CHAPTER 22: PANORAMIC IMAGING

Question 1

shows a wide view of the maxilla and the mandible and surrounding structures

Answer 1

PANORAMIC IMAGE

Question 2

allows for the visualization of the patient’s oral and facial structures spread out across a flat surface.

Answer 2

PANORAMIC IMAGING

Question 3

What kind of technique is panoramic imaging and what does it examine

Answer 3

extra oral technique

examines maxilla and mandible on a single projection .

Question 4

The panoramic image is typically used for the following purposes:

Answer 4

evaluate dentition and supporting structures

evaluate impacted teeth

detect diseases and lesions of the jaw

evaluate trauma

Question 5

a panoramic image can be used to detect caries. TRUE OR FALSE

Answer 5

FALSE

Question 6

an imaging technique that allows the imaging of one layer, or section, of the body while blurring the images of structures in other planes.

Answer 6

tomography

Question 7

The pivotal point, or axis, around which the receptor and the x-ray tubehead rotate is termed the

Answer 7

rotation center

Question 8

a three-dimensional curved zone in which structures are clearly demonstrated on a panoramic image.

Answer 8

focal trough

Question 9

this image results when a structure lies between the receptor and moving rotation center. this image is a “true” image; it appears in the correct anatomic location with varying degrees of sharpness and distortion.

Answer 9

real image

Question 10

results when an anatomic structure that is located behind the moving rotation center is penetrated twice by the x-ray beam. this image has the same proportions as the real image and is located in the same location on the opposite side of the receptor.this image appears as a mirror image, or the reverse of the real image.

Answer 10

double image

Question 11

This image results when an anatomic structure or object is located outside of the focal plane and close to the x-ray source. This image resembles its true image and is found on the opposite side of the receptor; it appears blurred, magnified, and higher than the actual counterpart

Answer 11

ghost image

Question 12

The main components of the panoramic unit, whether digital or film-based, include the following

Answer 12

xray tubehead

head positioner

exposure controls

Question 13

The function of the collimator

Answer 13

restrict size and shape of xray beam

Question 14

the tubehead of the panoramic unit always rotates _____ the patient’s head, while the receptor rotates in ________ of the patient.

Answer 14

behind

in front

Question 15

consists of a chin rest, notched bite-block, forehead rest, and lateral head supports or guides

Answer 15

head positioner

Question 16

In panoramic x-ray units, the image receptor may be a :

Answer 16

direct digital sensor

(CCD or CMOS),

a PSP plate,

or film.

Question 17

used in film-based panoramic imaging; this film is sensitive to the light emitted from intensifying screens

Answer 17

extra oral screen films

Question 18

where is a screen film placed

Answer 18

between t wo intersifying screens in a cassette holder.

Question 19

Two basic types of intensifying screens are used:

Answer 19

calcium tungstate

rare earth

Question 20

which screen requires less xray exposure

Answer 20

rare earth screens

Question 21

is a device that is used to hold the extraoral film and intensifying screens

Answer 21

casette

Question 22

an imaginary plane that passes through the top of the ear canal and the bottom of the eye socketbparallel to the floor

Answer 22

frankfort plane

Question 23

The panoramic image may be divided into six areas for review:

Answer 23

dentition

ramus & cervical spine

nasal cavity & maxillary sinus

body of the mandible

condoyle

hyoid

Question 24

It is important to note that with digital imaging, an overexposed image can be corrected with the use of software, but an underexposed image cannot. T OR F

Answer 24

TRUE

Question 25

The two most common patient preparation errors :

Answer 25

ghost image

lead apron artifact

Question 26

a radiopaque artifact seen on a panoramic image, is produced when a thick, dense object is located outside of the focal plane and close to the x-ray source

Answer 26

ghost image

Question 27

causes of ghost images

Answer 27

metal jewelry, glasses, necklaces

or normal anatomic landmarks (ramus of mandible, hard palate)

Question 28

If a lead apron with a thyroid collar is used during the exposure of a panoramic projection, a bilateral radiopaque artifact results that obstructs the mandible.

list the solution

Answer 28

lead apron artifcact

solution: use lead apron WITHOUT a thyroid collar.

Question 29

Answer 29

ghost image