imaging

Question 1

5 medical imaging modalities for cancer screening

Answer 1

1. X-rays
2. ultrasound
3. Computed tomography (CT)
4. magnetic resonance imaging (MRI)
5. Positron emission tomography (PET)

Question 2

which modalities are the only ones which are ionising?

Answer 2

CT and PET

Question 3

Pros of Ultrasound

Answer 3

1. Bedside
2. good evaluation of solid abdominal organs and superficial structures (e.g. breast, thyroid etc…)
3. good spatial resolution

Question 4

cons of ultrasound

Answer 4

1. user dependent
2. limited penetration
3. blind spots

Question 5

pros of CT

Answer 5

1. good for unstable patients
2. good for hollow organs, bones, blood
3. reasonable soft tissue contrast
   4 .excellent spatial resolution

Question 6

cons of CT

Answer 6

1. hard to evaluate tissue properties

Question 7

pros of MRI

Answer 7

1. excellent soft tissue contrast
2. excellent evaluation of tissue properties
3. v good spatial resolution

Question 8

cons of MRI

Answer 8

1. it takes a while
2. enclosed space

Question 9

pros of PET

Answer 9

1. high sensitivity for detection of metabolically active tumours

Question 10

cons on PET

Answer 10

1. poor spatial resolution
2. false positives

Question 11

MRI: what can enhancement/ elevated perfusion indicate

Answer 11

1. increased capillary density
2. capillary permeability

useful for establishing tumour grade

Question 12

MRI: diffusion-weighted imaging

Answer 12

1. reflects cellularity of tumour
2. low diffusion indicates densely cellular tumour

Question 13

MRI: what brain tumours can be detected by diffusion-weighted imaging

Answer 13

1. lymphoma
2. medulloblastoma
3. atypical teratoid rhabdoid tumours
4. germinomas

Question 14

what can magnetic resonance spectroscopy indicate about a tumour

Answer 14

1. increase choline
2. decrease NAA
3. increase in inositol
4. increase in mobile lipids

Question 15

what does progressive disease (PD) mean

Answer 15

≥ 20% increase in the sum of diameters of target lesions

Question 16

what does stable disease (SD) mean

Answer 16

neither sufficient shrinkage for partial response nor increase for progressive disease

Question 17

what does partial response (PR) mean

Answer 17

at least a 30% decrease in the sum of length diameters (SLD) of target lesions

Question 18

what does complete response (CR) mean

Answer 18

disappearance of all target and non-target lesions

Question 19

what does the T in TNM staging mean

Answer 19

the side of the original tumour and local invasion

Question 20

what does the N in TNM staging mean

Answer 20

regional lymph node involvement

Question 21

what does the M in TNM staging mean

Answer 21

distant metastasis

Question 22

what is pseudoprogression

Answer 22

aggressive appearing treatment effects

Question 23

when is pseudoregression mainly seen

Answer 23

with anti-angiogenic agents