Quantification of amide proton transfer effect pre‐ and post‐gadolinium contrast agent administration. Issue 4 (8th November 2013)

• Record Type: Journal Article
• Authors: Tee, Yee Kai; Donahue, Manus J.; Harston, George W.J.; Payne, Stephen J.; Chappell, Michael A.
• Is Part Of: Journal of magnetic resonance imaging. Volume 40:Issue 4(2014)
• Page Start: 832
• Page End: 838
• Publication Date: 2013-11-08
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24441
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24441-sec-0001" sec-type="section"> <title>Purpose</title> <p>To compare quantification of the amide proton transfer (APT) effect pre‐ and post‐gadolinium contrast agent (Gd) administration in order to establish to what extent Gd alters quantification of the APT effect.</p> </sec> <sec id="jmri24441-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>Four patients with internal carotid stenosis were recruited. APT imaging was acquired pre‐ and post‐contrast in two sessions (before and after surgery) to assess the extent of relaxation time, T<sub>1</sub>, change on APT effect calculated using magnetization transfer ratio asymmetry analysis at offsets of ±3.5 ppm relative to water resonance. Statistical and modeling evaluations were performed on the pre‐ and post‐contrast APT effect to study the sensitivity to contrast administration.</p> </sec> <sec id="jmri24441-sec-0003" sec-type="section"> <title>Results</title> <p>Before surgery, the post‐contrast T<sub>1</sub> was estimated to drop <10% of the pre‐value for the majority of the patients. After surgery, higher post‐contrast T<sub>1</sub> reductions were observed in all the patients (maximum decrease was about 20% of the pre‐value). Consistent differences between pre‐ and post‐contrast were seen in the APT effect quantified using the asymmetry measure in most regions of the brain, with significant differences found in the white matter at the group level and in 25% of the individual patient results.</p> </sec> <sec id="jmri24441-sec-0004" sec-type="section"> <title>Conclusion</title> <p>APT imaging should be performed prior to Gd administration to avoid potential misinterpretation of the APT effect. J. Magn. Reson. Imaging 2014;40:832–838. © <bold>2013 Wiley Periodicals, Inc</bold>.</p> </sec> </abstract>