CBCT - The Basics 2.2 Flashcards
describe CBCT basis image capture
two basis image capture sequences as the machine rotates counterclockwise
how many basis images are captures per rotational scan
100-600
what forms the projection data
multiple basis image projections
what is packaged from basis image projections
a volumetric data set
what makes the volumetric data set
an imaging software program
what is the multiplanar reconstruction
the primary reconstruction when volumetric data is first accessed by a viewing software program
what are the number and types of reconstructions dependent on
the power of the program
what forms the volumetric data set
original scan data ( projection scan)
scanner software can either store the volumetric data in either the:
- proprietary format
- universal format - DICOM
what does DICOM stand for
digital imaging and communications in medicine
which format is the InVivo format
proprietary format
define DICOM
standard information transfer method (file format) for transferring images and associated information between devices manufactured by various vendors
what does HIPAA stand for
health insurance portability and accountability act
what softwares do we have at the school
anatomage inVivo 3D
- CareStream 3D
which software is DICOM compatible
NobelClinician
which software is the free one
OsiriX DICOM viewer
which is the most widely used DICOM viewer
OsiriX DICOM Viewer
what are the non- DICOM compatible 3D software
- materialise SurgiCase CMF
- Simplant
- Sirona- SICAT
- Morita - i-dixel
what are stored in the UMKC SoD MiPACS server
only DICOM projection data files
where are proprietary (native) files stored
in the capture CPU or its server
why are multiple forms of datasets a problem
- it inhibits access to health care by:
- limiting the access to the patient’s information
- increasing cost of treatment
- delaying time of treatment
why is image transfer not as simple as transferring one or a series of intraoral images
one transfers an entire data set so the user may access the image files to construct the selected images needed
CBCT image reconstruction capacity _____ the ranges of intraoral, panoramic, and skull images
dwarfs
are 2D image reconstructions typically stored and transferred
no
why are entire volumetric data sets transferred
- 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
what are the two most common forms of inherent artifact
- beam hardening
- streaking
when is beam hardening seen
when there is metal
what does beam hardening create
pathology that is actually not there
what is beam hardening caused by
- 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
what does the streak implant create in the cross sectional reconstruction
the outline of a “ghost” implant
the streak artifact makes it more difficult to discern the:
validity of the cortical bone outlines
how is streak artifact created
- 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
what are the applications for CBCT image reconstruction
- MPR
- panoramic
- volume rendering (3D)
- TMJ
- implant planning
what are the types of data collected in CBCT
- basis images
- projection data- total set of basis images
- volumetric data set- image files managed by image software
what is the difference between 2D reconstruction and panoramic imaging
teeth are narrower in 2D reconstruction
