Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

22 spring: Radiology > Test 2: lecture 11 and 12 CT, MRI, nuclear > Flashcards

Test 2: lecture 11 and 12 CT, MRI, nuclear Flashcards

1
Q

___ uses x-rays. Measures attenuation of x-rays by tissue (number of x-rays absorbed or scattered). Gives cross-sectional anatomy

A

CT → slices through the patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why does superimposition decrease in CT scans

A

slices are so thin, there is very little overlap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why does CT have better contrast

A

can detect 4000 shades of grey

vs an xray that can detect 5 opacities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how does CT work

A

gantry: xrays taking 360 around patient and then moves slowly down

computer takes this info and turns it into slices

can make a 3D model from the slices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

a + CT number =

a - CT number =

A

attenuation greater then water (bone)

attenuation less then water (fat or gas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

disadvantages of CT

A

increases radiation dose

artifact- metal will cause artifact (confuses the computer)

soft tissue contrast- MRI is better for tiny lesions in brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

benefit of MRI

A

no ionizing radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the term used for opaque in CT and MRI

A

CT: hyper attenuating

MRI hyper intense

white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how to tell CT vs MRI

A

CT bone will be hyper attenuating → very white

fat→ hypo attenuating → black

MRI bone is hypo intense→ grey

Fat→ hyper intense → white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which one CT which one MRI

A

CT bone will be hyper attenuating → very white

fat→ hypo attenuating → black

MRI bone is hypo intense→ grey

Fat→ hyper intense → white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

CT or MRI

A

MRI

fat is bright → white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

MRI contrast

A

Paramagnetic substances such as rare earth metals: Gadolinium

In chelate form (Gd is toxic)

Principle: acts paramagnetic = enhances magnetic properties of neighboring molecules (shortens T1 relaxation)

Increased contrast uptake: increased vascularity, leaky vessels (tumor), BBB interruption, vascularized vs. non-vas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why use MRI

A

better picture for brain and Spine then CT

no radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is better for nasal picture and why

A

nasal → CT cause bone is white

in MRI bone is dark so cant really see as much detail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

scintigraphy

A

diagnostic imaging branch of nuclear medicine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

___ images provide information about the function of cells and tissues imaged.

A

Scintigraphic (nuclear medicine)

17
Q

radionuclide has an ___ nucleus and will undergo ___ by

A

unstable nucleus (excess protons or neutrons)

radioactive decay

photon and/or particulate emission

18
Q

MDP is used for ___

A

bone nuclear imaging

binds to the crystals in bones

highly sensitive for bone disease, but also non specific because increase uptake could be from a bunch of stuff: fracture, disease, infection, normal growth

19
Q
A

this is a bone scan using 99mTc MDP

nuclear imaging → scintigraphy

20
Q
A

99mTcO4- thyroid scan

technitium is taken up by thyroid gland, salivary gland, gastric mucosa and choroid plexus

nuclear medicine → Scintigraphy

21
Q

Which of the following is a good choice of imaging modality?

Ultrasound to rule out a brain tumor

MRI to rule out pulmonary metastatic disease

Radiography to rule out nasal tumor

Scintigraphy for surgical planning of a liver mass removal

CT to evaluate a maxillary mass

A

CT to evaluate a maxillary mass

22
Q

A gamma camera…

Attracts ferromagnetic objects

Is used after administration of a radionuclide

Is used to image the distribution of gadolinium throughout the body

Delivers high resolution images

Emits x-rays

A

Is used after administration of a radionuclide (scintigraphy)

23
Q

Which of the following involves ionizing radiation?

Scintigraphy

Ultrasound

Gadolinium-enhanced MRI

Non-gadolinium MRI

Contrast ultrasound

A

Scintigraphy

24
Q

On which of the following will urine appear darker?

Delayed post contrast CT

T1-weighted MRI

Bone scintigraphy

Cystogram

Plain radiography

A

T1-weighted MRI

25
Q

On which combination of imaging modality is cortical bone black?

Radiography and MRI

Radiography and ultrasound

CT and Nuclear Medicine

T1-weighted and T2-weighted MRI

CT and radiography

A

T1-weighted and T2-weighted MRI

22 spring: Radiology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions