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![TRANSDUCER
• Device which converts Electrical to Sound
energy [pulse ] and Sound to Electrical energy
[Echo]
• Basic Components –
Piezoelectric plate
Backing layer
Acoustic Matching layer
Acoustic lens](https://image.slidesharecdn.com/bscan-160315133840/85/B-scan-7-320.jpg)
![TRANSDUCER
• Device which converts Electrical to Sound
energy [pulse ] and Sound to Electrical energy
[Echo]
• Basic Components –
Piezoelectric plate
Backing layer
Acoustic Matching layer
Acoustic lens](https://image.slidesharecdn.com/bscan-160315133840/75/B-scan-7-2048.jpg)
Uploaded bySamuel Ponraj
B scan
B-scan ultrasonography provides two-dimensional images of the eye that can reveal information about the shape, location, extension, mobility, and thickness of tissues. It uses high frequency sound waves reflected off structures in the eye. The transducer sends pulses and receives echoes to build an image. B-scan is useful when the ocular media is opaque and for evaluating conditions like tumors, detachments, inflammation and measuring the eye's dimensions. Pathological features seen on B-scan include vitreous hemorrhage, asteroid hyalosis, retinoschisis, choroidal detachment, retinal detachment in various configurations, cysticercosis, choroidal melanoma and more.
In this document
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Introduction to B-scan and its functionality in providing 2D imaging for tissue assessment.
Different frequency ranges for various types of ultrasound applications: abdominals, ophthalmics, and ultrasound biomicroscopy.
Details on essential B-scan components including transducer mechanism, piezoelectric elements, and acoustic layers.
Overview of frequency resolution impact on scanning depth and the types of B-scans (immersion vs contact).
Techniques for probe positioning in standardized echography, emphasizing axial, transverse, and longitudinal approaches.
Glossary for ultrasound terminology, explaining acoustic impedance, echo characteristics, and sound behavior in tissues.
Normal ultrasound velocity benchmarks for different eye conditions—phakic, aphakic, pseudophakic, and silicone oil-filled.
Normal features of ocular structures as seen in ultrasound, focusing on reflectivity and clarity of different eye components.
Conditions warranting B-scan; differentiating opaque and transparent media and their relevance in eye pathology diagnostics.
Steps for approaching an ocular diagnosis using B-scan, including examination methods and interpretive strategies.
Characteristics of various pathological conditions diagnosed via ultrasound including features of hemorrhages, detachments, and anomalies.
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B scan
- 1. B SCAN USG Presenter: Dr Samuel Ponraj
- 2. • B-scan orbrightness modulation scan provides two dimensional images of a series of dots and lines. • B-scan provides the topographic information of shape, location, extension,mobility, and gross estimation of thickness of the tissue.
- 4. FREQUENCIES • 1-2 MHZ: ABDOMINAL ULTRASOUND • 8-10 MHZ : OPHTHALMIC ULTRASOUND (B SCAN) BEST FOR POSTERIOR SEGMENT • 35- 80 MHZ : ULTRASOUND BIOMICROSCOPY BEST FOR CORNEA & ANTERIOR SEGMENT
- 5. PULSE ECHO SYSTEM •TRANSDUCER • AMPLIFIER • DISPLAY MONITOR
- 6.
- 7. TRANSDUCER • Device whichconverts Electrical to Sound energy [pulse ] and Sound to Electrical energy [Echo] • Basic Components – Piezoelectric plate Backing layer Acoustic Matching layer Acoustic lens
- 8. • Piezoelectric Element: essential part generates ultrasonic waves . Coated on both sides with electrodes to which a Voltage is applied. Oscillation of Element with repeat expanding and contraction generates a sound wave. • Most common: Piezoelectric ceramic ( Lead zirconate titanate).
- 9. • Backing layer: located behind the piezoelectric element which dampens excessive vibrations from probe thereby improves image resolution • Acoustic matching layer : located in front of piezoelectric element which reduces the reflections from acoustic impedance between probe and object thereby improves trasmission.
- 10. • Acoustic Lens: gray coloured rubber on tip helps in focussing the ultrasonic waves as a slit beam.
- 15. Frequency Resolution PenetrationPossible Scanning depth High Fine Weak Shallow Low Rough Strong Deep
- 16. IMMERSION B SCANCONTACT B SCAN
- 18. PROBE POSITIONING • TRANSOCULARAPPROACH 1. AXIAL 2. TRANSVERSE 3. LONGITUDINAL • PARAOCULAR APPROACH
- 19. Standardized Echography ( ContactB Scan + A Scan) 3 Basic Positions :
- 29.
- 30. • Bell :Measurement of Sound Intensity • Hertz : Frequency of transducer • Acoustic impedence mismatch: - Resistance of tissue to passage of Sound waves. Difference of two tissues at the Interface. - Homogeneous ( Vitreous)- Sound passes through tissue with no returning signal. -Heterogeneous (Orbital Fat) - Different levels of Acousitc impedance mismatch within tissue.
- 31. • Echo –Reflected Sound wave. • Anechoic – No Echo. • Attenuation : Sound is absorbed ( Tumours) • Shadowing : Sound is strongly reflected , nothing passes through it.(Choroidal Osteoma Drusen of Optic nerve head , Air bubble). • Reverberation : Collection of Reflected sounds bouncing back and forth between tissue boundaries especially ( Foreign Body in Eyeball )
- 32. Ultrasound Velocity • NormalPhakic eyes = 1555 m/s • Aphakic eyes = 1532 m/s • Pseudophakic eyes (PMMA) = 1556 m/s (Acrylic )= 1549 m/s • Silicon Oil filled eyes = 980 m/s
- 33. Normal Ultrasonography Characteristics Lens:Oval highly reflective structure Vitreous : Echolucent Retina , Choroid , Sclera : Each is single highly reflective structure. Optic Nerve :Wedge shaped acoustic void in Retrobulbar region Extraocular muscles :Echolucent low reflective fusiform structure. Orbit : Highly reflective (Orbital fat)
- 35. Indications A. Opaque Media(Pathology of Posterior segment) B. Transparent Media
- 36. Opaque Media (Anterior) •Dense Cataract • Miosis • Hyphaema • Hypopyon • Corneal Opacity • Plan for Penetrating keratoplasty with Opaque Anterior segment.
- 37. Opaque Media (Posterior) •Vitrous Haemorrhage • Vitritis/ Endophthalmitis • Pupillary or Retrolenticular membrane
- 38. Transparent Media • Acquisitionof Axial Length for Highly Myopic surgical Candidates ( Caution for Posterior Staphyloma) • Inaccurate A – Scan data (Determination of dimensions of Eye ball) • Proptosis( Poorly represented Orbital Apex) • Orbital tumours • Carotico- cavernous fistula(Dilated Ophthalmic vein)
- 39. • Cysticercosis ofExtraocular Muscles • Suspected Intra Orbital Foreign Body • Orbital Cellulitis • Iris & Ciliary body anomalies • Optic Disc anomaly • Retinal Detachment (Rhegmatogenous /Exudati ve – shifting fluid) • Choroidal Detachment.
- 40. HOW TO APPROACHA DIAGNOSIS ??
- 41. 1. Examination ofeach quadrant 2. Look at each quadrant - coronal - sagital 3. Mentally assemble the Cross sections 4.Anticipate how it should look on moving probe.
- 42.
- 43. Multiple Fine EchoOpacities within the Vitreous Cavity suggestive of Vitreous Haemorrhage .
- 44. Multiple, densely packed,homogeneously distributed echodense dots of medium to high reflectivity with a Clear Preretinal space suggestive of Asteroid Hyalosis
- 45. Moderately elevated thinsmooth dome-shaped membrane echo (arrow) located in the inferotemporal periphery suggestive of Retinoschisis
- 46.
- 47. • Smooth, domeshaped , • thick, less mobile with • double high spike suggestive of Choroidal Detachment
- 48. PVD RD CD TopographicSmooth, with or without disc insertion Smooth or folded with disc insertion Smooth without disc insertion Quantitative < 100 % spike 100 % spike Double 100 % spike Kinetic Marked Moderate None
- 49. PVD or RD? • RD attached to the OD • RD is high reflective • RD is less mobile • Rd is 100% amplitude • Reflectivity of the periphery can differentiate between the two in difficult situations like trauma and inflammations .
- 50. Differentiating features ofRD Rhegmatogenous RD Tractional RD Exudative RD Convex elevation , Undulating folds, PVR Concave elevation,Fibrous tractional band Convex elevation, Shifting fluid changes Configuration with postural change
- 51. RD configurations Open Funnel Triangular Closedfunnel ( T shape)
- 52. Long standing RD Closedfunnel RD with PVR Retinal cysts
- 53. Configurations of TRD Tentlike ( point adherence ) Tabletop ( broad adherence ) Hammock appearance ( multiple tent)
- 54. Highly reflective, echo-densenodule located in Vitreous Cavity suggestive of Cysticercosis.
- 55. Collar stud pattern( Mushroom shape ) Regular internal structure , Acoustic shadowing Low to medium reflectivity , Internal vascularity suggestive of Choroidal Melanoma
- 56. Small globe ,Retrolenticular membrane A Moderate Reflective band extending from the optic disc to the posterior lens capsule suggestive of PHPV.
- 57. Globular/Oval Echoic structurein Posterior Vitreous signifying a Dislocated Lens
- 58. T sign collectionof fluid in subtenon space suggestive of Posterior Scleritis .
- 59. Posterior Staphyloma inHigh Myopia