{"id":4329,"date":"2020-07-09T11:41:21","date_gmt":"2020-07-09T09:41:21","guid":{"rendered":"https:\/\/ist.blogs.inrae.fr\/afs\/?p=4329"},"modified":"2020-07-09T11:41:21","modified_gmt":"2020-07-09T09:41:21","slug":"ultrasound-computed-tomography-on-standing-trees-accounting-for-wood-anisotropy-permits-a-more-accurate-detection-of-defects","status":"publish","type":"post","link":"https:\/\/ist.blogs.inrae.fr\/afs\/2020\/07\/09\/ultrasound-computed-tomography-on-standing-trees-accounting-for-wood-anisotropy-permits-a-more-accurate-detection-of-defects\/","title":{"rendered":"Ultrasound computed tomography on standing trees: accounting for wood anisotropy permits a more accurate detection of defects"},"content":{"rendered":"<script type='text\/javascript' src='https:\/\/d1bxh8uas1mnw7.cloudfront.net\/assets\/embed.js'><\/script><p align=\"justify\"><strong><a href=\"https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-4333 alignleft\" src=\"https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020-300x249.png\" alt=\"\" width=\"300\" height=\"249\" srcset=\"https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020-300x249.png 300w, https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020-768x636.png 768w, https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020-640x530.png 640w, https:\/\/ist.blogs.inrae.fr\/afs\/wp-content\/uploads\/sites\/5\/2020\/07\/Espinosa2020.png 910w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>Key message<\/strong><br \/>\nConsidering anisotropy in image reconstruction algorithm for ultrasound computed tomography of trees resulted in a more accurate detection of defects compared to common approaches used.<\/p>\n<p align=\"justify\"><strong>Abstract<\/strong><br \/>\n<strong>Context<\/strong> Ultrasound computed tomography is a suitable tool for nondestructive evaluation of standing trees. Until now, to simplify the image reconstruction process, the transverse cross-section of trees has been considered as quasi-isotropic and therefore limiting the defect identification capability.<br \/>\n<strong>Aims<\/strong> An approach to solve the inverse problem for tree imaging is presented, using an ultrasound-based method (travel-time computed tomography) suited to the anisotropy of wood material and validated experimentally.<br \/>\n<strong>Methods<\/strong> The proposed iterative method focused on finding a polynomial approximation of the slowness in each pixel of the image depending on the angle of propagation, modifying the curved trajectories by means of a raytracing method. This method allowed a mapping of specific elastic constants using nonlinear regression. Experimental validation was performed using sections of green wood from a pine tree (<em>Pinus pinea<\/em> L.), with configurations that include a healthy case, a centered, and an off-centered defect.<br \/>\n<strong>Results<\/strong> Images obtained using the proposed method led to a more accurate location of the defects compared to the filtered backprojection algorithm (isotropic hypothesis), considered as reference.<br \/>\n<strong>Conclusion<\/strong> The performed experiments demonstrated that considering the wood anisotropy in the imaging process led to a better defect detection compared to the use of a common imaging technique.<\/p>\n<p><strong>Keywords<\/strong><br \/>\nWood, Orthotropy, Ultrasonic, Wave propagation<\/p>\n<div class='altmetric-embed' data-badge-type='donut' data-doi='10.1007\/s13595-020-00971-z'  style='float: right; ' ><\/div>\n<p><strong>Publication<\/strong><br \/>\nEspinosa, L., Brancheriau, L., Cortes, Y. et al. Ultrasound computed tomography on standing trees: accounting for wood anisotropy permits a more accurate detection of defects. Annals of Forest Science 77, 68 (2020). <a href=\"https:\/\/doi.org\/10.1007\/s13595-020-00971-z\">https:\/\/doi.org\/10.1007\/s13595-020-00971-z<\/a><\/p>\n<p><strong>For the read-only version of the full text:<\/strong><br \/>\n<a href=\"https:\/\/rdcu.be\/b5vju\">https:\/\/rdcu.be\/b5vju<\/a><\/p>\n<p><strong>Data availability<\/strong><br \/>\nThe proposed inversion procedure was developed between the years 2015\u20132018. The numerical codes and datasets are available in the CIRAD dataverse (users may request access to files): <a href=\"https:\/\/doi.org\/10.18167\/DVN1\/GI8LSW\">https:\/\/doi.org\/10.18167\/DVN1\/GI8LSW<\/a><\/p>\n<p><strong>Handling Editor<\/strong><br \/>\nJean-Michel Leban<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Key message Considering anisotropy in image reconstruction algorithm for ultrasound computed tomography of trees resulted in a more accurate detection of defects compared to common approaches used. Abstract Context Ultrasound computed tomography is a suitable tool for nondestructive evaluation of standing trees. Until now, to simplify the image reconstruction process, the transverse cross-section of trees [&hellip;]<\/p>\n","protected":false},"author":109,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,110,15],"tags":[],"class_list":["post-4329","post","type-post","status-publish","format-standard","hentry","category-article-type","category-data-in-repository","category-research-paper","cat-14-id","cat-110-id","cat-15-id"],"_links":{"self":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts\/4329","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/users\/109"}],"replies":[{"embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/comments?post=4329"}],"version-history":[{"count":0,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts\/4329\/revisions"}],"wp:attachment":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/media?parent=4329"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/categories?post=4329"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/tags?post=4329"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}