Radiology- ABGD Flashcards by Melanie Whalen

Based on the ADA, what are the guidelines for prescribing xrays for a new, adult pt, adult recall with caries, and without caries

New adult: FMX (if evidence of generalized disease or hx of extensive tx) or pano and BWX and selected PAs

Adult Recall w/ caries: BWX Q6-18mo mo

Adult recall without caries: BWX Q24-36mo

How well did you know this?

Not at all

Perfectly

What is the max permissible dose of rad per year for a pregnant pt?

5 mSv/year (151 E speed films)

How well did you know this?

Not at all

Perfectly

What is the max permissible dose of rad per year for the average pt?

50 mSv/year

How well did you know this?

Not at all

Perfectly

What is the “safe zone” when taking xrays?

6 ft from pt and xray beam.
stand 90-135* to the central ray of the beam

How well did you know this?

Not at all

Perfectly

What extraoral films can be utilized to see the following conditions: body of the mandible fx?

body of the mandible fracture- pano, towns

How well did you know this?

Not at all

Perfectly

What extraoral films can be utilized to see the following conditions: neck of condyle fracture

neck of condyle fracture - reverse town, Submentovertex

How well did you know this?

Not at all

Perfectly

What extraoral films can be utilized to see the following conditions: zygomatic arch fx

zygomatic arch fx- waters, sub mento vertex

How well did you know this?

Not at all

Perfectly

What extraoral films can be utilized to see the following conditions: orbit fx?

orbit fx- ceph, water, PA ceph

How well did you know this?

Not at all

Perfectly

What is this?

Tonsilloliths

How well did you know this?

Not at all

Perfectly

what is this

Eagles syndrome if painful- calcified stylohyoid ligament

How well did you know this?

Not at all

Perfectly

Sialolith

How well did you know this?

Not at all

Perfectly

What is the error and how do you correct?

pt is too far forward

narrow blurred ant teeth
vertical distortion in the anterior

cause: anter teeth are infront of bite groove, position teeth in bitegroove

How well did you know this?

Not at all

Perfectly

What is the error and how do you correct?

pt is too far back

wide ant teeth, condyles off image
superimposition of the spine
teeth not in focal trough

postion ant teeth in bite groove
check position of the certical light layer

How well did you know this?

Not at all

Perfectly

What does kVp affect?

Increase kVp= decrease contrast
increase kVp= increase energy, penetration/quality
kilovolt peak in the tube voltage

high contrast = lower kVp = endo and caries. more black and white

How well did you know this?

Not at all

Perfectly

What does mA affect?

mA is the tube current (milliamp)
increase mA = increase in # of electrons and darkness

How well did you know this?

Not at all

Perfectly

What is the inverse law and how do you practice it?

doubling the distance from the xray source decreases the xray beam intensity by a factor of 4.

By making sure the staff is 6 ft away, it max safety

How well did you know this?

Not at all

Perfectly

How does time of exposure affect the image?

double time = double # of photons = double dose
does NOT increase energy
digital sensors need less time

How well did you know this?

Not at all

Perfectly

What kind of radiography system do you use and why?

dentrixdigital- xrayvision software
Rectangular collimation

Never less than E speed film type:
D= 0.081mS1
E= 0.033 mSv

How well did you know this?

Not at all

Perfectly

Describe scatter?

Study These Flashcards

defelction of xray photons through tissues and materials. Contributes to image degradation, loss of contrast and increase dose

Describe attenuation

Study These Flashcards

An xray beam passes through the tissue, photons get absorbed, so there is less energy. Result is absorption and scatter

Describe absorption

Study These Flashcards

tissues accept xray photon energy, which contributes to image contrast. increases dose to pt

Describe noise

Study These Flashcards

appearance of uneven density in a uniformly exposed image.
localized variation in “speckle” or grainy image

How do mA, mAs, kVp, time, and distance affect density?

Study These Flashcards

increases in all of them will increase the density except for distance.

Increase in distance decreases density

When someone refers to the darkness/blackness of an image what property are they referring to?

Study These Flashcards

Density
too dark- excess
too light = insufficient

If your xray is too dense, what can you do to correct?

less: time, kVp, mA, more distance

What is contrast

blacks and whites- less grays ability od an imaging system to distinguish between different densities of objects

On your xray unit how can you control or adjust the contrast?

kVp increase kVp= decrease contrast (more grey)

When would you want to use low kVp?

endo, caries

When would you use high kVp?

help visualize bone. good for perio and oral path eval

Why do xrays magnify? What is the clinical impact?

due to diverging xrays long cone and use of collimators can decrease this impact clinically max distance between the focal spot and sensor and minimizing distance between the object and the sensor will reduce magnification. IO radiography magnify about 4% wile a pano's magnify about 20

What is the long cone technique

use of paralleling device to direct the beam perpendicular to the long axis of the tooth which will minimize the distortion/magnification

Examples of quality control that be implemented in your practice?

use of a radiation health survey *physical: mechanical, electrical, including tube drift/movement *beam quality: validates the operating kVp *tube potential: kVp, timer, exposure vs normal *radiation dosimetry: scatter, suvery, leakage, within room any time facilities change Clinician is responsible for day to day operations and to assess clinical value and proper settings.

1, 2, 3