Radiography X ray, CT, MRI

What is X ray?
It is electromagnetic radiation . It has high energy and penetrate through obj. Medical X ray generate structure inside body.

• X-rays are invisible.

• X-rays are electrically neutral. They have neither a positive nor a negative charge. They cannot be accelerated or made to change direction by a magnet or electrical field.

• X-rays have no mass.

• X-rays travel at the speed of light in a vacuum.

• X-rays cannot be optically focuse

Cathode- provide source of e, contain coiled wire filament emit e . When energy exceed binding energy, cloud of e formed travel to anode by vacuum

collimator- restrict device control size of primary x ray, narrow beam partices 

Image receptor- light sensitive film contained in lightproof encasement cassette

Cassette is design to hold piece of double emulsion x ray film sandwiched between INTENSIFYING SCREEN (2 fluorescent sheets of plastic)- convert x ray radiation to visible light create latent image on x ray film

x ray film cassette

Latent image on x ray film after ionizing radiation , after process will convert to visible image

Difference between COMPUTATED radiograph, DIGITAL radiograph

Computed radiography (CR) cassettes use photo-stimulated luminescence screens to capture the X-ray image, instead of traditional X-ray film. The CR cassette goes into a reader to convert the data into a digital image.

 Digital radiography (DR) systems use active matrix flat panels consisting of a detection layer deposited over an active matrix array of thin film transistors and photodiodes. With DR the image is converted to digital data in real-time and is available for review within seconds.