Ch. 26 Three Dimensional Digital Imaging

resolution, spatial

A measurement of pixel size in multiplanar reconstruction

Plane, coronal

A vertical plane that divides the body into anterior and posterior sides; runs perpendicular to the ground

plane, sagittal

A vertical plane that divides the body into right and left sides; runs perpendicular to the ground. A midsagittal plane describes a plane that runs through the midline of the body.

voxel

The smallest element of a three-dimensional image; also referred to as volume element or three-dimensional pixel.

________ is the region of interest of the patient anatomy.

field of view (FOV)

Field of View (FOV)

the area that can be captured when performing imaging procedures

raw data is ___________ in volume and undergoes ________, forming a _____________ of axial images termed ____________

three dimensional; reconstruction; "stack", DICOM images

Outline some of the components to patient preparation for 3D digital imaging.

- remove jewelry and metallic items - depending on manufacturer guidelines, have pt. stand, sit or in supine position - referring specialists may request that pt have max. and mand. teeth slightly apart which requires a cotton roll, gauze, etc.

Name some of the common uses of CBCT imaging.

1. implant placement 2. extraction or exposure of impacted teeth 3. definition of anatomic structures, such as inferior alveolar nerve and mental foramen location 4. endodontic assessment 5. airway and sinus analysis 6. evaluation of TMJ disorders 7. orthodontic evaluation 8. evaluation of lesions and abnormalities 9. trauma evaluation

what are the 4 advantages of three-dimensional digital imaging?

1. lower radiation dose (comparable to 3-4 FMX intraoral series) 2. Brief Screening Time (8-10 second scan) 3. Anatomically accurate images (1:1 ratio) 4. Ability to save and easily transport images

what are the 4 disadvantages of three-dimensional digital imaging?

1. patient movement and artifacts 2. Size of the FOV. 3. cost of equipment; training needed for imaging software ($80,000 to $175,000) 4. lack of training in interpretation of image data on areas outside the max. and mand.

MPR images within the FOV provide a ___________ ratio relationship of dimensional measurements of the patient

1:1 ratio

three-dimensional volume rendering

A three-dimensional shape that is created from two-dimensional images.

The ____________ recommends that CBCT images be interpreted only by a ________ or by ____________

American Academy of Oral and Maxillofacial Radiology (AAOMR); board-certified oral and maxillofacial radiologist; a dentist with adequate training and/or experience.

three dimensional digital imaging

An image that demonstrates the anatomy in three dimensions.

What type of technology released in 1999 allowed for 3D imaging?

Cone-beam computed tomography (CBCT)

Factors that can be altered when scanning the patient with a CBCT are __________ and ____________.

FOV size and resolution

What is the purpose of the IAC? What does IAC stand for?

The Intersocietal Accreditation Commission is a nonprofit organization that has developed standards applicable to the minimal requirements for optimum patient care when using dental computed tomography.

resolution, contrast

The number of gray scale colors available for each pixel in the image

Multiplanar reconstruction (MPR)

The reconstruction of raw data into images when imported into viewing software to create three anatomic planes of the body

DICOM data

The universal format for handling, storing, and transmitting three-dimensional images; the acronym refers to Digital Imaging and Communications in Medicine.

What equipment is necessary for three dimensional digital imaging?

a CBCT machine, a computer, and viewing software

plane, axial

a horizontal plane that divides the body into superior and inferior parts; runs parallel to the ground

Once the images produced by CBCT are imported, the data is viewed in what three planes?

axial (X), coronal (lY), and sagittal (Z)

streak artifacts are caused by what?

caused by dense restorations (high attenuation) and may eliminate or obscure the surrounding anatomy

the specialized equipment necessary for three-dimensional imaging that accepts the raw data and converts it to a stack of axial images called DICOM images is called the

computer

a short exposure time for the CBCT ________ the chances for motion artifacts to occur, as well as __________ patient cooperation

decreases; increases

viewing software allows the practitioner to select the region of interest and to scroll through these images on a computer monitor to create three dimension information that will assist in what?

diagnosis and treatment planning

Radiation is stopped and may not reach the receptor when it interacts with an area of high attenuation, such as __________.

large amalgam restorations

The volume of data produced by CBCT is similar to medical CT, but uses much less/more radiation to acquire the images.

less

when viewed together, axial, coronal, and sagittal images are referred to as ______________________.

multiplanar reconstructed images (MPR images)

What must a dentist do to receive accreditation from the IAC?

must satisfactorily pass peer review processes and other requirements outline by the IAC to receive the IAC logo on their CBCT machine

the information that the receptor receives is termed what?

raw data

A computer connected to the CBCT machine accepts _________ and reconstructs the data into a stack of ________ also termed ___________ images.

raw data; axial images; DICOM images

prior to cone-beam computed tomography (CBCT), patient preparations include

removal of metallic items in head and neck, remove eyeglasses

CBCT is similar to panographic imaging in that the CBCT digital sensor captures the field of view by ____________ the patient head.

rotating around

The radiation produced by the CBCT that exits the patient is received by a ______________ and becomes the raw data that is sent to the computer. Scan times vary between ______ seconds.

solid-state flat panel detector; 7-30 seconds

Define cone-beam computed tomography (CBCT)

term used to describe computer-assisted digital imaging in dentistry; this imaging technique uses a cone-shaped x-ray beam to acquire info and present it in three dimensions

Cone-beam volume tomography (CBVT)

term used to describe computer-assisted digital imaging in dentistry; used interchangeably with cone beam volume imagining; these terms are used to differentiate this procedure from medical computed tomography (CT).

If your dental office has the IAC logo on their CBCT machine, what does this mean?

the CBCT machine is operating correctly, the dentist and staff members are using the technology appropriately, and the data is being read comprehensively