Intro Lectures Flashcards
What is an X-ray?
a photon of electromagnetic radiation
What was the first clinical use of X-rays?
John Hall-Edwards in Jan. 1896 to visualize a needle in an associates hand
Who discovered X-rays?
Wilhelm Conrad Röntgen, called the unknown radiation x
What is your role as a medical radiation tech?
- operate x-ray equipment
- Deal with patients
- Perform radiographic procedures
What responsibilities fall under operating x-ray equipment?
- understand how it works
- set proper exposure factors for the procedure (kVp, mA, time)
- be able to troubleshoot/perform QA
What responsibilities fall under deal with patients?
- have patient change into hospital attire
- obtain patient history prior to exam
What responsibilities fall under perform radiographic procedures?
- verify that the order is correct
- direct and manipulate patient into proper positions
- ensure that only the anatomy of interest is being radiated
- be able to respond to changing patient conditions
- follow proper radiation safety protocols
- ensure that resulting image is of diagnostic quality
What is a bucky?
it has the tray for the IR, and a grid to reduce scatter radiation
need to ensure tray is lined up with tube when in use
ensure it is actually inside
What are the four types of image receptors?
solid state digital detectors: used in digital radiography
CR cassette: used in computed radiography
Fluoroscopic IR: used in fluoroscopy
Film cassette: not commonly encountered anymore
How are CR cassettes read?
must be inserted into reader after exposure
must wait for image to be created on viewer
patient may have moved during processing
What are the benefits solid state detectors?
Image available for viewing immediately, shorter processing, much easier to adjust for repeats
What is a radiograph?
An image of a patient’s anatomy created by exposing it and an image receptor to X-rays
What is fluoroscopy?
Dynamic images, the colour is inverted, allows us to view movement, demonstrates the function as well as structure
What are the causes of motion that can affect X-rays?
- heart pulsation
- chills
- peristalsis
- tremors
- spasms
- pain
- nervousness
- discomfort
- excitability
- fear
- age
- breathing
How do you control motion for X-rays?
- give the patient clear instructions
- make the patients comfortable
- use support devices
- reduce exposure time
- immobilize if necessary
What is the central ray?
the principal beam of x-rays, entered to the anatomy of interest
What is SID?
Source to image receptor distance - distance from where the x-rays are produced to the image receptor
What does the SID affect?
Magnification, detail of the image and patient dose
What are the common SID’s?
For most tabletop imaging and some Bucky - 40in or 102cm
For some Bucky - 44-48in or 112-122cm
For Bucky with a large OID or field size - 72in or 180cm
What is collimation?
restricting the beam to reduce the amount of radiation hitting the patient
Why use collimation?
safer for patient and better looking image
What are standard precautions in the lab?
- Follow proper hand hygiene IN FRONT OF THE PATIENT
- Clean equipment with alcohol after use
- Wipe down any surface that patient’s face may come into contact with
What is the NOD approach?
A way to introduce yourself to the patient by sharing your name, occupation and duty
What should you do before imagining?
- ensure proper patient ID
- obtain clinical history
- verify order
- obtain consent
- rule out pregnancy
When ruling out pregnancy what are the rules to follow?
- always ask patients of reproductive age (10-55)
- 10 day rule (within 10 days of the start of their last period is okay
- Risk vs benefit (doesn’t mean you don’t image if pregnant, ask if absolutely necessary)
What is the ALARA principle?
As low as reasonably possible
3 core concepts of this are time, distance and shielding
How to achieve ALARA?
- minimize repeats
- proper filtration
- proper collimation
- optimal IR’s
- higher kVp, lower mAs techniques when possible
- SHIELDING
When is gonadal shielding advised?
- gonads lie within or close to X-ray beam
- the patient is of reproductive age
- image will not be compromised
What should your annual dose of radiation not exceed?
<20mSv to whole-body
What is the oblique plane?
Any angle between corneal and sagittal plane
What is the cronal plane?
a vertical plane running side to side that divides the body or any of its parts into anterior and posterior
What is the sagittal plane?
a vertical plane the passes through the body dividing it or any of its parts into right and left
What is the midsagittal plane?
A plane the goes through the midline of the body dividing it equally into left and right
What is the axial or transverse plane?
horizontal plane that splits the body into top and bottom
What is the intertiliac plane?
Runs horizontally across the top of hip bones
What is the occlusal plane?
along the bottom of the top teeth
What is the anatomic position?
face-forward, with palms forward
patient facing you
anterior of the hand would be the palm and of foot is top of foot
What is anterior?
front part of the anatomy
What is ventral?
also refers to the front
- the anterior part of the hand and posterior part of the foot
What is posterior?
back part of the anatomy
What is dorsal?
also refers to the back
- the posterior part of the hand and anterior part of the foot
What is palmer?
the anterior part of the hand (palm)
What is planter?
The posterior part of the foot (the sole)
What is superior?
Cephalad - nearer to the head or situated above
What is inferior?
Caudad - nearer to the feet or situated below
What is central?
the middle area or main part of an organ
What is peripheral?
parts at or near the surface, edge or outside of another body part
What is medial?
parts towards the midsagittal plane (pinky)
What is lateral?
parts away from the midsagittal planeq
What is distal?
farther from the point of attachment
What is proximal?
closer to the point of attachment
What is parietal?
the lining or wall of a body cavity
What is visceral?
the covering of an organ
What is ipsilateral?
when comparing 2 body parts on the same side of the body
What is contralateral?
when comparing 2 body parts on the opposite side of the body
What is bilateral?
when talking 2 body parts on opposite sides of the body at the same time
What is projection?
The path of the central ray from tube to IR, defined by the entrance and exit points on the patients body independent of position
What is AP?
Anteroposterior - enters through the anterior part of the anatomy, and leaves through the posterior part
What is PA?
Posteroanterior - enters through the posterior part of the anatomy, and leaves through the anterior part
What is an axial projection?
additional term added when the central ray is angled at least 10 degrees to the anatomy
angle can be cephalad or caudad
What are lateral projections?
mediolateral or lateromedial for extremities
How are lateral projections named for axial skeleton?
based on which side of the patient is touching the IR
What are oblique projections?
usually PA or AP oblique, achieved by having the patient rotated
What are superoinferior projections?
central ray enters above the anatomy and exits below
What are inferosuperior projections?
Central ray enters below the anatomy and exits above
What is a tangential projection?
central ray touches, but does not cross the anatomy
What are methods?
methods are projections that are named after the individuals that created them to show specific anatomy, will also have a standard projection name
What is view?
how the anatomy is seen by the IR
i.e. projections of PA hand, view (exit point) would be anterior
What is general body position?
the overall posture of the patient
What is radiographic position?
how the patient is placed relative to IR
What is upright or erect?
Patient is in vertical position
What is recumbent?
lying down in any position
What is supine?
recumbent, and laying on the back
What is prone?
recumbent, lying on the stomach
What is Trendelenburg?
supine with head tilted downward
What is Fowler?
supine with head tilted upwards
What is Sims?
recovery position, patient lying sei-prone on their left anterior side, left leg extended, right knee and hip partially flexed
What is Lithotomy?
Supine with knees and hips flexed, thighs are rotated externally
What are the radiographic positions?
lateral, oblique, decubitus and lordotic
What are the lateral radiographic positions?
named according to what side is against IR
- Right/left lateral
What are oblique radiographic positions?
named according to what side is against IR
RAO/LPO correspond and LAO/RPO correspond
RAO = right anterior oblique
What are decubitus radiographic positions?
named according to what is against the table
- left/right lateral decubitus
lateral projections
- ventral decubitus (prone)
- dorsal decubitus (supine)
What is the Lordotic radiographic position?
upright, patient leaning backwards
How many bones in the body?
206
How many bones make up the axial skeleton?
80, supports and protects head and trunk
How many bones make up the appendicular skeleton?
126 bones, allows body to move
How can you determine bone development in radiographs in long bones?
developing long bones have an epiphyseal plate
developed long bones have an epiphyseal line
How can you determine bone development in radiographs in short bones?
wrist bones ossify at different ages
How can you determine bone development in radiographs in flat bones?
cranial bones fuse as children develop
What are the 4 habits types?
Sthenic, Asthenic, Hyposthenic and Hypersthenic
What is Sthenic?
average
What is Asthenic?
not average (very petite)
What is hyposthenic?
less than average
What is hypersthenic?
more than average
What are the general rules in radiography?
Require a minimum of two projections (usually a lateral and an AP OR a PA)
- 90 degrees from each other
-removes superimposition
-determines alignment of fractures or foreign bodies
- some exceptions (i.e. kidney stones)
What are the rules regarding joints?
Radiographic projections of joints require a MINIMUM OF 3 PROJECTIONS
-AP/PA, Lateral and oblique
What are the 2 marker types required on radiographic images?
- Anatomic markers (left/right)
- Patient identification and date
What are the rules regarding anatomic markers?
- must be used on all radiographs
- usually lead
- should be in collimated light feel but NOT obstructing the anatomy
- should not be on lead shielding
- marker facing same was as patient (up or down)
- should be placed on the lateral side of the anatomy
What must radiographs include?
Date, patient name and/or ID, institution identity, right or left marker
How should you view a radiograph?
In anatomic position
What are exceptions to how you should view a radiograph?
Fingers, hands, wrists, forearms, feet and toes
- Done and hung PA
- fingers and toes pointing up
How are lateral radiographs viewed?
viewed from the prospective of the X-ray tube
How are oblique radiographs viewed?
as if the patient is in anatomic position
