Fluoroscopy

Question 1

When a flat panel detector is used instead of a conventional image intensifier for fluoroscopic imaging, _______ will not occur.

Answer 1

Vignetting

Question 2

Compared to that of a digital mammography detector, the linear dimension of a detector element (del) of a flat-panel fluoroscopy detector is _________.

Answer 2

About twice to size

Question 3

The U.S. Food and Drug Administration (FDA) regulatory limit for entrance air kerma rate in fluoroscopy is _____.

Answer 3

10 R/min for units with AEC
20 R/min for high level mode

Question 4

The focal spot size of the x-ray tube used in “fluoro mode” is typically __________.

Answer 4

0.6 mm

** Double check

Question 5

The US Food and Drug Administration (FDA) requires that all fluoroscopes sold in the US after May 2006 have what indicator related to radiation dose from a fluoroscopic procedure?

Answer 5

Total air kerma at the reference point

Question 6

How does changing the FOC from 30-cm mode to 23-cm magnification mode change the exposure rate?

Answer 6

Increase by a factor of equal to the square of the FOV ratios

= (30 cm / 23 cm)^2

Question 7

What techniques can be used to limit patient dose during fluoroscopy procedures?

Answer 7

1) Using last image held (LIH)
2) Using tight collimation
3) Decreasing the frame rate if feasible
4) Reducing use of mag modes if feasible