Intro to Rad Flashcards
What are the 8 types of imaging?
Radiography/x-ray
Fluoroscopy
CT
MRI
US
Nuclear medicine
PET
Interventional radiology
What are the advantages of x-rays?
Availability
Low cost
Few side-effects
What are the disadvantages of x-rays?
Uses ionizing radiation
Limited soft tissue contrast
2D representation of 3D structure - requires multiple views
What to variations of black and white on x-ray represent?
Air is black - least dense
Fat
Fluid
Bone
Metal is white - most dense
What forms the two heart borders in a frontal x-ray?
Right heart border - right atrium
Left heart border - left ventricle
What forms the two heart borders of a lateral x-ray?
Anterior heart border - right ventricle
Posterior heart border - left ventricle
What is conventional image orientation for CT and MRI?
Looking up from the patients feet with the anterior at top and posterior at bottom
What are the disadvantages of CT?
Patient claustrophobia
Ionizing radiation
May need IV contrast
Cannot use in pregnancy
Avoid in children
What are the advantages of CT?
Cross-sectional imaging
Can be reformatted into different planes
Excellent spatial and contrast resolution - good tissue differentiation
Painless and quick
What are the two MRI sequences?
T1 - anatomical - faster
T2 - pathological - slower
What are the complications specific to MRI?
Ferromagnetic objects
Electrical interference with medical implants
Artefacts from metal
Retroperitoneal fibrosis with gadolinium
How can you tell the difference between MRI and CT?
In MRI bone is dark
What are some common US studies?
OBGYN
Gallbladder/RUQ
Abdominal
Thyroid
Carotid/vascular
Biopsy guidance
What are some advantages and disadvantages of US?
Advantages - no radiation, no known side effects, useful in point of care imaging
Disadvantages - user dependent, little value in bone, or gas containing organs
What is the most common radioactive tracer in nuclear medicine?
Technetium-99m - emits gamma rays
