X-ray

what is "X-ray"

Introduction

Properties of xrays

Discovery of xrays

How are X-rays produced?

How to read an X-ray?

How do you prepare for an X-ray?

X-rays artifacts

Radiation protection for patients

 

Introduction

X-rays are a type of ionizing radiation known as electromagnetic radiation. X-rays provide images of inner body parts, on x-rays we can clearly see any fractures on any bone or joint. X-rays can be used to look at your dental issues, infections, and calcifications and to produce images of the tissues. X-rays are used in mammography, computed tomography (CT), and fluoroscopy. X-ray machines send single X-ray particles through the body and the data is recorded on the computer.

Properties of Xrays:

• X-rays always travel in a straight line
• X-rays are highly penetrating and are invisible rays
• X-rays always travel at the speed of light
• X-rays cannot be deflected by any magnetic or electric field
• X-rays when interacting with matter produce Compton and the photoelectric effect
• X-rays are electrically balanced
• Photographic films are blackened by X-rays
• Fluorescent materials grow when X-rays are aimed at them
• X-rays can produce any chemical and biological changes by ionization and excitation
• Xrays are poly-energetic and heterogenous
• X-rays produce secondary and scattered radiation

 

Discovery of Xrays:

X-rays were not developed however discovery of the X-rays was totally accidental. During the 1870s and 1880s, numerous university physics laboratories were investigating the conduction of cathode rays through a large, partly evacuated glass tube identified as a Crookes tube. It happened long ago in Germany when the scientist Wilhelm Roentgen was using the Crookes tube, Crookes tube is basically like a high-powered light bulb and it is completely evacuated by any type of air, on one side of the tube was an anode (the positive side of the the tube, conducts electricity, radiates heat and contains the target, consist of two types stationary and rotating) and the other side was the cathode (the negative side of the tube and has two primary parts, a filament, and a focusing cup) was connected to the negative pole of high voltage while anode was connected to the positive pole of the high voltage. He had darkened his laboratory and entirely enclosed his Crookes tube with black photographable paper, so he could better see the effects of the cathode rays in the tube. A plate covered with barium platinocyanide, a fluorescent substance, happened to be lying on the top of a table numerous meters from the Crookes tube. There was no visible light that escaped from the Crookes tube because of the black paper that enclosed it, although Roentgen noted that the barium platinocyanide glowed. The intensity of the glow increased as the plate was brought closer to the tube, therefore the doubt about the origin of the glow was cleared. This glow is called fluorescence. Roentgen’s immediate approach to investigate this X-light was to interpose different materials such as wood, and aluminum, and his hand between the Crookes tube and the fluorescing plate. X-rays were first discovered in 1895 by W.K Roentgen, He named them x-rays ‘x’ for unknown, He produced and published the first medical x-ray image in early 1896. The first image was his wife Bertha’s hand. The discovery of x-rays is characterized by several remarkable features and this was the reason to rank high among the events in human history. The first thing we know is that the discovery was accidental. Secondly possibly fewer colleagues of Roentgen until that time had observed x-radiation, however not any of these physicists had recognized its significance and investigated it. Thirdly Roentgen followed his discovery with such eagerness that within little more than one month, he had described x-rays with almost all of the properties we know today. In 1896 xrays were first time used in surgery while digital xrays were introduced in 1997.

 

How are X-rays produced?

X-rays are formed in an X-ray tube whilst high-speed electron decelerates promptly. A low voltage supply heats the filament once the filament is hot to an adequate amount of electrons are emitted, this entire process is called thermionic emission. Electrons are accelerated through a high Pd (50-100 KV) towards the anode after that anode which is generally made up of tungsten is very positive as compared to the filament, attracts the negatively charged electrons and causes them to accelerate. As a result, electrons collide with the metal target (anode), decelerate quickly losing kinetic energy and lastly, xrays are produced.

What are the Parts of an X-ray machine?

• A. operating console
• High-frequency generator
• X-ray tube

These are the main parts of the X-ray machine, the other parts include

• Collimator & Grid
• Bucky
• X-ray image receptor

What are the components of an X-ray tube?

• Focusing cup
• Filament
• Electron stream
• Vacuum (to control the number and speed of accelerated electrons independently)
• Target
• Copper stem 
• Leaded glass
• X-rays
• Beryllium window

 

How to read an X-ray?

Bones

• Bones block radiation
• They appear white

Muscles, fluid, and fat

• Some radiation passes through them
• They appear gray

Breaks or fractures

• Radiation entirely passes through them
• They appear black

 

How do you prepare for an X-ray?

Preparation for an x-ray usually depends on what type of xrays you are getting or on which body part x-ray is being performed:

• The first thing you need to do before entering the x-ray room is to remove any jewelry you are wearing or any metal object like any hairpin and coins etc, which you are carrying because xrays cannot pass through them and your scan will be inaccurate and scan needs to be redone which will result in double exposure to your body
• Wear comfortable clothes or wear gown before the x-ray
• Drink lots of water beforehand if your x-ray is KUB until your bladder feels full
• If you are pregnant or think you may be pregnant, inform the operator before the X-ray because X-rays can be harmful to the fetus

Always remember to follow these preparation instructions to avoid any mishaps.

 

Radiation protection for patients:

Radiation protection should be an important concern during every x-ray procedure, always practice ALARA (as low as reasonably achievable) for radiation exposures

• Use proper technique
• Minimize procedure time
• Minimize the distance of the detector from the patient
• Avoid using a large field of view (FOV)
• Do not use automatic exposure tome (AEC)
• Maximize the distance of the X-ray tube from the patient to the extent possible
• Educate patients about procedures and radiation exposure