imaging Flashcards
1
Q
5 medical imaging modalities for cancer screening
A
- X-rays
- ultrasound
- Computed tomography (CT)
- magnetic resonance imaging (MRI)
- Positron emission tomography (PET)
2
Q
which modalities are the only ones which are ionising?
A
CT and PET
3
Q
Pros of Ultrasound
A
- Bedside
- good evaluation of solid abdominal organs and superficial structures (e.g. breast, thyroid etc…)
- good spatial resolution
4
Q
cons of ultrasound
A
- user dependent
- limited penetration
- blind spots
5
Q
pros of CT
A
- good for unstable patients
- good for hollow organs, bones, blood
- reasonable soft tissue contrast
4 .excellent spatial resolution
6
Q
cons of CT
A
- hard to evaluate tissue properties
7
Q
pros of MRI
A
- excellent soft tissue contrast
- excellent evaluation of tissue properties
- v good spatial resolution
8
Q
cons of MRI
A
- it takes a while
- enclosed space
9
Q
pros of PET
A
- high sensitivity for detection of metabolically active tumours
10
Q
cons on PET
A
- poor spatial resolution
- false positives
11
Q
MRI: what can enhancement/ elevated perfusion indicate
A
- increased capillary density
- capillary permeability
useful for establishing tumour grade
12
Q
MRI: diffusion-weighted imaging
A
- reflects cellularity of tumour
- low diffusion indicates densely cellular tumour
13
Q
MRI: what brain tumours can be detected by diffusion-weighted imaging
A
- lymphoma
- medulloblastoma
- atypical teratoid rhabdoid tumours
- germinomas
14
Q
what can magnetic resonance spectroscopy indicate about a tumour
A
- increase choline
- decrease NAA
- increase in inositol
- increase in mobile lipids
15
Q
what does progressive disease (PD) mean
A
≥ 20% increase in the sum of diameters of target lesions
