Intro Flashcards
What 5 things does imaging help a PT visualize?
- Growth
- Development
- Healing
- Disease
- Pathology
What are 6 indications for the use of diagnostic imaging?
- When a clinical diagnosis is uncertain, and the patient management is affected by the diagnosis.
- When clinical red flags or sinister or systematic abnormalities need to be excluded.
- When the diagnosis is known, but the extent of injury/ complications are unknown and affect treatment
- Treatment has failed for unknown reasons
- Objective evidence required to document the presence, or progression of disease.
- When preoperative localization or planning information is needed
What 2 things does collaboration between PTs and other health professionals require?
- Understanding what each party has to offer
- Respecting professional boundaries
In direct access, PTs will need to refer patients for imaging. What 3 responsibilities will PTs have in regard to this future?
- Understand what studies are available, and what each type of imaging is appropriate for.
- Understand and integrate the radiologist’s report
- Review radiographs with patients (Pt ed)
What is the PTs role in radiology?
- Collaborate with diagnoses
What roles do PTs not play in radiology?
- Prevention
- Treatment
What is radiology?
- Use of radiant energy and radioactive substances to prevent, diagnose, and treat disease.
What is the most effective means of demonstrating a bone or joint abnormality?
Conventional radiology/ plain film/ x-ray.
What are x-rays?
- Invisible radiations of the EM spectrum.
How is wavelength related to penetrating power?
Shorter wavelength –> More penetrating power.
By what 2 methods does x-ray imprint an image?
- Expose film
- Excite charged coupled device
What are the 3 correct terms for images produced by x-ray?
- Radiograph
- Plain film
- Conventional radiograph
What are the 2 elements of an x-ray vacuum tube, and what are their role?
Heated filament: - Contains cathode (-) - Source of electrons Spinning Anode (+) - Electrons crash into anode - Energy lost in the form of x-ray protons
What controls x-ray emission/ beam size?
- Lead shutters/ also colluminate beams
How is the size of the x-ray beam determined by the operator?
- Visible light is also shown through lead shutters.
Once x-rays have passed through the x-ray vacuum, how is the image formed?
- Beam travels through patient
- Different density tissues absorb x-rays differing amounts
- X-rays exit patient
- Image intercepted by image receptor
What is the image that exits the patient termed?
- Aerial image
What are the 3 types of image receptors?
- Film/ screen
- Fluoroscopy
- Digital
What are film/screen image receptors?
- Cassettes that contain reflection and intensifying screens and photographic film
What effect do differing body parts have on film/screens?
- Different sizes for different body parts
Is film or digital better quality for plain film?
No difference.
What is another name for fluoroscopy?
- Dynamic radiographs
What are 3 uses of fluoroscopy?
- Motion studies
- Guiding needle placement to deeper anatomical structures
- Following the movement of contrast.
Where might contrast be tracked using fluoroscopy?
- Through GI tract
- Swallowing
What imaging is used for needle placement in more superficial areas?
- US
What vertebral injury is fluoroscopy used for?
Vertebral fractures.
What advantages does digital have over film?
- Post collection processing such as: zoom, overlay, contrast, etc…
Is the digital processing of x-rays a simple process?
No; there are many steps in converting X-ray to digital signal.
What is the advantage and disadvantage of fluoroscopy?
+: Motion
-: More exposure
What is the advantage of plain film?
- Hard, permanent copy
What are 6 disadvantages of film?
- Hard, permanent copy (misplacement, transport, storage)
- Can’t alter image
- Image degrades over time
- Takes time for chemicals to develop
- Supplies are not reusable (cost, environmental damage)
- Possible higher radiation exposure
What are 7 advantages of digital?
- Post collection processing
- Portability/ access around the world of past and present images
- Image doesn’t degrade over time
- May have soft or hard copy
- Computer assists in diagnosis
- Less supplies needed reducing cost and damage to environment
- May lead to less radiation exposure
What is the disadvantage of digital?
- Higher initial costs
How can the PT help guide the radiologist in their referral?
- History
- Signs/ symptoms
- Potential/ suspected problems
What are the 5 possible results of an imaging study?
- Positive for tentative clinical Dx
- Negative for tentative clinical Dx
- Negative for tentative clinical Dx, but suggestive of another Dx
- Inconclusive; requires further imaging
- Wrong Dx caused by false negative/ false positive
What is required most of the time to diagnose with imaging?
- Correlation with clinical findings
How much does a typical series of 5 radiographs cost?
- 350 doillars
What is the routine strength of an x-ray?
2000 - 3000 mrad
(milli)rad
