Simultaneous Multiparameter Mapping of the Liver in a Single Breath‐Hold or Respiratory‐Triggered Acquisition Using Multi‐Inversion Spin and Gradient Echo MRI

Abstract

BackgroundQuantitative parametric mapping is an increasingly important tool for noninvasive assessment of chronic liver disease. Conventional parametric mapping techniques require multiple breath‐held acquisitions and provide limited anatomic coverage.PurposeTo investigate a multi‐inversion spin and gradient echo (MI‐SAGE) technique for simultaneous estimation of T1, T2, and T2* of the liver.Study TypeProspective.SubjectsSixteen research participants, both adult and pediatric (age 17.5 ± 4.6 years, eight male), with and without known liver disease (seven asymptomatic healthy controls, two fibrotic liver disease, five steatotic liver disease, and two fibrotic and steatotic liver disease).Field Strength/Sequence1.5 T, single breath‐hold and respiratory triggered MI‐SAGE, breath‐hold modified Look–Locker inversion recovery (MOLLI, T1 mapping), breath‐hold gradient and spin echo (GRASE, T2 mapping), and multiple gradient echo (mGRE, T2* mapping) sequences.AssessmentAgreement between hepatic T1, T2, and T2* estimated using MI‐SAGE and conventional parametric mapping sequences was evaluated. Repeatability and reproducibility of MI‐SAGE were evaluated using a same‐session acquisition and second‐session acquisition.Statistical TestsBland–Altman analysis with bias assessment and limits of agreement (LOA) and intraclass correlation coefficients (ICC).ResultsHepatic T1, T2, and T2* estimates obtained using the MI‐SAGE technique had mean biases of 72 (LOA: −22 to 166) msec, −3 (LOA: −10 to 5) msec, and 2 (LOA: −5 to 8) msec (single breath‐hold) and 36 (LOA: −43 to 120) msec, −3 (LOA: −17 to 11) msec, and 4 (LOA: −3 to 11) msec (respiratory triggered), respectively, in comparison to conventional acquisitions using MOLLI, GRASE, and mGRE. All MI‐SAGE estimates had strong repeatability and reproducibility (ICC > 0.72).Data ConclusionHepatic T1, T2, and T2* estimates obtained using an MI‐SAGE technique were comparable to conventional methods, although there was a 12%/6% for breath‐hold/respiratory triggered underestimation of T1 values compared to MOLLI. Both respiratory triggered and breath‐hold MI‐SAGE parameter maps demonstrated strong repeatability and reproducibility.Level of Evidence1Technical EfficacyStage 2