ALU book chapter 1 Flashcards
A procedure that uses high frequency sound waves to image soft tissue
Ultrasonography
What are invasive tests?
Techniques that involve the puncture or cutting of the skin, or entry into an orifice, for the purpose of introducing an instrument or catheter
What are the most common diagnostic imaging tests
X-rays, Ct, ultrasound, MRI, and radionuclide studies
A common imaging technique that uses a beam of radiation that is scatter or absorbed in differing amounts by different tissues.
x-ray
an imaging tool that allows the physician to view, in real time, moving parts of the body, such as barium moving through the intestine–it is used for both diagnosis and treatment
fluoroscopy
Name 3 contrast agents
barium, iodine, and gadolinium-based contrast
The use of small amounts of short-lived radioactive substance that is formulated to be absorbed by targeted tissues
nuclear medicine
a nuclear medicine that can be attached to a carrier substance that is injected intravenously, taken orally, or inhaled by the individual
radionuclide or radiopharmaceutical
What are the most common radionuclides?
radioactive iodine, technetium, thallium, gallium, and indium
What are nuclear studies most useful for
useful for imaging bone, for determination of thyroid and hepatobiliary function, and assess for coronary artery disease
A procedure that utilizes high-frequency sound waves to image soft tissue and procedure an image
ultrasonography
The types of waves for ultrasonography
scattered, refracted, and attenuated
On an ultra sound, how is an organ measured?
it is calculated by measuring the time it takes for the sound waved to travel to the transducer to the reflecting surface being studied and back to the transducer where they are amplified and displayed on a monitor
3 different tissues that reflect sound waves in varying degrees
hyperechoic tissues show white on the image, hypoechoic tissues show gray on the image, and anechoic being the total absence of reflected sound waves
Advantages of ultrasound over MRI and CT
- its ability to differentiate solid from fluid-filled structures
- lower cost
- portability
- accessibility
- no exposure to ionizing raditation
Limitations of ultrasonography
- the skill level of the ultrasonologist
- image resolution that is not as good as other techniques
- “noise” produced when US waves hit gas and bone
different ultrasound techniques
a-mode, b-mode, m-mode, grayscale, real-time, and doppler
allows scanning at a rate rapid enough to create a moving image of the heart, including the motion of the valves and walls
real-time ultrasound
What is a doppler ultrasound
used to measure the velocity and direction of blood flow within the heart and blood vessels by measuring change in pitch. It is useful in the valuation of venous insufficiency, blood clots, arterial occlusion, or stenosis
What is a duplex scan
using a combination of b-mode with the doppler ultrasound
What is computed tomography (CT)
created by passing a rotating beam of x-rays into the individual and obtaining thousands of point images at specific depths. It is compared to taking a loaf of sliced bread then examining it one slice at a time
Limitation of CT
exposes an individual to a significantly higher dose of iodizing radiation
What is an electronic-beam computed tomography (EBCT)
use electronic beam that allows such rapid acquisition of images that it can produce images of the coronary arteries despite the motion of the heart
What is a magnetic resonance imaging (MRI)
uses a magnetic field to induce changes in proton spin within tissues. Radioactive waves are emitted at specific frequencies that make atoms resonate and absorb the energy. The tissue them release a weak radio wave that can be measured by a scanner and amplifies