Imaging in Cancer

Question 1

conventional diagnosis

Answer 1

endoscopy/biopsy and barium

w/o aid of computer

Question 2

radio-opaque contrast used for outlining GI

Answer 2

Barium Sulphate

high atomic no of barium absorbs more xray photons than other tisc - white on radiograph

Question 3

barium swallow and meal

Answer 3

oesophagus , stomach and duodenum

Question 4

barium follow through

Answer 4

small bowel

fast for 4-6 hrs

Question 5

barium enema

Answer 5

large bowel

low residue diet for 48 hours and bowel cleaning with Picolax

Question 6

Barium is limited than Endoscopy as … cannot be taken

Answer 6

biopsy

Question 7

double barium contrast is more than single as it doesn’t

Answer 7

obstruct the view of surrounding tissue

Question 8

…… is a modern version of barium enema

Answer 8

CT colonoscopy

Question 9

Which has higher radiation dose - barium meal or enema?

Answer 9

Barium enema - 7 mSv

meal - 1.5 mSv

Question 10

cross sectional imaging includes

Answer 10

CT, MRI, PET

Question 11

Xrays produce image of slice of tisc usually in an axial place using computing to create image

Answer 11

Computed tomography

CT

Question 12

CT image reconstructed when …. decay/absorbed depending on density

Answer 12

photons

Question 13

attenuation of values of voxels are expressed as a CT no. which relates the attenuation value to that of water

Answer 13

Hounsfield Unit (HU)

(air -1000; bone +3000; water 0)

Bone most dense

Question 14

gastrografin

Answer 14

oral CT contrast agent (dilute iodine based)

outline GI -but less common - better resolution in new gen scanners

used for elderly if enema & CT colonscopy not possible

Question 15

omnipaque

Answer 15

IV CT contrast agents - iodine based - injected into veins to demonstrate blood vessels or the vascularity of diff tisc

Question 16

occasionally allergy and anaphylactic reaction occur using this contrast

Answer 16

IV (CT) contrast - iodine based (Omnipaque)

Question 17

Diagnosis and staging of cancer is dependent on

Answer 17

1. depth of penetrance of tumour
2. position
3. involvement of regional lymph nodes
4. presence of distant metastases
5. relationship to adjacent structures

Question 18

what scan used for Identifying metabolism?

Answer 18

PET

so not used for liver, background disruption as it has high metabolism - so

Question 19

The object has to be stationary for these scans to be effective

Answer 19

MRI

CT

Question 20

….. not effective for airy areas (least dense)/less tisc

Answer 20

MRI

Question 21

Spinal cord, CNS and MSK visualised by

Answer 21

MRI

these structures are small to be detected by CT

Question 22

CT Radiation dose for abdomen and pelvis

Answer 22

-10mSv

Question 23

CT Radiation dose for chest

Answer 23

-8 mSv

Question 24

ALARA principle

Answer 24

examination necessary?
enough clinical info and appropriate protocol?
avoid rpt examinations

Question 25

Strong magnetic field aligns protons(H+) and this is measured by

Answer 25

MRI

magnetic force unit - tesla

Question 26

Radiofrequency pulse displaces …… and images created by displaying time taken for ……. to ….. back to the original alignment.

Answer 26

1 and 2: protons

3. relax

Water - very light - rotate long time

Fat - heavy - rotate less time

Question 27

MRI Indications

Answer 27

1. bone soft tisc detail
2. vessels
3. brain, spine and MSK
4. abdo and pelvis
5. cardiac

Question 28

MRI disadvantage

Answer 28

claustrophobic and noisy
motion artefact
cannot image patients with pacemakes and aneurysm clips

Question 29

gadolinium DTPA

Answer 29

IV contrast

easily see vascular lesions and some tumours

Question 30

NHS screening for:

Answer 30

BBC
Breast - Mammogram
Bowel
Cervix - PAP smear