Question 1

Dose in CT is considered to be:

Accepted Answer

A)  independent of size. 
B)  size dependent. 
C)  related to the CT numbers. 
D)  similar to a chest examination. 
A)  independent of size. 
B)  size dependent. 
C)  related to the CT numbers. 
D)  similar to a chest examination. B

Question 2

Contrast is adjusted by windowing, changing window width and window level. Window level determines the:

Accepted Answer

A)  number of gray levels displayed. 
B)  midpoint of the gray range. 
C)  size of the field of view. 
D)  slice thickness. 
A)  number of gray levels displayed. 
B)  midpoint of the gray range. 
C)  size of the field of view. 
D)  slice thickness. B

Question 3

The advantages of multislice helical CT (MSHCT) include:
1)multiphase studies.
2)isotropic viewing.
3)longer anatomic coverage.

Accepted Answer

A)  1 and 2 
B)  1 and 3 
C)  2 and 3 
D)  1, 2, and 3 
A)  1 and 2 
B)  1 and 3 
C)  2 and 3 
D)  1, 2, and 3 D

Question 4

The most common reporting method of dose reporting on the present scanners is:

Accepted Answer

A)  Multiple Scan Average Dose (MSA
D) . 
B)  Computed Tomography Dose Index (CTDI). 
C)  Dose-length product (DLP). 
D)  Computed Tomography Dose Index Volume (CTDIvol). 
A)  Multiple Scan Average Dose (MSA
D) . 
B)  Computed Tomography Dose Index (CTDI). 
C)  Dose-length product (DLP). 
D)  Computed Tomography Dose Index Volume (CTDIvol).

Question 5

All of the following are methods of 3D reconstruction techniques in CT except:

Accepted Answer

A)  volume rendering. 
B)  maximum intensity projection. 
C)  shaded surface display. 
D)  pixel-voxel reregistration. 
A)  volume rendering. 
B)  maximum intensity projection. 
C)  shaded surface display. 
D)  pixel-voxel reregistration.

Question 6

An array of numbers arranged in a grid of rows and columns is called a:

Accepted Answer

A)  pixel. 
B)  voxel. 
C)  matrix. 
D)  scan profile. 
A)  pixel. 
B)  voxel. 
C)  matrix. 
D)  scan profile.

Question 7

CT is able to differentiate between tissues with similar densities compared with conventional radiography because of:

Accepted Answer

A)  digital magnification. 
B)  the use of a computer for data processing. 
C)  improved contrast resolution. 
D)  axial slices. 
A)  digital magnification. 
B)  the use of a computer for data processing. 
C)  improved contrast resolution. 
D)  axial slices.

Question 8

Contrast is adjusted by windowing, changing window width and window level. Window width determines the:

Accepted Answer

A)  number of gray levels displayed. 
B)  midpoint of the gray range. 
C)  size of the field of view. 
D)  slice thickness. 
A)  number of gray levels displayed. 
B)  midpoint of the gray range. 
C)  size of the field of view. 
D)  slice thickness.

Question 9

Fourth-generation CT scanners use the following configuration:

Accepted Answer

A)  translate tube and rotating detectors. 
B)  rotating tube and detectors. 
C)  only rotating detectors. 
D)  only rotating tube. 
A)  translate tube and rotating detectors. 
B)  rotating tube and detectors. 
C)  only rotating detectors. 
D)  only rotating tube.

Question 10

The reference material for CT is _____ and is related to the _____ of the tissue.

Accepted Answer

A)  water; field of view 
B)  water; linear attenuation coefficient 
C)  muscle; gray level 
D)  bone; mass attenuation 
A)  water; field of view 
B)  water; linear attenuation coefficient 
C)  muscle; gray level 
D)  bone; mass attenuation

Question 11

Oral contrast for CT should be mixed so it is:

Accepted Answer

A)  the same as for general diagnostic examinations. 
B)  more concentrated than for general examinations. 
C)  less concentrated than for general examinations. 
D)  contrast media is not necessary. 
A)  the same as for general diagnostic examinations. 
B)  more concentrated than for general examinations. 
C)  less concentrated than for general examinations. 
D)  contrast media is not necessary.

Question 12

The CT system's ability to freeze any motion of a scanned object is termed:

Accepted Answer

A)  detector quantum efficiency. 
B)  temporal resolution. 
C)  reconstruction algorithm. 
D)  spatial resolution. 
A)  detector quantum efficiency. 
B)  temporal resolution. 
C)  reconstruction algorithm. 
D)  spatial resolution.

Question 13

Factors that affect image quality in CT consist of:
1)spatial resolution.
2)noise.
3)contrast media.

Accepted Answer

A)  1 and 2 
B)  1 and 3 
C)  2 and 3 
D)  1, 2, and 3 
A)  1 and 2 
B)  1 and 3 
C)  2 and 3 
D)  1, 2, and 3

Question 14

The most significant geometric factor that contributes to spatial resolution is:

Accepted Answer

A)  detector aperture width. 
B)  FOV. 
C)  slice thickness. 
D)  x-ray beam energy. 
A)  detector aperture width. 
B)  FOV. 
C)  slice thickness. 
D)  x-ray beam energy.

Question 15

The measured x-ray transmission values are called:

Accepted Answer

A)  raw data. 
B)  pixels. 
C)  voxels. 
D)  Hounsfield units. 
A)  raw data. 
B)  pixels. 
C)  voxels. 
D)  Hounsfield units.

Question 16

CT detectors are most commonly _____ detectors.

Accepted Answer

A)  ionization (xenon gas) 
B)  scintillation (solid-state) 
C)  thermoluminescent 
D)  phosphorescent 
A)  ionization (xenon gas) 
B)  scintillation (solid-state) 
C)  thermoluminescent 
D)  phosphorescent

Exam 29: Computed Tomography

Dose in CT is considered to be:

Contrast is adjusted by windowing, changing window width and window level. Window level determines the:

The advantages of multislice helical CT (MSHCT) include: 1)multiphase studies. 2)isotropic viewing. 3)longer anatomic coverage.

The most common reporting method of dose reporting on the present scanners is:

All of the following are methods of 3D reconstruction techniques in CT except:

An array of numbers arranged in a grid of rows and columns is called a:

CT is able to differentiate between tissues with similar densities compared with conventional radiography because of:

Contrast is adjusted by windowing, changing window width and window level. Window width determines the:

Fourth-generation CT scanners use the following configuration:

The reference material for CT is _____ and is related to the _____ of the tissue.

Oral contrast for CT should be mixed so it is:

The CT system's ability to freeze any motion of a scanned object is termed:

Factors that affect image quality in CT consist of: 1)spatial resolution. 2)noise. 3)contrast media.

The most significant geometric factor that contributes to spatial resolution is:

The measured x-ray transmission values are called:

CT detectors are most commonly _____ detectors.

Preliminary Steps in Radiography

Compensating Filters

General Anatomy and Radiographic Positioning Terminology

Upper Limb

Shoulder Girdle

Lower Limb

Pelvis and Upper Femora

Vertebral Column

Bony Thorax

Thoracic Viscera

Long Bone Measurement

Contrast Arthrography

Trauma Radiography

Mouth and Salivary Glands

Anterior Part of Neck

Abdomen

Digestive System: Alimentary Canal

Urinary System and Venipuncture

Reproductive System

Skull, Facial Bones, and Paranasal Sinuses

Mammography

Central Nervous System

Vascular, Cardiac, and Interventional Radiography

Pediatric Imaging

Geriatric Radiography

Mobile Radiography

Surgical Radiography

Sectional Anatomy for Radiographers

Magnetic Resonance Imaging

Diagnostic Ultrasound

Nuclear Medicine

Bone Densitometry

Radiation Oncology

Filters

The reference material for CT is _ and is related to the _ of the tissue.