Radiology II Flashcards
What is the most popular imaging modality in the US?
Film
*this is on the verge of changing
If the pt is bumped during imaging, what results?
Big wave - motion artifact
What is one difference between Cone Beam CT (CBCT) and pano?
CBCT has NO magnification
Pano has magnification
What has more radiation dose, Panoramic or FMX?
*how much is the dose?
FMX
175 microsievers
FMX with Round Collimation and Film has 175 microsievers.
How much with Rectangular Collimation and Digital or F speed film?
1/5 the Radiation
What are the advantages to a Pano? (3)
What is the drawback?
one shot overview, less radiation, easy to take
less detail
Pano’s are fast and convenient but won’t show what?
Interproximal caries
PSP is how many steps?
Digital is how many steps?
2 step process
1
PSP goes into processing machine that uses what?
Laser beam
In Direct Digital imaging (the CMOS or CCD sensors), what fluoresces when exposed to x-rays and forms visible light radiographic image?
*this is on the active side of the sensor
Scintillator screen
What is on the active side of a metal oxide semi-conductor sensor?
Scintillator
What couples the scintillator screen (fluorescing) to the CMOS chip to reduce image noise?
Fiberoptic face plate
What is a Matrix of Individual Blocks?
What technology uses this?
Voxels (volume elements)
CT (computed tomographic scanning)
Voxels (volume elements) are made up of square images of matrix called ______
pixels
In either CBCT or a Pano, you need to put the pt where?
In the Focal Layer
What is the universal way to store/transfer images in medicine?
Dicomm
A Pano is made with what shape of beam?
Vertical, narrow beam
A Pano rotates around what?
Focal plane/Focal trough
Describe the center of Rotation in a Pano:
moves continuously as tube/receptor rotate around pt
T/F
The closer an anatomic structure is positioned to the center of the trough, the more clearly it is imaged on resulting radiograph
True
Film, PSP, Digital Receptors - which are similar?
Film and PSP similar
Digital receptor black box solid state
If the mandible is positioned Anterior of the bite block, what happens to the image?
If Posterior?
Minification
Magnification
Rotate a pts head toward the Right, which side is minified, which is magnified?
Right side minified *rotated further away
Left side magnified
Excessive downward chin tip will produce what in a Pano?
Excessive upward chin tip will produce what in a Pano?
Too much “smile”
Frown