44 terms

NB - Radiology

who discovered xrays
Professor Wilhelm Conrad Roentgen (1895)
who was the first to use a lead apron
Professor Wilhelm Conrad Roentgen
who are the three people that may have taken the first radiograph in the US?
C.E. Kells
W.J. Morton
W.H. Rollins
Who published xlight kills
W.H. Rollins
Who was the first to make a dental radiograph
O. Walkhoff
It takes ________ energy to remove an eletron from a K shell than from outer shells
Most wavelengths used in dentistry vary from ____ to ____ A.U.
0.1 - 1.0
Name the type of radiation produced when a bombarding electron from the tube filament dislodges a K shell electron of the tungstontarget
characteristic radiation
(vs. General or bremsstrahlung which represents the majority of radiation produced and occurs when high speed electrons are stopped or slowed down by the tungsten atoms)
When an entering high speed electron is slowed down there is a loss of energy that is given off as xray or ______.
Heat - mainly generating heat, very little xrays actually produced
The desired type of radiation is called ________ and may only occur above ____ kVP with a tungston target
70 kVP
Systeme International (SI) unit for exposure:
coulombs per kilogram (C/kg)
SI unit for absorbed dose
gray (Gy)
SI unit for dose equivalent
sievert (Sv)
The ________ is the negative electrode in the x-ray tube and contains the tungsten wire and focusing cup
The _________ is the positive electrode in the x-ray tube and contains the target and copper stem/radiator
When the filament in the x-ray tube is heated electrons from metal escape. This boiling off of electrons is called ________ ________.
thermionic emission
How thick must aluminum be for machines 69kVp or lower?
1.5 mm
How thick must aluminum be for machines 70-90 kVp ?
2.5 mm
The purpose of the cathode is to
supply electrons neccesary to produce xrays. Also contains the tungsten wire/fillament and focusing cup.
If a herringbone pattern appears on a developed film x-ray what has occurred?
the clinician put the film packet in the XCP backwards
what is the main difference between manual and automatic processing?
with automatic processing the film goes directly from the developer to the fixer W/OUT a rinse
For manual processing of xrays there is a narrow range of temperature.
a. What is this range?
b. what is optium?
a. 60-75 degrees F
b. 68 degrees F
Motion of the tube head, even if slight, will produce a larger surface area of the focal spot (and magnification of the image) resulting in a
For manual processing of xrays, processing time is dependent on __________
the temperature of the solutions.
Developer: This converts exposed silver halide crystals into black metalic sillver...
Elon & hydroquinone (developer)
Developer: This prevents rapid oxidation of the developing agents...
sodium sulfite (preservative)
Developer: This softens the gelatin for the developing agents to work..
sodium carbonate (activato
Developer: This keeps the reducing agents from developiong enexposed silver halides to produce fog.
Potassium bromide (restrainer)
What is the name of the solution that stops the development process and hardens and removes silver halide crystals?
Fixer: This clears away the unexposed silver bromide crystals
Sodium thiosulfate (cleaning solution)
Fixer: This maintains chemical balance
(Sodium sulfite )preservative
Fixer:This shrinks and hardens the emulsion
Potassium aluminum sulfate ( hardener)
Fixer: This neutralizes the developer:
acetic acid (acidifier)
be able to id nutrient canals and nutrient foramens
The widening of the PDL indicative of occlusal trauma such as bruxing is called
know anatomy on pano
If starbursts appear on a pano film what error has the clinician made
removing the film from the packet too quickly causing static electricity
What is the SLOB rule?
- if object in question shifts in the SAME direction it is on the lingual
- If object in question shifts in the opposite direction it is on the buccal
the amount of radiation that comes out of the xray and unit and reaches the person is called?
the amount of xray energy actually deposited within the body tissues is called
dose/absorbed dose
which tissues are most sensitive to radiation?
the least?
-reproductive cells
-bone marrow
-small lymphocyte
-reproductive mucosa

review inverse square law - chap 5 powerpoint
the MPD (maximum permissible dose) for occupationally exposed people is
5 rem/yr = .05 microsieverts OR 5,000 millirem = 50millisieverts
The MPD for non-occupationally exposed people is
.5rem/yr = .0005microsieverts OR 500 millirem = 5 millisieverts