Radiographic Anatomy Flashcards
Properties of an X-ray
- travel straight lines at the speed of light
- diverge in space from the source
- cause certain crystals to flourecence
- cannot be detected by the human eye
- differential absorbtion
- cannot be refracted by lens
- produce biological effects
Clinical use
-harmful effects identified as ALARA
as low as reasonably achievable
Advanced Imaging
- computed tomography (CT)
- magnetic resonance imaging (MRI)
- Myelography (w/wout CT)
- diagnostic ultrasound
- nuclear medicine
- dual energy X-ray absorption (DEXA)
- mammography
Producing a radiograph
- minimal equipment: X-ray source->image recorder->subject
- xray beam travels from source, thru subject, to the film
Image formation
-x ray tube, source of electrons
-xray beam, focused source of photons based on density
-object, beam absorbed or passed based on density
-film, photons pass object to strike film with silver coating
Image - record of proton interactions
Xray Photons
produced when electrons hit the target
Xray photon interactions
xray photons penetrate object, absorbed or pass thru to hit film
Xray beam
- is cone shaped from a point source
- the most central portion is called central ray
- the central ray diverges less and gives the truest image
- typically the beam will be perpendicular to the film
Differential Absorbtion
- penetration dependant on density
- denser object=less penetration
- move beam striking film=dark
- less beam striking film=whiter
Tissue Density
- a product of type of tissue and thickness
- results in differential absorbtions
- increase tissue density = whiter
- decrease tissue dens = darker
Differential Absorbtion
black - Air (lungs, trachea,outside of body) fat (parietal fat, fascial fat) water (muscle, organs) bone (bone, atherosclerotic placing) metal (filling,markers,orthodevices)
X ray photon Pass thru
non dense object
air and soft tissue
immage apears blacker
radioleucent appearance
Xray photons absorbed
- by dense object
- metal and bone
- image appears white
- radioopaque appearance
Image Terminology
Projection
Body Position
Projection
Anteroposterior/Posteroanterior - x ray beam enters AP front to back or PA back to front
Lateral - x ray beam enters side project side of patient alone coronal plane and travels left to right, names for which side is against the film
Oblique - positioned on film so X-ray passes thru at 45 degree angle
Body Position
Upright - AP or PA or lateral
Recumbent - supine or prone or lateral
Oblique - right or left and anterior or posterior
Decubitis - laying on side and take PA or AP
Upright Positions
patient stands
allows for veal to postural information
chiros can use this to analyze upright lumbar and sacral
Recumbent
patient laying down
no reliable evaluation of postural elements
useful when patient is in a lot of pain
Minimum Diagnostic Series
- standard views required to evaluate an area
- variation by facility or circumstance
- add more views depending on case
- must take at least 2 views
- projection oriented 90 degrees to one another
- view 3D object in 2D
Choice of Postioning
place the structures closest to the film starts with standard series what structures you wish to visualize patients clinical presentation different diagnosis under consideration patients size patients protection (female pelvis)
Film Markers
Informational markers
Mitchell Markers
Name blockers
ID markers - Type of study, Clinic and Tech
Informational Markers
provide information about patient
provide information about the doctor and or facility
identifies side of patient or patient positioning
General marker rule
without a marker you cannot identify which side of the patient is the left and which is the right