3.0 Tesla MR Spectroscopy for the assessment of hepatic steatosis in severely obese patients before and after weight reduction

Hepatic steatosis is a benign condition characterized by an accumulation of
lipids in the liver. It is related to a range of etiological features such as
obesity, diabetes and dyslipidemia (the metabolic syndrome). Steatosis can
progress into a more serious variant, NASH (Non Alcoholic Steato Hepatitis).
This condition is associated with an inflammatory component, and in
approximately 20 percent of the patients it will ultimately result in liver
cirrhosis. Non-alcoholic fatty liver disease (NAFLD) is the term for the
spectrum of steatosis, NASH and cirrhosis, and is now recognized as the most
common chronic liver disease in the western world, affecting approximately 30 %
of the western population. These numbers are thought to increase even further
due to the obesity epidemic. Liver biopsy and histological examination has been
the reference standard for assessing hepatic steatosis but sampling errors are
considerable because of inhomogeneous distribution of fat in the liver.
However, imaging techniques (abdominal ultrasound and computed tomography) are
also prone to error and lack sensitivity and specificity. Proton Magnetic
Resonance Spectroscopy (1H-MRS) is a safe, non-invasive and reproducible
diagnostic tool that allows the semi-quantification of various components of
fat in the liver

- Is there a correlation between liver fat content and inflammation in patients
with or without STNFR-2
polymorphisms (-1031C, -863A)?
- What is the correlation between weight reduction and decrease of hepatic
steatosis?
- What is the correlation between a reduction of steatosis and improvement of
insulin sensitivity?
- Does a decrease in hepatic steatosis relate to a decrease of inflammation in
individuals with positive
inflammation parameters?

In this prospective pilot study consenting consecutive patients with severe
overweight will undergo bariatric surgery. After informed consent we intend to
perform MR Spectroscopy of the liver before surgery and 4 months after surgery,
as well as assessment of clinical parameters and blood tests. 1H*MRS will be
performed by the department of Radiology, assessment of clinical parameters and
blood tests will be performed by the department of Hepatology/ AMC liver
center. Because the sensitivity and specificity of 3.0 Tesla 1H*MRS for the
measurement of hepatic steatosis is unknown, we were not able to calculate by
power analysis the number of subject required for the study. Therefore we
intend to include 30 patients. A lower number of individuals can be expected to
lead to insufficient numbers to study the study objectives

The patients in this study will undergo bariatric surgery (standard treatment),
two 1H-MRS scans and two clinical assessments and blood sampling. 1H-MRS is a
non-invasive, non-ionizing 45 minute examination in the MRI scanner, which
requires two extra visits to the hospital. The patient has to lie still on his
back in a MRI scanner for about 45 minutes. There is not a direct advantage for
the patient, except for extra insight in their disease. Patients are not
delayed in treatment for their disease. There will be little extra physical and
psychological discomfort associated with participation.