Robert Adam Horch1,2, John C. Gore2,3, Mark D. Does1,2
1Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; 3Radiology & Radiological Sciences, Vanderbilt University, Nashville, TN, USA
Ultra-short echo time (uTE) MRI of the brain has demonstrated white matter-specific signal enhancement from short T2 (<1 ms) signals suspected to arise from myelin. However, the T2 characteristics of these signals, as well as their origins and possible relationship to myelin, remain uncharacterized. Herein, we perform T2 characterizations and isotopic 1H perturbations on myelin phantoms and myelinated central and peripheral nerves to determine the origins of short-lived T2s relevant to uTE MRI. We find sizeable signals in the ≈ 50 s 1 ms T2 domain and provide compelling evidence that they arise from myelin membrane methylene 1H.