Final; Panoramic Radiology

Question 1

This is a technique for making detailed radiographs of a plane section of a solid object while blurring out the images of adjacent planes

Answer 1

panoramic radiography

Question 2

This is a 3D curved zone in which structures are reasonably well defined

Answer 2

focal through/image layer

Question 3

A panoramic image is obtained how

Answer 3

by rotating a narrow beam of radiation in the horizontal plane; the image receptor is rotated in the same direction while the object (jaws) is stationary

Question 4

Magnification varies with the type of error in what

Answer 4

patient positioning

Question 5

This type of magnification varies little with object depth (focal spot to object distance)

Answer 5

vertical magnification

Question 6

Readily apparent different horizontal magnification of structures situated what what

Answer 6

different depths; (focal spot to object distance)

Question 7

Horizontal magnification varies in which direction

Answer 7

anterior; compared to posterior

Question 8

These arise from structures (foreign and normal) located on posterior aspect of opposite side, are blurry, and projected higher than the real object

Answer 8

ghost images

Question 9

What are the 10 steps in taking a panoramic radiograph

Answer 9

set exposure factors
have patient remove all metallic objects from head and neck area
have patient wear radiation protection apron plus thyroid shield in pediatric patients
walk patient to machine
have patient bite on bite stick
have patient stand up straight
position the ALA-tragus line
position the lateral guide
have patient swallow and place tongue in roof of mouth
make exposure

Question 10

This problem of a panoramic is a light, pale film with few dark areas

Answer 10

Underexposure; too little exposure

Question 11

How would you correct an under-exposure

Answer 11

increase mA or kVp or use next higher setting on machine

Question 12

This problem of a panoramic is a dark film with loss of detail, amalgam and unexposed areas are still clear

Answer 12

overexposure; too much exposure

Question 13

What would you correct an over-exposure

Answer 13

decrease machine settings

Question 14

This problem of a panoramic is a white opacity at the bottom of film shaped like an inverted “V” or shark fin

Answer 14

lead apron above collar line and in X-ray beam

Question 15

This problem of a panoramic is in the anterior posterior direction

Answer 15

too far forward or back

Question 16

This problem of a panoramic is in the vertical direction

Answer 16

ala-tragus
cantho-meatal
frankfurt plane

Question 17

This problem of a panoramic is in the sagittal direction

Answer 17

head twist or rotation

Question 18

What type of image distortion is in the enter of the focal trough, horizontal magnification = vertical magnification

Answer 18

there is no distortion

Question 19

When would an image develop distortion

Answer 19

outside the focal trough

Question 20

This problem of a panoramic is the anterior teeth are blurry, too small and narrow, spine visible on side of the film

Answer 20

patient biting too far forward on the bite rod

Question 21

This problem of a panoramic is anterior teeth are blurry and wide, ghosting of mandible and spine, condyles close to edge of film

Answer 21

patient biting too far back on the bite rod or not at all

Question 22

This problem of a panoramic is the roots of lower incisors blurry, mandible shaped like a “V”, too much smile line, condyles at top of film, spine forms arch or “gazebo” effect

Answer 22

patients chin is tipped too far down

Question 23

This problem of a panoramic is the maxillary incisors are blurry, hard palate superimposed on roots, flat occlusal place, mandible is broad and flat, condyles at the edge of film

Answer 23

patients chin is tipped too far up

Question 24

This problem of a panoramic is the teeth are wide on one side, narrow on the other side of midline, ramus is wider on one side than the other, uneven pattern of blurring throughout arch, nasal structures not clear

Answer 24

patient’s head is twisted in machine causing mid-line asymmetry

Question 25

This problem of a panoramic is the condyles are not equal in height, nasal structures are distorted

Answer 25

patients head is rotated in machine (tipped)

Question 26

This problem of a panoramic is white tapered opacity in middle of image (shaped like Washington’s monument)

Answer 26

ghost of spine due to slumping

Question 27

This problem of a panoramic is dark, vertical line extending from top to bottom of edge of film

Answer 27

cassette hit shoulder and temporarily stopped

Question 28

This problem of a panoramic is a large dark shadow over maxillary teeth between palate and dorsum of tongue

Answer 28

patient’s tongue not on roof of mouth

Question 29

This problem of a panoramic is portions of the radiograph are blurred, large step defects in inferior border of the mandible

Answer 29

panoramic exposure takes approx. 15 sec; patient moved during this time

Question 30

What are six advantages of panoramic radiology

Answer 30

large size
approximate measurement of lesions, etc.
simplicity
time
20% less dosage than a FMX
patient comfort/cooperation

Question 31

What are seven disadvantages of panoramic radiology involving image quality

Answer 31

image quality; magnification, geometric distortion, and poor definition
magnification; about 20-30%
limited use in caries diagnosis and evaluation of periodontium/endo
overlap
superimposition
ghost images
overuse

Question 32

Structures outside of this are poorly visualized or not see at all

Answer 32

focal trough