Lesson 2: Development Of Magnetic Resonance Imaging PDF

Krysta R. Josol BSRT 3- San Lazaro Magnetic Resonance Imaging LESSON 2: DEVELOPMENT OF MAGNETIC RESONANCE IMAGING DEVELOPMENT OF MAGNETIC RESONANCE IMAGING NUCLEAR MAGNETIC RESONANCE SCIENCE OF MAGNETIC RESONANCE IMAGING 1946:...

Krysta R. Josol BSRT 3- San Lazaro Magnetic Resonance Imaging LESSON 2: DEVELOPMENT OF MAGNETIC RESONANCE IMAGING DEVELOPMENT OF MAGNETIC RESONANCE IMAGING NUCLEAR MAGNETIC RESONANCE SCIENCE OF MAGNETIC RESONANCE IMAGING 1946: Felix Bloch and Edward Purcell  Discovered Nuclear Magnetic Resonance (NMR) AKA Nuclear Magnetic Resonance Imaging, is an imaging Phenomena. technique to create detailed images of the human body o Nuclear: that only the nuclei of certain without the use of ionizing radiation. atoms react.  The scanner uses a strong magnetic field and o Magnetic: use of a magnetic field is transmit radio waves, then converted by a necessary. computer to generate images. o Resonance: frequency dependence of  Such images sometimes has superior detail when magnetic and radiofrequency fields. compared to x-ray, CT scan, or ultrasound  1952: Bloch and Purcell received the Nobel Prize in Physics. THE ORIGINS 1768-1830: Jean Baptiste Joseph Fourier  Contributes the field involved the development of a mathematical technique to study the transfer of heat between solid objects called conduction. BIOLOGIC APPLICATION OF MAGNETIC RESONANCE 1967: Jasper Jackson produced the first magnetic resonance signal from a live animal. 1968: Jasper (and Wright Langham) published the first NMR signals from a living animal, a (anesthetized) rat. 1971: Raymond Damadian reported the NMR difference THE UNIT MEASUREMENT between tumors to normal tissues. 1856: Nikola Tesla DAMADIAN’S NMR FINDINGS  A Serbian inventor who made significant contributions to the field of electromagnetism. That tumors can be detected by NMR due to its longer (T1,  One of his notable discoveries was the rotating T2) relaxation times than normal tissue. magnetic field. o This suggests that found difference can be used to detect cancer, even on its early stages where it would be most treatable. o Later studies confirmed these differences, but are too variable for diagnostic purposes.  Tesla’s work revolutionized the understanding and application of magnetic fields, laying the foundation for numerous technological advancements in the field of electricity and magnetism. FIRST MAGNETIC RESONANCE IMAGE 1972: Paul Lauterbur  Produced the first magnetic resonance image, introduced projectional NMR tomography, and published in Nature (March 1973) o Involved 2 1mm-diameter tubes filled THE NUCLEUS with water placed in a 1.4T magnet. o Four different 1-dimensional 1898: Isidor Rabi projections of NMR signal were  An Austrian scientist conducted groundbreaking obtained after successive rotations of research while working in the Department of magnetic field gradients by 45 degrees. Physics at Columbia University in New York.  These data were mathematically back-projected  His discovery detects and measures the to form a 2-dimensional tomographic image. individual rotational states of atoms and o Zeugmatography: the results molecules. depended on the effects of two  Additionally, Rabi successfully determined the magnetic fields. magnetic moments of nuclei, providing valuable o Shortly, Lauterbur produced crude insights into their properties. images of his first living subject: a tiny  1944: Isidor Rabi was honored with the Nobel clam. Prize in Physics in understanding the behavior of atomic and molecular structures. Krysta R. Josol BSRT 3- San Lazaro Magnetic Resonance Imaging LESSON 2: DEVELOPMENT OF MAGNETIC RESONANCE IMAGING FIELD GRADIENTS FOR SLICE SELECTION 1977: Damadian  Produced the first diagnostic MR images, cross- 1973: Peter Mansfield sectional images of a human thorax.  Demonstrated how linear magnetic field o The first whole-body image was those gradient could be used to localize NMR signal on of Larry Minkoff's chest, obtained July a slice-by-slice basis. 1977. o Involved stacking multiple 1mm thick o Required approximately 5 hours to sheets of solid camphor into the bore produce. of an NMR spectrometer. 1978: Damadian  Produced the first human head MRI scan. DESIGNING THE FIRST MRI MACHINE o Damadian called his imaging method 1974: Raymond Damadian "fieldfocused NMR" (FONAR). o This became a concept company name  Received a US patent (filed 1972) for the design soon to be formed. of his MRI machine. o Unlike scientists Lauterbur and FIRST MRI SCANNER PRODUCTION Mansfield, Damadian was a physician that looked at NMR as a phenomenon 1978: Damadian that may be used to probe the body  Formed his own company FONAR Focused and diagnose diseases. Nuclear Magnetic Resonance for the o The patent application filed contained manufacturing of MRI scanners. details of an apparatus and method to o Damadian made his first prototype, detect cancer in tissue. named "Indomitable" FONAR 1978.  Although the details of exactly how this o Indomitable: impossible to subdue or “apparatus" would produce images were not defeat. included in the application, Damadian and his 1980: Damadian team set out to build such a device.  Produced the 1st commercial MRI scanner.  1975: Damadian produced the first magnetic resonance image of a live animal, a crosssection FONAR COMPANY image of a mouse. 1980: Damadian  Produced the first commercially available MRI scanner. o Soon recognized that the field-focused method was far too slow and clumsy for routine clinical imaging. o It was then abandoned in favor of the  1975: A Swiss physical chemist Richard Ernst methods of Lauterbur and Mansfield in described the use of Fourier transform of phase subsequent versions of the scanner. and frequency encoding to reconstruct 2D images. 2003 NOBEL PRIZE FOR MEDICINE 1991: Richard Ernst  Was honored with the Nobel Prize in Chemistry 2003: the Nobel Prizes for Medicine were awarded to for contributions to the development of the Lauterbur and Mansfield for the development of MRI. method of highresolution nuclear magnetic  Damadian considered it as a personal injustice resonance (NMR) spectroscopy that he was excluded and urged the Nobel committee to change its mind. APPLICATION TO HUMAN TEST SUBJECTS 1976: Mansfield  And his team produced the first human MRI scan, a cross-section image of a finger. o The finger belongs to Mansfield's research student Dr. A. Maudsley. o Imaging used line-scan technique obtained at 0.35T for 23 minutes. o The white oval is phalangeal bone marrow and the dark bands are tendon.