ULTRASOUND Flashcards
Resistance of sound as it propagates through a medium.
acoustic impedance
The ability of sonography to visualize a particular area, such as using a full urinary bladder to image the uterus.
acoustic window
Property of being free of echoes.
anechoic
The angle at which the ultrasound beam strikes an interface with respect to normal incidence.
angle of incidence
The ratio of ankle pressure to brachial pressure to determine the degree of lower extremity disability.
Ankle/Brachial Index (ABI)
The weakening of the sound wave as it propagates through a medium.
attenuation
The ability to distinguish two structures along a path parallel to the sound beam.
axial resolution
The largest dimension of the fetal head perpendicular to the midsagittal plane, used to measure fetal development
biparietal diameter (BPD)
A technique that assigns a color to each velocity frequency change in an ultrasound image.
color flow Doppler
What does “complex” mean in ultrasound?
A structure containing both anechoic and echogenic areas.
wave in which cycles repeat indefinitely, using separate transmit and receiver transducers.
continuous wave
What is the coronal image plane?
A plane perpendicular to the sagittal and transverse planes of the body.
What is the Doppler Effect in ultrasound?
A shift in frequency or wavelength caused by relative motion between the source, receiver, and medium.
What is duplex imaging?
The combination of gray-scale real-time imaging and color or spectral Doppler.
What does echogenic mean?
Refers to a medium that contains echo-producing structures.
Define embryo.
Term for the developing zygote through the 10th week of gestation.
What is the endometrium?
The inner layer of the uterine canal.
What is an endorectal transducer?
A high-frequency transducer inserted into the rectum to visualize the bladder and prostate gland.
What is an endovaginal transducer?
A high-frequency transducer inserted into the vagina to obtain high-resolution images of pelvic structures.
What is the false pelvis?
The region above the pelvic brim.
Term for the developing embryo from the 11th gestational week until birth.
fetus
A functional ovulatory cyst consisting of an ovum surrounded by a layer of cells.
follicular cyst
The length of time calculated from the first day of the last menstrual period.
gestational age
A fluid-filled structure in the uterus containing the pregnancy.
gestational sac
The range of amplitude (brightness) between black and white.
gray scale
What does heterogeneous mean?
Having a mixed composition.
Define homogeneous.
Having a uniform composition.
Producing more echoes than normal.
hyperechoic
What does hypoechoic mean?
Producing fewer echoes than normal.
The inner layer of a vessel.
intima
A bony ridge dividing the true and false pelvis.
iliopectineal line
Damage to the cardiac myocardium caused by disruption of the coronary artery blood supply.
ischemia
What does isoechoic mean?
Having a texture nearly the same as the surrounding tissue.
The ability to distinguish two structures lying perpendicular to the sound beam.
lateral resolution
What is leiomyoma?
The most common benign tumor of the uterine myometrium.
Define myometrium.
The thick layer of the uterine wall.
What is a non-invasive technique?
A procedure that does not require breaking the skin or entering an organ.
Define oblique plane.
Any plane that is not at a right angle to an axis.
What is parenchyma?
The functional tissue of an organ or gland.
What is the piezoelectric effect?
The conversion of pressure to electrical voltage or vice versa.
Normal venous respiratory variations.
phasic flow
What is posterior acoustic enhancement?
Increased reflection amplitude behind a weakly attenuating structure.
What is posterior acoustic shadowing?
Reduced reflection amplitude behind a strongly reflecting or attenuating structure.
Uses a transducer to emit short pulses of sound and receive reflections before emitting another pulse.
pulse wave ultrasound
Imaging with a rapid frame rate to visualize moving structures continuously.
real-time imaging
The redirection of part of the sound beam back to the transducer.
reflection
The bending of wavefronts as sound propagates through media of different acoustic velocities.
refraction
The area posterior to the peritoneal cavity, containing organs like the kidneys and adrenal glands.
retroperitoneal cavity
A pelvic space located anterior to the rectum and posterior to the uterus.
pouch of Douglas
The diffusion of sound in several directions upon encountering a rough surface.
scattering
A device used to discover underwater objects and determine their location.
sonar
Longitudinal mechanical energy propagated through a medium.
sound wave
Define transducer.
A device that converts energy from one form to another.
What is ultrasound?
Sound with a frequency greater than 20 kHz.
What is the velocity of sound?
The speed and direction of sound propagation through a medium.
Who developed the first ultrasound scanner?
Howry in 1948.
What did Hertz and Edler achieve in 1954?
They developed echocardiographic techniques.
Who built the early obstetric scanner in 1957?
Brown and Donald.
What significant development in ultrasound occurred in the 1970s?
Gray scale imaging and real-time scanning systems were introduced.
What type of energy is sound classified as, and can it travel through a vacuum?
Sound is a mechanical energy, and it cannot travel through a vacuum.
What is the frequency range of ultrasound?
Ultrasound has a frequency above 20,000 Hz (20 kHz) and is inaudible to humans.
What are the three main types of ultrasound waves?
Longitudinal/Compression waves, Transverse/Shear waves, and Surface/Rayleigh waves.
What is the function of piezoelectric crystals in ultrasound?
They generate ultrasound waves and convert electrical signals into mechanical waves and vice versa.
What is A-mode in ultrasound?
Echoes are shown as peaks to measure the distance between structures. Used to build B-mode images.
What is the Doppler effect in ultrasound?
It describes the change in frequency of a wave due to relative motion between the source and observer.
What are the two basic types of Doppler ultrasound units?
Continuous Wave Doppler (no depth resolution) and Pulsed Wave Doppler (good depth resolution).
How is wavelength related to frequency in ultrasound?
Wavelength is inversely proportional to frequency.
What are acoustic impedance?
Acoustic impedance describes particle behavior under pressure.
What is the purpose of the time-gain compensation (TGC) amplifier in ultrasound?
To compensate for ultrasound attenuation and improve image quality.
What type of transducer is best for obstetric ultrasound during early pregnancy?
A linear or convex transducer with 5.0 MHz focused at 7-9 cm.
What are the two regions of the ultrasound beam?
Near field (Fresnel zone) and Far field (Fraunhofer zone).
What is temporal resolution in ultrasound?
The system’s ability to display time-separated events as distinct images. Higher frame rate improves it.
What is the main cause of reverberation artifact?
False echoes caused by repeated reflections between two high impedance mismatch interfaces.
When was the Doppler technique introduced in ultrasound?
The Doppler technique was introduced in the 1980s.
What is the frequency range of audible sound for humans?
16 Hz to 20,000 Hz.
sound with a frequency below 16 Hz.
infrasound
What is the pulse duration and repetition rate for ultrasound pulses?
Pulse duration: 1 microsecond; Pulse repetition: 1000 times per second.
Name the three acoustic variables in ultrasound.
Period (T), Wavelength (λ), and Amplitude (Depth).
What happens with a small diameter piezoelectric crystal in ultrasound?
It increases beam divergence.
It depicts two-dimensional images using dots of different brightness for echo amplitude.
B-mode imaging
It shows movement as a function of time, particularly in cardiac scanning.
M-mode
What is the primary limitation of Continuous Wave Doppler ultrasound?
It has no depth resolution.
What is the average propagation speed of ultrasound in soft tissue?
1540 m/s.
reduces beam width and improve image resolution.
acoustic lenses
Name a synthetic piezoelectric material commonly used in ultrasound.
Lead zirconate titanate (PZT).
What does a high acoustic impedance indicate about a substance?
It indicates high density and a greater resistance to ultrasound waves.
What is the approximate acoustic impedance of bone?
7.80 rayls.
How does a wide bandwidth benefit ultrasound imaging?
It shortens spatial pulse length and provides a wider range of frequencies.
What transducer type is most useful for abdominal and obstetric scanning?
Sector/Curvilinear Array Transducer.
What is the role of backing or damping material in transducers?
It shortens ultrasound pulse length, controls vibrations, and improves axial resolution.
How does beam intensity relate to ultrasound imaging?
Beam intensity is the power flowing through a unit area, affecting image quality.
What causes side lobe artifacts in ultrasound imaging?
Echoes generated by side lobes are assumed to originate from the main beam axis.
What is the best method to eliminate reverberation artifacts?
Increase the amount of gel, use a stand-off pad, or reposition the transducer.
It provides a wide field of view and is useful for cardiac and cranial ultrasound.
phased array transducer
What determines the axial resolution in ultrasound?
The spatial pulse length and wavelength
What happens when ultrasound interacts with a large structure of differing impedance?
Reflection occurs, resulting in echoes.
What is acoustic enhancement, and where is it observed?
It is a bright area seen distal to weakly attenuating structures like fluid-filled cysts.
How heavy is the liver?
1.6 kg in males, 1.4 kg in females
What are the liver divisions?
left lobe
right lobe
caudate lobe
Divided into medial and lateral segments by the L hepatic vein and ligamentum teres
left lobe
Separated from the caudate lobe by the ligamentum venosum
left lobe
Divided into the anterior and posterior segments by the R hepatic vein
right lobe
How large is the r lobe of the liver?
6x larger than left lobe
what are the 3 posterior fossae found in the R lobe of the liver?
gallbladder, porta hepatis, and IVC
Smallest lobe of the liver
caudate liver
another name for the hepatorenal pouch
morison pouch
Lobe that Lies anterior to the porta hepatis and middle hepatic vein
left lobe
lobe that lies anterior to the R kidney
Right lobe
lobe that Lies anterior and medial to the IVC
caudate lobe
Extension of the R lobe inferior and anterior to the lower pole of the R kidney
Riedel’s Lobe
what gender is reidels lobe more prevalent?
females
uterine position wherein uterus is bent at the isthmus with body folded backwards on the cervix
retroflexed
uterine position wherein uterus is – straight but directed posteriorly
retroverted
normal size of fallopian tubes
7-12 mm in length
portion of the fallopian tube that transverse the myometrium
interstitial
what is the narrowest portion of the fallopian tube?
isthmus
what is the widest portion of the fallopian tube?
ampullary; it is also the site of implantation
what is the infundibulum portion of the fallopian tube?
opens into the peritoneal cavity;
with fimbriae and adjacent to the ovaries
Midcycle pain due to ovulation
MITTELSCHMERZ
Abnormal proliferation of endometrial gland
ENDOMETRIAL HYPERPLASIA
Localized or pedunculated broad-based
growth of endometrial tissues that cause bleeding
ENDOMETRIAL POLYPS
Common in puerperal endometritis 2 to 5 days after delivery or post-abortion D&C
ENDOMETRITIS
Presence of endometrial tissues in the
myometrium
ADENOMYOSIS
Cysts in the cervix
NABOTHIAN CYSTS
Solid nodules extending from the cervix
CERVICAL LEIOMYOMA
Located in the anterior inferior to neck
thyroid gland
normal size of thyroid
LENGTH: 4 to 6 cm
THICKNESS: 3-4 mm (isthmus)
linear used for imaging the thyroid gland
linear
what is the patient prep for abdominal utz?
4-8 hours of fasting
probe used in imaging the abdomen
curved array
Narrow tube approx. 10 cm in length arising from the tip of the cecum approx. 3 cm below the ICV
appendix
what is the percentage of blood supply to the liver?
a) PortalVein (70%)
b) Hepatic Artery (30%)
how many liters of blood does the liver carry?
1.5L
TYPES OF FATTY LIVER DISEASE:
diffuse fatty liver
focal fatty liver
focal fatty sparing
differentiate the TYPES OF FATTY LIVER DISEASE
- Diffuse Fatty Liver: entire liver is affected
- Focal Fatty Liver: lobar / segmental
- Focal Fatty Sparing: Whole liver is fatty but some parts are not
included
hepatitis that is caused by fecal-oral route;
Hep a
most common hepatitis
Hep A
What is Hepa B
from blood products, sexual contact
What is Hepa c
(blood transfusion)
what is hepa e?
from oral; water-borne
what is hepa d?
same with type B; can’t occur w/o type B
acute hepatitis has an appearnce of _____ in an ultrasound
starry sky
Most common 1° neoplasm in the liver
CAVERNOUS HEMANGIOMAS
Most common 1° hepatic malignancy
HEPATOCELLULAR CARCINOMA (HCC)
normal dimensions of gallbladder and gallbladder wall
3 cm wide, 7-10 cm long
GB wall: up to 3 mm
pathway of bile
intrahepatic ducts
common hepatic duct
cystic duct
cbd
ampulla of vater
sphincter of oddi
2nd portion of descending duodenum
normal dimensions of common hepatic duct
up to 4mm
normal dimensions of cbd
up to 6mm
“STRAWBERRY GB”
CHOLESTEROLOSIS
Support breast tissue
Cooper’s ligament
Suspensory ligaments that extend anteriorly from the deep muscle fascia, throught the breast, to the skin
Cooper’s ligament
How many lobes does the breast have?
15-20
Breast layer that contains Fat lobules, connective tissue, muscle
retromammary Layer
Breast layer that contains Skin and subcutaneous fat lobules
Subcutaneous Layer
