Preliminary experience with 3T magnetic resonance elastography imaging of the liver

摘要

Background: Magnetic resonance elastography (MRE) is a promising non-invasive technique for the identification and quantification of hepatic fibrosis. This manuscript describes our early experience with MRE for the assessment of the presence and staging of liver fibrosis on a 3T magnetic resonance imaging (MRI) system. Objectives: The purpose of this study was to describe the MRE physics, procedure, interpretation and drawbacks, along with a few recommendations as per our experience. Method: Magnetic resonance elastography was performed on 85 patients with a 3T MRI and the images were analysed both qualitatively and quantitatively. Liver stiffness was assessed by drawing freehand geographic regions of interest on the elastograms to cover the maximum portion of the hepatic parenchyma within the 95 confidence maps on each slice. Correlation with histopathology was performed whenever available. Results: Of the 80 patients who met the inclusion criteria, 41 patients displayed a normal liver stiffness measurement (LSM) and 39 patients had a raised LSM. In the patients who had a raised LSM, 14 patients had Stage I-II fibrosis, 8 patients had Stage II-III fibrosis, 6 patients had Stage III-IV fibrosis, 4 patients had Stage IV fibrosis or cirrhosis and 7 patients had nonalcoholic steatohepatitis. The mean thickness of the waves increased with increasing stages of fibrosis. The waves became gradually darker medially in patients with normal LSM as compared to the patients with raised LSM. Histopathology with METAVIR scoring was available in 46 patients, which agreed with the MRE findings in all except two patients. Conclusion: Magnetic resonance elastography is a suitable non-invasive modality for the identification and quantification of hepatic fibrosis.