9848 Lecture Notes - Lecture 1: Digital Radiography, Photostimulated Luminescence, Radiography
19 Jun 2018
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Introduction into Planar X-Ray
Objectives
• The uses of planar radiography
• An overview of x-rays
• An overview of x-ray production
• An overview of image capture devices
• The limitations of planar radiography
Medical imaging – looks at what is actually going on with body. Scans can easily see underlying
condition. Are a broad field and many different things to specialise in.
Imaging Modalities in Diagnostic Radiography – modalities (mode at which something exists)
• Planar radiography / x-ray -
- general radiography / x-ray :
- images are captured using computed radiography( CR); or direct / indirect radiography (DR)
(used to use screens & films – some developing countries still do)
• Mammography – x-ray of breast
• Tomography / tomosysnethesis- very useful where a plane of body is selected and seen in
detail.
• Fluoroscopy – able to see function take place as it takes place. Eg. Watches heart after heart
attack. Dye is put into patient which shows the flow of blood.
- Images to see motion direct radiographic plate (digital images) there still some image
intensifiers (II’s) in use (analogue)
• Angiography –
Imaging Modalities in DR
• computed tomography (CT) – use x-ray photons to get images. Is quite harmful to patient.
Uses large amount of radiation.
•magnetic resonance imaging – equipment has no x-rays used only uses magnetic resonance.
• Ultrasound – soundwaves are used
Who discovered x-rays?
find more resources at oneclass.com
find more resources at oneclass.com
Wilhelm Conrad Roentgen – discovered by accident
X-ray Production (overview)
To produce x-rays we need:
• Electron source → a cathode
• target → an anode
• An evacuated path for the electrons to travel → a vacuum
• External energy source to accelerate the electron
Heat is a by-product and lots of temp is need for cathode (-ve charged electrode)
Black dots = electrode
Orange arrow = x- ray photons
Coil = filament – is the point where electrons are
produced at cathode. These electrons hit the target
(anode) which is positively charged. These x-ray
photons are released.
There are lots of processes that occur at short
period of time.
find more resources at oneclass.com
find more resources at oneclass.com
Production of X-rays (cont’d)
• Process involves deceleration/stopping of a fast moving electron
Achieved as follows:
1. e- beam formed by heating cathode
2. e- attracted to anode
3. e- release energy as x-ray photons
Planar radiography
Uses x-ray (high energy EM radiation)
• X-ray photons are generated in the target of an x-ray tube
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Objectives: the uses of planar radiography, an overview of x-rays, an overview of x-ray production, an overview of image capture devices, the limitations of planar radiography. Medical imaging looks at what is actually going on with body. Are a broad field and many different things to specialise in. Dye is put into patient which shows the flow of blood. Images to see motion direct radiographic plate (digital images) there still some image intensifiers (ii"s) in use (analogue: angiography . Imaging modalities in dr: computed tomography (ct) use x-ray photons to get images. Uses large amount of radiation: magnetic resonance imaging equipment has no x-rays used only uses magnetic resonance, ultrasound soundwaves are used. Wilhelm conrad roentgen discovered by accident. To produce x-rays we need: electron source a cathode, target an anode, an evacuated path for the electrons to travel a vacuum, external energy source to accelerate the electron.
