MR Elastography (MRE) measures stiffness by assessing four images across the entire liver, resulting in a comprehensive and incredibly accurate diagnosis not available with other non-invasive technologies. In addition to a stiffness score measured in kPa, clinicians and patients often receive color-coded maps of their liver fibrosis, called Elastograms. In these intuitive maps, red corresponds to highly advanced fibrosis, while purple represents healthy liver tissue.
When to use MRE
MR Elastography is able to overcome many confounding factors that can impact the performance in other non-invasive technologies. Notably for fatty liver disease, this most often includes BMI and increased waist circumference, as ultrasound-based elastography (e.g., Fibroscan®) methods often perform poorly in these patient groups.
Because MRE is not affected by waist circumference or obesity, clinical guidelines recommend that MRE be incorporated into the clinical workflow to reliably estimate the degree of fibrosis present. Clinicians may also request fat fraction measurements (for steatosis), inflammation, and/or malignancy via traditional MR workup, resulting in a powerful and comprehensive liver assessment.
BMI ≤ 20
BMI ≥ 25
BMI ≥ 30
Clinical guidance suggests that the utilization of MR Elastography increases as BMI increases
“In adults with NAFLD and a higher risk of cirrhosis, MRE is suggested, rather than VCTE, for detection of cirrhosis”
American Gastroenterological Association Institute Guideline on the Role of Elastography in the Evaluation of Liver Fibrosis (2017)
"MRE is excellent for identifying varying degrees of fibrosis in patients with NAFLD."
The Diagnosis and Management of Nonalcoholic Fatty Liver Disease: Practice Guidance From the American Association for the Study of Liver Diseases (2017)
"MR elastography is the most accurate method for diagnosing liver fibrosis non-invasively because it assesses the whole liver and can stage liver fibrosis."
American College of Radiology Appropriateness Criteria®: Chronic Liver Disease (2017)
Magnetic Resonance Elastography
In a pooled analysis of data from individual participants with NAFLD in 3 independent studies, MRE demonstrated a significantly higher diagnostic accuracy than TE for the detection of individual stages of fibrosis using liver biopsy as a reference.
Hsu, C., et al. Magnetic Resonance Elastography versus Transient Elastography in detection of fibrosis in nonalcoholic fatty liver disease: A systematic review and meta-analysis of individual participant data. Poster presented at ILC 2018, April 13, 2018, Paris, France.
Are Your Patients Responding to Therapy?
MRE provides highly sensitive and comprehensive assessment to treatment response, something previously not possible with traditional T2w MR imaging.
A 57-YEAR-OLD MALE PATIENT WITH CHRONIC HEPATITIS C
Baseline liver stiffness = 4.2 kPa ± 0.88
3-year follow-up liver stiffness = 2.80 kPa ± 0.69
Decreasing liver stiffness indicating response to treatment