Module 1 : History of Ultrasound

Question 1

infrasound range

Answer 1

below 20 Hz

Question 2

audible sound range

Answer 2

20 - 20000Hz (20kHz)

Question 3

ultrasound range

Answer 3

above 20000 Hz

Question 4

diagnostic medical sonography range

Answer 4

1-30 MHz

Question 5

therapeutic ultrasound range

Answer 5

1 - 3 MHz

Question 6

what year did the currie brothers discover the piezoelectric effect

Answer 6

1880

Question 7

piezoelectric effect

Answer 7

applying pressure waves to a quartz crystal caused electrical pulses (voltage)

Question 8

A Mode ultrasound was first used for what

Answer 8

used as a metal flaw detector then to see a brain tumor

Question 9

what does the A in A mode stand for

Answer 9

A = amplitude

Question 10

A Mode led to the development of what other mode of ultrasound

Answer 10

M Mode

Question 11

who is Ian Donald and what measurement did he develop

Answer 11

• Father of Obstetrical ultrasound

- biparietal diameter measurement BPD

Question 12

real time scanning is also called

Answer 12

dynamic scanning

Question 13

how real time scanning is accomplished

Answer 13

a single frame is created several times per second to give the appearance of movement

Question 14

ultrasound modes

Answer 14

• A Mode
• B Mode
• Real time Mode
• M Mode
• Doppler ( spectral and color )
• 3D 4D

Question 15

characteristics of A Mode scanning

Answer 15

• most basic form
• distance between transducer and a structure determines where an echo is seen along the time axis
• a spike is produced according to an amplitude (strength) of echo

Question 16

characteristics of B Mode scanning

Answer 16

• B = brightness
• method of displaying intensity of an echo by varying the brightness of a dot to correspond to strength
• each bright dot represents an echo intensity and location
• compounding the dots results in a 2D image

Question 17

Bi-stable imaging

Answer 17

• a B-mode image represented by either a black dot or a white dot
• crappy for tissue differentiation but good contrast

Question 18

gray scale imaging

Answer 18

• B Mode image that has many shades of gray

- uses a scan converter

Question 19

characteristics of real time scanning

Answer 19

• B Mode pictures captured at a rate fast enough to mimc physiological imaging
• probe is firing and listening constantly

Question 20

characteristics of M Mode scanning

Answer 20

• M = motion

- series of B Mode dots displayed on a moving time base the motion of a mobile structure can be seen

Question 21

characteristics of doppler imaging

Answer 21

using the doppler equation the velocity of blood flow or frequency of blood is determined

Question 22

static scanning

Answer 22

• term used after real time invented

- static scan = b scan = articulated arm scan

Question 23

contact scanning

Answer 23

describes transition from having patients in water bath to having transducer touch the patient