Doppler Instrumentation and Hemodynamics

Question 1

a misrepresnetation of the doppler shift in a negative direction occuring when the pulse repetition frequency is set to low

Answer 1

aliasing

Question 2

smallest arteries in the circulatory system controlling the needs of organs and tissues

Answer 2

arterioles

Question 3

pressure reduction in a region of high flow speed

Answer 3

bernoulli effect

Question 4

auscultatory sound within an artery produced by turbulent blood flow

Answer 4

bruit

Question 5

the smallest of the body’s blood vessels connecting the arteriolies and venules and allowing the interchange of oxygen or carbon dioxide and nutrients to the tissue cells

Answer 5

capillaries

Question 6

noise in the doppler signal caused by high amplitude doppler shifts

Answer 6

clutter

Question 7

observed frequency change of the reflected sound resulting from movement relative to the sound source or observer

Answer 7

doppler effect

Question 8

frequency shift created between the transmitted frequency and received frequency by an interface moving with velocity at an angle to the sound

Answer 8

doppler shift

Question 9

energy difference between two points

Answer 9

energy gradient

Question 10

to move in a stream, continually changing position and direction

Answer 10

flow

Question 11

electronic device controlling the transmission or reception of a doppler signal; size of the gate is determined by the beam diameter, reciever gate length, and length of ultasound pulse

Answer 11

gate

Question 12

twisting type of blood flow

Answer 12

helical flow

Question 13

science or physical principles concerned with the study of blood circulation

Answer 13

hemodynamics

Question 14

the perceived color; any one or a combination of primary colors

Answer 14

hue color map

Question 15

the pressure created in a fluid system, such as circulatory system; when supine, the hydrostatic pressure is 0 mmHg. when upright the pressure is negative above the heart and positive below the heart

Answer 15

hydrostatic pressure

Question 16

the resistance to acceleration

Answer 16

inertia

Question 17

consists of the arterioles, capillaries and venules

Answer 17

microcirculation

Question 18

the highest frequency in a samples signal represented unambiguously; equal to one half the pulse rep frequency

Answer 18

nyquist limit

Question 19

positioning of multiple pulsed doppler gates over the area of interest

Answer 19

packet

Question 20

maximum velocity at any given time

Answer 20

peak velocity

Question 21

speed is constant across the vessel

Answer 21

plug flow

Question 22

predits volume flow in a cyndrical vessel

Answer 22

poiseuille’s equation

Question 23

difference in pressure required for flow to occur

Answer 23

pressure gradiant

Question 24

a parameter used to convey the pulsatility of a time-varying waveform

Answer 24

pulsatility index

Question 25

predicts the onset of turbulent flow

Answer 25

reynolds number

Question 26

difference between the max and min doppler frequency shifts divided by the max doppler frequency shift; also known as pourcelot index

Answer 26

resistant index

Question 27

electronic device that controls the region of the doppler flow detection

Answer 27

sample volume

Question 28

degree to ehich the original color is diluted with white; the paler the color (or the less saturated it is), the faster the flow velocity; the purer the color, the slower the flow velocity

Answer 28

saturation color map

Question 29

increase in the range of doppler shift frequencies displayed resulting in a loss of spectral window; ususally seen with stenosis

Answer 29

spectral broadening

Question 30

amount of blood moving in a forward direction; blood being ejected

Answer 30

stroke volume

Question 31

the average velocity id calculated, with the colors placed side to side

Answer 31

variance mode

Question 32

rate of motion with respect to time

Answer 32

velocity

Question 33

all measured velocitied for each gate are averaged, then colors are arranged up and down

Answer 33

velocity mode

Question 34

the smallest veins that receive blood from capillaries and drain into larger caliber veins

Answer 34

venules

Question 35

the quantity of blood moving trough the vesssel per unit of time

Answer 35

volume flow rate

Question 36

types of arterial blood flow

Answer 36

``` laminar parabolic flow plug pulsatile disturbed turbulant ```

Question 37

types of venous flow

Answer 37

``` augmentation phasic proximal pressure spontaneous unidirectional ```