scholarly journals Transmission and imaging characteristics of flexible gradually tapered waveguide at 03 THz

2021 ◽  
Vol 29 (6) ◽  
pp. 8430
Author(s):  
Menghui He ◽  
Jiafu Zeng ◽  
Xian Zhang ◽  
Xiaosong Zhu ◽  
Chengbin Jing ◽  
...  
Keyword(s):  
Imaging Characteristics ◽  
Tapered Waveguide

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

Clinical Manifestations and Radiological Characteristics on Rosai-Dorfman Disease: A Retrospective Observational Study

2020 ◽  
Vol 5 (5) ◽  
Keyword(s):  
Blood Vessels ◽  
Abdominal Cavity ◽  
Clinical Manifestations ◽  
Ct Images ◽  
High Signal ◽  
Radiological Features ◽  
Imaging Characteristics ◽  
Rosai Dorfman Disease ◽  
Heterogeneous Enhancement ◽  
The Masses

Background and Objective: Rosai-Dorfman disease (RDD) are usually misdiagnosed because of rarity and nonspecific clinical and radiological features. The aim of our study is to explore the clinical and imaging characteristics of RDD to improve diagnostic accuracy. Methods: Clinical and imaging data in 10 patients with RDD were retrospectively analyzed. 7 patients were underwent CT scanning and 3 patients were underwent MR examination. Results: 8 (8/10) patients presented with painless enlarged lymph nodes (LNs) or mass. 3 cases were involved with LNs, 5 cases were involved with extra-nodal tissues, and the remaining 2 cases were involved with LNs and extra-nodal tissue simultaneously. In enhanced CT images, enlarged LNs displayed mild or moderate enhancement, and 2 cases showed heterogeneous ring-enhancement. MR features of 3 patients with extra-nodal RDD, 2 cases showed a mass located in the subcutaneous and anterior abdominal wall respectively, and 1 case showed an intracranial mass. Besides, all lesions showed high signal foci on DWI images, and were characterized by marked heterogeneous enhancement with blurred edge. The dural/fascia tail sign and dilated blood vessels could be seen around all the lesions on enhanced MRI. Radiological features of 2 cases with LN and extranodal tissue involved, one case presented with the swelling and thickening of pharyngeal lymphoid ring and nasopharynx, meanwhile with enlarged LNs in bilateral submandibular area, neck and abdominal cavity, and also companied with osteolytic lesion in right proximal humerus. All these LNs displayed mild and moderate enhancement on CT images. Another case showed enlarged LNs in bilateral neck accompanied with soft tissue mass in the sinuses. Conclusions: RDD occurred commonly in young and middle-aged men and presented with painless enlarged LNs or mass.RDD had a huge diversity of imaging findings, which varied with different location. The radiological features, such as small patches of high signal foci in the masses on DWI images, heterogeneous enhancement and blood vessels around the masses, are helpful in diagnosis of extranodal RDD.

Condrosarcom laringian - prezentare de caz

ORL ro ◽  
2016 ◽  
Vol 4 (1) ◽  
pp. 32-35
Author(s):  
Bogdan Mocanu ◽  
Aida Petca ◽  
Daniela Safta ◽  
Cornelia Niţipir ◽  
Liliana Mirea ◽  
...  
Keyword(s):  
Gold Standard ◽  
Total Laryngectomy ◽  
Cricoid Cartilage ◽  
Good Prognosis ◽  
Rare Cancers ◽  
Imaging Characteristics ◽  
Laryngeal Tumors ◽  
Grade Ii

Chondrosarcomas of the larynx are rare cancers, representing less than 1% of all laryngeal tumors. The most often involved site is the cricoid cartilage. They have generally good prognosis, and low metastatic tendency. Surgery is the treatment of choice, partial in small limited tumors or total laryngectomy if tumor extends beyond the half of the cricoid and/or is poor differentiated. Although there are some pathognomonic imaging characteristics for chondrosarcomas, the histology remains the gold standard for diagnostic. The authors present a case of large, medium differentiated chondrosarcoma (grade II), surgically treated by total laryngectomy.   

Imaging of Pancreatic-Neuroendocrine Tumours: An Outline of Conventional Radiological Techniques

2019 ◽  
Vol 12 (2) ◽  
pp. 135-155 ◽  
Author(s):  
Muhammad Affan Zamir ◽  
Wasim Hakim ◽  
Siraj Yusuf ◽  
Robert Thomas
Keyword(s):  
Neuroendocrine Tumours ◽  
Treatment Options ◽  
Advantages And Disadvantages ◽  
Imaging Characteristics ◽  
Fundamental Understanding ◽  
Pancreatic Neuroendocrine Tumours ◽  
Direct Management ◽  
Important Disease ◽  
Similar Imaging

IIntroduction: Pancreatic Neuroendocrine Tumours (p-NETs) are an important disease entity and comprise of peptide-secreting tumours often with a functional syndrome. : Accounting for a small percentage of all pancreatic tumours, they have a good overall survival rate when diagnosed early, with surgery being curative. The role of nuclear medicine in the diagnosis and treatment of these tumours is evident. However, the vast majority of patients will require extensive imaging in the form of conventional radiological techniques. It is important for clinicians to have a fundamental understanding of the p-NET appearances to aid prompt identification and to help direct management through neoplastic staging. Methods: This article will review the advantages and disadvantages of conventional radiological techniques in the context of p-NETs and highlight features that these tumours exhibit. Conclusion: Pancreatic neuroendocrine tumours are a unique collection of neoplasms that have markedly disparate clinical features but similar imaging characteristics. Most p-NETs are small and welldefined with homogenous enhancement following contrast administration, although larger and less welldifferentiated tumours can demonstrate areas of necrosis and cystic architecture with heterogeneous enhancement characteristics. : Prognosis is generally favourable for these tumours with various treatment options available. However, conventional radiological techniques will remain the foundation for the initial diagnosis and staging of these tumours, and a grasp of these modalities is extremely important for physicians.

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