32 channel cardiac coil

Magnetic resonance imaging exams were performed using a 3.0-T scanner with a 32-channel cardiac coil (GE Healthcare, Waukesha, WI). Children fasted for at least 4 h before exams. Multiplanar, multisequence MR images of the abdomen were obtained for each child, with post-contrast images obtained following infusion of gadobenate dimeglumine (MultiHance; Bracco Diagnostics, Milan, Italy) or gadobutrol (Gadavist; Bayer Healthcare Pharmaceuticals, Leverkusen, Germany) gadolinium contrast agent. Echoplanar imaging (EPI) MR elastography was performed using a 60-Hz transducer placed on the abdomen. Protocol parameters were as follows: echo time (TE) 53.5 ms, field of view 42 x 42 cm, slice thickness 7 mm, reconstruction matrix 64 x 64. At least four measurements were obtained during breath-hold to generate a mean of means (normalized to region-of-interest size). Wave propagation maps were converted to kPa and were read by pediatric radiologists at the same tertiary-care pediatric academic hospital according to standard clinical care guidelines. We used the following kPa cutoff values to classify patients: normal (<3.0 kPa), mild–moderate (3.00–4.77 kPa) and severe (>4.77 kPa) [12 (link)–14 (link)].

To investigate the feasibility of the proposed method in a clinical setting, in vivo free-breathing abdominal and cardiac studies were carried out. For each study, ten subjects referred for MRI of the respective body parts were recruited at our institution. Subject demographics in these studies are listed in Supporting Tables S1-S3. All imaging was performed on a 3T GE scanner (GE Healthcare, Waukesha, WI) using a 32-channel cardiac coil. Both studies were approved by the institutional review board, and informed consent/assent was obtained prior to imaging.