Exams With Contrast

Question 1

In the brain, normally enhancing structures include:

Answer 1

1. Blood vessels
2. Choroid plexus
3. Dura

Question 2

Iodinated contrasts ____ cross an intact blood brain barrier.

Answer 2

Does not

Question 3

Name things that do not have a blood brain barrier and will enhance

Answer 3

Highly vascularized lesions:
Meningioma

Intracerebral lesions:
Glioblastomas

Question 4

A typical iodinated contras dose for brain scans

Answer 4

100 ml

Question 5

Scan delay for brain scan with contrast

Answer 5

Up to 5 minutes after complete injection

Question 6

Scan delay for brain scan with contrast, for metastatic diseases, AIDS, and MS

Answer 6

45 minutes after the injection.

Question 7

CT studies of the head without contrast include:

Answer 7

Ruling out:
Sinusitis
Trauma
Grave’s disease
Early-stage stroke
Early-stage hematoma
Hydrocephalus 
Dementia
Mastoiditis
Labyrinthitis
Facial or 7th nerve palsy
Petrous or temporal bone studies

Question 8

Reasons for using contrast when scanning the neck include:

Answer 8

Differentiation of blood vessels from lymph nodes

Outline the epidural venous plexus

Blood vessels and vascular tumors appear more dense than lymph nodes when IV contrast is used.

Question 9

A typical iodinated contrast dose for neck scans

Answer 9

Approximately 100 ml

Question 10

A typical rate for injecting iodinated contrast dose for neck scans

Answer 10

3 ml/sec

Question 11

Scan delay for neck scan with contrast

Answer 11

35 seconds following the START of the injection, assuming a helical scan is used.

Scanning is initiated after a saline flush is complete.

Question 12

Saline flush after contrast injection for a neck exam, does what?

Answer 12

Reduces high density streaking in the subclavian area.

Question 13

Neck Studies which call for contrast include

Answer 13

Neck mass
Lymph nodes
Parathyroid adenoma
Parotid mass
Oral pharynx
Larynx
Brachial plexus

Question 14

When scanning the brachial plexus, where should you inject?

Answer 14

In the arm, opposite the side of interest.

Question 15

brachial plexus is

Answer 15

a network of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit.

Question 16

A typical iodinated contrast dose for chest scans

Answer 16

100 ml

Question 17

A typical rate for injecting iodinated contrast dose for chest scans

Answer 17

3 ml/sec

Question 18

Scan delay for chest scan with contrast

Answer 18

Approx 30 second after the start of the injection

Question 19

Reasons for using contrast in a chest exam include:

Answer 19

Masses of chest
Lymphoma
Hilar or cardiac masses
Pulmonary emboli

Question 20

For adrenal masses, a ______ delay, with targeted scans through the adrenal glads are done _______.

Answer 20

10 minute delay

After chest scan

Question 21

A typical iodinated contrast dose for abdominal scans

Answer 21

75 to 150 ml

Question 22

A typical rate for injecting iodinated contrast dose for abdominal scans

Answer 22

2 to 4 ml/sec

Question 23

Scan delay for liver scan with contrast

Answer 23

70 to 80 seconds

Question 24

Scan delay for pancreas scan with contrast

Answer 24

50 to 60 seconds

Question 25

Scan delay for kidneys scan with contrast

Answer 25

80 to 90 seconds

Question 26

Bi-phasic study of the liver

Answer 26

Exam performed to differentiate liver lesions with arterial blood supplies from those with venous blood supplies.

Question 27

Tri-phasic study

Answer 27

Adds a non-contrast set of images

Question 28

A hepatic arterial phase may be visualized by using a ____ delay following _____.

Answer 28

30 second delay | Initiation of IV contrast injection

Question 29

Portal venous phase

Answer 29

1. After moving th table back to the most superior slice position. 2. About 70 seconds after the start of injection

Question 30

Equilibrium phase is about ____ after the start of the injection.

Answer 30

120 seconds

Question 31

A typical iodinated contrast dose for pelvic scans

Answer 31

Approx 100ml

Question 32

A typical rate for injecting iodinated contrast dose for pelvic scans

Answer 32

2 to 3 ml/sec

Question 33

Scan delay for pelvic scan with contrast

Answer 33

Usually a few minutes, to allow for ureter and bladder enhancement

Question 34

What conditions require pelvic scan immediately following injection of contrast

Answer 34

Prostate and ovarian cancer Lymphoma Melanoma

Question 35

A typical iodinated contrast dose for pediatric scans

Answer 35

1.0 ml per kg of body weight

Question 36

Scan delay for pediatric scan with contrast

Answer 36

Scan delay times are slightly less than adult delay times

Question 37

CT angiography is used for reasons including

Answer 37

1. Narrowing caused by atherosclerosis 2. Aneurysms 3. Dissections 4. Traumatic injury 5. Congenital anomalies 6. Effects of vascular treatments

Question 38

Why is a higher injection rate of 3 to5 ml/sec used during a CTA?

Answer 38

To keep the concentration of the contrast media in the vessels sufficiently dense.

Question 39

The slices during a CTA exam. Are acquired in what direction?

Answer 39

In the direction of the blood flow, in order to chase the contrast agent

Question 40

During a CTA, why are thin slices important?

Answer 40

1. For visualizing small structure 2. To minimize partial volume averaging. However, when large distances must be covered, sometimes thicker slices must be used.

Question 41

What is another way to cover the required distance during a CTA?

Answer 41

Increasing the pitch can scan the vessel more quickly.

Question 42

When reconstructing the images for a CTA exam, why should they be slightly overlapped?

Answer 42

Increasing the overlap of slices, increases resolution and decreases the effects of partial volume averaging.

Question 43

As a general rule, a reconstruction interval for a CTA ______ will produce excellent multi-planar recons, MIPS, or other 3D rendering

Answer 43

Interval equal to 1/3 to 1/2 of the slice thickness