Image Display

Question 1

A technologist completed a non-contrast scan of the heart for calcium scoring. If the technologist uses a window width (WW) of 300 and a window level (WL) of 30 how will dense calcifications in the heart be displayed?

Answer 1

White

Question 2

Which of the following changes will increase the spatial resolution of a computed tomography (CT) image?

Answer 2

Increase matrix size

Question 3

A technologist modifies the image windowing from -100 window level (WL) to -700 window level (WL). Following this change the image will demostrate:

Answer 3

increase brightness

As WL decreases, the image becomes brighter.

Question 4

How will increasing the window width (WW) of a digital images affect the overall appearance of the image?

Answer 4

Decrease contrast

Question 5

Which of these window settings would be appropriate for viewing the major organs of the abdomen?

Answer 5

400 WW and 40 Wl

Question 6

In the context of a digital matrix, 1024 x 1024 refers to the

Answer 6

number of pixel in the matrix

Question 7

in CT imaging, window width controls the

Answer 7

1. contrast of the displayed image

2. range of the Hounsfield values in the displayed image

Question 8

What anatomical section is typically displayed with a window width of 80 and a window level of 30

Answer 8

Brain

Question 9

Consider this scenario: A new CT scanner in the radiology department has a matrix size of 1024 x 1024. what variable change can increase the matrix size

Answer 9

increase DFOV
Increase SFOV
increase the acquisition thickness

none of those changes will affect of the matrix

Question 10

The individual pixels in a CT image are not visible to the unaided eye because modern CT equipment uses

Answer 10

Large matrices

Question 11

Changing the thickness of a voxel may also change

Answer 11

The tissue types included in the voxel

Question 12

Consider a voxel that includes equal parts bone (+1000 HU) and air (-1000 HU). the the reconstructed image, the displayed pixel value will be approximately

Answer 12

0 HU

Question 13

The thickness of a voxel in CT defined

Answer 13

Reconstruction thickness

Question 14

A CT myelogram calls for a 2100 WW and a 700 WL. what pixel values will be displayed as black?

Answer 14

CT numbers below -350

Question 15

If using a 400 WW and 40 WL, the cerebral spinal fluid the brain will appear as:

Answer 15

gray

Question 16

The three dimensional block of image data in CT is called a:

Answer 16

voxel

Question 17

increasing the WL of a CT image will result in:

Answer 17

Decreased brightness

Question 18

Which of these variable changes can a technologist make to increase the spatial resolution of a CT image

Answer 18

Decrease the DFOV