Resolving Arterial Phase and Temporal Enhancement Characteristics in DCE MRM at High Spatial Resolution with TWIST Acquisition

Purpose: To investigate the potential of a view-sharing 3D fast gradient-echo sequence using pseudo random trajectories (TWIST) to achieve very short acquisition times with high in-plane resolution and good volume coverage and its application to dynamic contrast-enhanced (DCE) breast magnetic resonance imaging (MRI). Materials and Methods: Two versions of a 3D fast gradient echo TWIST sequence were implemented and applied to patients: First, an ultrafast TWIST acquisition (TA = 5.7 sec) in combination with a routine DCE MRM protocol to allow the extraction of arterial input functions and to resolve the first pass of the contrast agent. Second, a dynamic full coverage TWIST DCE acquisition (TA = 10.6 sec) in a repeat examination, replacing the routine DCE MRM sequence. Results: The ultrafast acquisition enabled extraction of arterial input functions and the monitoring of the contrast agent's first pass through vessels and lesions. The dynamic full coverage TWIST acquisition captured the initial dynamic slope of the signal time curve of lesions accurately, in contrast to the routine protocol. Conclusion: TWIST acquisitions proved very robust and offer high flexibility in protocol timing. The ultrafast protocol achieved 5.7 seconds time resolution with good image quality and can be combined with any established routine protocol. The full dynamics TWIST DCE protocol offers improved time resolution of the CE dynamic time-course and closely matches the image quality of the routine protocol.