Comparison of 3D Acquisition Techniques for Amide Proton Transfer in Brain Tumor Applications

Mariya Doneva¹, Jochen Keupp¹, Silke Hey², Osamu Togao³, Takashi Yoshiura³

Amide proton transfer (APT) is a novel contrast mechanism enabling molecular MR imaging of proteins as well as the assessment of local pH. Clinical applications of APT imaging are often limited to a single slice acquisition due to the long scan time caused by multiple acquisitions at different saturation offset frequencies as well as SAR limitations. Previous studies were mainly focused on low resolution scans with large number of saturation offset frequencies and short saturation times Tsat < 1s. Parallel transmission based APT enables long saturation pulses at 100% duty cycle at clinical scanners and it was recently shown that an optimal CNR efficiency can be achieved at Tsat &#8776; 2s. The purpose of this work was to investigate the application of 3D APT sequences with optimized saturation length and whole brain coverage. 3D GRASE and fast spin echo (TSE) sequences for APT were compared in phantom and in vivo studies.