What is a type of computer software that allows for additional information to be supplied to the radiologist to enhance diagnosis?
Computer-aided Detection and Diagnosis (CAD)
True or False: CAD is thought of as a "second opinion" in DM.
What is a technique that uses the principles of conventional tomography to produce tomographic images that are intended to enhance the conspicuity of lesions by blurring out structures above and below the layer of interest?
When was the first image intensifier used in fluoroscopy?
What is a dynamic image?
an image in motion
What is the major advantage of the image intensifier?
to decrease dose to the patient
What is another name for dynamic imaging?
real time imaging
What refers to an images intensifier coupled to a video camera that converts the image from the output screen of the image intensifier into a video signal?
What are the major components of conventional fluoroscopy?
spot film device
image intensifier tube
optical image distributor
photo spot camera
What type of images are recorded by the spot film device?
single static images
What happens to mA when switching from fluoro to shooting a spot film?
it increases significantly (from about 1-3 mA to 200-400 mA)
What is the spot film stored in until a stationary image is ready to be taken?
lead incased section
What type of film moves out to be exposed at the film plane and continues to move through until exposure was complete?
photospot film (very similar to a 35 mm camera)
What are the 4 types of monitors?
In fluoroscopy, what helps to reduce dose to the patient and decrease blurring from moving objects?
pulsed fluoroscopy (as short as 3-10 ms/image)
Pulsed fluoroscopy requires a grid-controlled x-ray tube which can reduce the dose as much as _____ compared to non-pulsed fluoroscopy.
What are the technical factors for dynamic fluoroscopy?
1-3 mA and 65-120 kVp
List the parts of the image intensifer to show its function.
input screen (CsI phosphor: converts x-ray to light)
photocathode layer (SbCs3: converts light to electrons)
electrostatic lenses (takes image from cathode (-) to anode (+) side)
output screen (ZnCdS: converts electrons back to light)
How much energy helps accelerate the electrons in the II to move them to the anode side?
Which is smaller: the output screen or the input screen?
the output screen (image is intensified and flipped)
The output screen is ____ the size of the input screen.
Brightness gain ranges from:
The brightness gain concept has been replaced with the ____________________ which measures light gain at the output screen.
What is the unit of measurement for luminance or light brightness?
Candela/square meter (Cd/m2)
Conversion factor gain ranges from:
What is the glass envelope enclosed in that provides mechanical support and shielding?
a metal housing
What is the purpose of the optical image distributer?
to split the light received from the output screen
Name sizes for dual-field and triple-field intensifiers and give their exposure rates.
dual-field: 25cm (30 micro R/sec)
17cm (60 micro R/sec)
triple-field: 25cm (30 micro R/sec)
17cm (60 micro R/sec)
12cm (120 micro R/sec)
What are the typical contrast ratio values?
10:1 to 30:1
15:1 to 35:1
What are the five types of image intensifier artifacts?
What characteristic of the II causes pincushioning and S distortion?
the shape is convex
What artifact results when light is scattered in the image intensifier?
Why does the radiologist view images on a TV monitor instead of an output screen?
the image is too small and bright to be seen clearly for proper viewing and interpretation
For first generation video cameras that used television tubes, what was needed when it came to image lag and SNR?
low image lag
What is the SNR for conventional fluoroscopy? digital fluoroscopy?
in analog to digital conversion, digitizing the analog signal requires dividing it into a number of bits referred to as:
The __________ the bit, the more accurate the ADC.
Digital fluoroscopy uses a ____________ for receiving dynamic digital data from the ADC and processing it quickly for display and storage.
List the key components of the Flat-Panel Detector (Digital):