Bushong Chapter 8. Questions with Solutions

Bushong Chapter 8

X-ray quantity - answer The number of xrays in the useful beam

X-ray quality - answer The penetrability of the beam

The intensity of the X-ray beam of an X-ray imaging system is measured in
___________ and is called the X-ray __________. – answer Milligray in air (mGya) ;
quantity

Another term, _________ __________ is often used instead of X-ray intensity or X-ray
quantity. - answer Radiation exposure

The mGya is a measure of the number of _______ ________ produced in air by a
quantity of X-rays. – answer Ion pairs

__________ of air increases as the number of X-rays in the beam increases. - answer
Ionization

X-ray quantity is proportional to ______. – answer mAs

mAs is a measure of the total number of ________ that travel from cathode to anode to
produce X-rays. - answerElectrons

X-ray quantity is proportional to the ____ squared. - answerkVp

X-ray quantity varies rapidly with changes in _____. - answerkVp

The change in X-ray quantity is proportional to the ______ of the ratio of the kVp. -
answerSquare

Theoretically, doubling the X-ray intensity by kVp manipulation alone requires an
increase of _____ in kVp. - answer40%

Note that by increasing kVp and reducing mAs so that image receptor exposure
remains constant, the patient dose is ________ significantly. The disadvantage of such
a technique adjustment is reduced image contrast when screen film is the image
receptor. - answerReduced

There is no change in contrast when using ________ image receptors. - answerdigital

If you increase the mAs, (which is the biggest contributor), the X-Ray quantity is
_________ _________

, and the image receptor exposure is ___________. - answerincreased proportionately ;
increased

If you increase the filtration, the X-ray quantity is _______
and the image receptor exposure is ___________. - answerreduced ; reduced

Most general purpose radiographic tubes, when operated at approximately 70 kVp,
produce X-ray intensities of approximately _____ mGya/mAs at 100 cm source to image
receptor distance (SID). - answer50

X-Ray intensity varies inversely w/ the square of the ______ from the x-ray tube target.
This relationship is known as the __________ __________ ________. - answerdistance
; inverse square law

X-ray quantity is inversely proportional to the ________ of the distance from the source.
- answersquare

To maintain a constant exposure of the image receptor, an increase of _______ % in
kVp should be accompanied by a reduction of one half in mAs. - answer15

When SID is increased, ______ must be increased by SID squared to maintain constant
exposure to the image receptor. - answermAs

X-ray imaging systems have metal _______, usually ____ to _____ mm of aluminum
(AL), positioned in the useful beam, and the purpose of these filters is to reduce the
number of ______ _______ ________. - answerfilters ; 1 ; 5 ; low energy x-rays

Adding filtration to the useful x-ray beam ________ patient dose. - answerreduces

The disadvantage of x-ray beam filtration can be _______ _______ ________ when
using screen film caused by x-ray beam hardening. - answerreduced image contrast

X-ray beam hardening _________ the number of high energy x-rays in the beam by
removing the low-energy non-penetrating x-rays. - answerincreases

X-Ray Quality = ______ - answerkVp

_____________ refers to the ability of x-rays to penetrate deeper in tissue. -
answerPenetrability

_________ energy x-rays are able to penetrate tissue more deeply than ________
energy x-rays. - answerHigh ; low

The penetrability of an x-ray beam is called the ________ __________. - answerx-ray
quality