The role of magnetic resonance elastography in evaluation of hepatic fibrosis and liver regeneration.

• Main Authors: Chia-Tien Hsu, 許嘉恬
• Other Authors: Ran-Chou Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/32hyp5

碩士 === 國立陽明大學 === 生物醫學影像暨放射科學系 === 104 === Taiwanese have a high prevalence of HBsAg carrier rate and chronic liver diseases. Chronic liver disease can cause liver fibrosis, cirrhosis, and hepatocellular carcinoma, the degree and progression rate of liver fibrosis are important prognostic factors in these patients. The gold standard for detecting hepatic fibrosis is percutaneous liver biopsy. However, it’s an invasive examination which is not well accepted by patients, has risk of complications, and is subject to sampling error. A number of noninvasive imaging techniques have been evaluated for possible use in diagnosing hepatic fibrosis, such as ultrasound-based acoustic radiation force imaging (ARFI) elastography and magnetic resonance elastography ( MRE ). The purpose of study I was to compare the diagnostic accuracy of MRE with that of ARFI elastography for staging hepatic fibrosis in patients with primary liver neoplasms. For patients with end-stage liver disease, liver transplant is the only effective treatment. Due to the shortage of liver grafts and the advancement in modern techniques of hepatectomy, living donor liver transplant (LDLT) has been playing an important role in the field of liver transplantation. However, the donor operation is performed on a healthy person, donor safety should be considered as the first priority. The regenerative potential of the liver remnant in the donor is critical in LDLT. Liver regeneration is recognized to be one of the factors reflecting surgical stress and recovery, and close related to the incidence of complications. The purpose of study II was to assess the relationship between liver stiffness, CT contrast-enhanced ratio (CE ratio) and liver regeneration in donors of LDLT. In the study I, we prospectively enrolled 77 patients who were scheduled to undergo hepatectomy for primary liver neoplasm from August 2013 to September 2015. Fibrosis stage and necroinflammatory activity of resected specimens were assessed using the METAVIR scoring system. The values of liver stiffness/velocity were measured on MRE elastogram and ARFI elastography. The relationship between MRE liver stiffness values, ARFI elastography values, liver fibrosis stage and necroinflammatory activity score were evaluated. Our results showed that MRE was significantly more accurate than ARFI elastography in differentiating fibrosis stages ≥ F2 from stages F0 or F1. Using a cutoff value of 3.0kPa, MRE had a sensitivity of 75.93% and a specificity of 100% in predicting advanced stages of fibrosis (≥ F2), and ARFI elastography had sensitivity of 74.1% and specificity of 82.6% at cutoff value of 1.77 m/s for predicting advanced stages of fibrosis (F≥2). In the study II, we retrospectively enrolled 47 donors who underwent right lobe LDLT from February 2014 to February 2015. All of the donors underwent preoperative MRE and contrast-enhanced computed tomography (CECT) within 1 month before LDLT. CECT were acquired for routine follow-up at 1, 4, 12 weeks after the operation. Correlations in the liver regeneration between liver stiffness values and CE ratios were analyzed. The results indicated that the donors had the highest liver regeneration rate within 1 week after the operation. TLV increase was significantly correlated with preoperative CE ratio, remnant liver volume (RLV), and postoperative spleen enlargement. Using a cutoff value of 2.32, CE ratio had a sensitivity of 73.3% and a specificity of 64.7% in predicting liver fraction ≥ 80% of total liver volume at 12 weeks after the operation. However, the correlation between the liver stiffness values and liver regeneration was not significant. In conclusion, the study I showed that MRE provided better diagnostic performance than ARFI elastography for detecting advanced stages of fibrosis and cirrhosis. In the study of living liver donors, preoperative CE ratio, RLV, and postoperative spleen enlargement were independent factors of liver regeneration. Preoperative CE ratio can be used to predict whether liver fraction ≥ 80% of total liver volume at 12 weeks after the operation.