ULTRASONOGRAPHY

1. --MS. GEETASHREE MAJUMDAR
(Assist.Professor, Deptt of Radiology
&Imaging technology,RIMT UNIVERSITY)
(Bsc.Radiography and advanced imaging technology-
ADTU,Former CT technologist -Sualkuchi FRU hospital,
MSc.Radiation Imaging Technology-NIMS, Former Assist.
Professor-OM Sterling Global University)

2. WHAT IS SOUND ??????

3. a) Sound wave cosists of mechanical vibration
b) Sound is not electromagnetic .
c) Matter must be present for sound to travel

5. Categories of Sound-
A) infrasound
B) Audible Sound
C) Ultrasound

6. Ultrasound in diagnostic
Radiology:-

7. Imaging technology used to diagnose the internal
body structures by using high frequency sound
waves.
it does not use ionizing radiation.

9.  Piezoelectric effect
 Pulse echo principle

10.  This effect ws named "piezoelectricity" after
tge Greek piezein which means to squeeze or
press.
 The principle of converting energy by
applying pressure to a crystal. When an
electric voltage is applied to a transducer
crystal, the crystal gets excited and is
deformed.
 Piezoelectric effect explain how ultrasound
is generated from ceramic crystals in the
transducer. An electric current passes
through a cable to the transducer and is
applied to the crystal, causing them deform
and vibrate. This vibration produces the
ultrasound beam.

11.  It explain how the image is generated.
 Ultrasound waves are produced in pulses , not
continuously beacuse the same crystals are
used to generate and receive sound waves ,
they cannot do both at the same time.
 In the time between the pulses , the
ultrasound beam enter the patient and is
reflected back to the transducer.
 These reflected sound waves cause the crystals
in the transducer to deform again and
produced an electrical signal ,that is converted
into an image displayed on the monitor.
 The transducer generally emits ultrsound only
1% of the time , the rest of the time is spent
receiving the returning echoes.

12. What is piezoelectric crystal?
-lead zirconate titanate
(PZT)

13. Different parts of ultrasonic machine:

14. WHAT IS A TRANSDUCER???

16. Different types transducer

17.  Piezeolectric crystal arrangement is linear.
 The shape of the beam is rectangular.
 Near field resolution us good.
 The frequency , application depend on
wheather the product is for 2D And 3D
imaging .
 Linear transducer for 2D imaging:- frequency
2.5-12MHz. Application: blood vessels
visualization, breast , thyroid, tendon,
laproscopy.

18.  Tendon is a connective tissue which attaches
muscle to bone.
 Laproscopy is a type surgery that uses
smaller cut.(minimally invasive technque). A
slender tool that has a tinny video camera
and light on the end. When a surgeon insert
it through a small cut and into the patient
body , they can look at monitor.

19.  Linear transducer 3D Igmaing:- frequency
7.5-11MHz.
 Application- breast, thyroid.

20.  Also called curved transducer. Because the
piezeoelectric crystal arrangement is
curvillinear.
 The beam shape is convex and the
transducer is good for depth examination.
 Convex 2D imaging:- frequency-2.5 MHz-
7.5 MHz. Can be used for abdominal ,
transvaginal, transrectal examination.
 Convex 3D imaging:- 3.5- 6.5 MHz. used for
abdominal examination.
 **micro convex transducer is used for
pediatric***

21.  Frequency- 2-7.5 MHz.
 Can be used for cardiac examination ,
including transoesophageal examination ,
abdominal and brain examination.

22.  Also called CW doppler probe.
 Measure blood flow and Speed of sound in
blood.
 Uses low frequency- 2-8 MHz.

23.  Used for internal examination.
 Endovaginal, endo rectal and endocavity.
 Frequency- 3.5-11.5MHz.

24.  used in cardiology to obatin better image
of the heart .
 Frequency 3-10MHz.

25.  Produce electrical pulses that are applied
to the transducer.
 A rate if approximately 1000 pulses per
second.

26. Amplification is used to increase the
size of electrical pulses coming from the
transducer after an echo is received.

27. Controls the scanning of ultrasound
beam over the body section being
imaged.

28.  Convert Scanning ultrasound beam into a
digital image matrix format for processing

29.  gives specific contrast characteristics
and reformatting the image if necessary.

30.  Used to view the image.

31.  Contrast is the difference in density.
 Density is the amount of overall blackenning
ptoduced on the image after processing.
 Digital image is the numerical representation
of an image(a set of pixel)
 A matrix is a square arrangement of number
in column and rows.