scholarly journals Ultrasound biomicroscopy in ophthalmology

2021 ◽  
Vol 14 (1) ◽  
pp. 63-73
Author(s):  
Alexander V. Tereshchenko ◽  
Elena V. Erokhina ◽  
Denis P. Volodin
Keyword(s):  
Anterior Segment ◽  
Retinal Disease ◽  
Ultrasound Biomicroscopy ◽  
Limited Information ◽  
High Frequency Ultrasound ◽  
Non Invasive ◽  
Invasive Method ◽  
Adults And Children ◽  
Almost All ◽  
Diagnostic Capabilities

This review presents data on the use of the method of ultrasonic biomicroscopy (UBM) of the anterior segment of the eye in ophthalmological practice in adults and children. Ultrasound biomicroscopy (UBM) is a contact non-invasive method for visualizing structures of the anterior segment of the eye using high-frequency ultrasound in the range from 35 to 100 MHz. Literature data indicate that UBM can be used to visualize almost all structures of the anterior segment, including the cornea, iridocorneal angle, anterior chamber, iris, ciliary body and lens, as well as the peripheral parts of the retina, vasculature and vitreous. There is data on the use of this method in the study of pathogenetic aspects of glaucoma, pseudoecfoliative syndrome, various types of cataracts, post-traumatic injuries of the anterior segment of the eye, meimobium gland dysfunction and other ophthalmopathologies. The use of UBM in children, due to the peculiarities of its implementation, is not widespread, but due to the specificity of the data obtained using it, it is promising. The limited information about the use of UBM in retinopathy of prematurity and the diagnostic capabilities of the method makes its use especially relevant in this severe retinal disease of premature newborns.

scholarly journals Diagnostic methods for extra-temporal neocortical focal epilepsies: present and future

2010 ◽  
Vol 68 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Ricardo André Amorim Leite ◽  
Maria Concépcion Garcia Otaduy ◽  
Gilson Edmar Gonçalves e Silva ◽  
Maria Lúcia Brito Ferreira ◽  
Maria de Fátima Vasco Aragão
Keyword(s):  
Cerebral Metabolism ◽  
Diagnostic Methods ◽  
Epileptogenic Zone ◽  
Proton Spectroscopy ◽  
Non Invasive ◽  
Surgical Evaluation ◽  
Invasive Method ◽  
Almost All ◽  
Invasive Techniques ◽  
Video Eeg

The progress of epilepsies diagnosis has been great, but, amongst the diagnostic detailing that demand research, one of the most important is the essential lateralization and localization of epileptogenic zone, considered as the cerebral cortex region, that removed, will result in a free state of seizures. The present study aims to analyze the possible uses of proton spectroscopy for clinical and pre-surgical evaluation of focal extratemporal epilepsies, since this group presents the highest difficulty degree for lateralizing and locating epileptogenic zones. In almost all cases, a non invasive diagnosis can be performed using routine electroencephalography, video-electroencephalography - considered as gold standard, and magnetic resonance imaging. However, when the results of these exams are contradictory, some patients need invasive techniques, as the intra-cranial video-EEG, using deep electrodes, sub-dural strip and grid, that are associated with increased diagnostic cost and risk of complications, as cerebral hemorrhages and intra-cranial infections. Proton spectroscopy appears as a possibility, given its capacity to evaluate cerebral metabolism, by N-acetyl-aspartate (NAA), creatine (Cre) and choline (Cho) concentrations, amongst other metabolites. This non invasive method may provide time reduction of this evaluation and reliable level improvement for this topographical diagnosis.

scholarly journals Deep vascular imaging in the eye with flow-enhanced ultrasound

2021 ◽  
Author(s):  
Christian Damsgaard ◽  
Henrik Lauridsen
Keyword(s):  
Imaging Techniques ◽  
Three Dimensional ◽  
The Body ◽  
High Frequency Ultrasound ◽  
Spatiotemporal Resolution ◽  
Ultrasound Technique ◽  
Non Invasive ◽  
Nucleated Red Blood Cells ◽  
Invasive Method ◽  
Flow Enhancement

The eye's retina is one of the most energy-demanding tissues in the body and thus requires high rates of oxygen delivery from a rich blood supply. The capillary lamina of the choroid lines the outer surface of the retina and is the dominating source of oxygen in most vertebrates, but this vascular bed is challenging to image with traditional optical techniques due to its position behind the highly light-absorbing retina. Here we describe a high-frequency ultrasound technique with flow-enhancement to image deep vascular beds (0.5 - 3 cm) of the eye with a high spatiotemporal resolution. This non-invasive method works well in species with nucleated red blood cells (non-mammalian and fetal animal models), and it generates non-invasive three-dimensional angiographies without the use of contrast agents that is independent of blood flow angles and with a higher sensitivity than Doppler based ultrasound imaging techniques.

scholarly journals Non-invasive method for determining the level of stable intrathyroid iodine in the diagnosis and control of treatment of thyroid diseases (lecture)

1996 ◽  
Vol 42 (3) ◽  
pp. 29-32
Author(s):  
I. O. Tomashevsky
Keyword(s):  
Diagnostic Method ◽  
Fluorescence Analysis ◽  
Thyroid Diseases ◽  
Medical Sciences ◽  
Scientific Center ◽  
X Ray ◽  
Non Invasive ◽  
Invasive Method ◽  
Diagnostic Capabilities ◽  
And Control

The technology of non-invasive determination of the level of intrathyroid stable iodine (ISI), called X-ray fluorescence analysis or X-ray fluorescence scanning, began to be used since 1968 and is currently used in approximately 10 radiological laboratories around the world as a unique research methodology. Only in recent years have the technical difficulties of this diagnostic method been overcome, and it is gradually becoming more accessible. Since 1974, the efforts of the staff of the Radiological Scientific Center of the Russian Academy of Medical Sciences (Obninsk) and the clinical hospital of the Central Health Unit No. 119 of the Federal Administration for Biomedical and Extreme Problems at the Ministry of Health of the Russian Federation (Khimki) carried out the necessary scientific research and created an analyzer, a method for determining the level ISI and interpretations of the results obtained, allowed for use in Russia as serial laboratory technologies. The specified diagnostic method over the past few years has been successfully used in these institutions when examining more than 3,000 patients with various thyroid diseases (thyroid gland) and continues to be used in the comprehensive diagnosis of thyroid pathology. The purpose of this lecture is to familiarize endocrinologists with the diagnostic capabilities of this method.

scholarly journals Predicting the risk for angle closure as defined by the Shaffer System Using Anterior Segment Optical Coherence Tomography: A Simple Approach

2020 ◽  
Vol 82 (1) ◽  
pp. 100-105
Author(s):  
Dan Samaha ◽  
Sébastien Gagné ◽  
Marie-Eve Corbeil ◽  
Pierre Forcier
Keyword(s):  
Anterior Segment ◽  
Correlation Coefficients ◽  
Angle Closure ◽  
Spearman Correlation ◽  
Suitable Alternative ◽  
Non Invasive ◽  
Nearest Point ◽  
Patients At Risk ◽  
Invasive Method ◽  
Excellent Reproducibility

Purpose: To propose a simple non-invasive method for screening patients at risk for angle closure using anterior segment OCT. Methods: Scans of nasal and temporal iridocorneal angles in glaucoma suspect patients were performed using OCT. Upon identifying Schwalbe’s line, the integrated caliper tool was used to draw a line to the nearest point of the iris to produce a measure ‘S-I’. Gonioscopy was performed and angles graded according to Shaffer’s classification to assess the correlation between both methods. Results: Thirty-four images were available for analysis. Spearman correlation coefficients between S-I anf gonioscopy grades were 0.81 for nasal and 0.77 for temporal quadrants respectively. Intraobserver ICC calculations demonstrated excellent reproducibility (0.98 and 0.99 for nasal and temporal angles) and excellent interobserver correlation (0.94 and 0.93). The diagnostic cutoff value of S-I for occludable angles was established at 330mm. Conclusion: S-I measurement strongly correlates with gonioscopy and may be a suitable alternative for evaluating risk for angle closure.

Facile and Effective Phononic Structures for Ultrasound Focusing Application

2014 ◽  
Author(s):  
Qiuquan Guo ◽  
Xiaobing Cai ◽  
Jun Yang
Keyword(s):  
Penetration Depth ◽  
Acoustic Energy ◽  
Ultrasound Therapy ◽  
Acoustic Metamaterials ◽  
High Frequency Ultrasound ◽  
Low Frequencies ◽  
Non Invasive ◽  
Wavelength Resolution ◽  
Invasive Method ◽  
Sub Wavelength

Ultrasound therapy is a highly popular non-invasive method to treat diseases. It is desired to increase the resolution of ultrasound therapy, providing more efficient therapeutic effect. In this study, a simple but effective phononic structure was designed to achieve higher resolution close to wavelength resolution of ultrasound focusing. The objective of this study is to design a unique phononic structure to focus acoustic wave into human body more deeply and precisely. It is known that overheating by high frequency ultrasound will cause a series of side effects including bone burns, soft tissue burns, swelling and bleeding problems. In addition, due to the limited propagation of recovered evanescent wave, the penetration depth of acoustic energy being focused by the acoustic metamaterials is often hindered. In this study, we will design a multilayer acoustic metamaterial which shows sub-wavelength focusing ability at relatively low frequencies. More importantly, our design will also extend the ability of penetration depth by manipulating the focusing length through optimization of the phononic structure.

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