The Analysis of Prediction by Ultrasound of the Risk of Hepatic Cirrhosis in Cystic Fibrosis Cohort Using Advanced MRI to Characterize and Predict CF Liver Disease (PUSH-MRE) study was a prospective cross sectional ancillary study of children and adolescents with cystic fibrosis enrolled in the Prediction by Ultrasound of the Risk of Hepatic Cirrhosis in Cystic Fibrosis Liver Disease (CFLD PUSH) study. PUSH-MRE sought to determine the feasibility of MRI and magnetic resonance elastography (MRE) to predict the development of advanced liver disease in children and adolescents with CF. Participants were a subset to those enrolled in the CFLD PUSH study, at 8 of the 11 centers that had research MRE capability. This study is an ancillary study to the CFLD PUSH study. If requesting access to the PUSH-MRE data, it is recommended to also request access to the CFLD PUSH data to obtain comprehensive information collected on study participants.

The primary objectives were to:

• Determine the feasibility of unsedated MRI/MRE assessments of liver stiffness and hepatic lipid content in children and adolescents with CF
• Determine hepatic lipid content using HepaFat and liver stiffness by MRE compared to ultrasound data and vibration controlled transient elastography in the same cohort

The secondary objectives were to:

• Develop an imaging core to centralize MR imaging data
• Determine the correlation between local MRE and MRI interpretation and central interpretation
• Assess if MRI imaging data improves the discrimination of those participants at risk for advanced CF liver disease (as determined by ultrasound nodular pattern)

Outcome measures included changes over time in liver stiffness and lipid content using MRE. Analysis of variance (ANOVA) was used to compare the distribution of liver stiffness (in kPa) and lipid content measures between all groups defined by the CFLD PUSH study grayscale ultrasound results over time.

Inclusion criteria:

• Participation in the CFLD PUSH study which enrolled children aged 3 through 12 years of age diagnosed with cystic fibrosis and pancreatic insufficiency
• At a center with MRI/MRE capability
• Able to perform unsedated MRI for 10-20 minutes
• Signed informed consent and if appropriate assent

Exclusion criteria:

• Initial exclusion criteria for the CFLD PUSH study such as known cirrhosis prior to screening, presence of Burkholderia cepacian, short bowel syndrome, and presence of other serious disease preventing participation
• Inability to comply with longitudinal follow-up of the CFLD PUSH study
• Contraindication to MRI

There were 93 participants (51 females [54.8%]; mean 15.6 years [range 8.1–21.7 years]) that underwent MRI, in which MR elastography was feasible for 87 participants (93.5%), and 58 participants had an ultrasound within 1 year of MRI. In these participants, a nodular liver had significantly higher stiffness (p < 0.01) than normal or homogeneous hyperechoic livers. Participants with a homogeneous hyperechoic liver had a higher fat fraction (p < 0.005) than others.