CT Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What does a CT scan measures?

A

Density

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

On CT image, what is calculated for every slice?

A

Attenuation coefficient

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

What are the two types of CT imaging?

A

Sequential scanning

Helical scanning

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

In which type of CT scan do we usually use?

Sequential scanning
Helical scanning

A

Helical scanning

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

For lungs HRCT, which CT scan will we choose?

Sequential scanning
Helical scanning

A

Sequential scanning

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

2 new CT scan options

A

Multi Slice CT (256 and 320 detector row MSCT)

Dual source CT

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

HU for bones

A

+400 -> +1000

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

HU for Soft tissues

A

+40 -> +80

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

HU for water

A

0

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

HU for fat

A

-60 -> -100

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

HU for lungs

A

-400 -> -600

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

HU for air

A

-1,000

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

In windowing, above the interval values is shown in which color?

A

White

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

In windowing, below the interval values is shown in which color?

A

Black

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

Parameters for windowing (2)

A

Level (HU center)

Width (HU values within the window)

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

Non contrast CT is used for

Give examples

A
Foreign body
Kidney stone
Lung HRCT
Adrenal gland adenoma
Bone structure
Lipoma
Atherosclerosis
Exclude brain hemorrhage
17
Q

Contrast CT is used for

Give examples

A
Angiography
Study vascularization
Tumor differantiation
Inflammation process
Abscesses
18
Q

What are the phases of contrast enhancement? And time

A

(Non enhanced CT)
Early arterial - 20 sec (or 0 sec after bolus)
Late arterial- 40 sec (or 20 sec after bolus)
Hepatic- 80 sec (or 60 sec after bolus)
Nephrogenic- 100 sec (or 80 sec after bolus)
Delayed- 6 min

19
Q

Early arterial phase is useful for the diagnosis of

A

Aorta dissection

Arterial bleeding

20
Q

Late arterial phase is useful for the diagnosis of

A

Liver HCC
Pancreas AC
Insulinoma
Bowel ischemia

21
Q

Hepatic phase is useful for the diagnosis of

A

Hypovascular liver lesions

22
Q

Nephrogenic phase is useful for the diagnosis of

A

Renal cell carcinoma

23
Q

Delayed phase is useful for the diagnosis of

A
Cholangiocarcinoma
Fibrotic metastasis
Breast cancer
Transitional cell carcinoma
Liver Hemangioma
24
Q

In which parients will we have increased risk for Post Contrast Acute Kidney Injury?

A

GFR < 30 mL/min
Impaired kidney function
Multiple contrast admin.

25
Q

We should perform GFR test 7 days after the contrast CT for which patients?

A

GFR < 60 mL/min
Age > 70
Other diseases (kidney failure…)

26
Q

Which patient are at risk for lactate acidosis post contrast CT?

A

Patients who take Metformin for their DM-II

27
Q

Which patients can continue to take Metformin normally before contrast CT?

A

GFR > 45 mL/min

28
Q

Effective dose of CT is ___ mSV

A

5-20 mSV

29
Q

On HRCT, what is the thickness of the slice

A

< 1 mm

30
Q

Which Imaging modality is used in case of pelvic soft tissue imaging?

A

MRI