Radiation is energy within the kind of waves or streams of particles. There area unit several varieties of radiation all around us. Once individuals hear the word radiation, they usually think about nuclear energy, atomic power and radiation, however radiation has several different forms. Sound and visual light weight area unit acquainted types of radiation: different varieties embody ultraviolet light that produces a suntan), actinic ray (a kind of heat energy), and radio and tv signals.

An atom could be a variant of a selected matter. whereas all isotopes of a given component have constant variety of protons, every atom includes a totally different variety of neutrons.

For example, H has 3 isotopes (or variants):

*Hydrogen-1 (contains one nucleon and no neutrons)

*Hydrogen-2, that is termed Hydrogen atom (contains one nucleon and one neutron).

*Hydrogen-3, that is termed Hydrogen (contains one nucleon and 2 neutrons)

Isotopes that don’t seem to be stable and emit radiation area unit referred to as radioisotopes. A isotope is associate in nursing atom of part that undergoes spontaneous decay and emits radiation because it decays. Throughout the decay method, it becomes less radioactive over time, eventually changing into stable.

There area unit 3 main sorts of radioactive decay:
*Alpha decay:
Radioactive decay happens once the atom ejects a particle from the nucleus, that consists of 2 neutrons and 2 protons. Once this happens, the number decreases by a pair of and also the mass decreases by four. Samples of alpha emitters embody atomic number 88, radon, metallic element and atomic number 90.

*Beta decay:
In basic radioactive decay, a nucleon is become a nucleon associate in nursing an negatron is emitted from the nucleus. The number will increase by one, however the mass solely decreases slightly. samples of pure beta emitters embody strontium-90, carbon-14, hydrogen and sulphur-35.

*Gamma decay:
Gamma decay takes place once there’s residual energy within the nucleus following alpha or radioactive decay, or once nucleon capture (a sort of nuclear reaction) in a very reactor. The residual energy is discharged as a gauge boson of nonparticulate radiation. Gamma decay typically doesn’t have an effect on the mass or number of a isotope. samples of gamma emitters embody iodin. cesium-137, cobalt-60, radium-226 and technetium-99m.

Cancer risk assessment:
The ICRP has calculated the likelihood of fatal cancer by relying totally on the assessment of radiation effects by scientific bodies like UNSCEAR and BEIR. It then determined what it calls the “detriment” of radiation exposure. This includes:

*the likelihood of fatal cancer

*the likelihood of non-fatal cancer

*the likelihood of severe hereditary effects

* the length of life lost if the hurt happens





Xrays were discovered by sir Wilhelm Conrad roentgen in 1895.

He was working on the behavior of cathode rays in his lab and after passing high voltage in the tube.

 he observed some faint light on bench and source of the light is barium platinocyanide [BaPt(CN)] which is coated by small piece of paper.

 He concluded that some unknown rays originated from tube. Then sir roentgen performed various type of experiments on cathode tube by placing some objects between tube and fluorescent screen and every time when he changed the objects, the brightness of light is different.

then finally he placed his wife(Anna Bertha Ludwig) hand between the screen and tube and He was surprised about the results.

On that day he recorded the first x ray of his wife’s hand. Later he prepared a manuscript on the properties of x rays and on 1901 he awarded by noble prize in physics.


X rays are a type of ionizing radiation and a form of high energy electromagnetic radiation.

X rays are short in wavelength and have high frequency.

  • Wavelength of the x rays – 10 picometers to 10 nanometers.
  • Frequency of the x rays – 3×1016Hz to 3×1019 Hz
  • energy – 124 eV to 124 Kev

IONIZATION – it is the process by which an atom or molecule acquires a charge by gaining or losing electron

EXCITATION – it is the process in which an electron jump from lower to higher energy level.


x rays are produced from the  x ray tube. It is formed by energy conversion, when a fast moving stream of electron is suddenly strike on target metal (anode) then energy converted into x rays.


  • X rays are invisible
  • It travel in straight line
  • It produce ionization and excitation in the substance through which they pass
  • X rays are electromagnetic waves and not deflected/influenced by electrical or magnetic field
  • X rays are heterogenic and polyenergetic.
  • It cause secondary and scattered radiation
  • It travels at speed of light 3 X 108 m/s
  • It cause biological effect (mutation, carcinoma, cataract)
  • It is pure energy, no charge, they are neutral
  • It is shows luminescence
  • X rays are used in clinical, industry, science etc





Radiology is the medical branch that dealing with radiation to diagnose and treating disease.

Radiologist – radiologist is the doctor who are specialized to diagnose and treating disease with the help of radio- imaging technology.

Radiographer – radiographer are healthcare professionals who perform the procedure of medical imaging with the help of radio-imaging technology

Radio – imaging = making images of the internal body with the help of radiation.

Type of imaging machines

  • X ray
  • Ct scan
  • Mammography
  • Ultrasound
  • Mri
  • Dexa

Brief introduction

X ray

in this we use x rays for imaging, x rays are highly penetrating and ionizing radiation.

Use psp, xray film and digital receptor to record image and scanner to read it.


it is a real time image with the help of x ray. Procedure of this is also same as the x ray.

DARK ROOM – heart of the x ray

It is the area where x ray film is processed with the help of chemical.

Ct – scan

known as computed tomography or computed axial tomography. It uses rotating x ray machine and take different x ray image on different angle to produce virtual slice of body.

Mammography – is also called mammogram. This procedure is for Breast imaging with the help of low ionizing radiation to diagnose the breast cancer, tumor or lump.


also known as sonography which is used the high frequency sound waves to diagnose the disease. Basically it is non ionizing radiation which is used to less harmful than x ray and it is also used to diagnose complication of unborn babies.

US DOPPLER – it is used to estimate the blood flow in vessels.


also known as magnetic resonance imaging. which uses strong magnetic field to generate images of the internal body.


dual energy x ray absorptiometry, it is use to measure the bone density with the help of x ray imaging.


SPECT – single positron emission computed tomography is used the gamma camera 

PET – Positron emission tomography. It uses radioactive material, which act as tracer and PET machined scanned it and shows the activity within the body at cellular level.




• Rene Laennec – Stethoscope
• Alexander Fleming – Penicillin
• Friedrich Miescher – RNA
• Charles Laveran – Microbes of malaria
• William Harvey – Blood circulation
• G. A. Gerhad Henson – Bacteria of Leprosy
• Edward Jenner – Vaccination
• Charles Landersteiner – Rh factor in blood
• Eugen stainak – Sex Hormone
• Antoine van Leeuwenhoek – Sperm
• Barcroft – Spleen function
• Edward calvin Kendall – Thyroxin
• Henry Turner – Turner’s syndrome
• Wilhelm conrad Roentgen – X- Ray’s
• David Hubel – Visual system
• Roger Guillenin – Neuro Hormones
• James Watson and Francis crick – DNA structure
• Alec Jeffreys – DNA Fingerprinting
• Willem Einthoven – Electrocardiogram
• Jonas Salk – Polio vaccine
• Robert koch – TB Bacteria
• Leeuwenhoek – Bacteria
• Eduard Buchner Zymase , the first enzyme
• August Roesel Von Rosenhof – Amoeba
• Paul winchell – Artificial heart
• Karl Lohmann – ATP
• Marcello Malpighi – Blood Cappilaries
• Paul Morawitz – Blood Caugulation explain
• Luc Montagnier – HIV
• Bayliss and Starling – Hormones
• Camillo Golgi – Golgibodies
• Eugene Dubois – Evolution of man
• Keith parter – Endoplasmic Reticulum
• Robert hooke – Cell
• Robert brown Discovered, Nucleus
• Weismann & Strasbnrger Discovered Meiosis
• T. H. Morgan Discovered Sex – linkage in Drosophila
• A. V. Leeuwenhoek Discovered compound microscope
• Schleiden and Schwann – Cell Theory
• Dmitri Ivonovsky Discovered virus
• Robert koch – Cholera Bacteria
• Hugo von mohl – Cell division
• Walther Flemming – Chromosomes
• Albert von kolliker – Mitochondria
• Jan Baptist van Helmont – Photosynthesis




Erect – standing

Decubitus – patient is lying down

Supine – lying on the back

Prone – lying face down

Lateral decubitus – lying on the side

Right decubitus – lying on the right side

Left decubitus – lying on the left side

Extension – when the angle of joint increases.

Flexion –when the angle of joint decreases.

Abduction – refers to the movement away from the midline

Adduction – refers to the movement towards the midline

Rotation – angulation of a body part at particular point or its own axis.

Pronation – movement of hand and forearm in which the palm is moved from facing anteriorly to posteriorly.

Supination – reverse of pronation.

these are the position which is used during the x ray examination and many other medical field to determine the position of the body.

many positions are still remaining which will be added later.


NOTE – if you need any more information about any subject whether it is for your child or sibling’s school project, or for a friend or for your knowledge, you can contact us or send mail or by commenting on any of our posts. we will be very happy to help you.