advanced biomedical imaging n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Advanced Biomedical Imaging PowerPoint Presentation
Download Presentation
Advanced Biomedical Imaging

Loading in 2 Seconds...

play fullscreen
1 / 23

Advanced Biomedical Imaging - PowerPoint PPT Presentation


  • 138 Views
  • Uploaded on

Advanced Biomedical Imaging. Dr. Azza Helal A. Prof. of Medical Physics Faculty of Medicine Alexandria University. Intended learning outcomes of the course (ILOS). To understand physical principles of imaging modalities. Aiming to apply these modalities in a safe and effective way.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Advanced Biomedical Imaging' - peigi


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
advanced biomedical imaging
Advanced Biomedical Imaging

Dr. Azza Helal

A. Prof. of Medical PhysicsFaculty of MedicineAlexandria University

slide2

Intended learning outcomes of the course (ILOS)

  • To understand physical principles of imaging modalities.
  • Aiming to apply these modalities in a safe and effective way.
slide6

Structure of the atom

a)Attraction

1.(+ve nuc. & –ve e).

Prevent ele. from leaving atom

2. Neutron

b) repulsion

between p

-ve

Electron mass 1800 time < p or n

+ve

K shell, L,M,N,O

2n2

Energy levels

ZXA

potential energy

nucleons

Binding energy

Dr Azza Helal

slide7

Types of electromagnetic waves

10-12cm

X Rays are high-energy EM radiation and part of EM spectrum

slide8

Production of X- Rays, X ray tube

High-speed electrons suddenly slowed down releasing part of their energy as X-Rays.

Dr Azza Helal

slide9
X-Ray tube consists of:

Evacuated tube

Cathode (tungsten)

Focusing cup

Copper anode block

Tungsten target (high Z material)

high melting point

high thermal conductivity

More efficient X-Ray production

slide10

Interactions in a target

Bremsstrahlung

Characteristic radiation

slide11

Therapeutic x-ray tube: Mega electron volts (MeV) are used, a higher conversion of electrons into photons, high KV, larger focal spot, longer duration & stationary anode.

Diagnostic x ray tube: (KeV), there is more conversion of the electrons to heat, low KV, small focal spot, short duration & rotating anode.

Total number of electrons converted to heat is 99%.

Only 1% of the electrons are converted to photons

slide13

Computed Axial Tomography (CT)

Probing patient from different directions during 360

rotations with x-ray beam of known intensity (I0) &

measuring it after it has passed the pt (I).

Attenuation depends thickness and density of tissues

  • Image displays on computer

or multiple films

New technologies are

  • Helical CT &
  • Multiple slice / detector

arrays

ultrasound us
Ultrasound (US)
  • Ultrasound machine transmits high-frequency sound into body using a probe.
  • Sound waves travel into body & hit a boundary between tissues (fluid & soft tissue).
  • Some waves reflected back to the probe and are detected by probe while some travel on further until they reach another boundary and then reflect back to the probe.
  • So image depends on transmission

characteristics of the interfaces.

  • Image display on computer or films.
slide16

12cm

Time between pulse emission and echo return determines depth

Velocity =Distance/ Time

Echo

Reflection

160Us

20cm

260Us

Reflection

Echo

DR Azza Helal

magnetic resonance imaging mri
Magnetic Resonance Imaging(MRI)
  • Image formed by transmitting and receiving radio waves inside a high magnetic field.
  • All routine MRI techniques are based on receiving and processing of the signals from protons of hydrogen atom.
  • The image is mainly related to Patient hydrogen density
  • MRI makes great pictures because of large no of protons in the body, primarily in water and fat.
  • Image display on computer or multiple films
assignments
Assignments

One student will be selected for assignment

suggested readings
Suggested Readings

David Sutton’s Radiology

Physics for medical imaging by RF Fare & PJ Allisy-Roberts.

question
Question

Mention different components of x ray tube?