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Oncology + Palliative > Radiology > Flashcards

Flashcards in Radiology Deck (23):
1

MRI T1 image characteristics + uses

1 tissue type is bright (fat) Anatomical MRI is T1 weighted Best for looking a brain structure

2

MRI T2 images characteristics + uses

2 tissue types are bright (fat + water) Functional MRI is T2 weighted Ideal for tissue oedema

3

What tumours is MRI good for visualising, and what region of the brain is it good for visualising?

Soft tissue tumours

Good if PC is dizziness/ ataxia/ CN involvement - can see posterior fossa on MRI

4

How does a PET scan work?

Detects pairs of gamma rays emitted by postitron-emitting radionuclide = introduced into body on biologically active molecule

5

Use of FDG on PET scans - what is it, how does it work, what is it used to visualise + which cancers are show up well?

Fludeoxyglucose = conc of tracer imaged will indicate metabolic activity as it corresponds to regional glucose uptake Used to explore possibility of metastasis

Good for lymphomas + lung cancer

6

Other tracers used in PET scans

Acetate can be used for prostate cancer

7

How is a PET scan visualised?

Superimposed on CTs, which give anatomical landmarks

8

What is a DEXA scan used for + how are the results shown?

Gives you bone density - shown as a number or on a graph

9

How is a bone scan done + how does it work?

Technetium injected Excreted by kidneys Osteoblasts take up tracer

10

What does a bone scan show?

Tracer goes to site of increase bone remodelling (sclerotic bone mets, healing fractures, osteomyelitis)

11

What are the consequences of bone mets + how are they diagnosed?

Marrow involvement = increased fracture risk, anaemia + spinal cord compression

Bone scan 

12

Management of bone mets + SE?

Bisphosphonates = increase density but cause hairline fractures

NSAIDs + RT

13

What are the types of bone mets + what cancers cause each type?

Lytic (kidney, lung cancer) Sclerotic (prostate)

14

Kidney bone mets - what do they look like?

Mainly lytic but can be a mix Very vascular - needs to be embolised before operated on

15

What is CTPA + what is it used for?

CT pulmonary angiogram Used to look for blood clots

16

What imaging is used for staging cancers?

CT used for chest + abdo cancer

Supplemented with PET-CT to detect areas of intense metabolic activity (especially for lung + oesophageal cancer)

17

What is the RECIST system + what are the responses?

Compares treatments in clinical trials

Complete response = no disease detectable radiologically

Partial response = all lesions shrunk by at least 30%

Stable disease = less than 20% increase or less than 30% decrease

Progressive disease = new lesions, or lesions increased >20%

18

How does a CT scan work?

Rotating X ray tube + opposing detector

Computer reconstruction of axial cross-sectional images, based on X rays

19

What is a CT with contrast and what is it used for, when is it to be used with caution?

Outlines GI tract, used to delineate vascular structures + demonstrate tumour enhancement

Can be nephrotoxic

20

What is the risk of developing malignancy from CT scans?

1 cancer per 1000-2000 scans

21

What is MRI used for in oncology - which cancers?

Neurospinal, rectal, prostate + MSK tumours Staging of head + neck cancer

22

How does US work?

Reflection of high frequency sound waves at soft tissue generates image

23

What 3 ways is US used for in oncology?

Detecting mets in solid visceral abdo organs

Used to assess tumour blood flow

Used to guide biopsy