CBCT – 2

Question 1

CBCT Basis-image Capture

Answer 1

Two basis-image capture sequences as the machine
rotates counterclockwise from Position 1 to Position 2
scans routinely capture in the range of 100 to 600 basis
images per rotational scan.

Question 2

CBCT Image Production
Multiple — projections form the —

Answer 2

basis image
projection data.

Question 3

CBCT Image Production
A volumetric data set is then the

Answer 3

package of images constructed by an imaging
software program which then displays various image reconstructions

Question 4

CBCT Image Production
The — reconstruction is the primary reconstruction when volumetric data
is first accessed by a viewing software program

Answer 4

multiplanar

Question 5

CBCT Image Production
●The number and types of reconstructions (images) are dependent on the

Answer 5

power of
the program as specified by the software manufacturer(s).

Question 6

File Formats

Answer 6

1. Original scan data (projection data) forms
   the volumetric data set

Question 7

File Formats
2. Scanner software can either store the
volumetric data in either the
(2)

Answer 7

a. proprietary format (unique to vendor)
b. universal format – DICOM
(Digital Imaging andCommunications
in Medicine)

Question 8

proprietary format (unique to vendor)

Answer 8

InVivo format

Question 9

universal format – DICOM
(Digital Imaging and Communications
in Medicine)

Answer 9

EggViewer format

Question 10

DICOM

Answer 10

• standard information transfer method
  (file format) for transferring images
  and associated information between
  devices manufactured by various
  vendors

Question 11

DICOM
stands for

Answer 11

Digital Imaging and Communications
in Medicine

Question 12

Multiple third-party software available for
imaging DICOM Compatible CBCT
volumetric data

Answer 12

• Anatomage InVivo 3D
• CareStream 3D
• Cybermed 3D
• Dolphin 3D
• (Infinitt) Xelis Dental, Xelis 3D
• Keystone EasyGuide 3D
• NobelClinician
• OnDemand 3D
• OsiriX DICOM viewer

Question 13

OsiriX DICOM Viewer
most widely used DICOM viewer because
of

Answer 13

global recognition and longevity

Question 14

OsiriX DICOM Viewer
One of first to fully support the

Answer 14

DICOM
standard for easy integration

Question 15

Non-DICOM Compatible 3D software
(4)

Answer 15

• Materialise SurgiCase CMF
• Simplant (Materialise)
• Sirona – SICAT ($~400/kit)
• Morita – i-Dixel

Question 16

Only— data files
aretransferred to and stored in the UMKCSoD MiPACS server

Answer 16

DICOM projection

Question 17

Proprietary (Native) files are stored in the

Answer 17

capture CPU or its server

Question 18

skipped
Why are multiple forms of
datasets a problem?
(3)

Answer 18

• For final storage, proprietary
  volumetric data sets were used
  by 26% of respondents (n =
  68)
• Of the 74% storing in a DICOM
  format, 66% also stored in the
  proprietary format
• 26 % + [74% x 0.66],
  26 % + 48.9% = 74.8% of
  respondents save the
  proprietary format

Question 19

Why is this a problem?
It inhibits access to health care by:
(3)

Answer 19

• limiting the access to the
  patient’s information
• increasing cost and
• delaying time of treatment

Question 20

Why is this a problem?
* Image transfer is not as simple
as transferring one or a series
of intraoral images
* One transfers …

Answer 20

an entire data
set so the user may access the
image files to construct the
selected images needed. The
images needed will vary
between different practitioners

Question 21

Why is this a problem?
* CBCT image reconstruction capacity — the ranges of
intraoral, panoramic and skull images

Answer 21

dwarfs

Question 22

Why is this a problem?
* 2D image reconstructions are not typically stored and
transferred
* Entire volumetric data sets are transferred so practitioners
(2)

Answer 22

– are not limited to a limited number of reconstructions
– can determine their own preferred range of images needed for their
diagnostic and treatment needs

Question 23

Inherent Artifact
(2)

Answer 23

• Beam Hardening
• Streaking

Question 24

Beam Hardening

Answer 24

• is a reconstruction artifact in CT due to the total
  absorption of low energy photons by metal objects
• however, high energy photons in the
  heterogenous x-ray beam will create a signal in
  tissues adjacent the metal structure in the
  backprojection algorithm and these areas will be
  “burned out” thus creating dark areas

Question 25

streak artifact creates the outline of a

Answer 25

“ghost” implant (as
well as other radiopaque streak outlines) in the crosssectional reconstruction. The streak artifact makes it more
difficult to discern the validity of the cortical bone outlines.

Question 26

Streak Artifact
X-rays are heavily attenuated after passing
through metal objects which results in

Answer 26

very weak
signals reaching the detector

Question 27

Streak Artifact
* metal shadows in the raw projection data will then
introduce streak artifact in the backprojection
algorithm reconstructions which introduces the metal streak artifact primarily in — structures

Answer 27

low density (soft
tissue)

Question 28

CBCT:
Image Reconstruction
Applications
(5)

Answer 28

• MPR
• Panoramic
• Volume rendering (3D)
• TMJ
• Implant Planning

Question 29

CBCT Image Capture
and
Data Management:
* Basis Image(s)
* Projection Data –
* Volumetric Data Set –

Answer 29

total set of basis images
image files
managed by image software

Question 30

• Volumetric Data Set
  – image files managed by image software
  – Types
  (2)

Answer 30

a. proprietary (property of a vendor)
b. universal – DICOM

Question 31

2D Panoramic Reconstruction
● Imaging software packages can reconstruct panoramic
images from the
● CBCT scan is not indicated solely for

Answer 31

storage data

panoramic
imaging