Ultrasound is useful for evaluating ocular structures. It uses sound waves above the audible range that are reflected by tissues. The transducer produces pulses and detects echoes to create images. Different scan types provide 1D (A-scan) or 2D (B-scan) views. A-scans show acoustic density as spikes while B-scans show shape, location and extent of structures. Proper technique and interpretation of features like reflectivity, mobility and shadowing allow ultrasound to diagnose conditions like retinal detachment, tumors, inflammation and optic nerve diseases.
A quick guide to Ophthalmic Ultrasound/ B-Scan interpretation Mero Eye
Hello Everyone, Namaste!
We would like to notify you all that Mero Eye Foundation is going to conduct an "EYE TALKS-Webinar", we will be having our session.
Speaker Name: MR AMIT KUMAR SINGH
Topic: "A quick guide to Ophthalmic Ultrasound/ B-Scan interpretation"
DATE – MONDAY, 11th MAY 2020 @ 01.45PM IST, 02.00PM NPT (GTM +5.45)
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Antimicrobial stewardship to prevent antimicrobial resistanceGovindRankawat1
India is among the nations with the highest burden of bacterial infections.
India is one of the largest consumers of antibiotics worldwide.
India carries one of the largest burdens of drug‑resistant pathogens worldwide.
Highest burden of multidrug‑resistant tuberculosis,
Alarmingly high resistance among Gram‑negative and Gram‑positive bacteria even to newer antimicrobials such as carbapenems.
NDM‑1 ( New Delhi Metallo Beta lactamase 1, an enzyme which inactivates majority of Beta lactam antibiotics including carbapenems) was reported in 2008
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
2. • Safe
• Non – invasive
• Instant feedback
• Mostly useful in presence of opaque ocular
media
3. Basic physics
• Frequency - above the audible range of 20 kHz.
higher the frequency, more the resolution, lesser the
penetration
• Transducer - a piezoelectric crystal produses micro pulses
• Acoustic density
• At every interface, some of the echoes are reflected back
to the transducer, according to acoustic density.
4. • physical laws of acoustic energy:
reflection, refraction, and absorption.
• The angle of incidence
Needs to be directed perpendicular to the desired
structure.
oblique angle of incidence result in the reflection sound
beams causing a weaker signal.
• An irregular surface also causes loss of echo strength due to
reflection.
6. Biometric A-scan
• Optimized for axial length.
• Frequency used - 10–12 MHz and a linear amplification curve.
• The primary function – IOL calculation.
7. Standardized A-scan
• Frequency - 8 MHz and an S-shaped amplification curve - logarithmic
amplification and higher sensitivity.
• designed to scale acoustic density of retina 100% when the sound is
perpendicular. choroid and sclera also produce 100%
• Allows tumor cell structure to be evaluated and differentiated.
• In combination with B-scan, helps in the differentiation of
vitreoretinal membranes
8. B-scan
• Mostly contact
• Two-dimensional
• Display echoes using both the horizontal and vertical orientations to
show shape, location and extent.
• Strength of the echo is determined by the brightness.
• Mostly frequency is near by 10 MHz and uses logarithmic
amplification.
9. • evaluation of static B-scan images can lead to misdiagnosis. It is a
dynamic process requiring attention to the mobility of echoes.
• Three basic B-scan probe orientations are:
axial, transverse and longitudinal
immersion B-scan
• It is valuable in the evaluation of pathology near the ora - an area that
is too anterior for contact B-scan and too posterior for UBM (40 –
80Mhz)
10. Color Doppler ultrasonography
• Simultaneously allows B-scan and evaluation of blood flow.
• The red end of the spectrum - flow moving towards the transducer
and the blue end of the spectrum - flow is moving away.
• effective in the detection of ocular and orbital tumor vasculature,
carotid disease, central retinal artery and vein occlusions and non-
arteritic ischemic optic neuropathy
11. 3D ultrasonography
• Multiple consecutive B-scans are utilized to create a 3D block.
• The probe is held fixed, and serial images are rapidly obtained as the
transducer rotates.
• Useful in estimating the volume of intraocular lesions and for
evaluation of retro-bulbar optic nerve.
12. Axial resolution
• The axial resolution, is related to
frequency, piezoelectric crystal shape and the damping material
attached to the crystal.
• The damping material serves to shorten the pulses.
The shorter the pulse, the better the axial resolution.
• The concave shape of the crystal focuses the sound. The focused
sound increases not only axial, but also lateral resolution.
13. Amplification Curves
• The receiver processes echoes by
amplification, compression, compensation, demodulation and
rejection.
• Amplification –
linear, logarithmic or S-shaped
• Type of amplification curve affects the dynamic range - the range of
echoes that can be displayed (labeled in units dB).
14. • Linear curve amplifiers - small dynamic range, sensitive to minor
differences in the density
• logarithmic amplifiers - large dynamic range, lesser sensitive
• S-shaped amplifiers - offers the sensitivity of linear amplification
and the dynamic range of logarithmic amplification.
15. Gain
• The amplification of echoes are adjustable by adjusting the gain (dB).
• Lowering the gain :
decreases the depth of penetration and increases resolution.
• The choroid, sclera and orbital structures are usually best examined
at a low gain.
16. • At a high gain –
weaker echo sources are detected, but resolution is lost.
• Vitreous opacities and thin vitreous membranes are best examined at
high gain.
• Time gain compensation control (TGC)
Amplifies weaker echoes from deeper tissues more than those
from superficial, thus equalizing the echo strength from similar
tissues located at varied distances from the transducer.
17. patient preparation
• Ideally reclined position.
• Display and patient’s head should be parallel and in close proximity
• topical anesthesia
• methylcellulose-based gel as coupling agent
• both eyes be opened and gaze in the direction being imaged.
• B-scans through closed eyelids
1. Ultrasound waves are attenuated due to the soft eyelid
2. Difficult to determine the exact position of the probe on eye.
18. B-scan probe
• Have a marker along the side indicating the top of the display
• Probe tip - the white line on the far left side of display.
• Echoes to right of this line - ocular structures opposite the probe tip.
20. • Sound attenuation and refraction - crystalline lens - diminished
resolution.
• Pseudophakic - intense sound reverberation echoes
• Evaluation of macula, Tenon’s space, and the optic nerve.
Para-axial scans
• Peripapillary fundus.
• Sound attenuation not as marked as with the axial scan.
• Peripapillary mass lesions
21. Trans-scleral scans
• Longitudinal and transverse
• Bypass the crystalline lens - better resolution
• Patients are more cooperative.
• The patient’s gaze should be directed in the direction of the area to
be examined.
• anatomical references - optic nerve and extra-ocular muscles.
• Posterior pole - The macula is only evident when thickened.
• Optic disc is used as the reference center of the posterior segment.
23. • Five scan screening - four transverse and one longitudinal B-scan - the
entire posterior segment can be well imaged.
24. Diagnostic features for assessing intraocular lesions.
Topographic Quantitative Kinetic
Location Reflectivity Mobility
Shape Internal structure Vascularity
Extent Sound attenuation Convection movement
25. Topographic ultrasonography
• To determine location, shape and extent of the lesion.
• A transverse scan performed first to determine the maximal height
and lateral basal dimension of the lesion
• A longitudinal B-scan is performed next to evaluate the anterior to
posterior topographic features of the lesion
26. Compilation of topographic B-scan images to differentiate membranes. Transverse B-scan
showing a slightly rope-like, elevated membrane. Corresponding longitudinal B-scan at the same
clock hour showing a V-shaped elevated membrane inserting into the disk. Mental compilation
of scans into a three-dimensional image differentiates membrane as an open funnel-shaped
retinal detachment.
27. Quantitative ultrasonography
• Reflectivity - height of the spike on A-scan.
A-scan probe sh’d be calibrated for tissue sensitivity
sound directed perpendicular to the lesion
Internal structure - homogeneous - little variation in spikes
heterogeneous - marked variation
• Sound attenuation (acoustic shadowing) - Calcification, foreign
bodies and bones
28. (reflectivity). Arrow represents the path of sound beam used to generate the A-
scan. Diagnostic A-scan of the solid fundus mass shows high reflectivity of the
retina (arrow) and low to medium internal reflectivity of the mass lesion
(arrowheads).
29. Sound attenuation. Transverse B-scan shows an irregularly shaped lesion with
highly reflective areas (arrow) causing shadowing of the orbital structures
(asterix).
30. Angle kappa - greater the attenuation of sound, greater the angle kappa
31. Kinetic ultrasonography
• motion of a lesion
• within a lesion - mobility, vascularity, and convection movement
Mobility
• change in gaze
• Posterior vitreous detachments, retinal detachment, and choroidal
detachments all exhibit distinctive patterns of mobility
32. Vascularity
• Fast, low-amplitude flickering
• Detected on both B-scan and A-scan.
• Probe and patient’s gaze are held stationary
• Graded mild, moderate, or marked, corresponding to the intensity
33. Convection
• Slow, continuous movement - secondary to convection currents -
blood, layered inflammatory cells, or cholesterol debris
• Probe stationary and the patient’s gaze fixated.
• Long-standing vitreous hemorrhage that has settled beneath a tight
retinal detachment.
• Differentiation of settled debris and or intraocular solid mass lesions.
35. Fresh vitreous hemorrhage
showing diffuse low to medium
echoes
Pseudomembrane representing
the organization of blood
moderately dense vitreous
hemorrhage
37. Vitreous hemorrhage in a
vitrectomized eye in high gain,
arrowheads – vitreous skirt
Same patient on low gain. VH is
not visible as it does not
organize in a vitrectomized eye.
Discontinuities vitreous skirt
40. Total open funnel RD. B-scan at low gain shows open funnel
configuration and optic disc attachment. A-scan shows 100%
peak corresponding to the RD S – sclera, V – vitreous, R –
retina.
41. Thin posterior vitreous
detachment (arrows) tent-like
tractional retinal detachment
(arrowheads).
multiple intraretinal macrocysts in a
chronic retinal detachment.
42. B-scan shows PVD (arrow), choroidal detachment (arrowhead), and
vitreous hemorrhage (VH). A-scan shows the characteristic double
peak on initial spike The probe must be perpendicular to see the
double peak
43. Serous choroidal detachment. Two
choroidal detachments with
echolucent subchoroidal serous fluid
(SF).
Hemorrhagic choroidal detachment.
“kissing” choroidal detachment with
dense opacities in the suprachoroidal
space indicative of hemorrhage (SH).
44. Retinal tear (T) with the edges of the
retina (arrowheads) folded
posteriorly. PVD (arrow) can be seen
connected to the folded retina.
Pigment epithelial detachment
45. Echographic elongation of the
vitreous cavity by silicone oil and
limited visibility of posterior ocular
structures
Following removal of silicone oil. few
droplets of oil that remain in the eye are
visible as highly reflective surfaces
(arrowheads) B – scleral buckle
52. Circumscribed choroidal hemangioma. Axial B-scan showing dome-shaped mass
OCT shows anterior bowing of the retina due to underlying choroidal
hemangioma but the retinal architecture is normal
53. B-scan demonstrating that nevus less than 1 mm height. A-scan with
high internal reflectivity. OCT showing minimal choroidal thickening and
drusen
54. Choroidal melanoma. Clinical photograph showing large, partially amelanotic
dome-shaped choroidal mass. B-scan reveals a mushroom-shaped choroidal mass
that has broken through Bruch’s membrane (arrows) touching the posterior
surface of the lens
55. Choroidal melanoma with extrascleral extension. A-scan shows medium to high
internal reflectivity of the choroidal lesion (arrows–A) and high internal
reflectivity of the extraocular extension (arrows–B)
56.
57. Astrocytic hamartoma. Clinical photograph of peripapillary calcified astrocytic
hamartoma. B-scan demonstrating calcification near optic disc (arrow).
58. Choroidal metastasis. B-scan demonstrating a total retinal detachment, diffuse
choroidal thickening (arrowheads), and extraocular extension (arrows) near the
retrobulbar optic nerve
61. Ant. Vitritis Mild to moderately dense, vitreous opacities anterior to the posterior
vitreous detachment (arrows) and very mild subhyaloid opacities
62. B-scan in a patient with chronic uveitis at a low gain showing marked thickening
of the macular area (arrowhead) and moderate scleral thickening with a thin
band of low reflectivity in Tenon’s space (arrow) OCT of the macular area in the
same patient showing marked macular elevation with cystic spaces
63. Toxocariasis. Transverse B-scan demonstrating a taut membrane extending
across the vitreous and adherent to an irregularly shaped, highly reflective
granuloma that is causing shadowing of the orbit (arrowhead).
64. Toxoplasmosis. Marked vitreous haze with toxoplasmosis lesions of the fundus. B-
scan at a low gain demonstrating a posterior vitreous detachment (arrowhead)
and a dome-shaped, elevated lesion of the fundus (arrow).
66. Axial B-scan at a low gain showing
marked thickening of the posterior
fundus (arrows).
Transverse B-scan at a high gain showing
dense, clumped vitreous opacities
adjacent to the thickened choroid
(arrows)
67. B-scan demonstrating marked, diffuse
thickening of the posterior fundus and
sclera (arrows) with a thin band of low
reflectivity in Tenon’s space (black
arrows) indicative of posterior scleritis.
Diagnostic A-scan showing highly
reflective thickening of the posterior
fundus and sclera
68. bullous choroidal detachments (arrows) with moderate, clumped opacities
beneath on transverse B-scan of the peripheral fundus and corresponding fundus
photograph
69. “T-sign” in posterior scleritis. Axial B-scan shows posterior scleral thickening and low reflective infiltrate behind the
peripapillary sclera and optic nerve creating the classical “T-sign” (arrows). Axial B-scan showing marked thickening
of the sclera with only a very thin band of low reflectivity behind the peripapillary sclera (arrows).
70. Endophthalmitis. Transverse B-scan showing marked membrane formation
(arrow) throughout the vitreous space and marked, irregular fundus thickening
(small arrows)
71. Orbital myositis. External photograph demonstrating exotropia of the left eye. B-
scan shows marked enlargement of the medial rectus muscle (arrow) and its
inserting tendon (small arrow),
73. Large optic disc cup. B-scan demonstrates corresponding
concave bowing of the optic disc.
74. Normal retrobulbar optic nerve measurements
• Measured in two locations
• 3 mm posterior to the nerve head and
• as close as possible to the orbital apex
• Normal - 2.2 to 3.3 mm - variation can occur
• A difference of ≥0.5 mm may indicate an abnormal thickness in one
• No significant changes when measured in Trendelenburg or reverse
Trendelenburg position as compared with the supine position
75. Papilledema
30° test
• Increased subarachnoid fluid can be differentiated from thickening of
the parenchyma or perineural sheaths
• perineural sheaths measured anteriorly and posteriorly
• In primary gaze
• 30° lateral gaze
• A decrease in diameter of >10% in lateral gaze - a positive 30° test -
increased subarachnoid fluid.
76. Papilledema. Fundus photographs (A, right eye; B, left eye) show marked elevation of the optic disc that obscures
clarity of the retinal vessels at the optic disc nerve head margin (arrowhead).
77. Transverse B-scan - marked
elevation of the optic disc.
a cross section of the retrobulbar optic
nerve and crescent-shaped echolucent
area behind the nerve indicative of
increased subarachnoid fluid
78. Positive 30° test with diagnostic A-scan while the eye is in primary gaze with an
enlarged retrobulbar optic nerve (4.8 mm) When the eye is fixated 30° laterally, a
marked decrease in the size of the retrobulbar optic nerve (3.5 mm)
4.8 3.5
79. • Blaivas performed a prospective observational study on patients
suspected of having raised ICT (adults)
• Patients having raised ICT were predicted correctly by optic nerve
sheath diameters of >5 mm.
• The ultrasonographic measurements were correlated more closely to
the intracranial pathology than the clinical examination.
• Mean optic nerve sheath diameter for those not meeting CT criteria
for raised intracranial pressure was 4.4 mm.
80. • Kimberly also correlated optic nerve sheath diameters with directly
measured intracranial pressure
• In an adult, optic nerve sheath diameters >5 mm correlated with
intracranial pressure >20 cmH2O, with sensitivity of 88% and a
specificity of 93%.
• In children sheath diameter of greater than 4 mm in infants and of
greater than 4.5 mm in children age 1 to 15 years should be
considered abnormal.
81. Buried optic nerve head drusen. Fundus photograph shows optic nerve head
elevation and absence of optic cup mimicking papilledema.
B-scan shows highly calcified, round drusen at the with shadowing
Diagnostic A-scan shows normal retrobulbar optic nerve diameter measuring 3.2
mm
Pseudopappiledema
3.2
82. Optic disc coloboma. Fundus photograph and Longitudinal B-scan. Note
vitreous hemorrhage, a shallow retinal detachment (arrow) and coloboma at
the inferior portion of the optic nerve head (arrowhead)
83. Fundus photograph showing congestion and elevation of the right optic disc
Normal contralateral left optic disc
84. Diagnostic A-scan shows thickening
of right optic nerve with retrobulbar
diameter of 4.50 mm. 30° test was
negative for subarachnoid fluid
A-scan of normal left optic nerve with
retrobulbar diameter of 2.32 mm
4.5 2.3
85. B-scan right showing enlargement of optic nerve and Coronal MRI (T1 fat
suppression) showing thickening and enhancement of optic nerve sheath with
compression of optic nerve.