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