Radiological imaging ultrasound

1. ULTRASOUND

2. DEFINITION
it is a method for examination of a wide range of
clinical problems like abdominal mass,hepatic,
pancreatic,aortic,biliary,urinary tract and gynecological
diseases..it is also helpful in the diagnosis of disease
of small parts of body like thyroid,testes and breast.

3. ADVANTAGES
non invasive
painless
inexpensive
no radiation risks

4. INDICATIONS:
Vaginal bleeding, pelvic pain, or any concern for an ectopic
pregnancy.
To confirm intrauterine gestation and cardiac activity and to
estimate gestational age.
To evaluate pelvic or uterine masses

5. DISADVANTAGES
.operator dependant
.long learning curve
.interpretation only possible during examination
.resolution dependant

7. MECHANISM OF
ACTION
Transducer probe is main part of machine.
Its Role:transducer probe makes the sound waves and receive the echos it is so to speak,the mouth and ears of the ultrasound machine.High
frequency sound waves are directed into the body generated by transducer.As sound travels through the body,it is reflected by the tissue interface
to produce echo which are picked up by same transducer and are converted into electrical signals and these signals are converted into an image..
Frequency range : 3-20 MHz
(higher the frequency of ultrasound wave,the greater the resolution of
the image,but the less depth of viee from the skin)
5-10MHz is used for superficial
structures such as muscles,breast,and
testis.

8. TYPES OF
ULTRASOUND
B Scan (brightness scan)
it is ultrasound of eye ball /orbit with high frequency(10-15MHz).it is used to determine retinal'detachments,vitreous haemorrhge),
localizes foreign bodies.
Method :main method is contact method with patient lying supine,and transducer
placed directly on the closed eyelid with an intervening coupling gel.
since air,bone and other heavily calcified
materials absorb nearly all ultrasound
beams

9. DOPPLER UlTRASOUND
Reflection of ultrasound wave from moving objects such as red blood cells
cayse a change in frequency of ultrasound waves.by measuring frequency
change,we calculate speed and direction of movement of blood.this principle
form basis of doppler ultrasound..whereas velocities within major vessels can
be measured.it is widely uses in assesment of arterial and venous disease in
which stenotic lession cause an alteration in normal velocity..

10. doppler
ultrasound
image of
heart(chest)

11. LIMITATIONS
it is not used used for:
bowel,intestinal gas,deeper structures such
as pancreas and aorta.
It is also not used for obese patients.

12. CONTRAINDICATIONS
Infection, stone burden greater than 2.5 cm; coagulopathies,
untreated hypertension, pregnancy-ESWL.
MRgUS - Cardiac pacemaker or other implantable devices.
Ultrasound diathermy - Bone fracture, malignancy, arteriosclerosis,
application to eye, spine, active infection or ischemic tissues.

13. THANKS
By Dr.Maria Aslam