Multicenter R2* mapping in the healthy brain. Issue 3 (8th May 2013)

• Record Type: Journal Article
• Authors: Ropele, Stefan; Wattjes, Mike P.; Langkammer, Christian; Kilsdonk, Iris D.; de, Wolter L.; Frederiksen, Jette L; Fuglø, Dan; Yiannakas, Marios; Wheeler‐Kingshott, Claudia A. M.; Enzinger, Christian; Rocca, Maria A.; Sprenger, Till; Amman, Michael; Kappos, Ludwig; Filippi, Massimo; Rovira, Alex; Ciccarelli, Olga; Barkhof, Frederik; Fazekas, Franz
• Is Part Of: Magnetic resonance in medicine. Volume 71:Issue 3(2014:Mar.)
• Page Start: 1103
• Page End: 1107
• Publication Date: 2013-05-08
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24772
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24772-sec-0001" sec-type="section"> <title>Purpose</title> <p>The <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zkt9" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0003" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> relaxation rate constant has been suggested as a sensitive measure for iron accumulation. The aim of this multi‐center study was to assess the inter‐scanner and inter‐subject variability of <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zkqn" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0004" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> mapping and to investigate the relationship between brain volume and <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zkr6" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0005" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> in specific structures.</p> </sec> <sec id="mrm24772-sec-0002" sec-type="section"> <title>Methods</title> <p> <alternatives> <inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zkm0" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> <mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0006" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>R</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> </alternatives> mapping was performed in 81 healthy subjects in seven centers using different 3 T systems. <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zknj" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0007" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> was calculated from a dual‐echo gradient echo sequence and was assessed in several deep gray matter structures. The inter‐scanner and inter‐subject variability of <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zk8g" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0008" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> was calculated by means of the coefficient of variation before and after correcting for age.</p> </sec> <sec id="mrm24772-sec-0003" sec-type="section"> <title>Results</title> <p>Significant center effects were seen in some regions which get lost after age correction. The coefficient of variation for the inter‐center variability was much lower (<5.6%) than for the intra‐subject variability (6.7%–11.7%). <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zk6c" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0009" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> in the putamen and red nucleus scaled with cortical volume while <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zm5b" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0010" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>R</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> in the globus pallidus and the substantia nigra was negatively associated with white matter volume.</p> </sec> <sec id="mrm24772-sec-0004" sec-type="section"> <title>Conclusion</title> <p> <alternatives> <inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw2zmb3" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> <mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24772:mrm24772-math-0011" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>R</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> </alternatives> is a robust and reproducible measure in a multicenter setting provided that a standardized MRI protocol is used. The relationship between iron concentration in deep gray matter and volume of specific brain compartments needs further investigation. <bold>Magn Reson Med 71:1103–1107, 2014. © 2013 Wiley Periodicals, Inc.</bold></p> </sec> </abstract>