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Oncology > Imaging > Flashcards

Flashcards in Imaging Deck (57):
1

Reasons for Imaging in the Management of Cancer

Screening
Making the diagnosis
Staging
Operative planning
Response to treatment
Follow-up

2

Types of Imaging in Cancer

Plain films
CT scans
Fluoroscopy
Mammography
SPECT scans
PET scans
MRI
Ultrasound

3

What are X-rays good for?

Lungs
Kidney/gall stones
Bones

4

X-rays not good for

Soft tissues
Brain

5

What do x-rays rely on?

Differential absorption
Air
Fat
Water
Bone densities

6

Imaging for Bone Lesions

X-rays
CT scans
MRI
PET/CT

7

What are we looking at on x-rays for oncology imaging?

Nature of the bone matrix
Interface of lesion & bone
Cortex intact?
What part of bone?
Benign vs. malignant

8

Define Benign Bone Lesions

Well-defined
No cortical destruction
No periosteal reaction

9

What are CT scans best for evaluating?

Subtle bone changes

10

What are MRI scans best for evaluation of?

Soft-tissue & infiltrative marrow lesions

11

Define Latent Bone Lesions

Surrounded by reactive cortical rim

12

Define Active Bone Lesions

Easily discernible transition without reactive rim

13

Define Aggressive Bone Lesions

Broad infiltrating border

14

Define Fluoroscopy

Continuous X-rays used to obtain real time moving images of internal structures

15

Define CT Scan

X-rays taken in several planes are computer processed to show images in multiple slices: AP, lateral, sagittal, x-section & even as 3D images

16

Advantages of CT Scancs

Differentiate structures of close physical density
Eliminates superimposition of organs
Show calcified & hemorrhagic lesions
Show in multiple planes or even as a 3D image

17

Advantages of CT Scans in Neoplastic Disease

Very good in the abdomen for staging
Very good for evaluation of masses in the chest
Can do virtual colonoscopy
Most intracranial neoplasms are visible

18

Disadvantages of CT Scans

Risk of cancer
Contrast: allergic reactions, anaphylaxis, nephropathy
Expensive
Observer variation

19

Define Pancoast's Tumor

Extension of tumor at apex of the lung involving C8, T1, T2 nerves & possible destruction of ribs

20

Presentation of Pancoast's Tumor

Shoulder pain radiating in the ulnar direction

21

Virtual Colonoscopy

Done with CT
Requires bowel prep
No sedation needed
Not as sensitive as colonoscopy
Can't do biopsies

22

Mammography

Uses low energy X-rays to generate images

23

Abnormal Mammogram

Needs breast examination
Further mammography for confirmation
Ultrasound for better definition
BIRAD classification
MRI with gadolinium- implants very dense
Needle/surgical biopsy may be recommended
Tissue diagnosis key

24

What do nuclear scans measure?

Bone metabolism or remodeling

25

Nuclear Scans

Radio-isotope injected IV
3 hours later, the patient is scanned
Provides 2D image
Function test
Half material goes to the bones
Eliminated through the kidneys

26

Bone Scans

Show increased metabolic activity or increase blood flow
Assess activity or known lesions
Find unknown lesions
Overestimates lesions
MM cold scan until cortical disruption occurs

27

What does PET stand for?

Positron emission tomography

28

What can a PET be combined with?

CT
MRI

29

When are PET scans especially useful?

Lymphomas
Lung CA

30

PET Scans

Detects active, rapidly growing tumors
Higher grade malignancies detected more than benign processes

31

What does SPECT stand for?

Single Photon Emission Computer-Assisted Tomography

32

What is a SPECT scan good for?

Small spinal lesions
Osteoid osteoma
Osteoblastoma

33

How do MRI machines work?

Powerful magnets excite H+ protons to emit measurable electromagnetic radiation

34

Different MRI Techniques

Angiography
Functional MRI
Diffusion MRI
CSF dynamics

35

Disadvantages of MRIs

Expensive
Slow
Claustrophobia
Pacemakers, stents
Small metal fragments
Metal artifact
Need a calm patient
May be genotoxic

36

MRI of the Spine

Radiation free
Superior for soft tissue imaging
Can see subtle differences
Gadolinium assists in delineating surrounding vascularity

37

Ultrasound

High frequency sound waves
Reflect & echo off of tissues
Processed in ultrasonic scanner
Usually seen as 2D image

38

Advantages of Ultrasound

Cheap, quick, easy, safe, comfortable
Shows solids, fluids, muscle, tendon, bone surface
Hampered by bone, air, fat

39

Disadvantage of Ultrasound

Operator dependent

40

When to Use Ultrasound

Thyroid tumors/lesions (test of choice)
Supplement mammography

41

How to make a cancer diagnosis?

Tissue: open biopsy or needle biopsy

42

Lung Biopsy Complications

Pneumothorax
Hemoptysis

43

Which cancers primarily metastasize to the bones?

Breast
Prostate
Lung
Kidney

44

Where are spine mets typically seen?

Base of pedicle
Unilateral destruction of pedicle "winking owl sign"

45

Define Pathologic Fractures

Occur through area of weakened bone: osteoporosis, benign cystic tumor, malignant tumor

46

PROs of X-ray

Simple
Inexpensive
Readily available
Easily interpreted

47

CONs of X-ray

Radiation
Poor tissue contrast
Technician dependent
2D

48

PROs of CT Scans

Rapid
3D capability
Axial imaging
Good bony detail

49

CONs of CT Scans

Highest radiation
Motion & metal artifact
Limited ST contrast

50

PROs of Bone Scans

Images metabolic activity
Very sensitive in bones
Low cost

51

CONs of Bone Scans

Non-specific
Poor detail
Anatomic changes not visualized

52

PRO of MRI

Superior tissue resolution

53

CONs of MRI

Expensive
Motion & metal artifact
Can't use in some patients

54

PROs of PET/CT or MRI

Combines function & anatomy
Best for most cancers

55

CONs of PET/CT or MRI

Expensive (pre-auth)

56

PROs for Ultrasound

Very safe
Inexpensive
Quick

57

CONs for Ultrasound

Small field of view
Technician & radiologist dependent
Artifacts