Lecture 1 - Medical imaging Flashcards
What are examples of non-ionising imaging techniques?
Ultrasound and MRI
What are examples of ionising imaging techniques?
X-ray, CT and nuclear medicine
What are contract agents used for and give examples?
Contrast agents are used to enhance the differences between tissues of similar densities
e.g. barium or iodine, which are normally inserted via the rectum or directly to a blood vessel
How do CT scanners work?
Uses x-rays like plain radiography however the tube that produces the x-rays spins around the patient so that x-rays from different planes are created, forming a 3D reconstruction of tissue densities and water differences
How do ultrasounds work?
Uses high frequency sound to make images, which are produced and detected by the same device (transducer)
How do MRIs work?
A strong, supercooled (with helium) magenta is used, causing the protons in the body to line up. It then transmits radiowave pulses that pass through the patient and the return of the radiates is recorded, forming detailed 3D images
How do PET scans work?
Detect metabolic or functional changes in the body rather than structural changes and are particularly effective in identifying whether cancer is present or not.
What is the colour of bone on CT and the two types of MRI?
CT - White
MRI 1 - Black
MRI - Black
What is the colour of soft tissue on CT and the two types of MRI?
CT - Grey
MRI 1 - Grey
MRI 2 - Grey
What is the colour of fat on CT and the two types of MRI?
CT - Black
MRI 1 - White
MRI 2 - White
What is the colour of air on CT and the two types of MRI?
CT - Black
MRI 1 - Black
MRI 2 - Black
How can a pneumothorax be identified on an x-ray?
- Reduced/no vascular marking
- Hyperlucent lung field
How can pneumonia be identified on an x-ray?
Consolidation - dense or solid substance in alveoli or small airways (NOT the pleural space)
How many branches from the arch of aorta are there?
3
