Validation of pre-operative 3.0 Tesla H1-MR spectroscopy for assessment of hepatic steatosis as a risk factor for post-operative outcome after hepatectomy

Hepatic steatosis is fat accumulation in the liver. Hepatic steatosis is caused
by obesitas, diabetes and dyslipidemia, features of the metabolic syndrome. It
is estimated to be present in 30% of the western population. 10% of these
patients develop a more severe condition called non-alcoholic steatohepatitis
(NASH). Due to inflammation NASH eventually can develop into liver cirrhosis.
This process is called non-alcoholic fatty liver disease (NAFLD) and is at the
moment the most common chronic liver disease. Other causes of hepatic steatosis
are: alcohol induced hepatic steatosis, drug induced hepatic steatosis, chronic
hepatitis C infection and chemotherapy associated steatohepatitis (CASH).
On the other hand, steatosis in liver surgery and liver transplantation has
been recognized as a serious risk factor for postoperative recovery. Patients
undergoing an extended liver resection with a steatosis grade of more than 30%
(determined by histological evaluation of liver biopsy) are at high risk for
developing postoperative liver failure due to a compromised rest liver
function. Similarly, when a liver graft of 30-60% steatosis is being
transplanted there is a higher risk of poor functioning after implantation.
Preoperative assessment of hepatic steatosis would be desirable to estimate the
patients risk for liver resection surgery. Until now histological examination
of a liver biopsy has been the reference standard for invasive assessment of
hepatic steatosis, but major and minor complications and sampling errors
because of the heterogeneous distribution of fat in the liver are reported. At
the moment there are no suitable non-invasive techniques for quantifying
hepatic steatosis. Magnetic Resonance Proton Spectroscopy (1H-MRS) seems a
viable alternative, repeatable, patient friendly and non invasive, but is not
yet used as a standard clinical tool. We suggest that 1H-MRS at 3.0 Tesla can
be used for quantitative assessment of hepatic steatosis

Validation of pre-operative H1-MRS at 3.0 Tesla for assessment of hepatic
steatosis as a risk factor for postoperative morbidity and mortality after
hepatectomy.
Is there a close correlation between the 1H -MRS measurement of fat and the
histological and biochemical assessment of fat from multiple biopsies taken
from the resected part of the liver?
Is it possible to validate and quantify 1H -MRS so it can be used as a viable,
repeatable and non-invasive diagnostic tool for the assessment of hepatic
steatosis?

In this prospective pilot study consenting consecutive patients for liver
resection (hepatectomy) are recruited by the surgeon and included in the study
by 2 research fellows. These patients will have diagnostic liver evaluation by
ultrasound, CT and 1H *MRS preoperatively. Within normal timeframe the surgeon
will perform a liver resection. Multiple biopsies from the non-tumorous part of
the resected liver will be investigated histopathologically and biochemically.
This will be compared to the amount of fat measured by 1H *MRS for validation
and correlation studies. Also, a possible correlation of different measurements
of steatosis with the postoperative recovery up to 3 months will be
investigated

These patients require a liver resection, which would also have been performed
in normal clinical practise. CT scanning and ultrasound is also part of normal
clinical pre-operative work-up, as well as blood sampling during pre-operative
work-up, during admission and post-operative work-up.
During regular blood sampling at hospital admission one extra blood sample will
be taken. 1H-MRS is a non-invasive, non-ionizing 60 minute examination in the
MRI scanner, which requires one extra visit to the hospital. Patients are not
delayed in surgery for the extra diagnostic 1H-MRS. Biopsies for the evaluation
of steatosis will be obtained from the resected non-tumorous part of the liver,
in close consultation with the pathologist. No biopsies from remnant liver are
required, so the patient is not opposed to any additional risk. There will be
little extra physical and psychological discomfort associated with
participation.