imaging part a
radiographs of the knee should only be obtained
after acute injury only in pts >18 yrs who meet ANY of the ottawa criteria
ottawa criteria
- age >55
- isolated tenderness of patella
- tenderness at the head of the fibula
- inability to flex the knee to 90 deg
- inability to bear wear both immediately and in emergency department for four steps
(limping is ok)
high risk factors canadian c-spine
age > 65, dangerous mechanism, paresthesias in extremities
low risk factors canadian c-spine
simple rear end MVC, sitting position in ED, ambulatory at any time, delayed onset of
neck pain, absence of midline C-spine tenderness
if someone fits ones of the low risk factors in the candian c-spine rules
see if they can rotate their neck actively
clinical decision tools to help choose proper imaging
clinical decision rules, ACR appropriateness criteria, APTA/AOPT resources
clinical decision tools helps PT's make the correct choose which does what?
- reduce unnecessary imaging
- promote cost effective management
- help the clinician obtain proper diagnosis
- improve access for the patients
-promote collaboration with other healthcare providers
ALARA
as low as reasonably achievable - there is no safe level of exposure to radiation
using ALARA
use good clinical judgement, protect the public from harm, prevent exposures that
are unnecessary, limit exposures for chronic conditions
What is a key principle of radiation protection?
Shield body parts of interest
How should one approach imaging to reduce radiation exposure?
Avoid views with high known radiation exposure to at-risk areas
What precaution should be taken regarding pregnant patients during imaging?
Avoid radiation over a fetus whenever possible
What guidelines should be followed in imaging procedures?
Follow all clinical decision rules and appropriateness criteria
What should be considered when selecting imaging technology?
Consider newer technology, MRI over bone scan when possible; think about using
diagnostic ultrasounds
you need three things to create a radiograph
1. x-ray tube
, 2. patient
3. image receptor
x-rays are produced
in a tube via energy conversion, then exit the tube and pass thru the patient
x-rays exit the tube in
divergent straight lines & interact with the body
how do x-rays interact with the body?
absorption, scatter, transmitted
absorption
Body absorbs x-rays and prevents x-rays from reaching film or detector
scatter
X-rays scatter from the patient & other objects
transmitted
X-rays penetrate completely through the body
cervical special image
open mouth
shoulder and elbow special image
internal/external
knee special image
skyline
ankle special image
mortise
what is important to remember to when getting radiograph images?
always get at least 2 views bc x-rays are 2 dimensional images
with 2 views you can
assess length, depth, width, angulation, and displacement
AP projection
beam goes from anterior to posterior through the body, used for extremities except
hand which is PA
lateral projection
beam goes through the body from one side and exits the other side, 90 deg from AP
or PA view
oblique projection
body is rotated in a certain way, beam travels through body at a designated area
"specials" projection
certain joints have specific rules and requirements for capturing the image
amount of absorption and scatter of an x-ray is determined by
thickness and density of the structure
greater density of structure equates to
greater its ability to absorb energy -> more dense structures appear lighter,
transmission of x-rays is more difficult, less black
lower density structure equates to
easier for x-rays to be transmitted, less energy absorbed -> appear darker, more
black, fxs are black
radiographs of the knee should only be obtained
after acute injury only in pts >18 yrs who meet ANY of the ottawa criteria
ottawa criteria
- age >55
- isolated tenderness of patella
- tenderness at the head of the fibula
- inability to flex the knee to 90 deg
- inability to bear wear both immediately and in emergency department for four steps
(limping is ok)
high risk factors canadian c-spine
age > 65, dangerous mechanism, paresthesias in extremities
low risk factors canadian c-spine
simple rear end MVC, sitting position in ED, ambulatory at any time, delayed onset of
neck pain, absence of midline C-spine tenderness
if someone fits ones of the low risk factors in the candian c-spine rules
see if they can rotate their neck actively
clinical decision tools to help choose proper imaging
clinical decision rules, ACR appropriateness criteria, APTA/AOPT resources
clinical decision tools helps PT's make the correct choose which does what?
- reduce unnecessary imaging
- promote cost effective management
- help the clinician obtain proper diagnosis
- improve access for the patients
-promote collaboration with other healthcare providers
ALARA
as low as reasonably achievable - there is no safe level of exposure to radiation
using ALARA
use good clinical judgement, protect the public from harm, prevent exposures that
are unnecessary, limit exposures for chronic conditions
What is a key principle of radiation protection?
Shield body parts of interest
How should one approach imaging to reduce radiation exposure?
Avoid views with high known radiation exposure to at-risk areas
What precaution should be taken regarding pregnant patients during imaging?
Avoid radiation over a fetus whenever possible
What guidelines should be followed in imaging procedures?
Follow all clinical decision rules and appropriateness criteria
What should be considered when selecting imaging technology?
Consider newer technology, MRI over bone scan when possible; think about using
diagnostic ultrasounds
you need three things to create a radiograph
1. x-ray tube
, 2. patient
3. image receptor
x-rays are produced
in a tube via energy conversion, then exit the tube and pass thru the patient
x-rays exit the tube in
divergent straight lines & interact with the body
how do x-rays interact with the body?
absorption, scatter, transmitted
absorption
Body absorbs x-rays and prevents x-rays from reaching film or detector
scatter
X-rays scatter from the patient & other objects
transmitted
X-rays penetrate completely through the body
cervical special image
open mouth
shoulder and elbow special image
internal/external
knee special image
skyline
ankle special image
mortise
what is important to remember to when getting radiograph images?
always get at least 2 views bc x-rays are 2 dimensional images
with 2 views you can
assess length, depth, width, angulation, and displacement
AP projection
beam goes from anterior to posterior through the body, used for extremities except
hand which is PA
lateral projection
beam goes through the body from one side and exits the other side, 90 deg from AP
or PA view
oblique projection
body is rotated in a certain way, beam travels through body at a designated area
"specials" projection
certain joints have specific rules and requirements for capturing the image
amount of absorption and scatter of an x-ray is determined by
thickness and density of the structure
greater density of structure equates to
greater its ability to absorb energy -> more dense structures appear lighter,
transmission of x-rays is more difficult, less black
lower density structure equates to
easier for x-rays to be transmitted, less energy absorbed -> appear darker, more
black, fxs are black
