lesson 4 Flashcards
Provides the energy to treat tissue deep in the
body precisely and non-invasively by using ultrasonic energy to
target tissue deep in the body without incisions
or radiation
FOCUSED ULTRASOUND
- A minimally invasive medical procedure that uses ultrasound waves to treat certain conditions, such as tumors
- very high-intensity and highly focused sound waves interact with targeted
tissues in your body to modify or destroy them. - It is also used for skin tightening and is relatively new.
- doesn’t produce images
HIGH-INTENSITY FOCUSED ULTRASOUND (HIFU)
The ability of the ultrasound array to distinguish the space between two individual points. The ability to distinguish between distinct image points (reflectors) lying close to
each other.
SPATIAL or DETAIL RESOLUTION
The ability to see the two structures that are side by side as separate and distinct when parallel to the beam. So a higher frequency and short pulse length will provide a better
axial image.
AXIAL RESOLUTION
- is the ability to discern two closely spaced objects oriented perpendicular to the beam
- sometimes called Azimuthal Resolution
LATERAL RESOLUTION
receives the echoes and sends them to a computer that uses them to create a picture called a sonogram
transducer
Creates a narrow point in the cross-section of the ultrasound beam called the Focal Point
BEAM FOCUSING
Before the focal point is the BLANK, where beams converge
Near Field or Fresnel Zone
Distal to this focal point is the BLANK where beams diverge
Far Field or Fraunhofer Zone
The area beyond the near field where the ultrasonic
beam is more uniform is called the
Far Field
- The piezoelectric crystal arrangement is linear,
the shape of the beam is rectangular, and the
near-field resolution is good - for 2D imaging has a wide footprint and its central
frequency is 2.5Mhz -12Mhz
LINEAR TRANSDUCER/ HIGH FREQUENCY
PROBE
Part of the probe that is in contact with the
body and comes in different shapes and sizes
Footprint “Aperture”
- Also called the curved
transducer because the piezoelectric crystal arrangement is curvilinear. - The beam shape is
BLANK and the transducer is good for in-depth
examinations. - Its advantage is you can image an area larger than the footprint/transducer
itself because the sector gets wider as it
travels into the body
Curvilinear/CONVEX TRANSDUCERS
- It has a small footprint
and low frequency (its central frequency is 2Mhz – 7.5Mhz). The beam point is narrow but it expands depending on the applied
frequency. The beam shape is almost triangular and the near-field resolution is poor - Used in echocardiography
PHASED ARRAY TRANSDUCERS / SECTOR
PROBE
the echo transducer that produces the sound waves for BLANK is attached to a thin tube that passes
through the mouth, down the throat and into the esophagus. Because the esophagus is so close to the upper chambers of the heart
TEE PROBE
A probe that sends out high-energy sound waves is inserted into the rectum
TRANSRECTAL PROBE
- a procedure that provides a more detailed view of the pelvic organs
- monitor pregnancy
or plan for surgery
TRANSVAGINAL PROBE
- simplest type of ultrasound. A single
transducer scans a line through the body with the echoes plotted on screen as a function of depth. - allow for pinpoint accurate focus of the destructive wave energy
A-MODE (Amplitude Mode)
scans a plane through the body that can be viewed as a two-dimensional image on screen.
B-MODE or 2D MODE (Brightness Mode)
Pulses are emitted in quick succession – each time, either an A-mode or B-mode image is taken. Over time, this is analogous to recording a video in ultrasound
M-MODE or MOTION MODE
to see and evaluate blood flow through arteries and veins in the abdomen, arms, legs, neck and/or brain
DOPPLER “COLOR DOPPLER
ULTRASONOGRAPHY ”
