Radiography

Question 1

As high speed electrons strike the target in an x-ray tube, ________ are produced

Answer 1

Bremsstrahlung and characteristic x-rays

Question 2

The inherent filtration in a diagnostic x-ray tube results from ___________ and is usually specified in terms of ________.

Answer 2

Components of the x-ray tube itself;

mm Al equivalent

Question 3

Typical x-ray transformers for general radiography have a power rating of about _______.

Answer 3

100 kW

Question 4

What is the relationship between the mean free path (MFP) and the half-value layer (HVL)?

Answer 4

MFP = 1.44 x HVL

Question 5

The increase in x-ray beam intensity from the target end to the filament end of an x-ray tube is due to ___________.

Answer 5

The heel effect

Question 6

What design feature(s) is(are) used in x-ray tubes to manage the potentially excessive heat production in the anode?

Answer 6

Angled anode, rotating anode, and use of materials with high heat-storage capacity like tungsten

Question 7

How does adding filtration affect patient dose?

Answer 7

Patient dose is reduced since lower energy x-rays (which may not penetrate the patient) are removed.

** This applies to fixed technique and AEC

Question 8

The heel effect can be reduced by ______.

Answer 8

Increasing the source to image distance (SID)

Question 9

How do you calculate the grid ratio?

Answer 9

= height of the septa divided by the width of the interspace material

Question 10

Common values for grid ratios for radiographic units are ____

Answer 10

8-12

Question 11

What is the nyquist spatial frequency of a detector?

Answer 11

1 / (2 * detector element size)

**Note: the spacing between detector elements is sometimes referred to as the pitch