Radiology Flashcards
What is radiology?
Radiology is the science of medical imaging used to diagnose and
sometimes also treat diseases within the body using ionising radiation.
How are radiographs produced?
Radiographs are produced by transmitting X-rays through a patient. The X-rays are projected through the body onto a detector; an image is formed based on
which rays pass through (and are detected) versus those that are absorbed or scattered in the patient (and thus are not detected).
What are two common radiocontrast agents in fluroscopy and how are they given?
Barium sulphate- given orally or rectally for
evaluation of the GI tract.
Iodine, in multiple proprietary forms, is given by oral, rectal, vaginal, intra-arterial or intravenous routes
What do radiocontrast agents do?
strongly absorb or scatter X-rays, and in conjunction with the real-time imaging, allow demonstration of dynamic processes, such as peristalsis in the
digestive tract or blood flow in arteries and veins
Which radiocontrast can be in abnormal areas more or less than in normal tissues and make
abnormalities (tumours, cysts, inflammation) more conspicuous
Iodine contrast
Where can air be used as a contrast agent?
GI system
Where can CO2 be used as contrast agent?
venous system
Define nuclear medicine
Nuclear medicine imaging involves the administration of radiopharmaceuticals
labelled with radioactive tracer into the patient. These substances consist of material with affinity for specific body tissues
Name the most commonly used radioactive tracers
technetium-99m iodine-123 iodine-131 gallium-67 indium-111 thallium201 18F-fluorodeoxyglucose (18F-FDG)
Which organs are evaluated using nuclear medicine imaging?
The heart, lungs, thyroid, liver, brain,
gallbladder, and bones are commonly evaluated for particular conditions using these techniques.
What is limited in nuclear medicine?
anatomical detail
what are the principal imaging devices?
gamma camera
PET scanner
How can nuclear medicine images be improved?
nuclear medicine images can be fused with a CT scan taken quasi-simultaneously, so the physiological information can be overlaid with the
anatomical structures to improve diagnostic accuracy
What is interventional radiology?
subspecialty of radiology in which minimally invasive procedures are performed using image guidance
For what purposes is interventional radiology used?
diagnostic purposes (e.g., angiogram)
treatment purposes (e.g., angioplasty)
