T2 relaxometry with indirect echo compensation from highly undersampled data. Issue 4 (19th November 2012)

• Record Type: Journal Article
• Authors: Huang, Chuan; Bilgin, Ali; Barr, Tomoe; Altbach, Maria I.
• Is Part Of: Magnetic resonance in medicine. Volume 70:Issue 4(2013:Oct.)
• Page Start: 1026
• Page End: 1037
• Publication Date: 2012-11-19
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24540
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24540-sec-0001" sec-type="section"> <title>Purpose</title> <p>To develop an algorithm for fast and accurate <italic>T</italic><sub>2</sub> estimation from highly undersampled multi‐echo spin‐echo data.</p> </sec> <sec id="mrm24540-sec-0002" sec-type="section"> <title>Methods</title> <p>The algorithm combines a model‐based reconstruction with a signal decay based on the slice‐resolved extended phase graph (SEPG) model with the goal of reconstructing <italic>T</italic><sub>2</sub> maps from highly undersampled radial multi‐echo spin‐echo data with indirect echo compensation. To avoid problems associated with the nonlinearity of the SEPG model, principal component decomposition is used to linearize the signal model. The proposed CUrve Reconstruction via principal component‐based Linearization with Indirect Echo compensation (CURLIE) algorithm is used to estimate <italic>T</italic><sub>2</sub> curves from highly undersampled data. <italic>T</italic><sub>2</sub> maps are obtained by fitting the curves to the SEPG model.</p> </sec> <sec id="mrm24540-sec-0003" sec-type="section"> <title>Results</title> <p>Results on phantoms showed <italic>T</italic><sub>2</sub> biases (1.9% to 18.4%) when indirect echoes are not taken into account. The <italic>T</italic><sub>2</sub> biases were reduced (< 3.2%) when the CURLIE reconstruction was performed along with SEPG fitting even for high degrees of undersampling (4% sampled). Experiments in vivo for brain, liver, and heart followed the same trend as the phantoms.</p> </sec> <sec id="mrm24540-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The CURLIE reconstruction combined with SEPG fitting enables accurate <italic>T</italic><sub>2</sub> estimation from highly undersampled multi‐echo spin‐echo radial data thus, yielding a fast <italic>T</italic><sub>2</sub> mapping method without errors caused by indirect echoes. Magn Reson Med, 70:1026–1037, 2013. © 2012 Wiley Periodicals, Inc.</p> </sec> </abstract>