Comparison of spin-echo echoplanar imaging and gradient recalled echo-based MR elastography at 3 Tesla with and without gadoxetic acid administration

Abstract

• LS values are comparable between SE-EPI-MRE and GRE-MRE. • Administration of gadoxetic acid does not influence LS measurement. • The failure rate of SE-EPI-MRE is significantly lower than that of GRE-MRE.

Comparison of technical failure of MR elastography for measuring liver stiffness between gradient‐recalled echo and spin‐echo echo‐planar imaging: A systematic review and meta‐analysis

“…No significant heterogeneity was noted for either GRE (I 2 = 25%, P = 0.23) or SE‐EPI sequences (I 2 = 0%, P = 0.58). In addition, among six studies conducted with 3T MR imagers, less technical failure occurred under SE‐EPI than GRE (2.1% [95% CI, 1.1–3.9%] vs. 10.1% [95% CI, 7.4–13.7%], P < 0.01).…”

“…Finally, 31 studies fulfilled the eligibility criteria for our analysis, including eight studies using both GRE and SE‐EPI sequences, 22 studies using only a GRE sequence, , , , , , , , and one study using only an SE‐EPI sequence . As one study using both GRE and SE‐EPI sequences potentially overlapped with a population in another GRE sequence outcome study, we did not include the outcomes of this study in the evaluation of the pooled proportion of technical failure of GRE sequences, but used it only for the head‐to‐head comparison between GRE and SE‐EPI sequences.…”

“…Eight studies compared the proportions of technical failures between GRE and SE‐EPI sequences using the same subjects . As two eligible studies also performed MRE using both 1D‐ and 3D‐MEG, we used the outcomes with 1D‐MEG, given that all the GRE studies were performed with 1D‐MEG.…”

“…The difference in failure rates between the two sequences might be attributed to the difference in sensitivity to T 2 * susceptibility. In GRE‐based MRE, a motion‐encoding gradient that matches the vibration period of the active driver is used (typically, 1/60 Hz = 16.66 msec), and therefore both the echo time (TE) and repetition time (TR) are relatively long (longer than the vibration period) . Under GRE, this long TE makes the sequence heavily T 2 *‐weighted, resulting in considerable signal dephasing in tissues with short transverse relaxation times such as iron‐overloaded liver.…”

“…Nonetheless, as people tend to focus more on successful results rather than technical failure when presenting the results of studies, the failure rates of MRE have not been reported well. A limited number of studies have reported on the technical failure rate of MRE, and fewer studies have made comparisons regarding the failure rates between these two sequences. The results from the studies are also limited by their small sample sizes and the resulting low levels of evidence.…”