How can you fix ghosting and clutter?

(a)  

• “Mirror Image”.

• Spectral Doppler above and below the baseline.

• Insonation angle near 90 degrees and flow at the beam focus.

Spectral analysis displays all the doppler shift frequencies detected from moving at different (a)  

(a)   is used with pulse and continuous doppler that is accurate and displays all components

(a)   is used with color doppler which is less accurate than FFT and is faster than FFT

The (a)   represents intravascular variation in blood flow

The (a)   of the spectral line represents the range of velocities in a vessel

The width of the spectral line may vary during the normal cardiac cycle narrowing during __ and __ during diastole

(a)  

(a)   consists of a wide range of velocities includes reversed flow components and is readily appreciated

Fill in of the window associated with turbulence

(a)  

This shows

(a)  

Turbulent flow is visible as (a)  

The (a)   is a quantitive, doppler derived measurement

Resistive index reflects the vascular (a)   of a vessel

RI = (PSV-EDV)/PSV

(a)  

The (a)   is quantitve and is where MV is the mean flow velocity during the cardiac cycle

PI = (PSV-EDV)/MV

(a)  

Artifacts are (a)   representations of anatomy or motion caused by some problematic aspect of the imaging technique

(a)   are incorrect representations of anatomy or motion caused by some problematic aspect of the imaging technique

Artifacts are representations that are __ __

(a)  

Artifacts are representations that are (a)  

Artifacts are representations that are

(a)  

Artifacts are representations that are

(a)  

Ultrasound displays rely on (a)   to assign the location and intensity of each echo

Assumptions can cause artifacts when assumed conditions are (a)  

Sound travels at 1540m/s

(a)  

Sound beam travels directly to a reflector and back

(a)  

Sound travels in a straight line

(a)  

All sound attenuation exactly 0.5 db/cm/MHz

(a)  

Reflections arise only from structures positioned in the beams main axis

(a)  

The strength of a reflection is related to the characteristics of the tissue creating the reflection

(a)  

• The depth of an object is directly related to the amount of time for an ultrasound pulse to return to the transducer as an echo,

Axial and lateral resolution are (a)   artifacts

Grating and side lobe are (a)   artifacts

Mirror image, comet tail, and ring down are (a)   artifacts

Range ambiguity and refraction are (a)   artifacts

Section thickness, speckles, and ring down are (a)   artifacts

Enhancement/Focal enhancement, and shadowing/edge shadow are (a)   artifacts

(a)   is multiple equally spaced echoes caused by the BOUNCING of echoes BETWEEN strong reflectors

With reverberation, echoes are placed (a)   the real reflector

Reverbation artifacts are (a)   to the main axis

This image shows

(a)  

(a)   is associated with the assumption: sound travels directly to a reflector and back

The (a)   artifact is a form of reverberation that includes close spaced, discrete echoes

Comet tail is a hyperechoic line (a)  

(a)   is created by strong reflectors like surgical clips

The arrows are pointing to (a)   artifact

The (a)   artifact includes closed spaced, discrete echoes that CANNOT be separated

Hyperechoic line downward that is created by (a)   artifact

Ring down artifacts are created by gas bubbles are are (a)   to sound beams main axis

This image shows:

(a)  

This diagram is an example of the (a)   artifact

Shows structures that are on one side of a strong reflector as being present on the other side as well describes the (a)   artifact

With mirror image artifacts the artifact will appear (a)   than the real structure

In a mirror image, the strong reflector lies on a (a)   between the transducer and artifact

This image shows the (a)   artifact

The assumption that is correlated with (a)   is: sound travels in a straight line AND sound travels directly to a reflector and back

This image shows:

(a)  

This image shows:

(a)  

The echoes from the deeper reflective interface take longer to return to the transducer and are misplaced on the display

(a)  

(a)   are beams propagating from a single element in different directions from the primary beam

Side lobes are created by (a)   transducers

(a)   are additional beams emitted from an array transducer

Side and grating lobes are (a)   than the primary beam unless they hit a strong reflector

Lobe artifacts (a)   LATA

Dividing each PZT element into a small piece =

(a)  

Differential excitation = A

(a)  

A (a)   artifact is present in this image

This diagram displays (a)   artifact

(a)   artifact displaces reflectors laterally from their original location

(a)   could occur with a change of velocity when beam travels through tissues with different density and elastic properties

When refraction occurs, the incident beam changes (a)   .

Refraction is described by (a)  

With refraction, the object in the path of the refracted portion is misplaced bc the processor assumes:

(a)  

This image shows the (a)   artifact

Refraction artifacts affect the (a)   resolution

(a)   artifacts appear to be side by side of the same reflector

Refraction can cause the artifacts to be positioned (a)  

(a)   occurs when a sound wave travels at a speed other than 1540 m/s

When the assumed speed of 1.54 mm/us is incorrect, the 13 us/cm rule is ALSO incorrect

(a)  

When the medium has a (a)   speed of sound, the distance to the reflector will be smaller and the reflector will be TOO close to the transducer

When the speed of sound is (a)   in a medium the reflector will be located far away from the transducer

Sound travels at a speed of exactly 1.54 mm/us

(a)  

The arrow in this image is pointing to

(a)  

This image includes a (a)   artifact

(a)   describes artifactual images from above or below the assumed plane of scanning

Section thickness is related to the (a)   of the beam (perpendicular to the scan plane)

(a)   artifacts fill in anechoic structures

the assumption for (a)   is that the scan plane is very thin

(a)   is reduced by thinner planes (1 and 1 half transducer array)

This image shows (a)  

With a (a)   artifact, the texture seen on image may not correspond to the tissues texture

Speckle results from (a)   effects between multiple reflectors received simultaneously which can add together

(a)   is noise resulting from the constructive and destructive interference of small sound wavelets

This image includes the (a)   artifact

The (a)   artifact is when the beam is wider than separation between two reflectors positioned side by side

With LATA, two reflectors show as (a)  

The (a)   artifact is LEAST likely at the focus of the beam

This artifact occurs when two reflectors are close together in the main axis of the beam and the pulse is long

(a)  

With axial resolution only (a)   reflection will show

(a)   frequency transducers improve axial resolution artifact

When the ultrasound beam encounters a focal point lateral that attenuates sound to a greater or lesser extent than the surrounding tissue

(a)  

The strength of the beam distal to this structure will be either weaker or stronger than the surrounding field

(a)  

This image shows:

(a)  

The assumption that the intensity of a reflection is related to the tissue creating the reflection is invalid with ALL (a)   artifacts

Hypoechoic region arising from the border of a curve structure

(a)  

Shadow by "refraction" refers to

(a)  

This image shows:

(a)  

Occurs when the ultrasound beam encounters a focal weakly attenuating structure within the imaging field

(a)  

Regarding enhancement, the amplitude of the beam beyond this structure is (a)   than the beam amplitude at the same depth in the rest of the field

This image shows

(a)  

(a)   involves side to side regions being brighter than tissues at other depths. Appears as a line across the screen (almost like a TGC was increased in only 1 spot)

This image shows:

(a)