CCD
The difference between CCD and other image capture systems.
What are lenses or fiber optics (that receive x-ray photons from a scintillation material and transmit light to one or more small capacitors)?
CMOS was made by this group.
Who is NASA?
How many layers are in a PSP cassette? Name them?
6, 7 in newer systems. Protective layer, Phosphor, or Active layer, reflective layer, Conductive layer, Color Layer on newer systems, a support layer, and a backing layer.
This photoconductor material is typically used in Direct Conversion.
What is amorphous selenium (a-Se)?
Photodetector material used in Indirect Conversion.
What is (hydrogenated) amorphous silicon (a-Se:H)?
The difference between structured and unstructured (turbid) phosphors.
Is it that an unstructured phosphor will produce more light than a structured phosphor, thereby decreasing the efficiency?
The major advantage of CMOS.
What is the little to no power the system uses?
Quantum mottle/ Quantum Noise.
This makes Direct Conversion so efficient.
Is it that it immediately converts x-ray photons to an electrical charge?
Each pixel contains what?
A photodiode absorbs the light from the scintillator and generates electrical charges.
Three kinds of inherent noise in CCD systems.
What are Amplification noise, Dark Current Noise, and Statistical Noise?
The major disadvantage of CMOS systems.
Are they more susceptible to noise, therefore making them less efficient?
Fast vs Slow- Scan Directions.
Is Fast-scan the movement of the laser across the imaging plate, and slow-scan is the movement of the imaging plate through the reader; also known as the "scan"?
A photodiode does this.
Does it absorb the x-rays and generate electrical charges?
How to reduce image lag.
Is it increase the time between exposures, or start with the lowest exposure and work your way up in the exam?
Three layers that make up the CCD chip.
What are the polysilicon layer, the silicon dioxide layer, and a silicon substrate?
The (major) difference between CMOS and CCD
Is it that CMOS is a semiconductor element that conducts electrical currents in some conditions and not others?
What does L.A.S.E.R. stand for?
Light Amplification of Stimulated Emission of Radiation.
Define FET and describe what it does.
Field Effect Transmitter or silicon TFT isolates each pixel element and reacts like a switch to send the electrical charge to the image processor.
The most popular type of amorphous silicon detector.
What is the Cesium Iodide scintillator? Gadolinium Sulfide is another option, but less efficient.
Name one structured phosphor and one unstructured phosphor.
Is Gadolinium Oxysulfide (Gd^2O^2S) an unstructured phosphor, and Cesisuim Iodide (CsI) a structured phosphor?
The basic process of how CMOS converts x-rays to a digital processor.
What is the x-ray photons strike the scintillator, convert the x-rays into light which "switches on," each pixel converting light photons into an electrical charge?
The ADC does this.
Does it assign a numerical value to each pixel in a matrix according to the intensity of the detected light?
Define AMFPI and TFT.
Active Matrix Flat-Panel Imagers, and Thin-Film Transistors.
This makes Indirect a 2-step process.
X-rays are converted to light, then light is converted into an electrical charge.