Dynamic contrast enhanced‐MRI in rectal cancer: Inter‐ and intraobserver reproducibility and the effect of slice selection on pharmacokinetic analysis. Issue 3 (11th October 2013)

• Record Type: Journal Article
• Authors: Hötker, Andreas M.; Schmidtmann, Irene; Oberholzer, Katja; Düber, Christoph
• Is Part Of: Journal of magnetic resonance imaging. Volume 40:Issue 3(2014)
• Page Start: 715
• Page End: 722
• Publication Date: 2013-10-11
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24385
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24385-sec-0001" sec-type="section"> <title>Purpose</title> <p>To assess inter‐ and intraobserver reproducibility of DCE‐MRI measurements and possible differences between two directly adjacent slices.</p> </sec> <sec id="jmri24385-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>DCE‐MRI measurements of 30 patients with histologically proven rectal carcinoma were performed on a 1.5 Tesla (T) MR system during intravenous contrast agent application before and after neoadjuvant radiochemotherapy with two directly adjacent slices used for calculation per patient. Images were analyzed semiquantitatively (parameters <italic>TTP</italic> and <italic>MITR</italic>) and quantitatively using the Brix compartment model (parameters <italic>k<sub>ep</sub></italic> and <italic>A</italic>) by two different observers and at two different time points. The concordance correlation coefficient was calculated for every parameter in intra‐/interobserver comparison and slice comparison.</p> </sec> <sec id="jmri24385-sec-0003" sec-type="section"> <title>Results</title> <p>Median relative differences below 10% for all parameters and high values of the concordance correlation coefficient (CCC) were found for most pharmacokinetic parameters in inter‐/intraobserver comparison and slice comparison, with the exception of the parameter A before therapy in intra‐/ interobserver comparison (CCC: 0.315/0.452) and k<sub>ep</sub> before therapy in intraobserver comparison (CCC: 0.362).</p> </sec> <sec id="jmri24385-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Our results indicate good inter‐ and intraobserver reproducibility for most pharmacokinetic parameters and for the two adjacent slices measured. However, as there were some parameters that demonstrated poor correlation, testing for reproducibility and a multiobserver approach might be considered whenever using pharmacokinetic parameters as biomarkers. <bold>J. Magn. Reson. Imaging 2014;40:715–722</bold>. © <bold>2013 Wiley Periodicals, Inc</bold>.</p> </sec> </abstract>