Fluoroscopy Flashcards
A reduction in brightness at the periphery of the image captured with an image intensifier tube is referred to as
vignetting
At any combination of tube potential and current, fluoroscopic equipment with an automatic brightness control should not produce an entrance skin exposure exceeding ____ R/min.
10
Performance testing of fluoroscopic systems must include all the following except:
Automatic film processor
Quality control tests of fluoroscopic systems should be performed:
semiannually.
The input phosphor of an image intensifier tube converts a(n) _____ image into a(n) _____ image
x-ray; light
The maximum entrance exposure rate for fluoroscopic units equipped with AERC is
10 R/min (100 mGya/min).
The photocathode of a fluoroscopic image intensifier is a device that emits
electrons.
The television camera most commonly used to capture the fluoroscopic image from a tube type image intensifier is the
charge-coupled device or CMOS
Which type of distortion that can occur with tube-type fluoroscopic image intensifiers is most often caused by the presence of strong magnetic fields?
S distortion
Which type of test tool may be used to demonstrate pincushion distortion?
Wire mesh tool
Benefits of digital PACS images do not generally include:
improved spatial resolution.
Five images of a DR detector are acquired all at the same technical factors. The pixel brightness readings within a region of interest compare the relationship of the x-ray output to the pixel values. Which quality control test was performed?
Reproducibility
Photoconductors convert x-ray energy into:
electric current
Primary display monitors for viewing digital images should have a luminance value higher than ____ nit.
170
The contrast ratio of a viewing monitor should be higher than:
250
The limiting spatial resolution is also known as the:
Nyquist frequency
The most important component affecting the spatial resolution in digital subtraction angiography is the
Computer matrix size
When viewing digital images on a display monitor, the cosine law would apply to which of the following?
Off-axis viewing
Which of the following should be a part of initial acceptance testing of a digital radiographic system?
a. Evaluation of image uniformity
b. Accuracy of exposure indicator
c. Presence of dropped pixels
A, B and C
Which of the following PACS quality control tests are recommended to be performed on at least a quarterly basis?
a. Test pattern image transmit and receive
b. Image resolution evaluation
c. Compression recall
A, B and C
