Detection of normal mediastinal lymph nodes by ultrasonography

1997 ◽  
Vol 38 (6) ◽  
pp. 965-969 ◽  
Author(s):  
C. F. Dietrich ◽  
M. Liesen ◽  
R. Buhl ◽  
G. Herrmann ◽  
J. Kirchner ◽  
...  
Keyword(s):  
High Resolution ◽  
Lymph Nodes ◽  
Pathological Finding ◽  
Doppler Imaging ◽  
Colour Doppler Imaging ◽  
Asymptomatic Volunteers ◽  
Human Cadavers ◽  
Mean Size ◽  
Almost All ◽  
Node Diameter

Purpose: the detection by US (ín contrast to CT) of lymph nodes of any size in the mediastinum is usually considered to be a pathological finding. the aim of this study was to find out whether it was possible to detect normal lymph nodes by high-resolution mediastinal US Material and Methods: Six different mediastinal regions in 80 healthy asymptomatic volunteers and in 20 human cadavers were examined by means of US (with colour Doppler imaging) to assess US access to the respective regions and to demonstrate the number and size of detectable lymph nodes. All the cadaveric lymph nodes that were detected were examined histologically to exclude inflammatory or malignant infiltration Results: in almost all subjects, we obtained US access to the supra-aortic (100%), paratracheal (95%), prevascular (99%), and pencardial (98%) regions, and to the aorticopulmonary window (98%). US access to the subcarinal region was more difficult (75%). in the healthy subjects, lymph nodes were detected in the paratracheal region (in 35% of these subjects, mean lymph-node diameter 12×7 mm), in the aorticopulmonary window (45%, 14×8 mm), and in the subcarinal region (13%, 13×7 mm). in the cadavers, histologically normal lymph nodes were detected frequently in the paratracheal region (85%, mean size 11×6 mm) and in the aorticopulmonary window (90%, 11×5 mm) Conclusion: These results indicate that normal lymph nodes (and not only pathological lymph nodes) can be demonstrated by high-resolution mediastinal US

scholarly journals A Hospital Based Observational Study on Diagnostic Role of High-Resolution Ultrasound and Doppler Imaging in Evaluation of Non-Thyroidal Neck Masses of Patients Attending the Department of Radiodiagnosis, AMCH, Dibrugarh with FineNeedle Aspiration / Histopathological Correlation

2021 ◽  
Vol 8 (11) ◽  
pp. 597-602
Author(s):  
Kallol Prasad Das ◽  
Pronami Borah ◽  
Mondita Borgohain ◽  
Rudra Kanta Gogoi ◽  
Raamseena N.A.
Keyword(s):  
Lymph Node ◽  
High Resolution ◽  
Lymph Nodes ◽  
Adult Population ◽  
Cervical Lymphadenopathy ◽  
Doppler Imaging ◽  
Neck Swelling ◽  
Colour Doppler ◽  
Female Ratio ◽  
Study Results

BACKGROUND Neck swellings consists of a wide spectrum of pathological entities. These swelling can occur due to a variety of aetiologies consisting of congenital, acquired inflammatory, neoplastic, or vascular origin. It is essential to have an extensive knowledge of the anatomy and contents of each cervical compartment to achieve a diagnosis. The age of presentation and clinical findings often narrows down the differential diagnosis. Ultrasonography (USG) is helpful in differentiating the nature of the lesions and differentiating solid from cystic neck lesions. Ultrasound is often used as an initial modality for pre-treatment assessment of any neck swelling. METHODS Patients with clinically palpable / non-palpable neck swellings were scanned using 7.5 - 11 MHz transducers, excluding patients with diagnosed thyroid swellings. RESULTS In total 120 cases were studied; the mean age of patients was 34 years with a male to female ratio of 1.1:1. The age wise categorisation included paediatric population (34.2 %) and adult population (65.8 %). 96 (80 %) cases presented with painless neck swelling, 76 (63.3 %) cases were non-neoplastic and 44 (36.7 %) cases were neoplastic in nature. Cervical lymphadenopathy being the most common ultrasound finding in both paediatric and adult population. Malignant lesions were most common in adult age group. Heterogeneous echotexture, rounded nodes, intranodal necrosis, loss of echogenic hila, peripheral nodal blood flow and increased pulsatility index (PI) and resistive index (RI) were important features of malignant lymph nodes. Sensitivity and specificity of USG and Doppler in differentiating neoplastic from non-neoplastic lesions were 97.7 % and 98.3 % respectively and for differentiating benign from metastatic nodes were 97.7 % and 98.3 % respectively. CONCLUSIONS Considering the study results and observations, USG is the best initial investigation for the evaluation of inflammatory, cystic and neoplastic swellings in various age groups. It is non-invasive, cost effective readily available and repeatable technique. It is relatively easier to use and does not involve radiation hazards. Colour Doppler can evaluate the vascularity of the lesions and provide details of any vascular invasion of metastatic lesions. Ultrasound can differentiate aetiology of lymph node enlargement to a significant extent. KEYWORDS High Resolution Ultrasound, Paediatric Neck Mass, Metastatic Lymph Node, Histopathology, FNAC, Tubercular Lymph Nodes, Colour Doppler, Non-Thyroidal

scholarly journals Ultrasonic colour Doppler imaging

2011 ◽  
Vol 1 (4) ◽  
pp. 490-502 ◽  
Author(s):  
David H. Evans ◽  
Jørgen Arendt Jensen ◽  
Michael Bachmann Nielsen
Keyword(s):  
Three Dimensional ◽  
Ultrasonic Pulse ◽  
Doppler Imaging ◽  
Colour Doppler ◽  
Colour Doppler Imaging ◽  
Velocity Images ◽  
Doppler Techniques ◽  
Velocity Information ◽  
Almost All ◽  
Anatomical Information

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been found to be of great value in assessing blood flow in many clinical conditions. Although the method for obtaining the velocity information is in many ways similar to the method for obtaining the anatomical information, it is technically more demanding for a number of reasons. It also has a number of weaknesses, perhaps the greatest being that in conventional systems, the velocities measured and thus displayed are the components of the flow velocity directly towards or away from the transducer, while ideally the method would give information about the magnitude and direction of the three-dimensional flow vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new techniques that seek to overcome the vector problem mentioned above are described. Finally, some examples of vector velocity images are presented.

High-resolution scanning electron microscopy in biology

1990 ◽  
Vol 48 (3) ◽  
pp. 14-15
Author(s):  
Keiichi Tanaka
Keyword(s):  
High Resolution ◽  
Immunoglobulin M ◽  
Metal Coating ◽  
Biological Macromolecules ◽  
Ultrahigh Resolution ◽  
Preparation Methods ◽  
Low Contrast ◽  
Almost All ◽  
Charging Effect ◽  
Scanning Electron

With the development of scanning electron microscope (SEM) with ultrahigh resolution, SEM became to play an important role in not only cytology but also molecular biology. However, the preparation methods observing tiny specimens with such high resolution SEM are not yet established.Although SEM specimens are usually coated with metals for getting electrical conductivity, it is desirable to avoid the metal coating for high resolution SEM, because the coating seriously affects resolution at this level, unless special coating techniques are used. For avoiding charging effect without metal coating, we previously reported a method in which polished carbon plates were used as substrate. In the case almost all incident electrons penetrate through the specimens and do not accumulate in them, when the specimens are smaller than 10nm. By this technique some biological macromolecules including ribosomes, ferritin, immunoglobulin G were clearly observed.Unfortunately some other molecules such as apoferritin, thyroglobulin and immunoglobulin M were difficult to be observed only by the method, because they had very low contrast and were easily damaged by electron beam.

scholarly journals High-Performance Ultra-Thin Spectrometer Optical Design Based on Coddington’s Equations

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 323
Author(s):  
Zhiwei Feng ◽  
Guo Xia ◽  
Rongsheng Lu ◽  
Xiaobo Cai ◽  
Hao Cui ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectral Resolution ◽  
High Performance ◽  
Optical Design ◽  
Pixel Size ◽  
Simulation Design ◽  
Central Wavelength ◽  
Spot Radius ◽  
Unique Method ◽  
Almost All

A unique method to design a high-throughput and high-resolution ultrathin Czerny–Turner (UTCT) spectrometer is proposed. This paper reveals an infrequent design process of spectrometers based on Coddington’s equations, which will lead us to develop a high-performance spectrometer from scratch. The spectrometer is composed of cylindrical elements except a planar grating. In the simulation design, spot radius is sub-pixel size, which means that almost all of the energy is collected by the detector. The spectral resolution is 0.4 nm at central wavelength and 0.75 nm at edge wavelength when the width of slit is chosen to be 25 μm and the groove density is 900 lines/mm.

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