resolution- week 6

there are 3 types of RESOLUTION:

- ____

- contrast

- temporal

- elevational*

detail

there are 3 types of RESOLUTION:

- detail

- ____

- temporal

- elevational*

contrast

there are 3 types of RESOLUTION:

- detail

- contrast

- ____

- elevational*

temporal

DETAIL RESOLUTION:

if ___ reflectors are not sufficiently separated, they will not produce separate reflections and not be separated on the display

2

DETAIL RESOLUTION:

if 2 reflectors are not __ __, they will not produce separate reflections and not be separated on the display

sufficiently separated

DETAIL RESOLUTION:

if 2 reflectors are not sufficiently separated, they will not __ __ __ and not be separated on the display

produce separate reflections

DETAIL RESOLUTION:

if 2 reflectors are not sufficiently separated, they will not produce separate reflections and not be __ __ __ __

separated on the display

2 types of DETAIL RESOLUTION:

- ____

- lateral

axial

2 types of DETAIL RESOLUTION:

- axial

- _____

lateral

both types of DETAIL RESOLUTION are dependent on ultrasound pulse characteristics as they travel through ___

- ex: SPL, wavelength, beam width

tissue

both types of DETAIL RESOLUTION are ____ on ultrasound pulse characteristics as they travel through tissue

- ex: SPL, wavelength, beam width

dependent

both types of DETAIL RESOLUTION are dependent on __ __ __ as they travel through tissue

- ex: SPL, wavelength, beam width

ultrasound pulse characteristics

AXIAL RESOLUTION:

the ____ reflector separation required along the direction of travel to produce separate echoes

minimum

AXIAL RESOLUTION:

the minimum reflector separation required along the __ __ __ to produce separate echoes

direction of travel

AXIAL RESOLUTION:

the minimum reflector separation required along the direction of travel to produce __ __

separate echoes

AXIAL RESOLUTION aka

- _____

- range

- depth

- "LARD"

longitudinal

AXIAL RESOLUTION aka

- longitudinal

- _______

- depth

- "LARD"

range

AXIAL RESOLUTION aka

- longitudinal

- range

- _____

- "LARD"

depth

AXIAL RESOLUTION aka

- longitudinal

- range

- depth

- "_____"

"LARD"

axial resolution (mm) =

½ SPL (mm)

AXIAL RESOLUTION: the ____ the number, the better the ____

smaller; quality

decreased SPL, decreased __ __ __ __ __ (quality improved)

# value of axial resolution

____ cycles per pulse, increase # value of axial resolution (quality degrades)

increase

decreased SPL, _____ # value of axial resolution (quality improved)

decreased

______ SPL, decreased # value of axial resolution (quality improved)

decreased

increase cycles per pulse, ____ # value of axial resolution (quality degrades)

increase

increase cycles per pulse, increase __ __ __ __ __ (quality degrades)

# value of axial resolution

•increased frequency, decreased __ __ __ __ __ (improves)

# value of axial resolution

*damping material improves axial resolution by decreasing __ __ __*

cycles per pulse

•increased frequency, ___ # value of axial resolution (improves)

decreased

•___ frequency, decreased # value of axial resolution (improves)

increased

*damping material improves axial resolution by ____ cycles per pulse*

decreasing

*damping material ____ axial resolution by decreasing cycles per pulse*

improves

SAMPLE QUESTION:

with a spatial pulse length of 0.4mm, find the axial resolution

- axial resolution = ½ SPL

- ½ (0.4mm) = .2mm

SAMPLE QUESTION:

if there are three cycles of 3mm l in a pulse, find the axial resolution

- SPL = #cycle per pulse x wavelength

- SPL = 3 x 3 mm = 9mm

- axial resolution = 4.5mm

SAMPLE QUESTION:

for a pulse traveling through soft tissue with a frequency of 5MHz and there are 2 cycles per pulse, find the axial resolution

- SPL = #cycles per pulse x l

- SPL = 2 x 1.54 mm/µs / 5 MHz

- SPL = .6 mm

- axial resolution = .3 mm

LATERAL RESOLUTION:

•the minimum reflector separation required perpendicular to the direction of sound travel, so that when the sound beam is scanned across them, two separate echoes are produced

LATERAL RESOLUTION:

•the _____ reflector separation required perpendicular to the direction of sound travel, so that when the sound beam is scanned across them, two separate echoes are produced

minimum

LATERAL RESOLUTION:

•the minimum reflector separation required _____ to the direction of sound travel, so that when the sound beam is scanned across them, two separate echoes are produced

perpendicular

LATERAL RESOLUTION:

•the minimum reflector separation required perpendicular to the direction of sound travel, so that when the sound beam is __ ___ ___, two separate echoes are produced

scanned across them

LATERAL RESOLUTION:

•the minimum reflector separation required perpendicular to the direction of sound travel, so that when the sound beam is scanned across them, ___ __ __ are produced

two separate echoes

LATERAL RESOLUTION

•aka

- ____

- transverse

- azimuthal

- "LATA"

angular

LATERAL RESOLUTION

•aka

- angular

- ____

- azimuthal

- "LATA"

transverse

LATERAL RESOLUTION

•aka

- angular

- transverse

- ___

- "LATA"

azimuthal

LATERAL RESOLUTION

•aka

- angular

- transverse

- azimuthal

- "____"

LATA

•lateral resolution (mm) =

beam width or diameter (mm)

____ beam width, decreased # value of lateral resolution (improves)

decreased

• __ focusing, increased # value of lateral resolution (improves)

increased

•___ frequency, decreased # value of lateral resolution (improves)

increased

•increased frequency, ___ # value of lateral resolution (improves)

decreased

•increased frequency, decreased __ __ __ __ __ (improves)

# value of lateral resolution

• increased focusing, __ # value of lateral resolution (improves)

increased

• increased focusing, increased __ __ __ __ __ (improves)

# value of lateral resolution

decreased beam width, _____ # value of lateral resolution (improves)

decreased

decreased beam width, decreased __ __ __ __ __ (improves)

# value of lateral resolution

LATERAL RESOLUTION SAMPLE QUESTION

•The NZL of an unfocused transducer system is 8 cm. The element diameter is 9 mm. What is the lateral resolution at a depth of 8 cm, 16 cm and 32 cm?

8cm LR=4.5mm

16cm LR=9mm

32cm LR=18mm

•___ and axial resolution are best in the focal region

lateral

•lateral and ___ resolution are best in the focal region

axial

•lateral and axial resolution are best in the __ __

focal region

__ ___ is usually better than lateral

- pulse is typically wider than tall

axial resolution

axial resolution is usually better than ____

- pulse is typically wider than tall

lateral

axial resolution is usually better than lateral

- pulse is typically ____ than tall

wider

axial resolution is usually better than lateral

- pulse is typically wider than ___

tall

both axial and lateral resolutions are usually better than what the system can ____

display

MULTIPLE FOCAL REGIONS

reminder-focusing the beam may be performed by

- curving the element

- using a lens

- phasing

MULTIPLE FOCAL REGIONS

reminder- __ __ __ may be performed by

- curving the element

- using a lens

- phasing

focusing the beam

MULTIPLE FOCAL REGIONS

reminder- focusing the beam may be performed by

- __ __ __

- using a lens

- phasing

curving the element

MULTIPLE FOCAL REGIONS

reminder- focusing the beam may be performed by

- curving the element

- __ __ __

- phasing

using a lens

MULTIPLE FOCAL REGIONS

reminder- focusing the beam may be performed by

- curving the element

- using a lens

- ____

phasing

multiple focus can be used to create a __ __ __

long focal region

___ ___ can be used to create a long focal region

multiple focus

each scan line or pulse can be focused at __ __ __

one depth only

only echoes from __ __ are imaged, all other echoes are thrown out

focal regions

each scan line or ___ can be focused at one depth only

pulse

each ____ ___ or pulse can be focused at one depth only

scan line

only echoes from focal regions are imaged, all other echoes are __ __

thrown out

need multiple ___ or pulses to create multiple focal regions

lines

multiple ____ or pulses take more time to create one image or frame

lines

need multiple lines or ___ to create multiple focal regions

pulses

need multiple lines or pulses to create multiple __ ___

focal regions

multiple lines or ___ take more time to create one image or frame

pulses

multiple lines or pulses take more time to create __ __ __ __

one image or frame

___ ___ slows down with multiple focal regions

frame rate

frame rate __ __ with multiple focal regions

slows down

frame rate slows down with multiple ___ ___

focal regions

__ __ can be obtained by using dynamic aperture

multi focus

multi focus can be obtained by using __ __

dynamic aperture

__ ___ means firing only inner elements of the group for a short focus and the outer elements for a deeper focus

DYNAMIC APERTURE

DYNAMIC APERTURE means firing only ___ ___ of the group for a short focus and the outer elements for a deeper focus

inner elements

DYNAMIC APERTURE means firing only inner elements of the group for a ___ ___ and the outer elements for a deeper focus

short focus

DYNAMIC APERTURE means firing only inner elements of the group for a short focus and the ___ ___ for a deeper focus

outer elements

DYNAMIC APERTURE means firing only inner elements of the group for a short focus and the outer elements for a __ __

deeper focus

DYNAMIC FOCUSING

process where an ___ ____ can listen for echoes within a focal region

array transducer

DYNAMIC FOCUSING

process where an array transducer can listen for____ within a focal region

echoes

DYNAMIC FOCUSING

process where an array transducer can listen for echoes within a ___ ___

focal region

DYNAMIC FOCUSING

not ___ ___, but a receiving focus

output focusing

DYNAMIC FOCUSING

not output focusing, but a __ __

receiving focus

DYNAMIC FOCUSING

this _____ ___ combined with single focus or multi focus greatly improves resolution at all depths

receiving focus

DYNAMIC FOCUSING

this receiving focus combined with ___ ___ or multi focus greatly improves resolution at all depths

single focus

DYNAMIC FOCUSING

this receiving focus combined with single focus or __ __ greatly improves resolution at all depths

multi focus