Chapter 3 Flashcards
What is sound?
A form of energy
How does sound travel?
In waves
What does traveling sound require?
A medium (solid, liquid or gas)
Speed of sound in air
330 m/s
Speed of sound in lungs
500 m/s
Speed of sound in fat
1,450 m/s
Speed of sound in soft tissue (average)
1,540 m/s
Speed of sound in the liver
1,560 m/s
Speed of sound in blood
1,560 m/s
Speed of sound in muscles
1,600 m/s
Speed of sound in tendons
1,700 m/s
Speed of sound in bones
3,500 m/s
Sound travels _____ in solids, _____ in liquids, and _____ in gases.
- fastest
- slower
- slowest
What is ultrasound gel and it’s purpose?
Coupling gel:
removes the air from the path of ultrasound; sound can be transmitted into the tissue
Who are the 5 “ultrasound forefathers”?
Aristotle
Boethius
DaVinci
Galileo
Doppler
What did Aristotle discover?
350 BC - sound is carried to the ears by the movement of air (sound propagation)
What did Boethius discover?
524 AD - pebble theory; waves
What did DaVinci discover?
1500 AD - angle of reflection = angle of incidence
What did Galileo discover?
1638 - frequency determines pitch
What did Doppler discover?
1842 - pitch varies if source is moving
Who is the “Father of Ultrasound” and what did he discover?
Spallanzani; pulse echo location
What is audio ultrasound?
Sound that you can hear
What is color ultrasound?
Qualitative assessment of blood flow
What is spectral ultrasound?
Measurement of audio (until you hit the “freeze” button)
What is the piezoelectric effect?
Converts sound into electricity and electricity into sound.
What is inside the transducer?
crystals
What is pulse-echo technique?
Ultrasound is pulsed; transmit and recieve
3 imaging modes
A-mode, B-mode, M-mode
What is A-mode?
Amplitude mode
x-axis: location; depth of the returning echo
y-axis: height; strength of the reflector
What is B-mode?
Brightness mode; grayscale imaging
(anechoic, hypoechoic, hyperechoic)
What is M-mode?
Motion mode; captures the movement of structures along a single scan line represented over time
x-axis: time
y-axis: depth
Real time scanners: Krause and Soldner
If you have more than 1 crystal in the transducer you can create real time ultrasound
Define continuous wave doppler
2 crystals; one is sending and one is receiving constantly; transducer is always moving
ex: searching for fetal heart tones
Define pulse wave doppler
1 crystal; depth discrimination, choose the depth you want to sample
Define color power
Uses amplitude; is sensitive to slow, tiny vessels
does not show direction like “color”
What is tissue harmonic imaging
Harmonics are additional frequencies; the higher the frequency the better the resolution
Sonography specialities
Abdominal (small parts), Pediatric (neurosonography), OB/Gyn, Breast, Musculoskeletal, Vascular and Cardiac (echo)
List the parts in abdominal sonography
-Gallbladder
-Urinary bladder
-Kidneys
-Liver
-Pancreas
-Spleen
-Appendix
-Biliary Tree
-Major Abdominal Vessels (Aorta and Inferior Vena Cava)
-Abdominal wall, bowel, disphragm
-Interventional Procedures
List the parts in small parts sonography
-Thyroid
-Parathyroid
-Breast
-Testicular/Scrotal
-Prostate (performed transrectal)
-Superficial lesions/masses
-Interventional Procedures
List the parts in pediatric sonography
-Neurosonography (neonatal brain, infant spine)
-GI (pylorus, colon, appendix)
List the parts in OB 1st trimester sonography
13 weeks and 6 days
Performed intravaginal - most accurate for dating
-Gestational Sac
-Yolk Sac
-Embryo
-Cervix
-Uterus
-Ovaries
-Adnexa
-Interventional Procedures
List the parts in OB 2nd/3rd trimester sonography
Performed transabdominal
20 week anatomy scan
-Cervix (done transvaginal or translabial if necessary)
-Placenta
-Fetus
-Interventional Procedures
List the parts in Gynecology sonography
-Vaginal Canal
-Cervix
-Uterus (endometrium)
-Ovaries
-Adnexa
-Fallopian Tubes (only seen if fluid/pus filled)
-Cul-De-Sac
-Interventional Procedures
What is Therapeutic Ultrasound?
Used to increase blood supply to certain areas by heating the tissue to reduce healing time
What is High-Intensity Focused Ultrasound?
HIFU-Destroys tissues such as fibroids or tumors
What is Contrast-Enhanced Ultrasound?
Enhances the echogenicity of vessels and improves border recognition
What is Ultrasound-Guided Brachytherapy?
Uses ultrasound guidance to treat cancers with radioactive material
What is Ultrasound Elastography?
Evaluates a mass based on stiffness to predict if the mass is malignant or benign
What is Fusion Imaging?
Allows the ultrasound machine to communicate with the PACS system to call up previous MRI or CT Scans
What is Intravascular Ultrasound?
Uses a miniature probe to scan the circulatory system
What is Automated Ultrasound?
Steered by a computer system
What is Focused Assessment with Sonography for Trauma? (FAST)
Offers the E.R. physician a quick and sensitive method of diagnosing abdominal trauma
What is Minitaurization?
Miniaturization of equipment has lead to higher-definition monitors and smaller computer system housing
What is Wireless Technology?
Allows the transducer to communicate with the ultrasound machine without a cord getting in the way
Who is Robert Boyle?
He determined that sounds requires a medium to travel through
What are other names for power doppler?
Color Doppler energy or power angio
