The purpose of the study is to assess the diagnostic accuracy of Endoscopic Ultrasound (EUS) shear wave elastography in liver fibrosis staging in both normal subjects and subjects with advanced liver fibrosis/cirrhosis

This is a prospective, paired study. Study subjects who are scheduled to undergo EUS at Mayo Clinic will be identified through Epic. Chart review will be performed including review of prior imaging, medical history, and laboratory results as available in Epic to determine study eligibility. Subjects without history of chronic liver disease (screened by low FIB-4 score) and those with known advanced fibrosis/cirrhosis will be eligible for the study. Eligible study subjects will then be contacted either before, or at the time of their endoscopy procedure to discuss study participation. All subjects will then receive standard clinical care based on the indication for the EUS procedure. During the EUS procedure, study subjects with undergo shear wave measurements obtained in a non-invasive manner as part of the endosonographic evaluation of the liver. 10 measurements (including shear wave velocity (Vs), elastic modulus (E)) will be obtained for point SWE (pSWE). Measurements will be obtained from both left and right lobes of liver unless technically infeasible to do so. Study subjects will then undergo a paired MR elastography (same day or at later date) after completion of EUS and only if consistent and reliable shear wave measurements were obtained (e.g., VsN > 70%(reliability index of each measurement expressed in percentages), IQR/M (interquartile range/ Median) is <15% for Vs and <30% for E). Enrolled study subjects who had undergone a previous MRE (within 6 months of enrollment) would be eligible for the study, without the need to undergo further research MRE. After completion of MR elastography, the subjects will then continue through their routine clinical care and will not be followed up by research staff. The expected duration of subject participation is anticipated to begin at the time of study enrollment and terminate after completion of MR elastography. There will be no additional follow up.

Inclusion Criteria:

• Adults over 18 years of age who are undergoing EUS procedures.
• Subjects with history of chronic liver disease, advanced fibrosis or cirrhosis
• Subjects without any history of chronic liver disease
• Subjects who underwent MR elastography within six (6) months of enrollment will be eligible to participate in the study.
• Subjects able to give appropriate consent to the study or have an appropriate representative to do so.

Exclusion Criteria:

• Subjects who may have MRI-incompatible metal implants/devices.
• Subjects with severe claustrophobia who may not tolerate MR elastography.

Adverse Events were collected from baseline to end of study, approximately 1 day