Radiology Flashcards
What does Radiopaque mean?
not allowing the passage of x-rays (more white) - metal- shows up bright white
What does Radiolucent mean?
allow the passage of x-rays (more black) - air- nothing there to stop the xrays
Xrays are a fom of what?
radiation
How would you describe an Xrays wavelength and what kind of energy is associated with that?
Short wavelength
High energy
The shorter the wavelength the greater the energy
What are Xrays generated by?
an electrical source
What do Xrays consist of?
waveform packets of energy called photons
What is the amount of energy in an Xray measured in?
electron volts (KeV)
What would you do if your image turned out to be all white?
If the image turned out all white then you would adjust the KeV- too much energy
Where do Xrays leave the Xray tube?
through a small opening (collimator) that regulates the size of the beam
Where is the xray beamed at?
the part of the body to be imaged
Where is the film or screen placed at in relation to the patient?
The film or screen is placed behind the patient
What happens when the Xrays pass through human tissue?
The x-radiation is absorbed and attenuated (weakened), or even blocked as it passes through the different tissues
What is attenuation?
The greater the density of the tissues the greater the absorption of the X-rays
What is the most common diagnostoc Xray format?
film or digital
Is contrast used in Xray?
no
What are some factors that affect image quality?
5
- Motion
- Thickness of the body part - harder to xray
- Scatter (intensity of the x-ray beam)- can scale it down for smaller space (finger)
- Magnification (distance the body part is away from the film vs. x-ray beam)
- Distortion (when the image is not lined up with the film)- spine isnt straight so image is distorted
What kind of people are harder to Xray?
3
Obese people
Parkinsons
Kids
In an AP Xray where is the person situated compared to the film?
And how would you describe the quality of the film?
- Back is to the Xray
- Heart is further from the film
- Longer distance from heart to film = worse quality and more magnified
In a PA xray where is the persoon situated compared to the film?
And how would you describe the quality of the film?
- Front is to the Xray
- Heart is closer to the film
- Smaller distance from the heart to film= Better quality and less magnified
Why do we do AP xrays at all then?
in ER because they cant stand.
What is fluoroscopy?
Moving/real time x-rays
Images can be recorded and played back
Images can be captured as a still picture
An XRAY movie!
Examples of fluoroscopy?
4
GI studies like barium swallow;
angiography;
draining abscesses; intraoperative feedback
What can we diagnose with a barium swallow?
7
- Cancers of the head, neck and pharynx
- Tumors
- Hiatal hernia
- Structural problems
- Muscle disorders
- Esophageal Strictures
- GERD
Complications in barium swallows?
barium might not go down the esophagus. it aspirated into their lungs. could cause pneumonitis
What does an upper GI series include?
3
X-ray examination of the upper GI tract, esophagus, stomach and duodenum
What is an Upper GI series used to diagnose?
What specifically?9
Used to diagnose structural or functional abnormalities of the upper GI tract
- Ulcers (gastric or duodenal) - normally you scope them but sometimes you do upper gi for other things and find an ulcer
- GERD,
- inflammation,
- tumors
- Polyps,
- strictures,
- diverticula
- Dysphagia
- Motility disorders
What does CT stand for?
Computer Assisted Tomography
What are CTs best for?
Useful for the evaluation of soft tissue and bone as compared to plain x-rays
BEST AT BONE
What is MRI best as imaging?
soft tissue
What is a CT?
Medical imaging technique that uses x-rays to create pictures of cross-sections of the body
Thin XRAY beam rotates around the body making 3D images
How would you describe the amounts of radation with CT?
Large amounts
Why couldnt someone have a CT?
Iodine allergies (anaphelactic)
Describe the original CT scan?
took longer
Each “slice” that we took was independant and there was significantly more radiation
What was the distance between slices in the old CTs?
Distance between slices was 3mm, 5mm, 10 mm
What kind of CTs do we use now?
Spiral CTs or continuous CTs
What different kind of CT techniques/types are there?
5
- Bone windows
- Lung windows
- Venous phase acquisition
- IV contrast
- Oral contrast
What parts of the body can we image using CTs?
Can image any body part (head, chest, lungs, heart, abdomen, pelvis, extremities)
How would we perform a CT angiography?
IV contrast
Where is IV contrast cleared through?
The kidneys
What kind of complications can be seen with IV contrast?
Iodinated (Iodine allergies)
Cannot use for renal failure patients
What is Oral Contrast make of?
Barium
Water soluble iodinated contrast
Cannot Use CTs for any kind of patient with renal failure
statement
What is an MRI?
Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.
What is an MRI good for imaging?
imaging soft tissue such as the brain, spinal cord, muscles, tendons, ligaments, etc.