Development and Validation of Tools for Virtual Imaging Trials of Ultrafast Breast MRI

Abstract

Ultrafast MRI is an advanced technique used for identification of breast lesions, consistent with cancer. It is a contrast-enhanced scan which utilizes several undersampling techniques, all of which can be applied to varying degrees. This level of complexity, coupled with the inability to repeatedly inject contrast into a patient. makes the scan difficult to optimize in the clinic. To address this challenge, we designed an MRI simulator and corresponding phantom which operates on fundamental MRI principles to evaluate temporal performance of various TWIST settings and provide clinical recommendations. Our simulations revealed complex interactions between GRAPPA, Partial Fourier, TWIST, oversampling, and matrix size for both nominal temporal resolution and impulse response characteristics. We found there to be a optimal simulation setting for balancing temporal accuracy of lesion enhancement with the measured amount of enhancement. Under conditions of only modifying TWIST from clinical settings, our findings suggest that using a pA of .22% and a pB of .25 provides an ideal combination of the two, improving the ability resolve the enhancement of a lesion within the breast compared to clinical settings.