basics of bscan

1. B SCAN
Moderator :- Dr. Supreet Juneja Presentor:- Dr.Pushkar Dhir

2. D 4 CONCEPTS
1. How Bscan came into existence?
2. Concept of Frequency.
3. Concept of Gain.

3. ULTRASONOGRAPHY
• Non-invasive, efficient and inexpensive diagnostic tool.
• Examiner- dependent
• Expertise
• A correlation with clinical findings is essential to make a
diagnosis.
.

4. • 1793: Lazzaro Spallanzani (Italy) discovered that bats
orient themselves with the help of sound whistles while
flying in darkness. This was the basis of modern ultrasound
application

5. • 1956: Mundt and Hughes -
first used the A-scan technique.
• 1958: Baum and Greenwood
- B-scan (immersion method)
• 1962:Oksala and Lehtinen
further refined the technique
• In the sixties, imaging of the
eyeball and
orbit using ultrasound was
popularised by Ossoining.

6. Apna B Scan

7. INSTRUMENTATION
• An USG unit is composed of four basic elements :
– Pulser,
– Receiver
– Display screen
– Transducer

8. B SCAN CONTROL PANEL

9. USE OF INCREASING GAIN

10. Use of Decreasing Gain

11. PRINCIPLE OF
ULTRASOUND
VELOCITY REFLECTIVITY
ANGLE OF
INCIDENCE
ABSORPTION
•USG wave has a
frequency > 20 kHz.
•Wavelength α Depth
of penetration of the
ultrasound.
•Larger d frequency
= short wavelength
= shallow penetration
= better resolution
• Sound travels
faster through
solids than
liquids.
•Velocity of
sound wave is
depends on
the density of
the media .
•Vitreous 1532
m/s
•Cornea speed
of 1,641 m/s
• Greater the
density
difference at
interface,
stronger the
echo/higher the
reflectivity
• The stronger
the echo, the
higher the spike
•The stronger the
echo, the
brighter the dot.
• Perpendicular
d probe to the
area of interest,
=more of the
echo is reflected
directly back into
the probe tip.
= brighter d spot.
• More dense
the medium,
the greater the
amount of
absorption.
•B-scan should
be performed
on the open
eye unless the
patient is a
small child or
has an open
wound

12. PTR before doing Bscan
• For Best B scan results :-
– Put the Probe directly on globe ( improve resolution and
determine the patient gaze)
– Coupling jelly applied to probe tip
– In cases of suspected infection cover the probe tip with cling
film
– Clean the probe tip with alcohol wipe after every use.

13. REQUISITE 4 HIGH QUALITY
BSCAN
1. Lesion Must be Placed in the centre
2. Beam must be directed perpendicular to the surface
of interest
3. Lowest Possible decibel gain that is consistent with
adequate mantainence of intensity and resolution of
lesion.

14. ABOUT THE PROBE
• 1-5 MHZ = Abdominal USG
• 8-10 MHZ = Ophthalmic USG
• 50-100 MHZ = UBM

15. B Scan : Orientation & Labeling
1. Axial Section
2. Transverse Section
3. Longitudinal Section

29. Normal B-scan
• Cornea, AC and the anterior capsule-not easily visualised without immersion technique
• Lens –oval high reflective structure
• Vitreous- acoustically clear
• Retina, choroid and sclera-seen together as a high reflective structure
• Sclera – 100% reflective
• Optic nerve-wedge shaped acoustic void in retrobulbar space on axial scan
• Extraocular muscles-echolucent to low reflective fusiform orbital structures

30. Bscan in Various Pathologies

31. TOPOGRAPHIC
EXAMn.
SHAPE
LOCATION
EXTENSION
KINETIC
EXAMn.
MOBILITY
AFTER
MOBILITY
VASCULARITY
QUANTITATIVE
EXAMn.
REFLECTIVITY
(SPIKE Ht. &
PEAKS)
TEXTURE
SOUND
ATTENUATION

32. PVD
RETINA
DETACHMENT
CHOROID
DETACHMENT
SHAPE Linear
LOCATION
ATTCH. TO ON Variable Yes No
OTHER Thicker inferiorly Folds/Breaks Vortex Vein
SPIKE HT. 40-90% 80-100% 90-100%
SPIKE PEAKS Single Single
Double / M shape
peak
MOBILITY
Marked (Hammock
like)
Moderate Minimal
AFTER MOVMT. Marked
Moderate to
severe
Absent

44. References
• Most of the photographs and pics hav been
taken from Textbook of Ophthalmic
Ultrasound by Hatem R. Aata WITHOUT
PRIOR PERMISSION.

45. Correlation with clinical findings is
essential to make a diagnosis 

46. “ Thank you for listening B scan”
• THANK YOU EVERYONE FOR PATIENTLY LISTENING TO THIS SEMINAR.
• For feedbacks & brickbats plz mail at
• ykush@yahoo.co.in./drdhir2014@gmail.com