scholarly journals X-ray Digital Tomosynthesis Imaging — Comparison of Reconstruction Algorithms in Terms of a Reduction in the Exposure Dose for Arthroplasty

Author(s):  
Tsutomu Gomi
2016 ◽  
Vol 29 (4) ◽  
pp. 488-495 ◽  
Author(s):  
Tsutomu Gomi ◽  
Rina Sakai ◽  
Masami Goto ◽  
Yusuke Watanabe ◽  
Tohoru Takeda ◽  
...  

Author(s):  
Wenbing Yun ◽  
Steve Wang ◽  
David Scott ◽  
Kenneth W. Nill ◽  
Waleed S. Haddad

Abstract A high-resolution table-sized x-ray nanotomography (XRMT) tool has been constructed that shows the promise of nondestructively imaging the internal structure of a full IC stack with a spatial resolution better than 100 nm. Such a tool can be used to detect, localize, and characterize buried defects in the IC. By collecting a set of X-ray projections through the full IC (which may include tens of micrometers of silicon substrate and several layers of Cu interconnects) and applying tomographic reconstruction algorithms to these projections, a 3D volumetric reconstruction can be obtained, and analyzed for defects using 3D visualization software. XRMT is a powerful technique that will find use in failure analysis and IC process development, and may facilitate or supplant investigations using SEM, TEM, and FIB tools, which generally require destructive sample preparation and a vacuum environment.


1993 ◽  
Vol 34 (4) ◽  
pp. 346-350 ◽  
Author(s):  
S. Sone ◽  
T. Kasuga ◽  
F. Sakai ◽  
H. Hirano ◽  
K. Kubo ◽  
...  

Dual-energy subtraction digital tomosynthesis with pulsed X-ray and rapid kV switching was used to examine calcifications in pulmonary lesions. The digital tomosynthesis system used included a conventional fluororadiographic TV unit with linear tomographic capabilities, a high resolution videocamera, and an image processing unit. Low-voltage, high-voltage, and soft tissue subtracted or bone subtracted tomograms of any desired layer height were reconstructed from the image data acquired during a single tomographic swing. Calcifications, as well as their characteristics and distribution in pulmonary lesions, were clearly shown. The images also permitted discrimination of calcifications from dense fibrotic lesions. This technique was effective in demonstrating calcifications together with a solitary mass or disseminated nodules.


Author(s):  
Ho-Il Lee ◽  
Seok-Hwan Bae ◽  
Yeun-Chul Ryu ◽  
Young-Joon Park ◽  
Yong-Gwon Kim

Author(s):  
Junyoung Park ◽  
Amar Gupta ◽  
Wooseob Kim ◽  
Jongmin Lim ◽  
Seungjun Yeo ◽  
...  

Author(s):  
Alexandra Roberts ◽  
John True ◽  
Nathan T. Jessurun ◽  
Dr. Navid Asadizanjani

Abstract Printed Circuit Boards (PCBs) play a critical role in everyday electronic systems, therefore the quality and assurance of the functionality for these systems is a topic of great interest to the government and industry. PCB manufacturing has been largely outsourced to cut manufacturing costs in comparison with the designing and testing of PCBs which still retains a large presence domestically. This offshoring of manufacturing has created a surge in the supply chain vulnerability for potential adversaries to garner access and attack a device via a malicious modification. Current hardware assurance and verification methods are based on electrical and optical tests. These tests are limited in the detection of malicious hardware modifications, otherwise known as Hardware Trojans. For PCB manufacturing there has been an increase in the use of automated X-ray inspection. These inspections can validate a PCB’s functionality during production. Such inspections mitigate process errors in real time but are unable to perform highresolution characterization on multi-layer fully assembled PCBs. In this paper, several X-ray reconstruction methods, ranging from proprietary to open-source, are compared. The high-fidelity, commercial NRecon software for SkyScan 2211 Multi-scale X-ray micro-Tomography system is compared to various methods from the ASTRA Toolbox. The latter is an open-source, transparent approach to reconstruction via analytical and iterative methods. The toolbox is based on C++ and MEX file functions with MATLAB and Python wrappers for analysis of PCB samples. In addition, the differences in required imaging parameters and the resultant artifacts generated by planar PCBs are compared to the imaging of cylindrical biological samples. Finally, recommendations are made for improving the ASTRA Toolbox reconstruction results and guidance is given on the appropriate scenarios for each algorithm in the context of hardware assurance for PCBs.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pasquale Delogu ◽  
Vittorio Di Trapani ◽  
Luca Brombal ◽  
Giovanni Mettivier ◽  
Angelo Taibi ◽  
...  

Abstract The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22 keV–34 keV, some others instead suggested the range 50 keV–60 keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32 keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28 keV.


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