Quantitative evaluation of breast lesions using ultrafast MRI has come so far

Excerpt

In the decade since its introduction, ultrafast dynamic contrast-enhanced (UF-DCE) MRI has become a widely accepted sequence in breast MRI [1]. There is no strict definition of “ultrafast”, but it usually refers to DCE MRI with a time resolution of 7 s or shorter. The appeal of UF-DCE MRI is its ability to complete multiple imaging phases within 1–2 min to draw a detailed time-intensity curve (TIC) during breast lesion enhancement. Various parameters for evaluating the initial TIC from UF-DCE images have been introduced to demonstrate that malignant breast lesions are enhanced more rapidly and earlier than benign lesions. Among these parameters, the maximum slope (MS) proposed by Mann et al in 2014 [2] and the time to enhancement (TTE) proposed by Mus et al in 2017 [3] are the most popular. MS is determined from the slope of the tangent to the steepest part of the wash-in curve (percentage relative enhancement per second [%/s]) and represents the rate of the lesion enhancement [2]. TTE is calculated as “the time point where the lesion starts to enhance” minus “the time point where the aorta starts to enhance” and represents how fast the contrast agent travels from the aorta to the lesion [3]. A number of studies have demonstrated that these parameters have similar or better diagnostic ability than conventional TIC analysis using early and delayed phases, but many of these were small, single-center studies. …