Imaging

Question 1

An electromagnetic packet of energy(photon) with an extremely short wavelength between 0.1 and 10 nanometres.

Answer 1

Xray

Question 2

In xray, an electron gun fires high energy electrons at a heavy atom material, usually …. The collision of the electrons with tungsten creates “…..” in the form of x rays.

Answer 2

tungsten
braking radiation

These x-rays are then directed at the target being photographed. Some rays are absorbed by bone and others pass through and hit the imaging film.

The emulsion contains silver halide which forms clumps on the film upon exposure.

Question 3

Different types of tissues absorb different amounts of radiation.
In order of least absorption to most…..

Answer 3

air (black), fat, muscle, bone and then (contrast agent, metal implants) (white) (attenuation highest)

Depending on how much radiation is absorbed, the image produced will be different.

Question 4

Radiation loses power as it travels with matter and interact

Answer 4

ATTENUATION (absorption)

Increases with high atomic number (Z), dense, thickness of tisc

Question 5

firing sonic waves into the patient

scan soft tissues such as muscles, tendons and also to monitor embryonic development.

Answer 5

ultra sound

high freq sound pulses
do not travel through air, hence gel applied

o Weaknesses
 Trouble penetrating bone
 Operator dependent
 Trouble scanning through gas pockets

Question 6

xray rotate around target (diff angle)
multiple beams
single axis of rotation
create a 3 dimensional image of the patient.

Answer 6

CT

viewed in saggital, axial or coronal planes
high resolution - could differentiate between tissues of similar density.

Question 7

can increase chances of contracting cancer

Answer 7

CT scans

Question 8

imaging technique used to obtain RT moving images of the internal structures of a patient.

Answer 8

Fluoroscopy

fluoroscope (x ray source) & fluorescent screen between which the patient is placed.
o Strengths
 Moving images obtained using special camera
o Weaknesses
 Patient is exposed to ionising radiation as with all x rays

Question 9

enhances the visibility of vascular structures and organs during radiographic procedures.

Answer 9

Iodinated contrast (type of IV radiocontrast containing iodine)

iodine = nephrotoxic and can result in kidney failure. Extra fluids should always be administered after its use to “flush” the system.

Question 10

unit used to describe the absorption of radiation by human body

Answer 10

sievert (sV)