Introduction to Radiology Flashcards
What is radiology?
Use of medical imaging to diagnose and treat diseases within the body.
What are the types of medical imagine that is used most commonly in radiology?
X-ray (Mammography and fluoroscopy included)
CT
MRI
UltraSound
Nuclear medicine (PET/SPECT)
What kind of radiation are X-rays?
Electromagnetic generated by firing electrons at a metal anode within vacuum tube
How can an image be generated by X-ray?
X-ray is either passed through the body (very high energy)
Can be absorbed by the body
Can be scattered in tissue
These interactions generate x-ray image
What do less dense objects look like on x-ray?
They are black (Air or gas)
What do more dense objects look like on x-ray?
They appear white for example: bone or metal
What would X-ray imaging show in bones?
Trauma
Degenerative diorders
Pathological processes such as cancer
What would x-ray imaging show in soft tissue?
Infection (common first request)
Blockages (Bowel obstruction, constipation, etc)
Trauma (Pneumothorax, pneumoperitoneum)
Pathological changes (CCF, cancer)
How is a mammography different to typical X-ray?
Specialized x-ray equipment for breast tissue
Uses low intensity X-rays (25 - 30kV)
Requires compression of the breast to reduce overlap of structures and to reduce X-ray dose
What is fluoroscopy?
Live x-ray imaging used for theatre imaging and functional studies/assessments (Dysphagia)
Oftem employs the use of contrast
What is x-ray contrast?
Use of high attentuating solution intravenously or orally to observe structures filled with that liquid
What fluid is used for IV contrast?
Iodine based solutions
What fluid is used for oral contrast?
Barium based solutions
What is important to note regarding use of IV contrast?
Can cause serious allergic reactions and extravasation.
It can be toxic to the kidneys when processed by them.
What are the advantages and disadvantages of using X-ray?
Pros:
Fast
Easily available
Cheap
Excellent for bony pathology
Cons:
Radiation dose (can be problematic in pregnant women and children)
2D, overlapping structures
Relatively poor soft tissue visualization
How does CT help solve the issues associated with using X-ray?
It takes x-ray images around the patient creating a 3D image allowing visualization of neighbouring structures and to create 3D models.
How are images of a CT scan shown?
Transverse view (Looking up from patient’s feet)
Coronal (From the front)
Sagittal (From the left side)
What are the uses of CT scans?
Many uses:
Soft tissue (Volumetric scans for cancer detection, first line imagine for stroke)
Bones (Occult fractures and degenerative diseases)
Angiography with contrast imagine COW to see blockages in cerebral vessels.