Chapter 1, 2 (Modalities) Flashcards
What does noninvasive mean?
No break in the skin, without use of incision or puncture(needle)
In Ultrasound, what is stimulated?
A specialized crystal.
In Ultrasound, how is the crystal stimulated?
By electrical stimulation.
In ultrasound, what is produced when the crystal is stimulated?
High frequency sound waves.
What does hypoechoic mean?
Fluid filled structures show up black.
What does hyperechoic mean?
Solid structures show up white.
What is the major advantage of ultrasound?
Safety.
What is ultrasound highly dependent on?
Operator skill.
What is ultrasound used for?
Fetal age (age of the unborn child)
Placenta placement (organ present in pregnancy)
Congenital anomalies
Complications of pregnancy
Imaging guide for biopsies, aspirations and drain placement.
What is ultrasound of the abdomen used for?
Intraperitoneal and retroperitoneal structures
Abdominal and pelvic abscess
Obstruction of biliary tract (ducts of liver and gallbladder)
Obstruction of urinary tracts (ureters)
Prostrate gland
What is ultrasound of the breast used for?
Breast (to differentiate solid cystic masses)
Musculoskeletal (to visualize obvious superficial masses)
What is a biopsy?
To take a piece of an organ and analyze it in lab.
What is aspiration?
To withdraw fluid from the body. (Usually with a needle)
What is drain placement?
To place a tube in the body to drain fluid.
What does vascular or color flow Doppler ultrasound demonstrate? ( patent, major blood vessels)
Patency of major blood vessels
Patient- unobstructed, intact
Major blood vessels - aorta, vena cava and other large vessels)
What does Doppler do?
Demonstrates the motion of blood flow.
What does CT do?
Produces cross sectional images.
CT uses narrow or large x ray beams to expose patients?
Narrow.
What is an algorithm?
Complex mathematical computations performed by a computer.
Describe CT numbers.
Water = 0 ( appears gray) Bone = 1000 (appears white) Air = -1000 (appears black)
What does window width refer to in CT?
Contrast.
What does window level refer to in CT?
Density.
What is a CTA and what is it used for?
CT angiography.
CT of blood vessels.
In MR, what waves are applied?
Pulsed radio frequency.
In MR, when rf pulse is on what happens?
Protons in the body absorb energy.
In MR, when rf pulse is off what happens?
Protons in the body release the energy.
In MR, what does relaxation mean?
The releasing of the energy.
Does MR use ionizing radiation?
No.
What is radiopharmaceutical?
A drug that emits radiation.
In Nuclear medicine, what is the radiation detected by?
A gamma camera.
In Nuclear Medicine what does SPECT do?
Creates three dimensional images.
In Nuclear Medicine, what is difference between SPECT scans and PET scans?
The radiopharmaceuticals that are used emit radiation differently.
What is Ultrasound?
Used high frequency sound waves produced by electrical stimulation of a specialized crystal.
