{"id":698,"date":"2020-09-24T10:41:24","date_gmt":"2020-09-24T10:41:24","guid":{"rendered":"http:\/\/inverseprobleme.de\/?page_id=698"},"modified":"2020-09-24T12:16:21","modified_gmt":"2020-09-24T12:16:21","slug":"magnetic-particle-imaging-2","status":"publish","type":"page","link":"https:\/\/inverseprobleme.de\/?page_id=698&lang=en","title":{"rendered":"Magnetic Particle Imaging"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Magnetic particle imaging, in short MPI, is an imaging technique that has been invented in 2005 by B. Gleich and J. Weizenecker.<br>The main area of application is medical imaging and related applications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">MPI is a tracer-based technique which is currently in the preclinical phase exploring potential clinical applications:<br>Magnetic nano-particles, each consisting of a magnetic iron-oxide core and a non-magnetic coating, could potentially be injected into the blood stream of a patient.<br>The particles are distributed inside the cardiovascular system.<br>By determining the resulting concentration of particles in the body, it is possible to draw conclusions on, e.g., cloggings in blood vessels, or to locate tumors.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"alignright size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/inverseprobleme.de\/wp-content\/uploads\/2020\/09\/pic1.png\" alt=\"\" class=\"wp-image-707\" width=\"432\" height=\"464\" srcset=\"https:\/\/inverseprobleme.de\/wp-content\/uploads\/2020\/09\/pic1.png 823w, https:\/\/inverseprobleme.de\/wp-content\/uploads\/2020\/09\/pic1-279x300.png 279w, https:\/\/inverseprobleme.de\/wp-content\/uploads\/2020\/09\/pic1-768x826.png 768w\" sizes=\"auto, (max-width: 432px) 100vw, 432px\" \/><figcaption>Magnetization (right) of a particle in response to a dynamic external field (left); middle: initial magnetization vector <\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The basic idea is to exploit the response of the magnetic nano-particles to an external applied and highly dynamic magnetic field.<br>More specifically, a particle abruptly changes its magnetization if the external field changes rapidly in the vicinity of the position of this particle.<br>In order to encode information on the particles&#8216; positions, the external magnetic field is designed in such a way that these rapid changes are limited to a small area, which is then driven through the field of view to scan the entire region of interest.<br>A common realization of this is a magnetic field with a field-free point (FFP).<br>If the FFP is moved through a position with a non-zero concentration of magnetic particles, it causes the magnetization of the particles to flip.<br>This abrupt change in the particle magnetization induces voltages in the receive coils of the scanner.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The goal in MPI is thus to reconstruct the concentration of the magnetic nano-particles inside a body from measurements of the voltages that are caused by temporal changes in the particle magnetization in response to the external magnetic field.<\/strong><br>From an inverse problems point of view the imaging problem can be formulated by a Fredholm integral equation of the first kind for a given space-time-dependent integral kernel.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Magnetic particle imaging, in short MPI, is an imaging technique that has been invented in 2005 by B. Gleich and J. Weizenecker.The main area of application is medical imaging and<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-698","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/pages\/698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=698"}],"version-history":[{"count":3,"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/pages\/698\/revisions"}],"predecessor-version":[{"id":718,"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=\/wp\/v2\/pages\/698\/revisions\/718"}],"wp:attachment":[{"href":"https:\/\/inverseprobleme.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}