Lecture 1: Image Critique

Question 1

When do you review images in clinical placement?

Answer 1

1. After taking an exposure on a patient
2. When reviewing images with your CC to see if they can go in your logbook

Question 2

What are the reasons for repeating an image?

Answer 2

-Anatomy cut off
-Blurriness
-Metallic foreign bodies/artifacts
-Joint spaces are closed/poor positioning (improper rotation)
-Severe underexposure-(Image is very mottled & image burn)

Question 3

T/F

An overexposed image must be repeated.

Answer 3

False; unless it is severely mottled or burned, you do not have to repeat.

Most overexposures result in great looking images with no mottle (high SNR)..that is what leads to DOSE CREEP

Question 4

T/F

Images without markers must be repeated.

Answer 4

False; not a reason to repeat (use electronic marker)

Question 5

What is better for imaging the sacrum, AP or PA? Why?

Answer 5

AP; beam divergence

Question 6

How can you fix an image with clipped anatomy?

Answer 6

1. Include shadow of anatomy with collimation
2. Minimize OID
3. Maximize SID

Question 7

T/F

To decrease patient motion, use a small focal spot.

Answer 7

False; use a large focal spot

Question 8

T/F

To decrease patient motion, use the largest mA possible

Answer 8

True

Question 9

To decrease patient motion, what must you do to SID and OID?

Answer 9

Decrease SID and OID

Question 10

Read over the following questions to ask in a senario of severe underexposure:

Answer 10

1. Was the back-up time reached?
2. Were you centered over the anatomy of interest?
3. Did you use AEC rather than a fixed technique? (AC Joint, clavicle)
4. Is there an equipment issue (CR reader, x-ray generator)
5. Was an appropriate kVp set
6. Was the correct algorithm used to process the image

Question 11

Read over the following questions to ask in a senario of severe overexposure:

Answer 11

1. Were you centered over the anatomy of interest?
   Off centered detent: Grid cut off
2. Is there an equipment issue (x-ray generator, AEC)
3. Was the correct technique selected from the APR (arthroplasty)
4. Was a fixed technique used as opposed to AEC
5. Were you centered to the bucky
6. Did the patient have a metal arthroplasty?

Question 12

Read over the following questions to ask in a senario of poor positioning/inadequate joint space:

Answer 12

1. Was the proper angle used if needed
2. Was the body part properly rotated
3. Is there any preventable distortion

Question 13

What is the joint space/off centered/SID/ rule?

Answer 13

Approx. 1.5° for every 1” or 2.5 cm off-center at 40” or 100 cm SID

(will be asked)

Question 14

How do we move the petrous ridges below the orbits?

Answer 14

Angle Down

Question 15

T/F

Lift chin moves orbits above petrous ridges

Answer 15

True

Question 16

What landmark should you use for lateral projections of the facial bones?

Answer 16

Zygomatic process bones of the maxillae

Question 17

How can you tell which zygomatic process you hit first?

Answer 17

Find the more magnified zygomatic process

(is the furthest from the IR)

Question 18

What are some distinguishing factors of the medial tibial condyle which differenciate it from the lateral tibial condyle?

Answer 18

Medial condyle has roughened area (adductor tubercle) & the medial tibial plateau is curved

Question 19

T/F

The lateral condyle is smooth

Answer 19

True

Question 20

What information do we get from a lateral knee that helps us with other knee images?

Answer 20

-The angle of the tibial plateau
-Plan for standing AP

Question 21

What angle would you use for the AP?

Answer 21

3-5 degrees cephalad

Question 22

What pathology is shown here?

Answer 22

Lipo-hemarthrosis; tibial plateau fracture

Question 23

What angle would you use for the standing AP?

Answer 23

-10 degrees caudad

Question 24

What info do we get from this?

Answer 24

-5-degree caudad angle should be used for lateral (normal knee)
-Can be used to find the skyline angle

Question 25

What projection can this image help us to position for?

Answer 25

Gives us the angle that we need for the lateral