Chapter 8: Digital Imaging Flashcards
The fundamentals and types of Digital Imaging, Digital Imaging Equipment
Define the term: sensor
in digital imaging, an image receptor that is used to capture an intraoral or extraoral image
Define the term: indirect digital imaging
a method of obtaining a digital imaging from a sensor after exposure to x-rays by using a scanner to convert information into a digital form so that it can be viewed on a computer monitor
What are the two methods of obtaining a digital image?
- direct digital imaging
- indirect digital imaging
Define the term: digital imaging
a system of filmless imaging used to capture an image using a sensor, breaking it into electronic pieces, and presenting and storing the image using a computer
When comparing digital imaging to conventional film, what is the advantage of the gray-scale resolution?
digital imaging has a greater gray-scale resolution with up to 256 shades of gray, in comparison to 25 shades of gray on conventional film
Define the term: image
a picture or likeness of an object
Define the term: charge-coupled device (CCD)
a solid-state silicon chip detector found in an intraoral digital sensor that converts light or x-ray photons into an electrical charge or signal
Define the term: curve of Spee
the anterior-posterior anatomic curvature of the occlusal surfaces of the teeth
Define the term: digital subtraction
a feature of digital imaging used to reverse the gray scale as an image is being viewed, causing radiolucent images (normally black) to appear white and radiopaque images (normally white) to appear black
Define the term: digital image
an image composed of pixels
Define the term: bit-depth image
the number of possible gray-scale combinations for each pixel
Define the term: digitize
in digital imaging, to convert an image into digital form that, in turn, can be processed by a computer
Define the term: labial mounting
an image mounting method in which the radiographs are placed in the mount for the dental radiographer to view the images from the labial aspect
Define the term: analog-to-digital converter (ADC)
the method used to convert data elements acquired by the sensor are communicated to the computer in analog form and then converted into digital form
What is one of the main disadvantages of digital imaging in comparison to conventional film?
the size and thickness of the sensor can be uncomfortable for patients or can be more common in inducing their gag reflex
True or false: The PSP plate used in indirect digital imaging is a one-time-use product.
False
Define the term: direct digital imaging
a method of obtaining a digital image in which an intraoral sensor is exposed to x-radiation to capture an image that can be viewed on a computer monitor
Define the term: anatomic order
the order in which teeth are arranged within the dental arches
Define the term: mount
to place in an appropriate setting for display or study
Define the term: beam alignment device
- a device used to align the position-indicating device in relation to tooth and image receptor
- positions the intraoral image receptor in the mouth and retains the image receptor in position during exposure
- helps stabilize the image receptor in the mouth and reduces the chances of movement, thus reducing the patient’s exposure to x-radiation
Define the term: pixel / picture element
in digital electronic images, digital information is contained in, and presented as, discrete units of information
Define the term: complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)
- silicon-based detector used in digital imaging
- differs from the charge-coupled device in the way that pixels are read
Why does digital imaging require less radiation than conventional film?
the digital sensor is more sensitive to x-radiation than conventional film
What is the difference in the percentage of exposure time for digital imaging compared to conventional film?
50-90% less exposure time
Define the term: image receptor
a recording medium (ex: PSP plate, digital sensor)
Define the term: storage phosphor imaging
an indirect method of obtaining a digital image in which the image is recorded on phosphor-coated plates and then placed into an electronic processor, where a laser scans the plate and produces an image on a computer screen
What are the two most common types of direct digital imaging receptors?
- charge-coupled device (CCD)
- complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)
Define the term: lingual mounting
an image mounting method in which the radiographs are placed in the mount for the dental radiographer to view the images from the lingual aspect
What can be used to help stabilize the image receptor during exposure?
beam alignment device
When comparing digital imaging to conventional film, what is the advantage of the quality of diagnostic images?
the dimensional and geometric factors of digital imaging are greater
Define the term: analog image
an image produced on conventional film that looks like the thing it represents
What type of image receptor is common when using indirect digital imaging?
photo-stimulable phosphor imaging (PSP) plate
Define the term: line pairs/millimeter (lp/mm)
a measurement used to evaluate the ability of the computer to capture the resolution (detail) of an image
When comparing digital imaging to conventional film, what is the advantage of the radiation dose?
digital imaging requires less radiation than conventional film, thus reducing the patient’s exposure
True or false: Digital imaging requires less radiation than conventional film.
True
When comparing direct digital imaging to conventional film, what is the advantage of speed?
direct digital imaging produces the image instantly and does not require any processing time
