tomography with the use of extreme ultraviolet and soft X-ray radiation (XCT). XCT is a cross-sectional imaging method that has emerged as a derivative of optical coherence tomography (OCT). In contrast to OCT, which typically uses near-infrared light, XCT utilizes broad bandwidth extreme ultraviolet (XUV) and soft X-ray (SXR) radiation (Fuchs et al in Sci Rep 6:20658, 2016). As in OCT, XCT’s axial resolution only scales with the coherence length of the light source. Thus, an axial resolution down to the nanometer range can be achieved. This is an improvement of up to three orders of magnitude in comparison to OCT. XCT measures the reflected spectrum in a common-path interferometric setup to retrieve the axial structure of nanometer-sized samples. The technique has been demonstrated with broad bandwidth XUV/SXR radiation from synchrotron facilities and recently with compact laboratory-based laser-driven sources. Axial resolutions down to 2.2 nm have been achieved experimentally. XCT has potential applications in three-dimensional imaging of silicon-based semiconductors, lithography masks, and layered structures like XUV mirrors and solar cells.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Silvio Fuchs ◽  
Christian Rödel ◽  
Alexander Blinne ◽  
Ulf Zastrau ◽  
Martin Wünsche ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yasushi Shimada ◽  
Michael F. Burrow ◽  
Kazuyuki Araki ◽  
Yuan Zhou ◽  
Keiichi Hosaka ◽  
...  

Abstract Optical coherence tomography (OCT) can create cross-sectional images of tooth without X-ray exposure. This study aimed to investigate the diagnostic accuracy of 3D imaging of OCT for proximal caries in posterior teeth. Thirty-six human molar teeth with 51 proximal surfaces visibly 6 intact, 16 slightly demineralized, and 29 distinct carious changes were mounted to take digital radiographs and 3D OCT images. The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the diagnosis of enamel caries and dentin caries were calculated to quantify the diagnostic ability of 3D OCT in comparison with digital radiography. Diagnostic accuracy was evaluated by the agreement with histology using weighted Kappa. OCT showed significantly higher sensitivity, AUC and Kappa values than radiography. OCT can be a safer option for the diagnosis of proximal caries in posterior teeth that can be applied to the patients without X-ray exposure.


2015 ◽  
Vol 1 (1) ◽  
pp. 257-260 ◽  
Author(s):  
Thomas Hoffmann ◽  
Axel Boese ◽  
Sylvia Glaßer ◽  
Martin Skalej ◽  
Oliver Beuing

AbstractEvaluation of the vascular stent position, shape and correct expansion has a high relevance in therapy and diagnosis. Hence, the wall apposition in vessel areas with differing diameters and the appearance of torsions or structural defects of the implant body caused by catheter based device dropping are of special interest. Neurovascular implants like braided flow diverter and laser cut stents consist of metal struts and wires with diameters of about 40 µm. Depending on the implants material composition, visibility is poor with conventional 2D X-ray fluoroscopic and radiographic imaging. The metal structures of the implants also lead to artifacts in 3D X-ray images and can hamper the assessment of the device position. We investigated intravascular optical coherence tomography (OCT) as a new imaging tool for the evaluation of the vascular stent position, its shape and its correct expansion for 3 different vascular implants.


2013 ◽  
Vol 06 (02) ◽  
pp. 1350015 ◽  
Author(s):  
JONATHAN G. SUN ◽  
STEVEN G. ADIE ◽  
ERIC J. CHANEY ◽  
STEPHEN A. BOPPART

Pre-operative X-ray mammography and intraoperative X-ray specimen radiography are routinely used to identify breast cancer pathology. Recent advances in optical coherence tomography (OCT) have enabled its use for the intraoperative assessment of surgical margins during breast cancer surgery. While each modality offers distinct contrast of normal and pathological features, there is an essential need to correlate image-based features between the two modalities to take advantage of the diagnostic capabilities of each technique. We compare OCT to X-ray images of resected human breast tissue and correlate different tissue features between modalities for future use in real-time intraoperative OCT imaging. X-ray imaging (specimen radiography) is currently used during surgical breast cancer procedures to verify tumor margins, but cannot image tissue in situ. OCT has the potential to solve this problem by providing intraoperative imaging of the resected specimen as well as the in situ tumor cavity. OCT and micro-CT (X-ray) images are automatically segmented using different computational approaches, and quantitatively compared to determine the ability of these algorithms to automatically differentiate regions of adipose tissue from tumor. Furthermore, two-dimensional (2D) and three-dimensional (3D) results are compared. These correlations, combined with real-time intraoperative OCT, have the potential to identify possible regions of tumor within breast tissue which correlate to tumor regions identified previously on X-ray imaging (mammography or specimen radiography).


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