Breath-held high-resolution cardiac T2 mapping with SKRATCH

Background Several cardiac T2 mapping techniques with varying T2 preparation (T2Prep) times have been proposed for the quantification of cardiac edema [1-3]. Among these, radial T2 mapping, which is robust to motion artifacts, suffers from a low signal-to-noise ratio (SNR) caused by the undersampling of the k-space periphery and by its density compensation function (DCF) (Fig. 1a). However, since the contrast of an image is mainly determined by the center of its k-space, the T2-weighted images can share their k-space periphery using the KWIC (K-space Weighted Image Contrast) filter (Fig. 1b) to reduce undersampling artifacts [4]. This allows for higher undersampling (Fig. 1c) and thus for a decrease in acquisition time [5]. We demonstrated that navigator-gated KWIC-filtered cardiac T2 mapping (Shared K-space RAdial T2 Characterization of the Heart, SKRATCH) enables a considerable decrease in acquisition time while maintaining the T2 precision [5]. The goal of this study was to extend this approach to a short breath-held high-resolution T2 map acquisition and to compare its performance to navigatorgated T2 mapping.