MEDRADSC 2Z03 Chapter Notes - Chapter 11: Godfrey Hounsfield, Cerebrospinal Fluid, Johann Radon
29 Jun 2016
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Film - poor medium to record different x-ray attenuation. Contrast resolution - reduction in strength of densities: air - less dense, fat - dark grey, water/ soft tissue - only easy to tell on ct, bone, metal. Cerebral spinal fluid - provides nutrients as a cushion. Water in brain appear similar on a plane film image. Multiple projections: 1d projection to 2d object, 2d projections to a 3d object. The more projections taken, the more information. Advantages of x-rays --> can pass through the body, get content info. Scan all the way around 180 : operated 9 days continuously, took a supercomputer 2. 5 hours to process o. 2: x-ray generator instead of radioactive material. Increase number of radiation beams available o: placed whole bed on lathe bed scanner, rotate and translate. Images created after each patch o: get a series of grayscale, reconstruct by passing the grayscale images back to the imaging plane, all the way around 180 .
