A.eliwa US physics

1. BASIC UROLOGIC US
Ahmed Eliwa

3.  Why you need it ?
 How you are going to use it?

4.  surgeon-performed ultrasound has become one of the most
integral parts of the surgeon’s clinical practice.
 Because surgeons are highly motivated to provide the best
possible care for their patients, including the use of the latest
technologic advances in diagnosis and treatment.
 Ultrasound equipment is compact, affordable and user-
friendly so that extensive training is not required to master
focused ultrasound techniques.
 Cost containment initiatives by patients, clinicians and third-
party payers have encouraged the use of modalities, such as
ultrasound, that save time and money

6. Basic ultrasound physics
 The piezoelectric effect
 The pulse-echo principle
 Acoustic impedance

7.  The term SONAR refers to Sound
Navigation and Ranging. Ultrasound
scanners can be regarded as a form of
'medical' Sonar.

8.  Karl Theo Dussik, a neurologist/ psychiatrist at
the University of Vienna, Austria, who had begun
experiments in the late 1930s, was generallly
regarded as the first physician to have employed
ultrasound in medical diagnosis.

9.  H Gohr and Th. Wedekind at the Medical
University of Koln in Germany in 1940 presented
in their paper "Der Ultraschall in der Medizin"
the possibility of ultrasonic diagnosis basing on
echo-reflection methods similar to that used in
metal flaw detection.
 They suggested that the method would be able to
detect tumours, exudates or abscesses. However
they were unable to publish convincing results
from their experiments.

10. Types of ultrasound
 Conventional grayscale (B-mode)
 Doppler ultrasound

11. Ultrasound Physics

12. frequency
1 cycle in 1 second = 1Hz
1 second
= 1 Hertz

13. High Frequency
 High frequency (5-10 MHz)
greater resolution
less penetration
 Shallow structures
vascular, abscess, t/v gyn,
testicular

14. Low Frequency
 Low frequency (2-3.5 MHz)
greater penetration
less resolution
 Deep structures
Aorta, t/a gyn, card, gb, renal

15. Image properties
 Echogenicity- amount of energy reflected
back from tissue interface
 Hyperechoic - greatest intensity - white
 Anechoic - no signal - black
 Hypoechoic – Intermediate - shades of gray

16. Hyperechoic
Hypoechoic
Anechoic

21. Urologic US
 Urinary US
 Genital US
 Use in the Operation Room

37. Unlike the left kidney, the right kidney is readily scanned
from the anterior aspect by using the liver as an acoustic
window.

38.  The liver serves as an acoustic window for scanning the
right kidney
 The central echo complex of the kidney is a summation
effect produced by the pyelocaliceal system, blood
vessels, lymphatics, fatty tissue, and the renal sinus

40.  There is no good acoustic window
available for scanning the left kidney

52.  Is there hydronephrosis?
 Unilateral or bilateral?
 Is there fluid around the kidney?
 Is the bladder distended?
 Are stones seen?

65. THANK YOU