212 Radiology Flashcards
List the 5 densities on xray and their associated shade
- Black > Gas
- Dark-grey > Fat
- Light-grey > Soft tissue, Fluid
- Nearly white > Bone, Calcification
- White > Metal
What are the 4 imaging modalities?
- Xray (plain film)
- Computed Tomography (CT)
- Magnetic Resonance Imaging (MRI)
- Ultrasound
Explain “plain films”
X-Ray/standard radiograph. Radiation is projected through tissue and onto photographic plate. Different densities cause gradation changes
Explain CT
Computed tomography or computerized axial tomography (CAT). Focused beams examine an area that is then reconstructed by computer to give a high-resolution view.
Can be non-contrast or with contrast (CTA- angiography)
Explain MRI
Magnetic resonance imaging. A powerful magnet is used to align water molecules present in body compartment to visualize internal structure and function. Image is obtained from this alignment and the speed at which molecules alter or release
Explain ultrasound
Echoes from high-frequency sound waves transmitted into body map denser material and reflect waves back to transducer to produce image
How do you assess the CXR for rotation?
Vertebral spinal process should be evenly between the medial ends of the clavicles
How do you assess for penetration on CXR?
Vertebral bodies should be just visible through cardiac shadow
How do you assess for adequate inspiration on CXR?
6 ribs anteriorly above the diaphragm and/or 10 ribs posteriorly. Poor inspiration can make the heart look larger
What is a hilum
Aka lung roots, or hila (singular – hilum), are complicated anatomical structures containing the pulmonary vessels and the major bronchi, arranged asymmetrically with the left higher than the right
Explain costophrenic angle
Where the diaphragm meets the ribs. Should be sharp, blunting usually indicates a pleural effusion but may be from other causes such as hyperexpansion
