Diagnostic Performance of MR Elastography and Vibration-controlled Transient Elastography in the Detection of Hepatic Fibrosis in Patients with Severe to Morbid Obesity

Abstract

Purpose To evaluate the diagnostic performance and examination success rate of MR Elastography (MRE) and Vibration-Controlled Transient Elastography (VCTE) for detecting hepatic fibrosis in patients with severe to morbid obesity. Methods This prospective and HIPAA (The Health Insurance Portability and Accountability Act) compliant study was IRB approved. A total of 111 patients (71 women) participated with written informed consent. Patients underwent MRE with 2 readers and VCTE with 3 observers to acquire liver stiffness measurements for liver fibrosis assessment which was compared to liver biopsy. Each pathology specimen was evaluated by two hepatopathologists according to the METAVIR scoring system or Brunt classification when appropriate. All imaging observers were blinded to the biopsy results, and all hepatopathologists were blinded to the imaging results. Examination success rate, inter-observer agreement, and diagnostic accuracy for fibrosis detection were assessed. Results In this obese patient population (Body Mass Index = 40.3 (38.7, 41.8) kg/m2), the examination success rate was 95.8% (92/96) for MRE, and 81.3% (78/96) or 88.5% (85/96) for VCTE. MRE had a higher interobserver agreement than biopsy: ICC (Intra-class Correlation Coefficient) = 0.95 vs. 0.89. For detecting clinically significant hepatic fibrosis (F2 – F4) in patients with successful MRE and VCTE exams (excluding unreliable VCTE exams), both MRE and VCTE had excellent diagnostic accuracy (Area Under the Receiver Operating Characteristic curve, AUROC): 0.93 (0.85, 0.97) vs. 0.91 (0.83, 0.96), p = 0.551. Conclusion The results of our study show that in this obese patient population, both MRE and VCTE had excellent diagnostic performance for assessing hepatic fibrosis; MRE was more technically stable than VCTE and had a higher interobserver agreement than liver biopsy.

The Role of Three‐Dimensional Magnetic Resonance Elastography in the Diagnosis of Nonalcoholic Steatohepatitis in Obese Patients Undergoing Bariatric Surgery

“…To increase the sample size and improve the study power, we added a retrospective cohort of 87 NAFLD patients with liver biopsy and mf3D‐MRE at 40Hz and 60 Hz, as described . The median time interval between liver biopsies and MRE was 27 (IQR = 20‐30) days.…”

Comparison of technical failure of MR elastography for measuring liver stiffness between gradient‐recalled echo and spin‐echo echo‐planar imaging: A systematic review and meta‐analysis

“…In addition, obscure terms used in the studies, eg, poor wave propagation, which can be caused by iron overload, respiratory artifact, and obesity, also limited to explore other potential factors. For example, there are mixed results on whether obesity or high BMI would affect the technical failure of MRE . Since high BMI is the major cause of failure in US elastography, MRE can be an alternative for obese patients.…”

Evaluation of hepatic fibrosis: a review from the society of abdominal radiology disease focus panel

“…In addition liver biopsy results are variable due to sampling errors related to both small sample size and spatial variation in degree of fibrosis and variability of pathologist interpretation [9,10]. A recent study reported a difference of at least one fibrosis stage in 30% of series of 111 biopsy specimens evaluated by different pathologists [11]. While liver biopsies remain an important clinical tool, modern medical management of liver disease often relies on regular, interval assessments of liver fibrosis.…”