Child ; Young adult ; Liver ; Magnetic resonance imaging ; Elasticity imaging techniques
Abstract
Purpose: To assess the feasibility of the use of spin-echo echo-planar imaging (SE-EPI)
magnetic resonance elastography (MRE) in livers of children and young adults.
Materials and Methods: Patients (≤ 20 years old) who underwent 3T SE-EPI MRE
were included retrospectively. Subjects were divided into three groups according to
the purpose of the liver MRI: suspicion of fatty liver or focal fat deposition in the
liver (FAT group), liver fibrosis after receiving a Kasai operation from biliary atresia
(BA group), and hepatic iron deposition after receiving chemotherapy or transfusions
(IRON group). Technical failure of MRE was defined when a stiffness map showed
no pixel value with a confidence index higher than 95%, and the patients were
divided as success and failure groups accordingly. Clinical findings including age,
gender, weight, height, and body mass index and magnetic resonance imaging results
including proton density fat fraction (PDFF), T2*, and MRE values were assessed.
Factors affecting failure of MRE were evaluated and the image quality in wave
propagation image and stiffness map was evaluated using the appropriate scores.
Results: Among total 240 patients (median 15 years, 211 patients in the FAT, 21
patients in the BA, and 8 patients in the IRON groups), technical failure was noted in
six patients in the IRON group (6/8 patients, 75%), while there were no failures noted
in the FAT and BA groups. These six patients had T2* values ranging from 0.9 to 3.8
ms. The image quality scores were not significantly different between the FAT and BA
groups (P > 0.999), while the scores were significantly lower in the IRON group (P <
0.001).
Conclusion: The 3T SE-EPI MRE in children and young adults had a high technical
success rate. The technical failure was occurred in children with decreased T2* value (≤
3.8 ms) from iron deposition.