Ultrasound Physics
_____________ Is the ability to create accurate images. - ANSWER-Resolution
T/F
Axial Res. is the ability to distinctly identify 2 structures that are very close together side
by side. - ANSWER-False
_______________________ measures the ability of a system to display 2 structures
that are very close together when structures are parallel to the beam. - ANSWER-Axial
Resolution
____________ Refers to accuracy in imaging. - ANSWER-Resolution
The minimum distance that two structures positioned front-to-back can be apart & still
produce two distinct echoes is termed what? - ANSWER-Axial Resolution
LARRD stands for
A) Longitudinal, Azimuthal, Range, Radial, Depth
B) Lens, Angular, Range, Radial, Depth
C) Lateral, Angular, Range, Radial, Depth
D) Longitudinal, Axial, Range, Radial, Depth - ANSWER-D) Longitudinal, Axial, Range,
Radial, Depth
T/F
Longer pulses improve axial resolution? - ANSWER-False ( Shorter pulses do)
When structures aren't back to front but side to side, that is termed: - ANSWER-Lateral
Resolution
The Units for Lateral Resolution are:
A) mm only
B) cm
C) cm3
D) cm2
E) W/cm2 - ANSWER-B) cm ( so is A but remember that Axial and Lat. can be ANY unit
of distance)
The UNITS for Axial Res. is/are:
A) mm
B) cm
C) Watts
D) Any other unit of distance - ANSWER-D) Any other unit of distance
, T/F
Axial Resolution is determined by the width of the beam - ANSWER-False, That is
Lateral Resolution
T/F
In Lateral Res., Narrower beams have better resolution - ANSWER-True
What material within the TRNSD. helps shorten the pulses?
A) Backing Material
B) Matching Layer
C) Crystal Itself
D) None of the above - ANSWER-A) Backing Material
T/F
Lateral Res. changes with depth? - ANSWER-True
Name the synonyms for Lateral Resolution: - ANSWER-LATA
Lateral, Angular, Transverse, Azumithal
Resolution is related to.....
A) Spatial Pulse Length
B) Number of cycles / sec.
C) Pulse Duration
D) Period - ANSWER-A) Spatial Pulse Length
Name the 5 other synonyms for Axial Res. - ANSWER-LARRD
Longitudinal, Axial, Range, Radial & Depth
T/F
Axial resolution is BEST at the focus - ANSWER-False, Lateral Res. is best @ the focus
Can we as Sonographers adjust the Spatial Pulse length? Yes or no? describe why. -
ANSWER-No, the SPL is fixed, something we can't adjust on the machine or the
TRNSD.
In clinical imaging, Typical Values are:
A) 0.1-1.0mm
B) 2.5-4.0mm
C) 1.0-1.5mm
D)0.1-1.5cm - ANSWER-A) 0.1-1.0mm
Which resolution is best in clinical imaging, Axial or Lateral resolution? - ANSWER-Axial