Whole Body Scans

Question 1

what are the indications for a wb image?

Answer 1

• staging and follow up for metastatic bone disease
• following course of chemo/radiation therapy
• evaluating Paget’s disease
• detection and extent of primary bone lesions
• bone pain of unknown origin
• ALP and PSA blood results abnormal
• arthritis

Question 2

what kind of collimators are used?

Answer 2

LEHR or LEAP

Question 3

what is the typical matrix size?

Answer 3

256 x 1024

Question 4

why does the camera need to be as close to the patient as possible?

Answer 4

• increase resolution

Question 5

what is the typical speed for a wb scan?

Answer 5

10-15 cm/min

Question 6

a total of _____ counts should be accumulated

Answer 6

> =1.5M

Question 7

if abnormal areas on wb is seen, what can be done? what should be done?

Answer 7

it can be assessed with spot views or a SPECT/CT

Question 8

why might you need a slower scan speed?

Answer 8

if the patient has a larger body habitus; this is because there is more tissue to absorb the radiation so slowing it down can give it more stats

Question 9

what is linear intensity is best to view which skeletal area?

Answer 9

regions of the axial skeleton

Question 10

what is log intensity best to view which skeletal area?

Answer 10

regions of the appendicular skeleton

Question 11

linear intensity = _____ number of counts are collected
log intensity = _____ number of counts are collected

Answer 11

linear intensity = greater number of counts are collected
log intensity = smaller number of counts are collected

Question 12

in grayscale, what are the highest counts shown as?

Answer 12

white

Question 13

in inverse grayscale, what are the highest counts shown as?

Answer 13

black

Question 14

what are the steps to processing your images?

Answer 14

• make sure to check the images before patients leave
• display the images in linear and log intensity
• display in inverse/grayscale
• label ant/post, r/l
• take screen captures of processed images
• send to radiologist and PACS

Question 15

what is a superscan?

Answer 15

diffuse activity in the skeleton due to metastases
- appearance to be good and relatively uniform
“beautiful bone scan” - increase activity in axial skeleton

Question 16

What would be an advantage of acquiring static spot images after the Whole Body Bone Scan?

Answer 16

• allows for better focus/localization of abnormality
• provides greater detail
• able to use different camera angles

Question 17

what can cause superscans?

Answer 17

• prostatic carcinoma (can be breast cancer or lymphoma)
• hyperparathyroidism

Question 18

what can cause and increase in activity in peripheral skeleton in a superscan?

Answer 18

• hematologic disorders

Question 19

how can you distinguish a superscan from a normal bone scan?

Answer 19

little to no activity in the kidneys

Question 20

what is the flare phenomenon?

Answer 20

when you scan the patient within 6 months of chemo and there seems to be a “worsening” of a disease but it is actually due to healing

Question 21

how do you avoid flare phenomenon then?

Answer 21

scan the patient 6 months post chemo

Question 22

what is radiation therapy deficit?

Answer 22

cold spots on the scan even 6 months post treatment