{"id":6190,"date":"2019-08-06T08:39:51","date_gmt":"2019-08-06T05:39:51","guid":{"rendered":"https:\/\/umram.bilkent.edu.tr\/?p=6190"},"modified":"2019-10-18T16:04:06","modified_gmt":"2019-10-18T13:04:06","slug":"fast-robust-dejitter-and-interslice-discontinuity-removal-in-mri-phase-acquisitions-application-to-magnetic-resonance-elastography-by-cemre-ariyurek-as-co-author","status":"publish","type":"post","link":"https:\/\/umram.bilkent.edu.tr\/index.php\/2019\/08\/06\/fast-robust-dejitter-and-interslice-discontinuity-removal-in-mri-phase-acquisitions-application-to-magnetic-resonance-elastography-by-cemre-ariyurek-as-co-author\/","title":{"rendered":"&#8221;Fast Robust Dejitter and Interslice Discontinuity Removal in MRI Phase Acquisitions: Application to Magnetic Resonance Elastography&#8221; by Cemre Ariyurek as co-author"},"content":{"rendered":"<section class=\"kc-elm kc-css-178817 kc_row\"><div class=\"kc-row-container  kc-container\"><div class=\"kc-wrap-columns\"><div class=\"kc-elm kc-css-644051 kc_col-sm-12 kc_column kc_col-sm-12\"><div class=\"kc-col-container\"><div class=\"kc-elm kc-css-658408 kc_text_block\"><\/p>\n<p>Our PhD student Cemre Ariyurek has contributed to and published a paper as co-author, entitled \u201cFast Robust Dejitter and Interslice Discontinuity Removal in MRI Phase Acquisitions: Application to Magnetic Resonance Elastography\u201d, with her collaborators Eric Barnhill, Mila Nikolova, Florian Dittmann, Jurgen Braun and Ingolf Sack.\u00a0 <\/p>\n<\/p>\n<p>The authors were honored to have co-authored<br \/>this publication with the great mathematician Mila Nikolova and dedicate it to<br \/>her memory.<\/p>\n<\/p>\n<p>Abstract: <\/p>\n<\/p>\n<p>MRI phase contrast imaging methods that<br \/>assemble slice-wise acquisitions into volumes can contain interslice phase<br \/>discontinuities (IPDs) over the course of the scan from sources, including<br \/>unavoidable physiological activity. In magnetic resonance elastography (MRE),<br \/>this can alter wavelength and tissue stiffness estimates, invalidating the<br \/>analysis. We first model this behavior as jitter along the z-axis of the phase<br \/>of 3D complex-valued wave volumes. A two-step image processing pipeline is then<br \/>proposed that removes IPDs. First, constant slicewise phase shift is removed<br \/>with a novel, non-convex dejittering algorithm. Then, regional physiological<br \/>noise artifacts are removed with novel filtering of 3D wavelet coefficients.<br \/>Calibration of two pipeline coefficients, the dejitter parameter \u03b1 and the<br \/>wavelet band high-pass coefficient \u03c9c , was first performed on a finite-element<br \/>method brain phantom. A comparative investigation was then performed, on a<br \/>cohort of 48 brain acquisitions, of four approaches to IPDs: 1) the proposed<br \/>method; 2) a &#8220;control\" condition of neglect of IPDs; 3) an<br \/>anisotropic wavelet-based method; and 4) a method of in-plane (2D) processing.<br \/>The present method showed medians of [Formula: see text] Pa for a<br \/>multifrequency wave inversion centered at 40 Hz which was within 6% of methods<br \/>3) and 4), while neglect produced [Formula: see text] estimates a mean of 17%<br \/>lower. The proposed method reduced the value range of the cohort against<br \/>methods 3) and 4) by 29% and 31%, respectively. Such reduction in variance<br \/>enhances the ability of brain MRE to predict subtler physiological changes. Our<br \/>theoretical approach further enables more powerful applications of fundamental<br \/>findings in noise and denoising to MRE. <\/p>\n<\/p>\n<p>Barnhill, E., Nikolova, M., Ariyurek, C.,<br \/>Dittmann, F., Braun, J., &amp; Sack, I. (2019). Fast Robust Dejitter and<br \/>Interslice Discontinuity Removal in MRI Phase Acquisitions: Application to<br \/>Magnetic Resonance Elastography.&nbsp;Ieee Transactions on Medical<br \/>Imaging,&nbsp;38(7), 1578\u20131587.&nbsp;<a href=\"http:\/\/doi.org\/10.1109\/TMI.2019.2893369\">http:\/\/doi.org\/10.1109\/TMI.2019.2893369<\/a><\/p><\/p>\n<\/div><\/div><\/div><\/div><\/div><\/section>","protected":false},"excerpt":{"rendered":"","protected":false},"author":7,"featured_media":6198,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[256],"tags":[],"_links":{"self":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/6190"}],"collection":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/comments?post=6190"}],"version-history":[{"count":13,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/6190\/revisions"}],"predecessor-version":[{"id":7168,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/6190\/revisions\/7168"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media\/6198"}],"wp:attachment":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media?parent=6190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/categories?post=6190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/tags?post=6190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}