Olivier Maciej Girard1, Kazuki N. Sugahara2, Lilach Agemy2, Erkki Ruoslahti2, Graeme M. Bydder3, Robert F. Mattrey3
1Department of Radiology , University of California, San Diego, CA, United States; 2Vascular Mapping Center, Burham Institute for Medical Reserach at UCSB, Santa Barbara, CA, United States; 3Department of Radiology, University of California, San Diego, CA, United States
Iron oxide nanoparticles (IONPs) are used in various MRI applications. They are usually considered to be negative contrast agents due to their strong T2* effect, but they also have intrinsic T1 shortening properties that can produce positive contrast using appropriate pulse sequences. Here we show that a multiecho ultrashort TE sequence can be used very efficiently to generate three different contrasts (T1, T2* and hybrid T1-T2*) in a single acquisition, providing increased detection sensitivity and specificity while benefiting from positive contrast Contrary to conventional wisdom, T1-contrast can be superior to the T2*-contrast when imaging with IONPs.