Diagnostic Imaging Flashcards
What are the modalities that use ionizing radiation?
- Radiograph
- CT
- Fluoroscopy
- Angiography
What are the modalities that do NOT use ionizing radiation?
- Ultrasound
- MRI
Bergoine and Tribondeau’s law
-What are the characteristics of tissues that have increased radio-sensitivity?
- Cells are undifferentiated
- Greater proliferative capacity
- Divide more rapidly
What are the adverse effects of ionizing radiation?
- Carcinogenesis-leukemia, thyroid, breast, lung, skin
- Genetic consequences-gonadal irradiation
What are some clinical considerations/contraindications of ionizing radiation?
- Previous allergy to contrast
- Renal patients
- Pregnant patients (days 16-45 are critical)
- Children
What medication is contraindicated with ionizing radiation and why?
Metformin-beware of the lactic acidosis
What is the point of contrast?
Increases difference in density between anatomic structures
-3 ways to administer-PO, IV, PR
What is used for GI contrast?
GI contrast-Barium and gastrograffin
What is used for IV contrast?
IV contrast-Iodine based
What is used for MRI contrast?
MRI contrast-Gadolinium
Contrast reactions
- Hypersensitivity rxns
- Chemotoxic rxns
- Vasovagal rxns
What are the symptoms of hypersensitivity rxns?
- Hives, anaphylaxis, urticaria, pruritis, angioedema
- Immediate = less than 1 hour
- Delayed = greater than 1 hour to days
What is the Pre-Tx for hypersensitivity rxns to contrast?
prednisone w/ diphenhydramine
What is the rapid Tx for hypersensitivity to contrast?
epi, saline, and albuterol
Chemotoxic reactions to contrast
Self limited symptoms-nausea, vomiting, and flushing
-Very common
Vasovagal reactions to contrast
Vasovagal rxns to contrast
- Increased vasovagal tone
- Decreased SA and AV node conduction
How do ultrasounds work?
Ultrasounds use high frequency sound waves to generate an image
Coupling gel-aids in wave transmission
hat are the pros and cons of ultrasounds
-Pros-no radiation, cheaper than other modalities
-Cons-Bowel gas and lung tissue hinder the image, technician skills variable
Can body habitus affect results?