• Medical imaging refers to several different technologies that are used to view the human body in order to diagnose, monitor, or treat medical conditions.
  • There are several imaging techniques that can provide imaging of biological samples.

  • An X-ray imaging is based on the absorption of X-rays as they pass through the different parts of a patient’s body. 
  • Differences in the densities of body tissue allow us to see inside the body by creating a shadow gram.

  • This instrument consists of a small bell-shaped cavity attached to a hollow flexible tube. 
  • The bell is placed on the skin over the source of the body sound (such as the heart, intestines, or lungs). 
  • The sound is then conducted by the pipe to the ears of the examiner who evaluates the functioning  of the organ.
  • A stethoscope can detect sound waves with frequency ranging from tens to thousands of Hertz

  • If the frequency of sound is higher than 20 KHz (0.02MHz), it is called ultrasonic or ultrasound. 
  • Typical frequencies used in medical ultrasound are 3.5-10 MHz.
  • Ultrasonic waves penetrate tissue and are reflected, scattered and absorbed within it. 
  • The scattered and reflected ultrasound contains information about the form and structure of the tissue.

  • The photons of X-rays and gamma-rays and the particles emitted by radioactive nuclei all have energies far greater than the energies that bind  electrons to atoms and molecules.
  • In controlled doses radiation can be used therapeutically. In the treatment of certain types of cancer. 
  • By careful placement of the radioactive material and by controlling the dose, the cancer cell can be destroyed without greatly damaging the healthy tissue.

Last modified: Wiixata, 14 Adoolessa 2025, 1:07 PM