Others - Radio Flashcards
(16 cards)
Types of imaging - 6
- Ultrasound
- MRI
Uses Ionizing radiation (associated cancer risk, minimized use on pediatric patients): - Plain film
- CT
- Fluoroscopy
- Nuclear medicine imaging
Contrast Media – 3
Injected (IV or intra-arterially), orally or by enema. Most common:
1. Iodine based Contrast Media - used in CT & Interventional/Fluoroscopy
2. Gadolinium based Contrast Media - used in MRI
3. Barium Sulphate – used for GIT studies such as Barium Swallows
Cough, Fever & Pneumonia X-Rays - 3
- CXR used to diagnosed: diagnosis of pneumonia requires CXR changes (like above)
- Called appearance consolidation; means the lung is full of something other than air e.g. pus, fluid, cells.
- This absorbs X-Rays more than air, so shows up more-white.
Nasogastric tube – 3
- used for feeding patients who can’t take in orally
- Must be checked via X-Ray
- Risk if feed into lung = pneumonia, pneumonitis, death.
Ultrasound - 4
- High frequency sound waves
- Real time examination but take pictures which get saved.
- Need jelly to get good contact- ultrasound can’t pass through air.
- For: Obstetric, Gynecology, Abdominal, Testicular or Paediatrics
Obstetric ultrasound – 5
- 12 & 20 weeks
- Non-ionizing
- Real-time
- Cheap
- Effective
Abdominal ultrasound – 4
- Abdominal pain: Gallstones
- Liver cirrhosis: Screening for hepatocellular carcinoma
- Renal tract: Recurrent infections, Renal impairment
- Screening for aortic aneurysm
Computed Tomography – 4
- Ionising radiation
- X-ray tube rotates around the patient shooting a narrow beam of x-rays through the body
- Detectors directly opposite the x-ray source
- Produces stacked images that can be scrolled through to assess the anatomy & pathology & make likely diagnoses
Iodinated contrast – 4
- Usually IV, but oral sometimes used
- Dense, so shows up white on CT images, because it absorbs the x-rays.
- Useful in CT for looking at chest & abdominal organs & looking at blood vessels.
- Scans are done at pre-defined times after administration of the contrast, or sometimes the contrast is tracked until the amount of contrast is at its peak, then the scan starts
Risks of iodinated contrast – 3
- Adverse reactions: Nausea/vomiting, Hives/itching, Anaphylaxis
- Renal impairment: Contrast is a risk factor for kidney injury
- In practice, often getting the scan is important for diagnosis & kidney injury can often be managed afterwards
MRI Adv 3 & Dis 4
Adv
1. Non-ionizing
2. Anatomic detail
3. Can be more sensitive than CT in certain conditions (i.e. stroke)
Dis
1. Some patients cannot have MRI (pacemaker, cochlear implant)
2. Can be noisy/claustrophobic & some patients can’t tolerate
3. Much slower than CT. Patient needs to stay still otherwise images are degraded.
4. More costly.
MRI Common uses - 3
- MRI brain: Stroke, Tumor evaluation
- Magnetic resonance cholangiopancreatography: Gallstones in the common bile duct
- MRI spine: Spinal cord compression, Cauda equina syndrome
Nuclear medicine - 3
- Nuclear medicine use radioactivematerial combined with a carrier molecule. This compound is called aradiotracerorradiopharmaceutical.
- Nuclear medicine is used to diagnose & evaluate diseases. E.g. cancer, heart disease or GI
- Able to find disease in its earliest stages, target treatment to specific cells & monitor response to treatment.
Bone scan – 4
- Inject technetium-99 with methylene-diphosphonate.
- Taken up through bone metabolism.
- Scanned with special camera which detects radiation.
- More active bone metabolism (tumour, infection, fracture) shows increased uptake
Interventional radiology – 5
Radiologist performs image guided procedures
1. Biopsies
2. Drains (chest/abdomen)
3. Treatment of brain aneurysms
4. Mechanical thrombectomy in stroke
5. Vascular procedures such as angioplasty & stenting (non-cardiac)
