CBCT - The Basics 2.2

Question 1

describe CBCT basis image capture

Answer 1

two basis image capture sequences as the machine rotates counterclockwise

Question 2

how many basis images are captures per rotational scan

Answer 2

100-600

Question 3

what forms the projection data

Answer 3

multiple basis image projections

Question 4

what is packaged from basis image projections

Answer 4

a volumetric data set

Question 5

what makes the volumetric data set

Answer 5

an imaging software program

Question 6

what is the multiplanar reconstruction

Answer 6

the primary reconstruction when volumetric data is first accessed by a viewing software program

Question 7

what are the number and types of reconstructions dependent on

Answer 7

the power of the program

Question 8

what forms the volumetric data set

Answer 8

original scan data ( projection scan)

Question 9

scanner software can either store the volumetric data in either the:

Answer 9

• proprietary format
• universal format - DICOM

Question 10

what does DICOM stand for

Answer 10

digital imaging and communications in medicine

Question 11

which format is the InVivo format

Answer 11

proprietary format

Question 12

define DICOM

Answer 12

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

Question 13

what does HIPAA stand for

Answer 13

health insurance portability and accountability act

Question 14

what softwares do we have at the school

Answer 14

anatomage inVivo 3D
- CareStream 3D

Question 15

which software is DICOM compatible

Answer 15

NobelClinician

Question 16

which software is the free one

Answer 16

OsiriX DICOM viewer

Question 17

which is the most widely used DICOM viewer

Answer 17

OsiriX DICOM Viewer

Question 18

what are the non- DICOM compatible 3D software

Answer 18

• materialise SurgiCase CMF
• Simplant
• Sirona- SICAT
• Morita - i-dixel

Question 19

what are stored in the UMKC SoD MiPACS server

Answer 19

only DICOM projection data files

Question 20

where are proprietary (native) files stored

Answer 20

in the capture CPU or its server

Question 21

why are multiple forms of datasets a problem

Answer 21

• it inhibits access to health care by:
• limiting the access to the patient’s information
• increasing cost of treatment
• delaying time of treatment

Question 22

why is image transfer not as simple as transferring one or a series of intraoral images

Answer 22

one transfers an entire data set so the user may access the image files to construct the selected images needed

Question 23

CBCT image reconstruction capacity _____ the ranges of intraoral, panoramic, and skull images

Answer 23

dwarfs

Question 24

are 2D image reconstructions typically stored and transferred

Answer 24

no

Question 25

why are entire volumetric data sets transferred

Answer 25

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

Question 26

what are the two most common forms of inherent artifact

Answer 26

• beam hardening
• streaking

Question 27

when is beam hardening seen

Answer 27

when there is metal

Question 28

what does beam hardening create

Answer 28

pathology that is actually not there

Question 29

what is beam hardening caused by

Answer 29

• a reconstruction artifact in CT due to the total absorption of low energy photons by metal objects
• 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 30

what does the streak implant create in the cross sectional reconstruction

Answer 30

the outline of a “ghost” implant

Question 31

the streak artifact makes it more difficult to discern the:

Answer 31

validity of the cortical bone outlines

Question 32

how is streak artifact created

Answer 32

• X- rays are heavily attenuated after passing through metal objects which results in very weak signals reaching the detector
• 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 low density (soft tissue) structures

Question 33

what are the applications for CBCT image reconstruction

Answer 33

• MPR
• panoramic
• volume rendering (3D)
• TMJ
• implant planning

Question 34

what are the types of data collected in CBCT

Answer 34

• basis images
• projection data- total set of basis images
• volumetric data set- image files managed by image software

Question 35

what is the difference between 2D reconstruction and panoramic imaging

Answer 35

teeth are narrower in 2D reconstruction