Cardiac R2* values are independent of the image analysis approach employed. Issue 2 (1st October 2013)

• Record Type: Journal Article
• Authors: Meloni, Antonella; Rienhoff, Hugh Young; Jones, Amber; Pepe, Alessia; Lombardi, Massimo; Wood, John C.
• Is Part Of: Magnetic resonance in medicine. Volume 72:Issue 2(2014:Aug.)
• Page Start: 485
• Page End: 491
• Publication Date: 2013-10-01
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24942
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24942-sec-0001" sec-type="section"> <title>Purpose</title> <p>To determine whether systematic differences were present between myocardial R2* values obtained with two different decay models: truncation and exponential + constant (Exp‐C).</p> </sec> <sec id="mrm24942-sec-0002" sec-type="section"> <title>Methods</title> <p>Single‐center cohorts were used to compare black and bright blood sequences separately, and a multicenter cohort of mixed bright and black blood studies was used to assess the generalizability. Truncated exponential estimates were calculated with CMRtools, which uses a single region of interest (ROI) method. Exp‐C estimates were calculated using a pixelwise approach.</p> </sec> <sec id="mrm24942-sec-0003" sec-type="section"> <title>Results</title> <p>No differences could be distinguished based upon whether a white or black blood sequence was examined. The two fitting algorithms yielded similar R2* values, with R‐squared values exceeding 0.997 and a coefficient of variation of 3% to 4%. Results using the pixelwise method yielded a small systematic bias (∼3%) that became apparent in patients with severe iron deposition. This disparity disappeared when Exp‐C fitting was used on a single ROI, suggesting that the use of pixelwise mapping was responsible for the bias. In the multicenter cohort, the strong agreement between the two fitting approaches was reconfirmed.</p> </sec> <sec id="mrm24942-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Cardiac R2* values are independent of the signal model used for its calculation over clinically relevant ranges. Clinicians can compare results among centers using these disparate approaches with confidence. Magn Reson Med 72:485–491, 2014. © 2013 Wiley Periodicals, Inc.</p> </sec> </abstract>