scholarly journals Paintings of Metal Artifacts according to the Arabic School in Iraq and Syria

2022 ◽  
Vol 13 (1) ◽  
pp. 20-45
Author(s):  
Samah Mahmoud ◽  
Essam Morsi ◽  
Shaaban Abdelrazik ◽  
Enas Abdel gaber
Keyword(s):  
Metal Artifacts

scholarly journals Metal artifacts in intraoperative O-arm CBCT scans

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juha I. Peltonen ◽  
Touko Kaasalainen ◽  
Mika Kortesniemi
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Nonlinear Effects ◽  
Exposure Level ◽  
Metal Artifacts ◽  
Imaging Protocol ◽  
Metal Implants ◽  
Comprehensive Determination

Abstract Background Cone-beam computed tomography (CBCT) has become an increasingly important medical imaging modality in orthopedic operating rooms. Metal implants and related image artifacts create challenges for image quality optimization in CBCT. The purpose of this study was to develop a robust and quantitative method for the comprehensive determination of metal artifacts in novel CBCT applications. Methods The image quality of an O-arm CBCT device was assessed with an anthropomorphic pelvis phantom in the presence of metal implants. Three different kilovoltage and two different exposure settings were used to scan the phantom both with and without the presence of metal rods. Results The amount of metal artifact was related to the applied CBCT imaging protocol parameters. The size of the artifact was moderate with all imaging settings. The highest applied kilovoltage and exposure level distinctly increased artifact severity. Conclusions The developed method offers a practical and robust way to quantify metal artifacts in CBCT. Changes in imaging parameters may have nonlinear effects on image quality which are not anticipated based on physics.

scholarly journals Robust and Accurate Mandible Segmentation on Dental CBCT Scans Affected by Metal Artifacts Using a Prior Shape Model

2021 ◽  
Vol 11 (5) ◽  
pp. 364
Author(s):  
Bingjiang Qiu ◽  
Hylke van der van der Wel ◽  
Joep Kraeima ◽  
Haye Hendrik Glas ◽  
Jiapan Guo ◽  
...  
Keyword(s):  
State Of The Art ◽  
Maxillofacial Surgery ◽  
Cone Beam ◽  
Oral And Maxillofacial Surgery ◽  
Metal Artifacts ◽  
Shape Model ◽  
High Attenuation ◽  
Mandible Shape ◽  
Prior Shape ◽  
Segmentation Models

Accurate mandible segmentation is significant in the field of maxillofacial surgery to guide clinical diagnosis and treatment and develop appropriate surgical plans. In particular, cone-beam computed tomography (CBCT) images with metal parts, such as those used in oral and maxillofacial surgery (OMFS), often have susceptibilities when metal artifacts are present such as weak and blurred boundaries caused by a high-attenuation material and a low radiation dose in image acquisition. To overcome this problem, this paper proposes a novel deep learning-based approach (SASeg) for automated mandible segmentation that perceives overall mandible anatomical knowledge. SASeg utilizes a prior shape feature extractor (PSFE) module based on a mean mandible shape, and recurrent connections maintain the continuity structure of the mandible. The effectiveness of the proposed network is substantiated on a dental CBCT dataset from orthodontic treatment containing 59 patients. The experiments show that the proposed SASeg can be easily used to improve the prediction accuracy in a dental CBCT dataset corrupted by metal artifacts. In addition, the experimental results on the PDDCA dataset demonstrate that, compared with the state-of-the-art mandible segmentation models, our proposed SASeg can achieve better segmentation performance.

GOD OF METALS: TLATLAUHQUI TEZCATLIPOCA AND THE SACRED SYMBOLISM OF METALLURGY IN MICHOACAN, WEST MEXICO

2010 ◽  
Vol 21 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Hans Roskamp
Keyword(s):  
Sixteenth Century ◽  
Present Article ◽  
Crucial Role ◽  
Metal Artifacts ◽  
Technology Studies ◽  
West Mexico

AbstractIn recent years the development of metallurgy in West Mexico has received increasing attention in the field of archaeological and technology studies. Considering that the latter already include excellent descriptions and analysis of the ritual and sumptuary functions of metal artifacts, the present article focuses on the sacred symbolism of the metal resources and the metalworking process itself according to several indigenous cosmogonical narratives and other additional pictorial and alphabetical sources from sixteenth-century Michoacan and adjacent cultural areas. The available documentation clearly shows that a crucial role was attributed to the native god Tlatlauhqui Tezcatlipoca.

3-T MRI in Patients Received Anterior Cervical Discectomy and Fusion Surgery with MAVRIC SL IR Sequence: A Feasibility Study

2021 ◽  
Vol 24 ◽  
Author(s):  
Renjie Yang ◽  
Changsheng Liu ◽  
Liang Li ◽  
Liang Chen ◽  
Weiyin Vivian Liu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Soft Tissues ◽  
Fat Suppression ◽  
Anterior Cervical Discectomy ◽  
Peek Cage ◽  
Metal Interface ◽  
Metal Artifacts ◽  
Stir Sequence ◽  
3.0 T ◽  
3.0 T Mri

Objective: We aimed to investigate the feasibility of multi-acquisition with variable resonance image combination slab selectivity inversion recovery (MAVRIC SL IR) sequence on 3.0 T MRI in patients with anterior cervical discectomy and fusion (ACDF) surgery compared to bandwidth-optimized short tau inversion recovery (STIR) sequence. Methods: Paired sagittal MR images of MAVRIC SL IR and bandwidth-optimized STIR sequences were acquired and analyzed for 21 patients after ACDF surgery with PEEK cage-plate construct. Quantitative comparisons were made on the metal artifact areas of paired mid-sagittal images. In qualitative analysis, the consistency of fat suppression and visibility of anatomic structures (bone-metal interface, surrounding soft tissues, and spinal cord) were independently assessed, based on a five-point scale by two musculoskeletal radiologists, who were blind to the images and patient details. Results: The application of the MAVRIC SL IR sequence resulted in a significant reduction of 48% in the mean area of metal artifacts (t =-7.141, P < 0.001). Based on the comments received from both the reviewers, MAVRIC SL IR sequence showed greater visibility of the bone-metal interface (P < 0.001), considerable visibility of the surrounding soft tissues (P > 0.05) but worse visibility obtained of the spinal cord (P < 0.001), including the consistency of fat suppression (P < 0.001) relative to the bandwidth-optimized STIR sequence. Conclusion: With significantly reduced metal artifacts, the MAVRIC SL IR sequence can be implemented in patients undergoing ACDF surgery with PEEK cage-plate construct for 3.0 T MRI, despite the poor visibility of the spinal cord.

ՆՈՐԱՀԱՅՏ ՈԻՇՄԻՋՆԱԴԱՐՅԱՆ ԵԿԵՂԵՑԻ ԹԵՂՈՒՏՈՒՄ (2010 թ. պեղումների արդյունքները)

2021 ◽  
pp. 343-357
Author(s):  
Astghik Babajanyan
Keyword(s):  
Medieval Period ◽  
Metal Artifacts ◽  
Late Medieval ◽  
Late Medieval Period ◽  
Evil Eye ◽  
Grave Markers

THE NEWFOUND CHAPEL OF THE LATE MEDIEVAL PERIOD IN TEGHUT (The Results of the Excavations in 2010) In 2010 in the results of the excavations carried out at the site of "Lands of Gharakotuk" in Teghut a cemetery chapel with almost a square floorplan (8.7x7.7 m2) was uncovered. The chapel has a rectangular apse highlighted from both inside and outside which is not common in Armenian architecture. The architectural plan of the chapel was distorted in the result of multiple and often incorrect reconstructions. The excavations revealed a variety of tombstones of the 14th17th centuries, including two grave markers with Georgian inscriptions (deciphering and commentaries by Temo Jojua), two complete and two dozen fragmentary khachkars (two of them dated 1513 and 1604), ceramic and metal artifacts. Based on the analysis of the found materials and the architectural structure, the chapel dates to the 16th-17th centuries. According to the environment ‒ sacred trees (Celtis caucasica) growing around the chapel and the cemetery, as well as a collection of specially hidden metal objects (human figurines, animal shoes, lock etc.) which had protective significance from the evil eye or various diseases, the chapel served also as a place for pilgrimage.

Usefulness of slice encoding for metal artifact correction (SEMAC) technique for reducing metal artifacts after total knee arthroplasty

2018 ◽  
Vol 29 (3) ◽  
pp. 659-666 ◽  
Author(s):  
Ahmed Jawhar ◽  
Miriam Reichert ◽  
Michael Kostrzewa ◽  
Mathias Nittka ◽  
Ulrike Attenberger ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Metal Artifact ◽  
Metal Artifacts ◽  
Artifact Correction ◽  
Total Knee
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