Shared Flashcard Set

Details

Chapter 22-Panoramic Radiographs
Panoramic Radiographs
62
Art History
4th Grade
11/05/2012

Additional Art History Flashcards

 


 

Cards

Term
What does a panoramic radiograph show?
Definition
a wide view of the upper and lower jaws in a single image
Term
What does panoramic radiograph supplement?
Definition
periapicals and bitewings
Term
How are panoramic images compared to intraoral images?
Definition
not as defined or sharp
Term
How does the receptor and xray tube move in a panoramic machine?
Definition
around the patients head. The x-ray tube rotates in one direction while the receptor rotates opposite
Term
Can a patient stand during a pan radiograph?
Definition
yes they may stand or sit in a stationary position
Term
What is tomography?
Definition
process by which movement of the receptor and tubehead produce an image
Term
What does the tomography radiograph technique show?
Definition
allows the imaging of one section of the body while bluring images from structures in other planes
Term
What is the location center?
Definition
the pivotal point around which the cassette carrier and x-ray tubehead rotate
Term
How does the number and location of rotation centers impact the focal trough?
Definition
impact the size and shape
Term
What is the focal trough?
Definition
three-dimensional curved zone where the oral structures are well defined on a panoramic radiograph
Term
What are positioned within the focal trough?
Definition
the teeth
Term
What determines if the teeth will be in the focal trough or not?
Definition
patient positioning
Term
What is the xray tubehead on a pan machine like?
Definition
similar to intraoral xray tubehead
Term
Is the pan collimator the same as intraoral?
Definition
differs from the one in intraoral tubehead
Term
What is a collimator on a pan machine like?
Definition
lead plate with an opening in the shape of a narrow vertical slit
Term
What is the x-ray beam like on a pan machine?
Definition
exits xray tube through collimator as a narrow band
Term
Where does the beam go?
Definition
passes through the patient and exposes the receptor through another vertical slit in the cassette carrier
Term
What is the vertical angulation on pan machines?
Definition
fixed so the x-ray beam is directed slightly upward
Term
What is the purpose of the head positioner?
Definition
alligns the patient's teeth
Term
What are the components of the head postitioner? (4)
Definition
1.chin rest
2.notched biteblock
3.forehead rest
4.lateral head supports or guides
Term
Is the mA and kVp fixed for each patient?
Definition
no they are varied for different sized patients
Term
Does the exposure time vary on pan machines?
Definition
no, it is fixed
Term
What kind of film is used in pan machines?
Definition
screen film
Term
What is screen film sensitive to?
Definition
light from an intensifying screen
Term
What is screen film placed in?
Definition
placed between two intensifying screens in a cassette holder
Term
How do the screens produce an image?
Definition
converts xray energy to into light which then exposes the film and a latent image is produced
Term
What color light does calcium tungstate emit?
Definition
blue light
Term
What color light does rare earth emit?
Definition
green light
Term
Does calcium tungstate or rare earth require less xray exposure?
Definition
rare earth(green)
Term
What is the cassette?
Definition
device used to hold the extraoral film and intensifying screens
Term
What are the different types of casssettes? (4)
Definition
1.rigid
2.flexible
3.curved
4.straight
Term
What must the cassette be?
Definition
light-tight
Term
How is the cassette marked and why?
Definition
-to orient the finished radiograph
-labeled L for patient left and R for patients right
Term
Where do you load the film into the panoramic cassette?
Definition
in the darkroom under safelight conditions
Term
What should be done with the biteblock?
Definition
either covered with barrier or sterilized between each patient
Term
Should you explain the pan radiograph procedure to a patient?
Definition
yes
Term
Does a patient getting a pan wear a lead apron? Do they wear the thyroid collar?
Definition
yes, they wear one without a thyroid collar
Term
What kind of lead apron is used?
Definition
a double sided lead apron
Term
What are some things that must be removed before a patient gets a pan radiograph?
Definition
jewelry and removable dental appliances
Term
How should you instruct a patient to sit or stand?
Definition
as tall as possible with the back straight and erect
Term
After you instruct a patient on how to stand/sit what should they do next?
Definition
bite on the biteblock
Term
How should the patients midsaggital plane be?
Definition
perpendicular to the floor
Term
How should the patients frankfort plane be positioned?
Definition
parallel to the floor: from tragus of the ear to the floor of the eye orbit
Term
Where should the lateral vertical line run?
Definition
center of the maxillary canine
Term
How can you check the position of the lateral vertical line?
Definition
have the patient say cheese so you can see their teeth
Term
How should you instruct the patient to place their tongue and lips during a pan radiograph?
Definition
-tongue in roof of mouth whole time
-close lips around biteblock
-remain still
-expose the patient
Term
What are ghost images?
Definition
radiographic artifact seen on panoramic image
Term
When are ghost images produced?
Definition
produced with a radiodense(metalicm bony) object is penetrated twice by the xray beam
Term
What is a lead apron artifact?
Definition
radiopaque cone-shaped artifact that obscures diagnostic information
Term
What is a lead apron artifact caused from?
Definition
lead apron being improperly placed
Term
**stopped at 28 in slide show**
Definition
Term
How should the frankfort plane be alligned?
Definition
through tragus and bottom of eye orbit
Term
What happens if lips are not closed?
Definition
dark shadow obscures anterior teeth
Term
What happens if tongue is not on the roof of the mouth?
Definition
shadow obscures apicies of maxillay teeth
Term
What happens if a patients chin is too high?
Definition
reverse smile appears on radiograph
Term
What happens if a patients chin is too low?
Definition
exaggerated smile line
Term
What happens if a patients teeth are too far foward on the biteblock?
Definition
the anterior teeth appear skinny and out of focus
Term
What happens if a patients teeth are too far back on the biteblock?
Definition
teeth appear fat and out of focus
Term
What happens if a patients head(midsaggital plane) is not centered?
Definition
the ramus and postetior teeth further from the receptor appear magnified
Term
What happens if a patient is not sitting or standing with a straight spine?
Definition
the cervical spine appears as a radiopacity in the image, obscures diagnostic information
Term
What are some advantages of panoramic radiography?
Definition
-field size
-simplicity
-patient cooperation
-minimal exposure
Term
What are some disatvantages of panoramic radiography?
Definition
-image quality(not as sharp, cant be used to detect decay, perio disease, or periapical lesions)
-focal trough limitations
-distortion
-cost
Supporting users have an ad free experience!