1!Bioengineering 280A"Principles of "Biomedical Imaging"Fall Quarter 2009"Lecture 1"Goals of the Course!1. Develop a firm understanding of the fundamentals of medical imaging, including an appreciation for the common principles underlying the various modalities. !2. Gain a basic understanding of the physical principles underlying the major modalities, including X-ray, computed tomography, MRI, and ultrasound.!Basic Imaging!Imaging!Device!Object!Reconstruction!Algorithm!Measured Data!Image of object!Brief History of Medical Imaging!1895 - Roentgen discovers X-rays!1942 - Dussik demonstrates transmission ultrasound in the brain. !1946 !- Bloch and Purcell discover nuclear magnetic resonance (NMR)!1972 - Hounsfield develops the first computed tomography scanner.!1973 - Lauterbur invents magnetic resonance imaging (MRI) !1974 - Ledley develops the first whole body CT scanner.!2!X-Rays!8 November 1895, Wilhelm Conrad Roentgen discovers X-rays. Receives first Nobel Prize in Physics in 1901. !22 November 1895 X-ray of Mrs. Roentegen’s hand. !X-Ray!An early X-ray imaging system!X-Ray!Computed Tomography!1917 Johann Radon establishes the mathematical framework for tomography, now called the Radon transform. !1972 Godfrey Hounsfield develops first CT system. Unaware of either Radon or Cormack’s work, develops his own reconstruction method. !1979 Hounsfield and Cormack receive the Nobel Prize in Physiology or Medicine. !1963. Allan Cormack publishes mathematical analysis of tomographic image reconstruction. Is unaware of Radon’s work. !3!Computed Tomography!From http://www.sprawls.org/resources/CTIMG/classroom.htm!Computed Tomography!From http://www.sv.vt.edu/xray_ct/parallełParallel_CT.html!Computed Tomography!From http://www.sprawls.org/resources/CTIMG/classroom.htm!Computed Tomography!Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. !Modern CT image acquired with a Siemens scanner. 512x512 matrix.!4!Computed Tomography!5!History of Ultrasound!1942 Dr.Karl Theodore Dussik Transmission ultrasound investigation of the brain First published work on medical ultrasonics. History of Ultrasound!Holmes and Howry, 1955 !Subject submerged in water tank to achieve good acoustic coupling.!Image of normal neck. !History of Ultrasound!Automatic scanner, Glasgow, ca 1959. Image shows twin gestation sacs (s) and bladder (B). !Ultrasound Systems!Acuson Sequoia!Sonosite 180!6!Doppler Ultrasound!3D Ultrasound!History of MRI!1946: Felix Bloch (Stanford) and Edward Purcell (Harvard) demonstrate nuclear magnetic resonance (NMR)!1973: Paul Lauterbur (SUNY) published first MRI image in Nature. !History of MRI!Late 1970’s: First human MRI images!Early 1980’s: First commercial MRI systems!1993: functional MRI in humans demonstrated!7!Clinical MRI System!3 Tesla Magnet at UCSD!Magnet!Image from http://www.fmrib.ox.ac.uk/~stuart/lectures/lecture1/!Image Contrast!Image from Rick Buxton!T1-weighted" T2-weighted"Density-weighted"8!MR Angiography!Image from R. Buxton!Perfusion Imaging with ASL!Image from E.C. Wong!Cardiac Imaging!Image fromhttp://www.bidmc.harvard.edu/cmr/smash/smash.html!Cardiac Tagging!Image from http://www.mri.jhu.edu/~emcveigh/LabIntrøtagging.html!9!Functional MRI!Image from http://www.brainvoyager.de/!Diffusion Tensor Imaging!Image from L. Frank!MR Microscopy!Image from http://mouseatlas.caltech.edu/!MR Spectroscopy!Image from http://www.sf.med.va.gov/mrs/ad/result.htm!10!Molecular Imaging!Image from
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