Deck 13: Three-Dimensional Computed Tomography: Basic Concepts

Question 1

Which type of 3D imaging approach generates multiplanar reconstruction (MPR) (coronal and sagittal) images?

A) Modeling imaging
B) Projective imaging
C) Slice imaging
D) Volume imaging

Answer 1

Slice imaging

Question 2

Which type of 3D imaging approach produces a true 3D visualization?

A) Modeling imaging
B) Projective imaging
C) Slice imaging
D) Volume imaging

Answer 2

Volume imaging

Question 3

The creation of the simulated 3D image from data collected from the object space is called:

A) 3D transformation.
B) lighting and shading.
C) modeling.
D) rendering.

Answer 3

rendering.

Question 4

In the scene (xyz) coordinate system, the axes are positioned at __________ angles.

A) 30-degree
B) 45-degree
C) 60-degree
D) 90-degree

Question 5

Virtual endoscopy allows the viewer to "fly through" each of these structures except:

A) colon.
B) tracheobronchial tree.
C) vessels.
D) cortical bone.

Question 6

Which of the following uses voxel information to transform the images into a collection of objects with subsequent processing concentrating on the display of the objects?

A) Model-based processing
B) Object-based processing
C) Surface-based processing
D) Voxel-based processing

Question 7

What space does the x, y, and z coordinates define in which multidimensional data are represented?

A) Matrix
B) Virtual space
C) Scene space
D) Blank space

Question 8

All of the following are volume imaging methods except:

A) anaglyphic.
B) holography.
C) polygonal methods.
D) varifocal mirrors.

Question 9

Which stage of volume rendering assigns the different brightness levels or color to a voxel?

A) Modeling
B) Preprocessing
C) Surfacing
D) Rendering

Question 10

An internal representation of surfaces that will be visible in the displayed image and then "lights" according to a standard protocol describes:

A) multiplanar rendering.
B) SR.
C) volume rendering.
D) voxel rendering.

Question 11

Anatomy missed as a result of patient respiration can have what type of appearance on the final 3D image?

A) Band artifact
B) Ring artifact
C) Stairstep artifact
D) Streak artifact

Question 12

Which modeling technique transforms a 2D profile into a 3D object?

A) Extrusion
B) Image mapping
C) Procedural texturing
D) Surface mapping

Question 13

All of the following are major elements of a typical 3D imaging system except:

A) detector array.
B) output.
C) the user.
D) workstations.

Question 14

All of the following are shading algorithms except:

A) flat shading.
B) Gouraud shading.
C) Phong shading.
D) polygonal shading.

Question 15

The most familiar coordinate system is the:

A) display coordinate system.
B) object coordinate system.
C) scanner coordinate system.
D) scene coordinate system.

Question 16

The zero point is also called the:

A) Cartesian point.
B) height of the axes.
C) point of intersection.
D) width of the axes.

Question 17

__________ information is used to assess the three elements of technique of the 3D imaging procedure.

A) Reconstructed
B) Qualitative
C) Quantitative
D) Virtual

Question 18

The generation of a 3D object by using computer software is called:

A) lighting.
B) modeling.
C) rendering.
D) shading.

Question 19

Which is an example of a 3D rendering algorithm?

A) Virtual rendering
B) Surface rendering (SR)
C) Pixel rendering
D) Voxel rendering

Question 20

Which of the following is not a step in the processing of an object-based model into a simulated 3D image?

A) Segmentation
B) Object delineation
C) Preprocessing
D) Rendering

Question 21

The fourth dimension involved in 4D angiography is ____________.

A) density
B) opacity
C) pressure
D) time

Question 22

Clinical applications of 3D imaging in CT include all of the following except:

A) craniomaxillofacial complex.
B) endocrine system.
C) gastrointestinal (GI) system.
D) pulmonary system.

Question 23

Which of the following is a volumetric imaging technique that displays bone, soft tissue, and vessels at the same time?

A) 3D rendering
B) Compositing
C) Dissection
D) Volumizing

Question 24

Which of the following is an algorithm intended to create a thick MPR by using the average of the attenuation through the tissues of interest?

A) AIP
B) Maximum intensity projection
C) Minimum intensity projection
D) Total intensity projection

Question 25

Algorithms for sliding thin slabs (STS) include all of the following except:

A) average intensity projection (AIP).
B) maximum intensity projection.
C) minimum intensity projection.
D) total intensity projection.

Question 26

Which of the following algorithms uses only the tissues with the greatest attenuation?

A) AIP
B) Maximum intensity projection
C) Minimum intensity projection
D) Total intensity projection

Question 27

In the semiautomatic mode of __________, the user selects objects to include the data set through the use of windowing.

A) 3D rendering
B) image segmentation
C) SR
D) volume extraction

Question 28

Which algorithm provides a valuable perspective in defining lesions for surgical planning or detecting subtle small airway diseases?

A) AIP
B) Maximum intensity projection
C) Minimum intensity projection
D) Total intensity projection

Question 29

Volume rendering provides multiple benefits for virtual CT endoscopy except its ability to:

A) add lifelike reality to the images.
B) produce optimum visualization of the anatomy.
C) minimize partial volume-averaging artifacts.
D) combine SR techniques.

Question 30

Which of the following is a technique whereby 3D surfaces are extracted from a volume or whereby voxels are extracted from a volume into another 3D segmented region?

A) 3D rendering
B) Image segmentation
C) MPR
D) Volume extraction

Question 31

Limitations of maximum intensity projections include each of the following except:

A) artifacts from pulsating vessels.
B) inability to show superimposed structures.
C) images are three-dimensionally ambiguous unless depth cues are provided.
D) uses large amounts of data in the 3D space.

Question 32

Typical 3D processing techniques include software to perform all of the following except:

A) disarticulation.
B) MPR.
C) computer-aided diagnosis.
D) transparency visualization.

Question 33

What technique is used to virtually unroll, slice open, and display a 3D model of the colon?

A) Virtual cropping
B) Virtual cutting
C) Virtual dissection
D) Virtual splicing

Question 34

All of the following are tissue types used for voxel classification except:

A) bone.
B) connective.
C) fat.
D) soft tissue.

Question 35

Preprocessing involves the use of all of the following except:

A) classification.
B) delineation.
C) image segmentation.
D) noise-filtering algorithms.

Question 36

Virtual endoscopy includes all of the following applications except:

A) virtual arthroscopy.
B) virtual colonoscopy.
C) virtual cholangiopancreatoscopy.
D) virtual labyrinthoscopy.

Question 37

Which imaging technique uses virtual reality (VR) concepts in the creation of inner views of tubular structures?

A) Virtual cardiology
B) Virtual endoscopy
C) Virtual gastroenterology
D) Virtual bronchoscopy

Question 38

Equipment for 3D image processing does not include:

A) CT scanner console.
B) memory and archiving computer.
C) MRI scanner console.
D) stand-alone computer workstations.

Question 39

What is the first step in virtual endoscopy imaging?

A) Careful selection of scan parameters
B) Image segmentation
C) 3D rendering
D) Image display

Question 40

The next step after data acquisition that is intended to optimize the images before they are subject to further processing and analysis is:

A) 3D rendering.
B) image display.
C) image preprocessing.
D) patient preparation.

Question 41

Only some of the information collected from the voxels that compose each of the scanned slices goes to the computer for image reconstruction.

Question 42

VR is a branch of computer science that immerses users in a computer-generated environment and allows them to interact with 3D scenes.

Question 43

Surface rendered images are superior in all parameters like edge delineation, depiction of vessel lumen, and demonstration of overlapping structures.

Question 44

The following factors must be considered before the use of virtual endoscopy becomes commonplace except:

A) it must be better than real endoscopy.
B) it must be accepted by the public.
C) it must reduce patient dose.
D) radiologists must be well versed in interpreting normal versus abnormal features of anatomy being investigated.

Question 45

Studies have shown that virtual endoscopies would be more expensive than real endoscopies.

Question 46

The purpose of 3D imaging is to use large amounts of data collected from the patient to provide both qualitative and quantitative information.

Question 47

MinIP is an algorithm that only the tissues with the greatest attenuation will be displayed for viewing by an observer.

Question 48

Most experts agree that SR is not best suited for use in CTVR imaging.

Question 49

Computer-aided diagnosis helps the observer view 3D space by displaying the front, back, top, and bottom of an object.

Question 50

In SR, surface formation is the first step, and it involves the operation of contouring.

Question 51

Computed tomographic colonoscopy is an integral tool for the examination of colorectal polyp detection.

Question 52

Volume rendering produces 3D images that have a better image quality and provide more information compared with SR.

Question 53

One advantage of virtual endoscopy is that it can reduce complications that might arise from conventional endoscopy.

Question 54

Describe the role of the radiological technologist in 3D CT imaging.

Question 55

Voxel-based processing makes determinations about each voxel and decides to what degree each should contribute to the final 3D image.

Question 56

Slice imaging is the most complex of all 3D imaging.

Question 57

Proper patient preparation is not important for the success of virtual colonoscopy.

Question 58

The development of computed tomographic angiography and 3D imaging has not proved effective in the evaluation of cerebral aneurysms and arteriovenous malformations.

Question 59

Semiautomatic segmentation allows the operator to select objects to be included in the VR image data set through the use of windowing.

Question 60

Ray tracing involves a mathematical ray sent from the observer's eye through the 2D computer screen to pass through the 3D volume that contains opaque and transparent objects.