Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
A Scan Ultrasonography
Presenter : Dr Samuel Ponraj
Moderator : Dr PRR
Physics of Ultrasound
• Ultrasound passes through the tissue , part of the
wave is reflected back towards the probe
• Echo...
Instrumentation
• Pulser
• Reciever
• Display System
A Scan Mode
GAIN
Highest gain widest sound beam
Highest penetration Max Spike Height
(Visualisation of Weak Signals)-PVD,Vitreous Opac...
Indications
• To detect ,measure and differentiate tumours
and follow up.
• Biometry for accurate Axial length
measurement...
ADVANTAGES
• Easy to use
• No Ionizing radiation
• Excellent Tissue Differentiation
• Cost Effectiveness
Interpretation
a: Initial spike (probe tip and cornea)
b: Anterior lens capsule
c: Posterior lens capsule
d: Retina
e: Scl...
Topographic Echography
Category Point-like Membrane-like Space-occupying
Echogram Single spike Single spike or
chain of sp...
Quantitative Echography
1. Internal Structure Reflectivity
(Size & Arrangement of interfaces)
- Regular low – Melanoma
- R...
2. SOUND ATTENUATION
Scattering,absorption or reflectivity of
Sound energy
Steeper the Kappa
angle
Greater the Sound
atten...
KINETIC ECHOGRAPHY
Kinetic Echography
(Low gain)
Spontaneous
movements
(Stationary eye ) –
vascular lesion
After movements...
Common Ocular Pathologies
VITREOUS
FLOATER
VITREOUS
HAEMORRHAGE
ENDOPHTHALMITIS
POSTERIOR
VITREOUS
DETACHMENT
RETINAL
DETACHMENT
Intra Ocular Lens
CHOROIDAL MELANOMA
CHOROIDAL HEMANGIOMA
METASTATIC CARCINOMA
RETINOBLASTOMA
CHOROIDAL
DETACHMENT
DISLOCATED LENS INTO
VITREOUS
APHAKIC EYE
CONTACT TECHNIQUE
IMMERSION TECHNIQUE
Immersion B-scan/vector A-scan
technique
Adjustments to UltraSound Velocity
settings
OCULAR
MEDIA
ULTRA SOUND
VELOCITY
THICKNESS CORRECTION
FACTOR
CORNEA 1641 M/SE...
COMPARISON BETWEEN CONTACT
TECHNIQUE AND IMMERSION
TECHNIQUE OF BIOMETRY
Contact technique Immersion technique
Patient is ...
Limitations and Pitfalls
• Multiple Artifacts
• Attenuation Artifacts
• Low reflective Spike
• Small tumours with False Ne...
MISALIGNMENT
SILICON OIL
GLOBE
A scan ultrasonography
A scan ultrasonography
A scan ultrasonography
A scan ultrasonography
A scan ultrasonography
A scan ultrasonography
A scan ultrasonography
Upcoming SlideShare
Loading in …5
×

A scan ultrasonography

5,278 views

Published on

A Scan Ultrasonography - Basic for Lens

Published in: Health & Medicine
  • Be the first to comment

A scan ultrasonography

  1. 1. A Scan Ultrasonography Presenter : Dr Samuel Ponraj Moderator : Dr PRR
  2. 2. Physics of Ultrasound • Ultrasound passes through the tissue , part of the wave is reflected back towards the probe • Echoes formed at -- acoustic interfaces that are created at the junction of media with different sound velocities. • The greater the difference in sound velocities of the media at the interface, the stronger is the echo.
  3. 3. Instrumentation • Pulser • Reciever • Display System
  4. 4. A Scan Mode
  5. 5. GAIN Highest gain widest sound beam Highest penetration Max Spike Height (Visualisation of Weak Signals)-PVD,Vitreous Opacities LOWEST GAIN WEAKEST PENETRATION DECREASED SPIKE HEIGHT (RETINA , SCLERA )
  6. 6. Indications • To detect ,measure and differentiate tumours and follow up. • Biometry for accurate Axial length measurement for IOL calculation. • Morphological characteristics – AC depth, Corneal thickness,Lens thickness and relative position.
  7. 7. ADVANTAGES • Easy to use • No Ionizing radiation • Excellent Tissue Differentiation • Cost Effectiveness
  8. 8. Interpretation a: Initial spike (probe tip and cornea) b: Anterior lens capsule c: Posterior lens capsule d: Retina e: Sclera f: Orbital fat
  9. 9. Topographic Echography Category Point-like Membrane-like Space-occupying Echogram Single spike Single spike or chain of spikes Chain of Spikes Differential diagnosis Foreign body Retinal detachment Melanoma Vitreous opacities Choroidal detachment Retinoblastoma Vitreous membranes Hemangioma Tumor surfaces Vitreous Haemorrhage Assessment of shape, location and elevation of lesions
  10. 10. Quantitative Echography 1. Internal Structure Reflectivity (Size & Arrangement of interfaces) - Regular low – Melanoma - Regular High – Haemangioma - Irregular – Metastatic Carcinoma
  11. 11. 2. SOUND ATTENUATION Scattering,absorption or reflectivity of Sound energy Steeper the Kappa angle Greater the Sound attenuation (Bone, Foreign Body)
  12. 12. KINETIC ECHOGRAPHY Kinetic Echography (Low gain) Spontaneous movements (Stationary eye ) – vascular lesion After movements { Following Cessation of Eye Movements } - PVD,RD
  13. 13. Common Ocular Pathologies VITREOUS FLOATER VITREOUS HAEMORRHAGE
  14. 14. ENDOPHTHALMITIS POSTERIOR VITREOUS DETACHMENT
  15. 15. RETINAL DETACHMENT Intra Ocular Lens
  16. 16. CHOROIDAL MELANOMA CHOROIDAL HEMANGIOMA METASTATIC CARCINOMA
  17. 17. RETINOBLASTOMA CHOROIDAL DETACHMENT
  18. 18. DISLOCATED LENS INTO VITREOUS APHAKIC EYE
  19. 19. CONTACT TECHNIQUE
  20. 20. IMMERSION TECHNIQUE
  21. 21. Immersion B-scan/vector A-scan technique
  22. 22. Adjustments to UltraSound Velocity settings OCULAR MEDIA ULTRA SOUND VELOCITY THICKNESS CORRECTION FACTOR CORNEA 1641 M/SEC +0.55 +0.04 mm AQUEOUS 1532 M/SEC LENS 1628 + 4.72 +0.28 mm VITREOUS 1532 M/SEC TRUE AXIAL LENGTH = AAL 1532 + 0.04 mm + 0.28 mm = AAL 1532 + 0.32 mm
  23. 23. COMPARISON BETWEEN CONTACT TECHNIQUE AND IMMERSION TECHNIQUE OF BIOMETRY Contact technique Immersion technique Patient is in a more comfortable position, sitting Patient is in a supine or reclining position Variability from one test to next is present due inconsistent corneal compression No variability since probe does not come in contact with cornea Axial length measured is shorter by an average of 0.24 mm Axial length measured is closer to the true value
  24. 24. Limitations and Pitfalls • Multiple Artifacts • Attenuation Artifacts • Low reflective Spike • Small tumours with False Negatives • Intraocular foreign body • Contact technique problem • Misalignment
  25. 25. MISALIGNMENT SILICON OIL GLOBE

×