ENG BE 515 Lecture Notes - Lecture 4: Radon Transform, Niobium, Superconducting Wire
21 Sep 2017
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Spatial resolution - current high resolution in medical imaging is half mm by half mm. Speed - need to freeze motion (now, hard to image the heart), fastest is ultrasound / projectional imaging (x-ray) Geometric space tomogram: slices are digitally stacked together to form 3d image of patient, dense body structures are easy to image or stop a x-ray, soft tissues vary. What stops x-ray are both inner (photoelectric ionization) and outer electrons (compton absorption) in the patients. Whiter pixels means tissues are good at stopping x-rays. Fat (stops best) > bone > muscle > air (darkest; does not stop x-rays ) Linear attenuation coefficient ( ) describes the fraction beam of x-rays or gamma rays is absorbed per unit thickness of the body/ absorber: use intravenous (iv) contrast agent such as, iodine-derivative injectable, Made out of superconducting wire - niobium titanium, which gets very hot.
