Dual-echo, chemical shift gradient-echo magnetic resonance imaging to quantify hepatic steatosis: Implications for living liver donation

Abstract

In living liver donation, a fatty liver poses risks for both recipient and donor. Currently, liver biopsy is the standard for assessing the presence and extent of steatosis. The goals of this study were to correlate a steatosis index derived from magnetic resonance imaging (MRI) to the histologic grade on biopsy as well as to determine the topographic distribution of steatosis within the liver. We examined the ability of dual-echo, chemical shift gradientecho MRI to predict the degree of steatosis on liver biopsy. A total of 22 subjects received both a liver biopsy and detailed MRI evaluation. These individuals included 15 potential living donors and 7 patients with nonalcoholic fatty liver disease. MRI steatosis index was then compared with histologic grade on liver biopsy. The topographic distribution of hepatic steatosis was determined from those subjects in whom MRI detected hepatic steatosis.

Relationship of steatosis grade and zonal location to histological features of steatohepatitis in adult patients with non-alcoholic fatty liver disease

“…This is a clinically relevant observation because imaging tests (ultrasound, CT, and MRI) often report the severity of steatosis, and until now the significance of severity of steatosis has not been systematically investigated. As it was recently demonstrated that degree of steatosis quantified by imaging correlates significantly with histological grading of steatosis (5,6), we propose that radiologically-evident severe steatosis should be explored as another variable increasing the risk for the presence of NASH and zone 3 fibrosis in patients with NAFLD. Previous studies have shown that diabetes, older age, and morbid obesity increase the likelihood of NASH in patients with NAFLD (7,8).…”

“…If other studies confirm significant correlation between (a) steatosis severity by imaging and steatosis grade by histology (5,6) and (b) steatosis grade by histology and prevalence of steatohepatitis, then one potentially could consider the degree of hepatic steatosis (as quantified by imaging) as a surrogate therapeutic endpoint in pilot studies treating NASH as well as a surrogate safety endpoint in drug development. Many pharmaceutical companies developing compounds to treat metabolic conditions such as diabetes, obesity, and hyperlipidemia are routinely performing MR spectroscopy of the liver to monitor hepatic steatosis.…”

Renal Relevant Radiology

“…The technique involves acquiring in-phase (water 1 fat) and out-of-phase (water 2 fat) images to generate water-only and fat-only images ( Figure 5). In the liver, quantification of hepatic fat becomes inaccurate in the presence of high fat content (50). Due to its lower fat fraction, it is unlikely that this issue limits the application of this method in the kidney.…”

Noninvasive estimation of hepatic steatosis using plain CT vs. Chemical‐shift MR imaging: Significance for living donors

“…Recently, plain computed tomography (CT) (23) and chemical-shift MR imaging (CSI) (24) were applied for the evaluation of the severity of steatosis, and relatively good correlation between the index derived from either modality and histological grade of steatosis has been reported. To the best of our knowledge, however, there has been no report in which these two modalities were directly compared.…”